Enhanced multi-year predictability after El Niño and La Niña events

Several aspects of regional climate including near-surface temperature and precipitation are predictable on interannual to decadal time scales. Despite indications that some climate states may provide higher predictability than others, previous studies analysing decadal predictions typically sample a variety of initial conditions. Here we assess multi-year predictability conditional on the phase of the El Niño-Southern Oscillation (ENSO) at the time of prediction initialisation. We find that predictions starting with El Niño or La Niña conditions exhibit higher skill in predicting near-surface air temperature and precipitation multiple years in advance, compared to predictions initialised from neutral ENSO conditions. This holds true in idealised prediction experiments with the Community Climate System Model Version 4 and to a lesser extent also real-world predictions using the Community Earth System Model and a multi-model ensemble of hindcasts contributed to the Coupled Model Intercomparison Project Phase 6 Decadal Climate Prediction Project. This enhanced predictability following ENSO events is related to phase transitions as part of the ENSO cycle, and related global teleconnections. Our results indicate that certain initial states provide increased predictability, revealing windows of opportunity for more skillful multi-year predictions.

Effects of EDTA on chemiluminescent immunoassay measurement of ACTH, cortisol, and thyroid hormones in dogs

When measuring blood hormones, pre-analytical sample handling can impact the quality of the results. Previous studies have shown improved stability of canine cortisol in ethylenediaminetetraacetic acid (EDTA) plasma compared to serum and interchangeability of serum and plasma when cortisol is measured by radioimmunoassay. Additionally, cortisol samples were also interchangeable when measured by chemiluminescent immunoassay if the EDTA concentration was consistent with that of optimally filled tubes, whereas excess EDTA interfered with the measurement of cortisol and serum and EDTA plasma were not interchangeable when measuring total thyroxine (TT4). The main limitation of these studies was that they were performed by spiking pooled serum samples with EDTA or in previously collected blood samples submitted to a clinical pathology laboratory. The purpose of the present study was to evaluate the effect of EDTA on the measurement of adrenocorticotropic hormone (ACTH), cortisol, TT4, free thyroxine (FT4), and thyroid stimulating hormone (TSH) in healthy dogs using the Siemens IMMULITE 1000. Whole blood from forty dogs was aliquoted into three Monoject sample tubes: no additive, completely filled EDTA tube, and 50% filled EDTA tube. Handling and storage conditions were identical, and all samples were analyzed on the same day. Bland-Altman plots and Passing-Bablok regression were used to assess agreement and risks for error, respectively. Proportional errors were found between serum and plasma samples for ACTH, cortisol, TT4, FT4, and TSH; systematic errors were also found for FT4. There was poor agreement and clinically significant differences between the measured concentrations of all hormones in serum and plasma, proving that these sample types are not interchangeable. Incompletely filled EDTA tubes were associated with significantly lower ACTH concentrations compared to completely filled EDTA tubes. When measured by chemiluminescent immunoassays that utilize alkaline phosphatase at the reporter enzyme, serum should be used for cortisol, TT4, FT4, and TSH, while plasma from completely filled EDTA tubes should be used for ACTH.

Warming of hot extremes alleviated by expanding irrigation

Irrigation affects climate conditions - and especially hot extremes - in various regions across the globe. Yet how these climatic effects compare to other anthropogenic forcings is largely unknown. Here we provide observational and model evidence that expanding irrigation has dampened historical anthropogenic warming during hot days, with particularly strong effects over South Asia. We show that irrigation expansion can explain the negative correlation between global observed changes in daytime summer temperatures and present-day irrigation extent. While global warming increases the likelihood of hot extremes almost globally, irrigation can regionally cancel or even reverse the effects of all other forcings combined. Around one billion people (0.79-1.29) currently benefit from this dampened increase in hot extremes because irrigation massively expanded throughout the 20[Formula: see text] century. Our results therefore highlight that irrigation substantially reduced human exposure to warming of hot extremes but question whether this benefit will continue towards the future.

Modelled biophysical impacts of conservation agriculture on local climates

Including the parameterization of land management practices into Earth System Models has been shown to influence the simulation of regional climates, particularly for temperature extremes. However, recent model development has focused on implementing irrigation where other land management practices such as conservation agriculture (CA) has been limited due to the lack of global spatially explicit datasets describing where this form of management is practiced. Here, we implement a representation of CA into the Community Earth System Model and show that the quality of simulated surface energy fluxes improves when including more information on how agricultural land is managed. We also compare the climate response at the subgrid scale where CA is applied. We find that CA generally contributes to local cooling (~1°C) of hot temperature extremes in mid-latitude regions where it is practiced, while over tropical locations CA contributes to local warming (~1°C) due to changes in evapotranspiration dominating the effects of enhanced surface albedo. In particular, changes in the partitioning of evapotranspiration between soil evaporation and transpiration are critical for the sign of the temperature change: a cooling occurs only when the soil moisture retention and associated enhanced transpiration is sufficient to offset the warming from reduced soil evaporation. Finally, we examine the climate change mitigation potential of CA by comparing a simulation with present-day CA extent to a simulation where CA is expanded to all suitable crop areas. Here, our results indicate that while the local temperature response to CA is considerable cooling (>2°C), the grid-scale changes in climate are counteractive due to negative atmospheric feedbacks. Overall, our results underline that CA has a nonnegligible impact on the local climate and that it should therefore be considered in future climate projections.

A spatially explicit representation of conservation agriculture for application in global change studies

Conservation agriculture (CA) is widely promoted as a sustainable agricultural management strategy with the potential to alleviate some of the adverse effects of modern, industrial agriculture such as large-scale soil erosion, nutrient leaching and overexploitation of water resources. Moreover, agricultural land managed under CA is proposed to contribute to climate change mitigation and adaptation through reduced emission of greenhouse gases, increased solar radiation reflection, and the sustainable use of soil and water resources. Due to the lack of official reporting schemes, the amount of agricultural land managed under CA systems is uncertain and spatially explicit information about the distribution of CA required for various modeling studies is missing. Here, we present an approach to downscale present-day national-level estimates of CA to a 5 arcminute regular grid, based on multicriteria analysis. We provide a best estimate of CA distribution and an uncertainty range in the form of a low and high estimate of CA distribution, reflecting the inconsistency in CA definitions. We also design two scenarios of the potential future development of CA combining present-day data and an assessment of the potential for implementation using biophysical and socioeconomic factors. By our estimates, 122-215 Mha or 9%-15% of global arable land is currently managed under CA systems. The lower end of the range represents CA as an integrated system of permanent no-tillage, crop residue management and crop rotations, while the high estimate includes a wider range of areas primarily devoted to temporary no-tillage or reduced tillage operations. Our scenario analysis suggests a future potential of CA in the range of 533-1130 Mha (38%-81% of global arable land). Our estimates can be used in various ecosystem modeling applications and are expected to help identifying more realistic climate mitigation and adaptation potentials of agricultural practices.

Climate extremes, land-climate feedbacks and land-use forcing at 1.5°C

This article investigates projected changes in temperature and water cycle extremes at 1.5°C of global warming, and highlights the role of land processes and land-use changes (LUCs) for these projections. We provide new comparisons of changes in climate at 1.5°C versus 2°C based on empirical sampling analyses of transient simulations versus simulations from the 'Half a degree Additional warming, Prognosis and Projected Impacts' (HAPPI) multi-model experiment. The two approaches yield similar overall results regarding changes in climate extremes on land, and reveal a substantial difference in the occurrence of regional extremes at 1.5°C versus 2°C. Land processes mediated through soil moisture feedbacks and land-use forcing play a major role for projected changes in extremes at 1.5°C in most mid-latitude regions, including densely populated areas in North America, Europe and Asia. This has important implications for low-emissions scenarios derived from integrated assessment models (IAMs), which include major LUCs in ambitious mitigation pathways (e.g. associated with increased bioenergy use), but are also shown to differ in the simulated LUC patterns. Biogeophysical effects from LUCs are not considered in the development of IAM scenarios, but play an important role for projected regional changes in climate extremes, and are thus of high relevance for sustainable development pathways.This article is part of the theme issue 'The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.

Biogeophysical Impacts of Land-Use Change on Climate Extremes in Low-Emission Scenarios: Results From HAPPI-Land

The impacts of land use have been shown to have considerable influence on regional climate. With the recent international commitment to limit global warming to well below 2°C, emission reductions need to be ambitious and could involve major land-use change (LUC). Land-based mitigation efforts to curb emissions growth include increasing terrestrial carbon sequestration through reforestation, or the adoption of bioenergy crops. These activities influence local climate through biogeophysical feedbacks, however, it is uncertain how important they are for a 1.5° climate target. This was the motivation for HAPPI-Land: the half a degree additional warming, prognosis, and projected impacts-land-use scenario experiment. Using four Earth system models, we present the first multimodel results from HAPPI-Land and demonstrate the critical role of land use for understanding the characteristics of regional climate extremes in low-emission scenarios. In particular, our results show that changes in temperature extremes due to LUC are comparable in magnitude to changes arising from half a degree of global warming. We also demonstrate that LUC contributes to more than 20% of the change in temperature extremes for large land areas concentrated over the Northern Hemisphere. However, we also identify sources of uncertainty that influence the multimodel consensus of our results including how LUC is implemented and the corresponding biogeophysical feedbacks that perturb climate. Therefore, our results highlight the urgent need to resolve the challenges in implementing LUC across models to quantify the impacts and consider how LUC contributes to regional changes in extremes associated with sustainable development pathways.

Folliculitis ulerythematosus reticulata: a report of four cases and brief review of the literature

Folliculitis ulerythematosus reticulata (FUR) is an uncommon genodermatosis best classified as one of the keratosis pilaris atrophicans group of disorders. It is characterized by erythema and follicular plugging of the cheeks that evolves into honeycomb atrophy. Associated cutaneous and visceral abnormalities can occur. This report describes four patients with FUR, one with an unaffected twin, a finding not previously reported. The significance of an early and accurate diagnosis is emphasized.

Comparison of high pressure liquid chromatographic and chemical methods for vitamin D3 concentrates. II. Collaborative study

A collaborative study was carried out which compared the official chemical method, 43.B14-43.B24, the official rat bioassay, 43.165, and the high pressure liquid chromatographic method for vitamin D3 resin, vitamin D3 resin in oil, and dry concentrate. A total of 340 samples were distributed to 17 collaborators for analysis. Five laboratories performed both the chemical and HPLC methods on 5 sets of blind duplicates. A 2-way analysis of variance comparing both methods for each sample showed a significant (P less than 0.01) difference between methods only for Sample 5. When the 2 methods were compared over all the samples, no significant (P less than 0.05) difference was found. Except for Sample 5, there were no differences in the repeatability of the methods. Per cent recoveries on Sample 3, which contained exactly 0.200 X 10(6) IU/g, showed 98.2% for the chemical method and 100.6% for the HPLC method for the 5 laboratories that performed both methods. The assay results of the HPLC and chemical methods are in good agreement with those found by the biological assay on Samples 1-4, but not for Sample 5. Evidence indicates that Sample 5 degraded partially to isotachysterol, and while the HPLC method yielded a reasonable value on this material, the chemical method erroneously showed full potency. An amendment is included for the collaboratively studied HPLC method which detects and eliminates 5,6-trans-vitamin D3, a possible interferant.