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King KE, Cook ER, Anchukaitis KJ, Cook BI, Smerdon JE, Seager R, Harley GL, Spei B. Increasing prevalence of hot drought across western North America since the 16th century. Sci Adv 2024; 10:eadj4289. [PMID: 38266096 PMCID: PMC10807802 DOI: 10.1126/sciadv.adj4289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 12/22/2023] [Indexed: 01/26/2024]
Abstract
Across western North America (WNA), 20th-21st century anthropogenic warming has increased the prevalence and severity of concurrent drought and heat events, also termed hot droughts. However, the lack of independent spatial reconstructions of both soil moisture and temperature limits the potential to identify these events in the past and to place them in a long-term context. We develop the Western North American Temperature Atlas (WNATA), a data-independent 0.5° gridded reconstruction of summer maximum temperatures back to the 16th century. Our evaluation of the WNATA with existing hydroclimate reconstructions reveals an increasing association between maximum temperature and drought severity in recent decades, relative to the past five centuries. The synthesis of these paleo-reconstructions indicates that the amplification of the modern WNA megadrought by increased temperatures and the frequency and spatial extent of compound hot and dry conditions in the 21st century are likely unprecedented since at least the 16th century.
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Affiliation(s)
- Karen E. King
- Department of Geography and Sustainability, University of Tennessee, Knoxville, 1000 Phillip Fulmer Way, Knoxville, TN 37996, USA
| | - Edward R. Cook
- Tree Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964, USA
| | - Kevin J. Anchukaitis
- Tree Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964, USA
- School of Geography, Development, and Environment, University of Arizona, 1064 Lowell Street, Tucson, AZ 85721, USA
- Laboratory of Tree-Ring Research, University of Arizona, 1215 E Lowell Street, Tucson, AZ 85721, USA
| | - Benjamin I. Cook
- NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA
- Ocean and Climate Physics Division, Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964, USA
| | - Jason E. Smerdon
- Ocean and Climate Physics Division, Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964, USA
- Columbia Climate School, Columbia University, New York, NY 10027, USA
| | - Richard Seager
- Ocean and Climate Physics Division, Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964, USA
| | - Grant L. Harley
- Department of Earth and Spatial Sciences, University of Idaho, 875 Perimeter Drive MS3021, Moscow, ID 83843, USA
| | - Benjamin Spei
- Department of Forest, Rangeland, and Fire Sciences, University of Idaho, 975 West 6th Street, Moscow, ID 83843, USA
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2
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Simpson IR, McKinnon KA, Kennedy D, Lawrence DM, Lehner F, Seager R. Observed humidity trends in dry regions contradict climate models. Proc Natl Acad Sci U S A 2024; 121:e2302480120. [PMID: 38147646 PMCID: PMC10769846 DOI: 10.1073/pnas.2302480120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 11/13/2023] [Indexed: 12/28/2023] Open
Abstract
Arid and semi-arid regions of the world are particularly vulnerable to greenhouse gas-driven hydroclimate change. Climate models are our primary tool for projecting the future hydroclimate that society in these regions must adapt to, but here, we present a concerning discrepancy between observed and model-based historical hydroclimate trends. Over the arid/semi-arid regions of the world, the predominant signal in all model simulations is an increase in atmospheric water vapor, on average, over the last four decades, in association with the increased water vapor-holding capacity of a warmer atmosphere. In observations, this increase in atmospheric water vapor has not happened, suggesting that the availability of moisture to satisfy the increased atmospheric demand is lower in reality than in models in arid/semi-arid regions. This discrepancy is most clear in locations that are arid/semi-arid year round, but it is also apparent in more humid regions during the most arid months of the year. It indicates a major gap in our understanding and modeling capabilities which could have severe implications for hydroclimate projections, including fire hazard, moving forward.
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Affiliation(s)
- Isla R. Simpson
- Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO80305
| | - Karen A. McKinnon
- Department of Statistics and Data Science, University of California, Los Angeles, CA90095
- Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA90095
- Institute of the Environment and Sustainability, University of California, Los Angeles, CA90095
| | - Daniel Kennedy
- Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO80305
- Earth Research Institute, University of California, Santa Barbara, CA93106
| | - David M. Lawrence
- Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO80305
| | - Flavio Lehner
- Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO80305
- Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY14850
- Polar Bears International, Bozeman, MT59772
| | - Richard Seager
- Ocean and Climate Physics, Lamont-Doherty Earth Observatory, Columbia University, New York, NY10964
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3
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Yucel BP, Al Momany EM, Evans AJ, Seager R, Wilkinson KA, Henley JM. Coordinated interplay between palmitoylation, phosphorylation and SUMOylation regulates kainate receptor surface expression. Front Mol Neurosci 2023; 16:1270849. [PMID: 37868810 PMCID: PMC10585046 DOI: 10.3389/fnmol.2023.1270849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 09/11/2023] [Indexed: 10/24/2023] Open
Abstract
Kainate receptors (KARs) are key regulators of neuronal excitability and synaptic transmission. KAR surface expression is tightly controlled in part by post-translational modifications (PTMs) of the GluK2 subunit. We have shown previously that agonist activation of GluK2-containing KARs leads to phosphorylation of GluK2 at S868, which promotes subsequent SUMOylation at K886 and receptor endocytosis. Furthermore, GluK2 has been shown to be palmitoylated. However, how the interplay between palmitoylation, phosphorylation and SUMOylation orchestrate KAR trafficking remains unclear. Here, we used a library of site-specific GluK2 mutants to investigate the interrelationship between GluK2 PTMs, and their impact on KAR surface expression. We show that GluK2 is basally palmitoylated and that this is decreased by kainate (KA) stimulation. Moreover, a non-palmitoylatable GluK2 mutant (C858/C871A) shows enhanced S868 phosphorylation and K886 SUMOylation under basal conditions and is insensitive to KA-induced internalisation. These results indicate that GluK2 palmitoylation contributes to stabilising KAR surface expression and that dynamic depalmitoylation promotes downstream phosphorylation and SUMOylation to mediate activity-dependent KAR endocytosis.
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Affiliation(s)
| | | | | | | | - Kevin A. Wilkinson
- Centre for Synaptic Plasticity, School of Biochemistry, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - Jeremy M. Henley
- Centre for Synaptic Plasticity, School of Biochemistry, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
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4
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Sobel AH, Lee CY, Bowen SG, Camargo SJ, Cane MA, Clement A, Fosu B, Hart M, Reed KA, Seager R, Tippett MK. Near-term tropical cyclone risk and coupled Earth system model biases. Proc Natl Acad Sci U S A 2023; 120:e2209631120. [PMID: 37549274 PMCID: PMC10438837 DOI: 10.1073/pnas.2209631120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023] Open
Abstract
Most current climate models predict that the equatorial Pacific will evolve under greenhouse gas-induced warming to a more El Niño-like state over the next several decades, with a reduced zonal sea surface temperature gradient and weakened atmospheric Walker circulation. Yet, observations over the last 50 y show the opposite trend, toward a more La Niña-like state. Recent research provides evidence that the discrepancy cannot be dismissed as due to internal variability but rather that the models are incorrectly simulating the equatorial Pacific response to greenhouse gas warming. This implies that projections of regional tropical cyclone activity may be incorrect as well, perhaps even in the direction of change, in ways that can be understood by analogy to historical El Niño and La Niña events: North Pacific tropical cyclone projections will be too active, North Atlantic ones not active enough, for example. Other perils, including severe convective storms and droughts, will also be projected erroneously. While it can be argued that these errors are transient, such that the models' responses to greenhouse gases may be correct in equilibrium, the transient response is relevant for climate adaptation in the next several decades. Given the urgency of understanding regional patterns of climate risk in the near term, it would be desirable to develop projections that represent a broader range of possible future tropical Pacific warming scenarios-including some in which recent historical trends continue-even if such projections cannot currently be produced using existing coupled earth system models.
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Affiliation(s)
- Adam H. Sobel
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY10027
- Lamont Doherty Earth Observatory, Columbia University, Palisades, NY10964
| | - Chia-Ying Lee
- Lamont Doherty Earth Observatory, Columbia University, Palisades, NY10964
| | | | - Suzana J. Camargo
- Lamont Doherty Earth Observatory, Columbia University, Palisades, NY10964
| | - Mark A. Cane
- Lamont Doherty Earth Observatory, Columbia University, Palisades, NY10964
| | - Amy Clement
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL33149
| | - Boniface Fosu
- Department of Geosciences, Mississippi State University, Mississippi State, MS39762
| | | | - Kevin A. Reed
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY11794
| | - Richard Seager
- Lamont Doherty Earth Observatory, Columbia University, Palisades, NY10964
| | - Michael K. Tippett
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY10027
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5
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Nair JD, Braksator E, Yucel BP, Fletcher-Jones A, Seager R, Mellor JR, Bashir ZI, Wilkinson KA, Henley JM. Sustained postsynaptic kainate receptor activation downregulates AMPA receptor surface expression and induces hippocampal LTD. iScience 2021; 24:103029. [PMID: 34553130 PMCID: PMC8441151 DOI: 10.1016/j.isci.2021.103029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 07/27/2021] [Accepted: 08/20/2021] [Indexed: 01/21/2023] Open
Abstract
It is well established that long-term depression (LTD) can be initiated by either NMDA or mGluR activation. Here we report that sustained activation of GluK2 subunit-containing kainate receptors (KARs) leads to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) endocytosis and induces LTD of AMPARs (KAR-LTDAMPAR) in hippocampal neurons. The KAR-evoked loss of surface AMPARs is blocked by the ionotropic KAR inhibitor UBP 310 indicating that KAR-LTDAMPAR requires KAR channel activity. Interestingly, however, blockade of PKC or PKA also reduces GluA2 surface expression and occludes the effect of KAR activation. In acute hippocampal slices, kainate application caused a significant loss of GluA2-containing AMPARs from synapses and long-lasting depression of AMPAR excitatory postsynaptic currents in CA1. These data, together with our previously reported KAR-LTPAMPAR, demonstrate that KARs can bidirectionally regulate synaptic AMPARs and synaptic plasticity via different signaling pathways.
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Affiliation(s)
- Jithin D Nair
- Centre for Synaptic Plasticity, School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Ellen Braksator
- Centre for Synaptic Plasticity, School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Busra P Yucel
- Centre for Synaptic Plasticity, School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Alexandra Fletcher-Jones
- Centre for Synaptic Plasticity, School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Richard Seager
- Centre for Synaptic Plasticity, School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Jack R Mellor
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Zafar I Bashir
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Kevin A Wilkinson
- Centre for Synaptic Plasticity, School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Jeremy M Henley
- Centre for Synaptic Plasticity, School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK.,Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
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6
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Henley JM, Nair JD, Seager R, Yucel BP, Woodhall G, Henley BS, Talandyte K, Needs HI, Wilkinson KA. Kainate and AMPA receptors in epilepsy: Cell biology, signalling pathways and possible crosstalk. Neuropharmacology 2021; 195:108569. [PMID: 33915142 DOI: 10.1016/j.neuropharm.2021.108569] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/13/2021] [Accepted: 04/09/2021] [Indexed: 02/06/2023]
Abstract
Epilepsy is caused when rhythmic neuronal network activity escapes normal control mechanisms, resulting in seizures. There is an extensive and growing body of evidence that the onset and maintenance of epilepsy involves alterations in the trafficking, synaptic surface expression and signalling of kainate and AMPA receptors (KARs and AMPARs). The KAR subunit GluK2 and AMPAR subunit GluA2 are key determinants of the properties of their respective assembled receptors. Both subunits are subject to extensive protein interactions, RNA editing and post-translational modifications. In this review we focus on the cell biology of GluK2-containing KARs and GluA2-containing AMPARs and outline how their regulation and dysregulation is implicated in, and affected by, seizure activity. Further, we discuss role of KARs in regulating AMPAR surface expression and plasticity, and the relevance of this to epilepsy. This article is part of the special issue on 'Glutamate Receptors - Kainate receptors'.
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Affiliation(s)
- Jeremy M Henley
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK; Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia.
| | - Jithin D Nair
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Richard Seager
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Busra P Yucel
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Gavin Woodhall
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK
| | - Benjamin S Henley
- Faculty of Medical Sciences, The Medical School, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK
| | - Karolina Talandyte
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Hope I Needs
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Kevin A Wilkinson
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK.
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7
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Anderson W, Taylor C, McDermid S, Ilboudo-Nébié E, Seager R, Schlenker W, Cottier F, de Sherbinin A, Mendeloff D, Markey K. Violent conflict exacerbated drought-related food insecurity between 2009 and 2019 in sub-Saharan Africa. Nat Food 2021; 2:603-615. [PMID: 37118167 DOI: 10.1038/s43016-021-00327-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 06/16/2021] [Indexed: 04/30/2023]
Abstract
Conflict, drought and locusts are leading concerns for African food security but the relative importance and spatiotemporal scale of crises resulting from each hazard is poorly characterized. Here we use continuous, subnational data to demonstrate that the rise of food insecurity across sub-Saharan Africa that began in 2014 is attributable to an increase in violent conflict, particularly in South Sudan and Nigeria. Although drought remains a leading trigger of food crises, the prevalence of drought-related crises did not increase from 2009 to 2018. When exposed to drought, pastoralists experienced more widespread, severe and long-lasting food crises than people living in agricultural zones. Food insecurity remained elevated in pastoral regions for 2 years following a drought, while agricultural regions returned to pre-drought food-security levels in ~12 months. The few confirmed famines during the 2009-2018 period coincided with both conflict and drought, while locusts had little effect on food security during this period.
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Affiliation(s)
- Weston Anderson
- International Research Institute for Climate and Society, Palisades, NY, USA.
- The Earth Institute, Columbia University, New York, NY, USA.
| | - Charles Taylor
- School of International and Public Affairs, Columbia University, New York, NY, USA
| | - Sonali McDermid
- Department of Environmental Studies, New York University, New York, NY, USA
| | - Elisabeth Ilboudo-Nébié
- International Research Institute for Climate and Society, Palisades, NY, USA
- The Earth Institute, Columbia University, New York, NY, USA
| | | | - Wolfram Schlenker
- School of International and Public Affairs, Columbia University, New York, NY, USA
| | | | - Alex de Sherbinin
- Center for International Earth Science Information Network, Columbia University, Palisades, NY, USA
| | - Dara Mendeloff
- Center for International Earth Science Information Network, Columbia University, Palisades, NY, USA
| | - Kelsey Markey
- Department of Environmental Studies, New York University, New York, NY, USA
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8
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Mukherjee S, Seager R, Lee Y, Conroy J, Pabla S. SO-5 Tumor inflammation and proliferative status as biomarkers in gastroesophageal adenocarcinoma. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.05.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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9
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Zhao X, Alibhai D, Sun T, Khalil J, Hutchinson JL, Olzak K, Williams CM, Li Y, Sessions R, Cross S, Seager R, Aungraheeta R, Leard A, McKinnon CM, Phillips D, Zhang L, Poole AW, Banting G, Mundell SJ. Tetherin/BST2, a physiologically and therapeutically relevant regulator of platelet receptor signalling. Blood Adv 2021; 5:1884-1898. [PMID: 33792632 PMCID: PMC8045503 DOI: 10.1182/bloodadvances.2020003182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 01/20/2021] [Indexed: 11/20/2022] Open
Abstract
The reactivity of platelets, which play a key role in the pathogenesis of atherothrombosis, is tightly regulated. The integral membrane protein tetherin/bone marrow stromal antigen-2 (BST-2) regulates membrane organization, altering both lipid and protein distribution within the plasma membrane. Because membrane microdomains have an established role in platelet receptor biology, we sought to characterize the physiological relevance of tetherin/BST-2 in those cells. To characterize the potential importance of tetherin/BST-2 to platelet function, we used tetherin/BST-2-/- murine platelets. In the mice, we found enhanced function and signaling downstream of a subset of membrane microdomain-expressing receptors, including the P2Y12, TP thromboxane, thrombin, and GPVI receptors. Preliminary studies in humans have revealed that treatment with interferon-α (IFN-α), which upregulates platelet tetherin/BST-2 expression, also reduces adenosine diphosphate-stimulated platelet receptor function and reactivity. A more comprehensive understanding of how tetherin/BST-2 negatively regulates receptor function was provided in cell line experiments, where we focused on the therapeutically relevant P2Y12 receptor (P2Y12R). Tetherin/BST-2 expression reduced both P2Y12R activation and trafficking, which was accompanied by reduced receptor lateral mobility specifically within membrane microdomains. In fluorescence lifetime imaging-Förster resonance energy transfer (FLIM-FRET)-based experiments, agonist stimulation reduced basal association between P2Y12R and tetherin/BST-2. Notably, the glycosylphosphatidylinositol (GPI) anchor of tetherin/BST-2 was required for both receptor interaction and observed functional effects. In summary, we established, for the first time, a fundamental role of the ubiquitously expressed protein tetherin/BST-2 in negatively regulating membrane microdomain-expressed platelet receptor function.
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Affiliation(s)
- Xiaojuan Zhao
- School of Physiology, Pharmacology, and Neuroscience, and
| | - Dominic Alibhai
- Wolfson Bioimaging Facility, University of Bristol, Bristol, United Kingdom
| | - Ting Sun
- State Key Laboratory of Experimental Hematology, Key Laboratory of Gene Therapy for Blood Disease, Institute of Hematology and Blood Disease Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China; and
| | - Jawad Khalil
- School of Physiology, Pharmacology, and Neuroscience, and
| | | | - Kaya Olzak
- School of Physiology, Pharmacology, and Neuroscience, and
| | | | - Yong Li
- School of Physiology, Pharmacology, and Neuroscience, and
| | - Richard Sessions
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Stephen Cross
- Wolfson Bioimaging Facility, University of Bristol, Bristol, United Kingdom
| | - Richard Seager
- School of Physiology, Pharmacology, and Neuroscience, and
| | | | - Alan Leard
- Wolfson Bioimaging Facility, University of Bristol, Bristol, United Kingdom
| | | | - David Phillips
- School of Physiology, Pharmacology, and Neuroscience, and
| | - Lei Zhang
- State Key Laboratory of Experimental Hematology, Key Laboratory of Gene Therapy for Blood Disease, Institute of Hematology and Blood Disease Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China; and
| | | | - George Banting
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
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10
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McDermid SS, Cook BI, De Kauwe MG, Mankin J, Smerdon JE, Williams AP, Seager R, Puma MJ, Aleinov I, Kelley M, Nazarenko L. Disentangling the Regional Climate Impacts of Competing Vegetation Responses to Elevated Atmospheric CO 2. J Geophys Res Atmos 2021; 126:e2020JD034108. [PMID: 34513547 PMCID: PMC8409678 DOI: 10.1029/2020jd034108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/16/2020] [Accepted: 01/24/2021] [Indexed: 05/05/2023]
Abstract
Biophysical vegetation responses to elevated atmospheric carbon dioxide (CO2) affect regional hydroclimate through two competing mechanisms. Higher CO2 increases leaf area (LAI), thereby increasing transpiration and water losses. Simultaneously, elevated CO2 reduces stomatal conductance and transpiration, thereby increasing rootzone soil moisture. Which mechanism dominates in the future is highly uncertain, partly because these two processes are difficult to explicitly separate within dynamic vegetation models. We address this challenge by using the GISS ModelE global climate model to conduct a novel set of idealized 2×CO2 sensitivity experiments to: evaluate the total vegetation biophysical contribution to regional climate change under high CO2; and quantify the separate contributions of enhanced LAI and reduced stomatal conductance to regional hydroclimate responses. We find that increased LAI exacerbates soil moisture deficits across the sub-tropics and more water-limited regions, but also attenuates warming by ∼0.5-1°C in the US Southwest, Central Asia, Southeast Asia, and northern South America. Reduced stomatal conductance effects contribute ∼1°C of summertime warming. For some regions, enhanced LAI and reduced stomatal conductance produce nonlinear and either competing or mutually amplifying hydroclimate responses. In northeastern Australia, these effects combine to exacerbate radiation-forced warming and contribute to year-round water limitation. Conversely, at higher latitudes these combined effects result in less warming than would otherwise be predicted due to nonlinear responses. These results highlight substantial regional variation in CO2-driven vegetation responses and the importance of improving model representations of these processes to better quantify regional hydroclimate impacts.
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Affiliation(s)
- Sonali Shukla McDermid
- Department of Environmental
StudiesNew York UniversityNew YorkNYUSA
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
| | - Benjamin I. Cook
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
| | - Martin G. De Kauwe
- ARC Centre of Excellence for Climate ExtremesSydneyNSWAustralia
- Change Research CentreUniversity of New South WalesSydneyNSWAustralia
- Evolution & Ecology Research CentreUniversity of New South WalesSydneyNSWAustralia
| | - Justin Mankin
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
- Department of
GeographyDartmouth CollegeHanoverNHUSA
| | - Jason E. Smerdon
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
| | - A. Park Williams
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
| | - Richard Seager
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
| | - Michael J. Puma
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
- Center for Climate Systems
ResearchColumbia UniversityNew YorkNYUSA
| | - Igor Aleinov
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
- Center for Climate Systems
ResearchColumbia UniversityNew YorkNYUSA
| | | | - Larissa Nazarenko
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
- Center for Climate Systems
ResearchColumbia UniversityNew YorkNYUSA
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11
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Henley JM, Seager R, Nakamura Y, Talandyte K, Nair J, Wilkinson KA. SUMOylation of synaptic and synapse-associated proteins: An update. J Neurochem 2021; 156:145-161. [PMID: 32538470 PMCID: PMC8218484 DOI: 10.1111/jnc.15103] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 12/13/2022]
Abstract
SUMOylation is a post-translational modification that regulates protein signalling and complex formation by adjusting the conformation or protein-protein interactions of the substrate protein. There is a compelling and rapidly expanding body of evidence that, in addition to SUMOylation of nuclear proteins, SUMOylation of extranuclear proteins contributes to the control of neuronal development, neuronal stress responses and synaptic transmission and plasticity. In this brief review we provide an update of recent developments in the identification of synaptic and synapse-associated SUMO target proteins and discuss the cell biological and functional implications of these discoveries.
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Affiliation(s)
- Jeremy M. Henley
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Richard Seager
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Yasuko Nakamura
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Karolina Talandyte
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Jithin Nair
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Kevin A. Wilkinson
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
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12
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Anderson WB, Seager R, Baethgen W, Cane M, You L. Synchronous crop failures and climate-forced production variability. Sci Adv 2019; 5:eaaw1976. [PMID: 31281890 PMCID: PMC6609162 DOI: 10.1126/sciadv.aaw1976] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 05/24/2019] [Indexed: 05/30/2023]
Abstract
Large-scale modes of climate variability can force widespread crop yield anomalies and are therefore often presented as a risk to food security. We quantify how modes of climate variability contribute to crop production variance. We find that the El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), tropical Atlantic variability (TAV), and the North Atlantic Oscillation (NAO) together account for 18, 7, and 6% of globally aggregated maize, soybean, and wheat production variability, respectively. The lower fractions of global-scale soybean and wheat production variability result from substantial but offsetting climate-forced production anomalies. All climate modes are important in at least one region studied. In 1983, ENSO, the only mode capable of forcing globally synchronous crop failures, was responsible for the largest synchronous crop failure in the modern historical record. Our results provide the basis for monitoring, and potentially predicting, simultaneous crop failures.
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Affiliation(s)
- W. B. Anderson
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
- International Research Institute for Climate and Society, Palisades, NY, USA
- Department of Earth and Environmental Sciences, Columbia University, Palisades, NY, USA
| | - R. Seager
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - W. Baethgen
- International Research Institute for Climate and Society, Palisades, NY, USA
| | - M. Cane
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - L. You
- International Food Policy Research Institute, Washington, DC, USA
- Macro Agriculture Research Institute and College of Economics and Management, Huazhong Agricultural University, Wuhan, Hubei, China
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13
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Steiger NJ, Smerdon JE, Cook BI, Seager R, Williams AP, Cook ER. Oceanic and radiative forcing of medieval megadroughts in the American Southwest. Sci Adv 2019; 5:eaax0087. [PMID: 31355339 PMCID: PMC6656535 DOI: 10.1126/sciadv.aax0087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 06/17/2019] [Indexed: 05/13/2023]
Abstract
Multidecadal "megadroughts" were a notable feature of the climate of the American Southwest over the Common era, yet we still lack a comprehensive theory for what caused these megadroughts and why they curiously only occurred before about 1600 CE. Here, we use the Paleo Hydrodynamics Data Assimilation product, in conjunction with radiative forcing estimates, to demonstrate that megadroughts in the American Southwest were driven by unusually frequent and cold central tropical Pacific sea surface temperature (SST) excursions in conjunction with anomalously warm Atlantic SSTs and a locally positive radiative forcing. This assessment of past megadroughts provides the first comprehensive theory for the causes of megadroughts and their clustering particularly during the Medieval era. This work also provides the first paleoclimatic support for the prediction that the risk of American Southwest megadroughts will markedly increase with global warming.
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Affiliation(s)
- Nathan J. Steiger
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
- Corresponding author.
| | - Jason E. Smerdon
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | | | - Richard Seager
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | - A. Park Williams
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | - Edward R. Cook
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
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14
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Bishop DA, Williams AP, Seager R, Fiore AM, Cook BI, Mankin JS, Singh D, Smerdon JE, Rao MP. Investigating the causes of increased 20 th-century fall precipitation over the southeastern United States. J Clim 2018; 32:575-590. [PMID: 31831943 PMCID: PMC6907404 DOI: 10.1175/jcli-d-18-0244.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Much of the eastern United States (US) experienced increased precipitation over the 20th century. Characterizing these trends and their causes is critical for assessing future hydroclimate risks. Here, US precipitation trends are analyzed during 1895-2016, revealing that fall precipitation in the southeastern region north of the Gulf of Mexico (SE-Gulf) increased by nearly 40%, primarily increasing after the mid-1900s. As fall is the climatological dry season in the SE-Gulf and precipitation in other seasons changed insignificantly, the seasonal precipitation cycle diminished substantially. The increase in SE-Gulf fall precipitation was caused by increased southerly moisture transport from the Gulf of Mexico, which was almost entirely driven by stronger winds associated with enhanced anticyclonic circulation west of the North Atlantic Subtropical High (NASH) and not by increases in specific humidity. Atmospheric models forced by observed SSTs and fully-coupled models forced by historical anthropogenic forcing do not robustly simulate 20th-century fall wetting in the SE-Gulf. SST-forced atmospheric models do simulate an intensified anticyclonic low-level circulation around the NASH, but the modeled intensification occurred farther west than observed. CMIP5 analyses suggest an increased likelihood of positive SE-Gulf fall precipitation trends given historical and future GHG forcing. Nevertheless, individual model simulations (both SST-forced and fully-coupled) only very rarely produce the observed magnitude of the SE-Gulf fall precipitation trend. Further research into model representation of the western ridge of the fall NASH is needed, which will help us better predict whether 20th-century increases in SE-Gulf fall precipitation will persist into the future.
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Affiliation(s)
- Daniel A Bishop
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
- Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA
| | - A Park Williams
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - Richard Seager
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - Arlene M Fiore
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
- Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA
| | - Benjamin I Cook
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
- NASA Goddard Institute for Space Studies, New York, NY 10025, USA
| | - Justin S Mankin
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
- NASA Goddard Institute for Space Studies, New York, NY 10025, USA
- Department of Geography, Dartmouth College, Hanover, NH 03755, USA
| | - Deepti Singh
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
- School of the Environment, Washington State University, Vancouver, WA 98686, USA
| | - Jason E Smerdon
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - Mukund P Rao
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
- Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA
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15
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Mankin JS, Smerdon JE, Cook BI, Williams AP, Seager R. The Curious Case of Projected Twenty-First-Century Drying but Greening in the American West. J Clim 2017; 30:8689-8710. [PMID: 33154610 PMCID: PMC7641105 DOI: 10.1175/jcli-d-17-0213.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Climate models project significant twenty-first-century declines in water availability over the American West from anthropogenic warming. However, the physical mechanisms underpinning this response are poorly characterized, as are the uncertainties from vegetation's modulation of evaporative losses. To understand the drivers and uncertainties of future hydroclimate in the American West, a 35-member single model ensemble is used to examine the response of summer soil moisture and runoff to anthropogenic forcing. Widespread dry season soil moisture declines occur across the region despite increases in total water-year precipitation and ubiquitous increases in plant water-use efficiency. These modeled soil moisture declines are initially forced by significant snowpack losses that directly diminish summer soil water, even in regions where water-year precipitation increases. When snowpack priming is coupled with a warming- and CO2-induced shift in phenology and increased primary production, widespread increases in leaf area further reduces summer soil moisture and runoff by outpacing decreased stomatal conductance from high CO2. The net effects lead to the cooccurrence of both a "greener" and "drier" future across the western United States. Because simulated vegetation exerts a large influence on predicted changes in water availability in the American West, these findings highlight the importance of reducing the substantial uncertainties in the ecological processes increasingly incorporated into numerical Earth system models.
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Affiliation(s)
- Justin S Mankin
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, and NASA Goddard Institute for Space Studies, New York, New York, and Department of Geography, Dartmouth College, Hanover, New Hampshire
| | - Jason E Smerdon
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York
| | - Benjamin I Cook
- NASA Goddard Institute for Space Studies, New York, and Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York
| | - A Park Williams
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York
| | - Richard Seager
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York
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16
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Williams AP, Cook BI, Smerdon JE, Bishop DA, Seager R, Mankin JS. The 2016 southeastern US drought: an extreme departure from centennial wetting and cooling. J Geophys Res Atmos 2017; 122:10888-10905. [PMID: 29780677 PMCID: PMC5956230 DOI: 10.1002/2017jd027523] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The fall 2016 drought in the southeastern United States (SE US) appeared exceptional based on its widespread impacts, but the current monitoring framework that only extends from 1979-present does not readily facilitate evaluation of soil-moisture anomalies in a centennial context. A new method to extend monthly gridded soil-moisture estimates back to 1895 is developed, indicating that since 1895, October-November 2016 soil moisture (0-200 cm) in the SE US was likely the second lowest on record, behind 1954. This severe drought developed rapidly and was brought on by low September-November precipitation and record-high September-November daily maximum temperatures (Tmax). Record Tmax drove record-high atmospheric moisture demand, accounting for 28% of the October-November 2016 soil-moisture anomaly. Drought and heat in fall 2016 contrasted with 20th-century wetting and cooling in the region, but resembled conditions more common from 1895-1956. Dynamically, the exceptional drying in fall 2016 was driven by anomalous ridging over the central United States that reduced south-southwesterly moisture transports into the SE US by approximately 75%. These circulation anomalies were likely promoted by a moderate La Niña and warmth in the tropical Atlantic, but these processes accounted for very little of the SE US drying in fall 2016, implying a large role for internal atmospheric variability. The extended analysis back to 1895 indicates that SE US droughts as strong as the 2016 event are more likely than indicated from a shorter 60-year perspective, and continued multi-decadal swings in precipitation may combine with future warming to further enhance the likelihood of such events.
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Affiliation(s)
- A. Park Williams
- Lamont-Doherty Earth Observatory of Columbia University; Palisades, NY 10964, USA
| | - Benjamin I. Cook
- NASA Goddard Institute for Space Studies; New York, NY 10025, USA
| | - Jason E. Smerdon
- Lamont-Doherty Earth Observatory of Columbia University; Palisades, NY 10964, USA
| | - Daniel A. Bishop
- Lamont-Doherty Earth Observatory of Columbia University; Palisades, NY 10964, USA
- Department of Earth and Environmental Sciences, Columbia University; New York, NY 10025, USA
| | - Richard Seager
- Lamont-Doherty Earth Observatory of Columbia University; Palisades, NY 10964, USA
| | - Justin S. Mankin
- Lamont-Doherty Earth Observatory of Columbia University; Palisades, NY 10964, USA
- NASA Goddard Institute for Space Studies; New York, NY 10025, USA
- Department of Geography, Dartmouth College; Hanover, NH 03755, USA
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17
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Baek SH, Smerdon JE, Coats S, Williams AP, Cook BI, Cook ER, Seager R. Precipitation, temperature, and teleconnection signals across the combined North American, Monsoon Asia, and Old World Drought Atlases. J Clim 2017; 30:7141-7155. [PMID: 30449951 PMCID: PMC6235455 DOI: 10.1175/jcli-d-16-0766.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The tree-ring-based North American Drought Atlas (NADA), Monsoon Asia Drought Atlas (MADA), and Old World Drought Atlas (OWDA) collectively yield a near-hemispheric gridded reconstruction of hydroclimate variability over the last millennium. To test the robustness of the large-scale representation of hydroclimate variability across the drought atlases, the joint expression of seasonal climate variability and teleconnections in the NADA, MADA, and OWDA are compared against two global, observation-based PDSI products. Predominantly positive (negative) correlations are determined between seasonal precipitation (surface air temperature) and collocated tree-ring-based PDSI, with average Pearson's correlation coefficients increasing in magnitude from boreal winter to summer. For precipitation, these correlations tend to be stronger in the boreal winter and summer when calculated for the observed PDSI record, while remaining similar for temperature. Notwithstanding these differences, the drought atlases robustly express teleconnection patterns associated with the El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO). These expressions exist in the drought atlas estimates of boreal summer PDSI despite the fact that these modes of climate variability are dominant in boreal winter, with the exception of the Atlantic Multidecadal Oscillation. ENSO and NAO teleconnection patterns in the drought atlases are particularly consistent with their well-known dominant expressions in boreal winter and over the OWDA domain, respectively. Collectively, our findings confirm that the joint Northern Hemisphere drought atlases robustly reflect large-scale patterns of hydroclimate variability on seasonal to multidecadal timescales over the 20th century and are likely to provide similarly robust estimates of hydroclimate variability prior to the existence of widespread instrumental data.
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Affiliation(s)
- Seung H. Baek
- Corresponding author: Seung H. Baek, 61 Route 9W, Oceanography 205E, Palisades, NY 10964,
| | - Jason E. Smerdon
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York
| | - Sloan Coats
- Cooperative Institute for Research in Environmental Sciences, University of Colorado-Boulder, and National Center for Atmospheric Research, Boulder, Colorado
| | - A. Park Williams
- Lamont-Doherty Earth Observatory, Columbia University, Palisades
| | - Benjamin I. Cook
- NASA Goddard Institute for Space Studies, New York, and Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York
| | - Edward R. Cook
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York
| | - Richard Seager
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York
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18
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Rawlings N, Lee L, Martin J, Seager R, Guo C, Wilkinson K, Halestrap A, Henley J. 229 Role of sumoylation and desumoylation of mitochondrial fission proteins in myocardial ischaemia-reperfusion injury. Heart 2017. [DOI: 10.1136/heartjnl-2017-311726.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Coats S, Smerdon JE, Cook BI, Seager R, Cook ER, Anchukaitis KJ. Internal ocean-atmosphere variability drives megadroughts in Western North America. Geophys Res Lett 2016; 43:9886-9894. [PMID: 29780186 PMCID: PMC5956231 DOI: 10.1002/2016gl070105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Multidecadal droughts that occurred during the Medieval Climate Anomaly represent an important target for validating the ability of climate models to adequately characterize drought risk over the near-term future. A prominent hypothesis is that these megadroughts were driven by a centuries-long radiatively forced shift in the mean state of the tropical Pacific Ocean. Here we use a novel combination of spatiotemporal tree-ring reconstructions of Northern Hemisphere hydroclimate to infer the atmosphere-ocean dynamics that coincide with megadroughts over the American West, and find that these features are consistently associated with ten-to-thirty year periods of frequent cold El Niño Southern Oscillation conditions and not a centuries-long shift in the mean of the tropical Pacific Ocean. These results suggest an important role for internal variability in driving past megadroughts. State-of-the art climate models from the Coupled Model Intercomparison Project phase 5, however, do not simulate a consistent association between megadroughts and internal variability of the tropical Pacific Ocean, with implications for our confidence in megadrought risk projections.
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Affiliation(s)
- S. Coats
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado
| | - J. E. Smerdon
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York
| | - B. I. Cook
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York
- NASA Goddard Institute for Space Studies, New York, New York
| | - R. Seager
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York
| | - E. R. Cook
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York
| | - K. J. Anchukaitis
- Department of Geography and Development and Laboratory of Tree Ring Research, University of Arizona, Tucson, Arizona
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20
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Cook ER, Seager R, Kushnir Y, Briffa KR, Büntgen U, Frank D, Krusic PJ, Tegel W, van der Schrier G, Andreu-Hayles L, Baillie M, Baittinger C, Bleicher N, Bonde N, Brown D, Carrer M, Cooper R, Čufar K, Dittmar C, Esper J, Griggs C, Gunnarson B, Günther B, Gutierrez E, Haneca K, Helama S, Herzig F, Heussner KU, Hofmann J, Janda P, Kontic R, Köse N, Kyncl T, Levanič T, Linderholm H, Manning S, Melvin TM, Miles D, Neuwirth B, Nicolussi K, Nola P, Panayotov M, Popa I, Rothe A, Seftigen K, Seim A, Svarva H, Svoboda M, Thun T, Timonen M, Touchan R, Trotsiuk V, Trouet V, Walder F, Ważny T, Wilson R, Zang C. Old World megadroughts and pluvials during the Common Era. Sci Adv 2015; 1:e1500561. [PMID: 26601136 PMCID: PMC4640589 DOI: 10.1126/sciadv.1500561] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/04/2015] [Indexed: 05/07/2023]
Abstract
Climate model projections suggest widespread drying in the Mediterranean Basin and wetting in Fennoscandia in the coming decades largely as a consequence of greenhouse gas forcing of climate. To place these and other "Old World" climate projections into historical perspective based on more complete estimates of natural hydroclimatic variability, we have developed the "Old World Drought Atlas" (OWDA), a set of year-to-year maps of tree-ring reconstructed summer wetness and dryness over Europe and the Mediterranean Basin during the Common Era. The OWDA matches historical accounts of severe drought and wetness with a spatial completeness not previously available. In addition, megadroughts reconstructed over north-central Europe in the 11th and mid-15th centuries reinforce other evidence from North America and Asia that droughts were more severe, extensive, and prolonged over Northern Hemisphere land areas before the 20th century, with an inadequate understanding of their causes. The OWDA provides new data to determine the causes of Old World drought and wetness and attribute past climate variability to forced and/or internal variability.
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Affiliation(s)
- Edward R. Cook
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
- Corresponding author. E-mail:
| | - Richard Seager
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - Yochanan Kushnir
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - Keith R. Briffa
- Climatic Research Unit, University of East Anglia, Norwich NR4 7TJ, UK
| | - Ulf Büntgen
- Swiss Federal Research Institute WSL, Birmensdorf 8903, Switzerland
| | - David Frank
- Swiss Federal Research Institute WSL, Birmensdorf 8903, Switzerland
| | - Paul J. Krusic
- Navarino Environmental Observatory, Messinia 24001, Greece
| | - Willy Tegel
- Institute for Forest Growth (IWW), University of Freiburg, Freiburg 79106, Germany
| | | | - Laia Andreu-Hayles
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - Mike Baillie
- Paleoecology Center, Queens University, Belfast BT7 1NN, Northern Ireland
| | | | - Niels Bleicher
- Competence Center for Underwater Archaeology and Dendrochronology, Office for Urbanism, City of Zürich, Zürich 8008, Switzerland
| | - Niels Bonde
- National Museum of Denmark, Copenhagen DK-1220, Denmark
| | - David Brown
- Paleoecology Center, Queens University, Belfast BT7 1NN, Northern Ireland
| | - Marco Carrer
- TeSAF Department, Università degli Studi di Padova, Agripolis, Legnaro I-35020, Italy
| | - Richard Cooper
- Climatic Research Unit, University of East Anglia, Norwich NR4 7TJ, UK
| | - Katarina Čufar
- Biotechnical Faculty, University of Ljubljana, Ljubljana SI-1000, Slovenia
| | - Christoph Dittmar
- Environmental Research and Education (UFB), Mistelbach 95511, Germany
| | - Jan Esper
- Department of Geography, Johannes Gutenberg University, Mainz 55099, Germany
| | - Carol Griggs
- Cornell Tree Ring Laboratory, Cornell University, Ithaca, NY 14853, USA
| | - Björn Gunnarson
- Department of Physical Geography, Stockholm University, Stockholm SE-106, Sweden
| | - Björn Günther
- Technische Universität Dresden, Tharandt D-01737, Germany
| | - Emilia Gutierrez
- Department of Ecology, University of Barcelona, Barcelona 08028, Spain
| | | | - Samuli Helama
- Natural Resources Institute Finland, Rovaniemi FI-96301, Finland
| | - Franz Herzig
- Bavarian State Department for Cultural Heritage, Thierhaupten 86672, Germany
| | | | | | - Pavel Janda
- Department of Forest Ecology, Czech University of Life Sciences, Prague 16521, Czech Republic
| | | | - Nesibe Köse
- Faculty of Forestry, Istanbul University, Bahcekoy, Sariyer 34473, Istanbul, Turkey
| | - Tomáš Kyncl
- Moravian Dendro-Labor, Brno 61600, Czech Republic
| | - Tom Levanič
- Slovenian Forestry Institute, Ljubljana SI-1000, Slovenia
| | - Hans Linderholm
- Department of Earth Sciences, Gothenburg University, Gothenburg SE-405, Sweden
| | - Sturt Manning
- Cornell Tree Ring Laboratory, Cornell University, Ithaca, NY 14853, USA
| | - Thomas M. Melvin
- Climatic Research Unit, University of East Anglia, Norwich NR4 7TJ, UK
| | - Daniel Miles
- Oxford Dendrochronology Laboratory, Oxford University, Oxford RG4 7TX, UK
| | | | - Kurt Nicolussi
- Institut für Geographie, Universität Innsbruck, Innsbruck A-6020, Austria
| | - Paola Nola
- Dipartimento di Scienze della Terra e dell’Ambiente, Università degli Studi di Pavia, Pavia 27100, Italy
| | - Momchil Panayotov
- Dendrology Department, University of Forestry, Sophia 1756, Bulgaria
| | - Ionel Popa
- Forest Research and Management Institute, Calea Bucovinei, Campulung Moldovenesc 725100, Romania
| | - Andreas Rothe
- Faculty of Forestry, University of Applied Sciences Weihenstephan-Triesdorf, Freising 85354, Germany
| | - Kristina Seftigen
- Department of Earth Sciences, Gothenburg University, Gothenburg SE-405, Sweden
| | - Andrea Seim
- Department of Earth Sciences, Gothenburg University, Gothenburg SE-405, Sweden
| | - Helene Svarva
- NTNU University Museum, Norwegian University of Science and Technology, Trondheim 7012, Norway
| | - Miroslav Svoboda
- Department of Forest Ecology, Czech University of Life Sciences, Prague 16521, Czech Republic
| | - Terje Thun
- NTNU University Museum, Norwegian University of Science and Technology, Trondheim 7012, Norway
| | - Mauri Timonen
- Natural Resources Institute Finland, Rovaniemi FI-96301, Finland
| | - Ramzi Touchan
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ 85721, USA
| | - Volodymyr Trotsiuk
- Department of Forest Ecology, Czech University of Life Sciences, Prague 16521, Czech Republic
| | - Valerie Trouet
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ 85721, USA
| | - Felix Walder
- Competence Center for Underwater Archaeology and Dendrochronology, Office for Urbanism, City of Zürich, Zürich 8008, Switzerland
| | - Tomasz Ważny
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ 85721, USA
- Nicolaus Copernicus University, Torun 87-100, Poland
| | - Rob Wilson
- School of Geography and Geosciences, University of St. Andrews, St. Andrews KY16 9AL, Scotland
| | - Christian Zang
- Ecoclimatology, Technische Universität München, Freising 85354, Germany
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Tierney JE, Smerdon JE, Anchukaitis KJ, Seager R. Multidecadal variability in East African hydroclimate controlled by the Indian Ocean. Nature 2013; 493:389-92. [PMID: 23325220 DOI: 10.1038/nature11785] [Citation(s) in RCA: 249] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 11/08/2012] [Indexed: 11/10/2022]
Abstract
The recent decades-long decline in East African rainfall suggests that multidecadal variability is an important component of the climate of this vulnerable region. Prior work based on analysing the instrumental record implicates both Indian and Pacific ocean sea surface temperatures (SSTs) as possible drivers of East African multidecadal climate variability, but the short length of the instrumental record precludes a full elucidation of the underlying physical mechanisms. Here we show that on timescales beyond the decadal, the Indian Ocean drives East African rainfall variability by altering the local Walker circulation, whereas the influence of the Pacific Ocean is minimal. Our results, based on proxy indicators of relative moisture balance for the past millennium paired with long control simulations from coupled climate models, reveal that moist conditions in coastal East Africa are associated with cool SSTs (and related descending circulation) in the eastern Indian Ocean and ascending circulation over East Africa. The most prominent event identified in the proxy record--a coastal pluvial from 1680 to 1765--occurred when Indo-Pacific warm pool SSTs reached their minimum values of the past millennium. Taken together, the proxy and model evidence suggests that Indian Ocean SSTs are the primary influence on East African rainfall over multidecadal and perhaps longer timescales.
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Affiliation(s)
- Jessica E Tierney
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
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Abstract
Climate models robustly predict that the climate of southwestern North America, defined as the area from the western Great Plains to the Pacific Ocean and from the Oregon border to southern Mexico, will dry throughout the current century as a consequence of rising greenhouse gases. This regional drying is part of a general drying of the subtropics and poleward expansion of the subtropical dry zones. Through an analysis of 15 coupled climate models it is shown here that the drying is driven by a reduction of winter season precipitation associated with increased moisture divergence by the mean flow and reduced moisture convergence by transient eddies. Due to the presence of large amplitude decadal variations of presumed natural origin, observations to date cannot confirm that this transition to a drier climate is already underway, but it is anticipated that the anthropogenic drying will reach the amplitude of natural decadal variability by midcentury. In addition to this drop in total precipitation, warming is already causing a decline in mountain snow mass and an advance in the timing of spring snow melt disrupting the natural water storage systems that are part of the region's water supply system. Uncertainties in how radiative forcing will impact the tropical Pacific climate system create uncertainties in the amplitude of drying in southwest North America with a La Niña-like response creating a worst case scenario of greater drying.
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Affiliation(s)
- Richard Seager
- Lamont Doherty Earth Observatory of Columbia University, Paisades, NY 10025, USA.
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Seager R, Ting M, Held I, Kushnir Y, Lu J, Vecchi G, Huang HP, Harnik N, Leetmaa A, Lau NC, Li C, Velez J, Naik N. Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America. Science 2007; 316:1181-4. [PMID: 17412920 DOI: 10.1126/science.1139601] [Citation(s) in RCA: 489] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
How anthropogenic climate change will affect hydroclimate in the arid regions of southwestern North America has implications for the allocation of water resources and the course of regional development. Here we show that there is a broad consensus among climate models that this region will dry in the 21st century and that the transition to a more arid climate should already be under way. If these models are correct, the levels of aridity of the recent multiyear drought or the Dust Bowl and the 1950s droughts will become the new climatology of the American Southwest within a time frame of years to decades.
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Affiliation(s)
- Richard Seager
- Lamont Doherty Earth Observatory (LDEO), Columbia University, Palisades, NY 10964, USA.
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Abstract
An analysis of historical sea surface temperatures provides evidence for global warming since 1900, in line with land-based analyses of global temperature trends, and also shows that over the same period, the eastern equatorial Pacific cooled and the zonal sea surface temperature gradient strengthened. Recent theoretical studies have predicted such a pattern as a response of the coupled ocean-atmosphere system to an exogenous heating of the tropical atmosphere. This pattern, however, is not reproduced by the complex ocean-atmosphere circulation models currently used to simulate the climatic response to increased greenhouse gases. Its presence is likely to lessen the mean 20th-century global temperature change in model simulations.
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Affiliation(s)
- MA Cane
- M. A. Cane, A. C. Clement, A. Kaplan, Y. Kushnir, D. Pozdnyakov, R. Seager, S. E. Zebiak, Lamont-Doherty Earth Observatory, Palisades, NY 10964-8000, USA. R. Murtugudde, Universities Space Research Association, Laboratory for Hydrospheric Processes, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
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Crawley BE, Seager R. Monitoring of blood sugar during surgery. Anaesthesia 1970; 25:73-8. [PMID: 5413232 DOI: 10.1111/j.1365-2044.1970.tb00160.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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