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Sekiya T, Miyazaki K, Eskes H, Bowman K, Sudo K, Kanaya Y, Takigawa M. The worldwide COVID-19 lockdown impacts on global secondary inorganic aerosols and radiative budget. SCIENCE ADVANCES 2023; 9:eadh2688. [PMID: 37506199 PMCID: PMC10381952 DOI: 10.1126/sciadv.adh2688] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023]
Abstract
Global lockdown measures to prevent the spread of the coronavirus disease 2019 (COVID-19) led to air pollutant emission reductions. While the COVID-19 lockdown impacts on both trace gas and total particulate pollutants have been widely investigated, secondary aerosol formation from trace gases remains unclear. To that end, we quantify the COVID-19 lockdown impacts on NOx and SO2 emissions and sulfate-nitrate-ammonium aerosols using multiconstituent satellite data assimilation and model simulations. We find that anthropogenic emissions over major polluted regions were reduced by 19 to 25% for NOx and 14 to 20% for SO2 during April 2020. These emission reductions led to 8 to 21% decreases in sulfate and nitrate aerosols over highly polluted areas, corresponding to >34% of the observed aerosol optical depth declines and a global aerosol radiative forcing of +0.14 watts per square meter relative to business-as-usual scenario. These results point to the critical importance of secondary aerosol pollutants in quantifying climate impacts of future mitigation measures.
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Affiliation(s)
- Takashi Sekiya
- Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
| | - Kazuyuki Miyazaki
- Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
- Jet Propulsion Laboratory/California Institute for Technology, Pasadena, CA, USA
| | - Henk Eskes
- Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands
| | - Kevin Bowman
- Jet Propulsion Laboratory/California Institute for Technology, Pasadena, CA, USA
- Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, CA, USA
| | - Kengo Sudo
- Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
- Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan
| | - Yugo Kanaya
- Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
| | - Masayuki Takigawa
- Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
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Wang F, Zhang X, Wang F, Song M, Li Z, Ming J. Urban air quality in Xinjiang and snow chemistry of Urumqi Glacier No. 1 during COVID-19's restrictions. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:76026-76035. [PMID: 35665455 PMCID: PMC9166164 DOI: 10.1007/s11356-022-21167-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
The unprecedented COVID-19 outbreak impacted the world in many aspects. Air pollutants were largely reduced in cities worldwide in 2020. Using samples from two snow pits dug separately in 2019 and 2020 in Urumqi Glacier No. 1 (UG1) in the Xinjiang Uygur Autonomous Region (Xinjiang), China, we measured water-stable isotopes, soluble ions, and black and organic carbon (BC and OC). Both carbon types show no significant variations in the snow-pit profiles dated from 2018 through 2020. The deposition of anthropogenically induced soluble ions (K+, Cl-, SO42-, and NO3-) in the snow decreased to 20-40% of their respective concentrations between 2019 and 2020; however, they increased 2- to fourfold from 2018 to 2019. We studied the daily concentrations of SO2 (2019-2020), NO2 (2015-2020), CO (2019-2020), and PM2.5 (2019-2020) measured in the sixteen major cities and towns across Xinjiang. The variabilities in these air pollutants were supposed to illustrate the air quality in the urban area and represent the change in the source area. The NO2 decreased in response to mobility restrictions imposed by local governments, while SO2, CO, and PM2.5 did not consistently correspond. This difference indicates that the restriction measures primarily affected traffic. The increases in chemical species in the snow from 2018 to 2019 and the subsequent decreases from 2019 to 2020 were consistent with the variations in SO2 and NO2 measured in urban air and estimated by MERRA-2 model. Therefore, the pandemic could possibly have an impact on snow chemistry of the Tien-Shan glaciers via reduced traffic and industrial intensity; more evidence would be obtained from ice cores, tree rings, and other archives in the future.
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Affiliation(s)
- Feiteng Wang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Xin Zhang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Fanglong Wang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Mengyuan Song
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Zhongqin Li
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Jing Ming
- Beacon Science & Consulting, Adelaide, SA, 5000, Australia.
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Diamond MS, Gristey JJ, Kay JE, Feingold G. Anthropogenic aerosol and cryosphere changes drive Earth's strong but transient clear-sky hemispheric albedo asymmetry. COMMUNICATIONS EARTH & ENVIRONMENT 2022; 3:206. [PMID: 36118252 PMCID: PMC9466336 DOI: 10.1038/s43247-022-00546-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
A striking feature of the Earth system is that the Northern and Southern Hemispheres reflect identical amounts of sunlight. This hemispheric albedo symmetry comprises two asymmetries: The Northern Hemisphere is more reflective in clear skies, whereas the Southern Hemisphere is cloudier. Here we show that the hemispheric reflection contrast from differences in continental coverage is offset by greater reflection from the Antarctic than the Arctic, allowing the net clear-sky asymmetry to be dominated by aerosol. Climate model simulations suggest that historical anthropogenic aerosol emissions drove a large increase in the clear-sky asymmetry that would reverse in future low-emission scenarios. High-emission scenarios also show decreasing asymmetry, instead driven by declines in Northern Hemisphere ice and snow cover. Strong clear-sky hemispheric albedo asymmetry is therefore a transient feature of Earth's climate. If all-sky symmetry is maintained, compensating cloud changes would have uncertain but important implications for Earth's energy balance and hydrological cycle.
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Affiliation(s)
- Michael S. Diamond
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309 USA
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305 USA
| | - Jake J. Gristey
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309 USA
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305 USA
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 USA
| | - Jennifer E. Kay
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309 USA
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Ren L, Yang Y, Wang H, Wang P, Yue X, Liao H. Widespread Wildfires Over the Western United States in 2020 Linked to Emissions Reductions During COVID-19. GEOPHYSICAL RESEARCH LETTERS 2022; 49:e2022GL099308. [PMID: 35941985 PMCID: PMC9349500 DOI: 10.1029/2022gl099308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/05/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
Widespread wildfires struck the western United States in 2020, damaging properties and threating human lives. Meanwhile, the COVID-19 pandemic spread across the globe, which disrupted human activities. Here, we investigate the effects of the emissions reductions during the pandemic on fire weather in 2020 over the western United States by using an earth system model together with observations. We show that reductions in aerosols dominate the increases in wildfire risks, whereas greenhouse gas decrease counteracts this influence. The aerosol emissions reductions increased surface air temperature and decreased precipitation and relative humidity due to a weakened moisture transport, which explains one-third of the observed increase in wildfire risks during August-November over the western United States in 2020. This study suggests that COVID-19-related emissions reductions have an unexpected influence on wildfires, highlighting a different but important role of human activities in affecting wildfire risks.
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Affiliation(s)
- Lili Ren
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlJiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjingChina
| | - Yang Yang
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlJiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjingChina
| | - Hailong Wang
- Atmospheric Sciences and Global Change DivisionPacific Northwest National LaboratoryRichlandWAUSA
| | - Pinya Wang
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlJiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjingChina
| | - Xu Yue
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlJiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjingChina
| | - Hong Liao
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlJiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjingChina
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Sun H, Shin YM, Xia M, Ke S, Wan M, Yuan L, Guo Y, Archibald AT. Spatial Resolved Surface Ozone with Urban and Rural Differentiation during 1990-2019: A Space-Time Bayesian Neural Network Downscaler. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:7337-7349. [PMID: 34751030 DOI: 10.1021/acs.est.1c04797] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Long-term exposure to ambient ozone (O3) can lead to a series of chronic diseases and associated premature deaths, and thus population-level environmental health studies hanker after the high-resolution surface O3 concentration database. In response to this demand, we innovatively construct a space-time Bayesian neural network parametric regressor to fuse TOAR historical observations, CMIP6 multimodel simulation ensemble, population distributions, land cover properties, and emission inventories altogether and downscale to 10 km × 10 km spatial resolution with high methodological reliability (R2 = 0.89-0.97, RMSE = 1.97-3.42 ppbV), fair prediction accuracy (R2 = 0.69-0.77, RMSE = 5.63-7.97 ppbV), and commendable spatiotemporal extrapolation capabilities (R2 = 0.62-0.76, RMSE = 5.38-11.7 ppbV). Based on our predictions in 8-h maximum daily average metric, the rural-site surface O3 are 15.1±7.4 ppbV higher than urban globally averaged across 30 historical years during 1990-2019, with developing countries being of the most evident differences. The globe-wide urban surface O3 are climbing by 1.9±2.3 ppbV per decade, except for the decreasing trends in eastern United States. On the other hand, the global rural surface O3 tend to be relatively stable, except for the rising tendencies in China and India. Using CMIP6 model simulations directly without urban-rural differentiation will lead to underestimations of population O3 exposure by 2.0±0.8 ppbV averaged over each historical year. Our original Bayesian neural network framework contributes to the deep-learning-driven environmental studies methodologically by providing a brand-new feasible way to realize data fusion and downscaling, which maintains high interpretability by conforming to the principles of spatial statistics without compromising the prediction accuracy. Moreover, the 30-year highly spatial resolved monthly surface O3 database with multiple metrics fills in the literature gap for long-term surface O3 exposure tracing.
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Affiliation(s)
- Haitong Sun
- Centre for Atmospheric Science, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K
- Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, U.K
| | - Youngsub Matthew Shin
- Centre for Atmospheric Science, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Mingtao Xia
- Department of Mathematics, University of California, Los Angeles, California 90095, United States
| | - Shengxian Ke
- Centre for Atmospheric Science, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Michelle Wan
- Centre for Atmospheric Science, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Le Yuan
- Centre for Atmospheric Science, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Yuming Guo
- School of Public Health and Preventive Medicine, Monash University, Melbourne Victoria 3004, Australia
| | - Alexander T Archibald
- Centre for Atmospheric Science, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K
- National Centre for Atmospheric Science, Cambridge CB2 1EW, U.K
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Yu X, Zhang H, Xie B, Wang Z, Zhao S, Zhao D. Effective Radiative Forcings Due To Anthropogenic Emission Changes Under Covid-19 and Post-Pandemic Recovery Scenarios. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2022; 127:e2021JD036251. [PMID: 35600238 PMCID: PMC9111337 DOI: 10.1029/2021jd036251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 06/15/2023]
Abstract
With the continuation of the Coronavirus Disease 2019 (Covid-19) pandemic, the impacts of this catastrophe on anthropogenic emissions are no longer limited to its early stage. This study quantitatively estimates effective radiative forcings (ERFs) due to anthropogenic well-mixed greenhouse gases (WMGHGs) and aerosols for the period 2020-2050 under the three latest Covid-19 economic-recovery scenarios using an aerosol-climate model. The results indicate that reductions in both WMGHG and aerosol emissions under the Covid-19 green recoveries lead to increases ranging from 0 to 0.3 W m-2 in global annual mean anthropogenic ERF over the period 2020-2050 relative to the Shared Socioeconomic Pathway 2-4.5 scenario (the baseline case). These positive ERFs are mainly attributed to the rapid and dramatic decreases in atmospheric aerosol content that increase net shortwave radiative flux at the top of atmosphere via weakening the direct aerosol effect and low cloud cover. At the regional scale, reductions in aerosols contribute to positive ERFs throughout the Northern Hemisphere, while the decreased WMGHGs dominate negative ERFs over the areas away from aerosol pollution, such as the Southern Hemisphere oceans. This drives a strong interhemispheric contrast of ERFs. In contrast, the increased anthropogenic emissions under the fossil-fueled recovery scenario lead to an increase of 0.3 W m-2 in global annual mean ERF in 2050 compared with the baseline case, primarily due to the contribution of WMGHG ERFs. The regional ERF changes are highly dependent on local cloud radiative effects.
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Affiliation(s)
- Xiaochao Yu
- Department of Atmospheric and Oceanic Sciences & Institute of Atmospheric SciencesFudan UniversityShanghaiChina
- State Key Laboratory of Severe WeatherChinese Academy of Meteorological SciencesBeijingChina
| | - Hua Zhang
- State Key Laboratory of Severe WeatherChinese Academy of Meteorological SciencesBeijingChina
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjingChina
| | - Bing Xie
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjingChina
- Laboratory for Climate Studies of China Meteorological AdministrationNational Climate CenterChina Meteorological AdministrationBeijingChina
| | - Zhili Wang
- State Key Laboratory of Severe Weather and Key Laboratory of Atmospheric Chemistry of CMAChinese Academy of Meteorological SciencesBeijingChina
| | - Shuyun Zhao
- Department of Atmospheric ScienceSchool of Environment StudiesChina University of GeosciencesWuhanChina
| | - Defeng Zhao
- Department of Atmospheric and Oceanic Sciences & Institute of Atmospheric SciencesFudan UniversityShanghaiChina
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A New Methodology for Reference Evapotranspiration Prediction and Uncertainty Analysis under Climate Change Conditions Based on Machine Learning, Multi Criteria Decision Making and Monte Carlo Methods. SUSTAINABILITY 2022. [DOI: 10.3390/su14052601] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In the present study, a new methodology for reference evapotranspiration (ETo) prediction and uncertainty analysis under climate change and COVID-19 post-pandemic recovery scenarios for the period 2021–2050 at nine stations in the two basins of Lake Urmia and Sefidrood is presented. For this purpose, firstly ETo data were estimated using meteorological data and the FAO Penman–Monteith (FAO-56 PM) method. Then, ETo modeling by six machine learning techniques including multiple linear regression (MLR), multiple non-linear regression (MNLR), multivariate adaptive regression splines (MARS), model tree M5 (M5), random forest (RF) and least-squares boost (LSBoost) was carried out. The technique for order of preference by similarity to ideal solution (TOPSIS) method was used under seven scenarios to rank models with evaluation and time criteria in the next step. After proving the acceptable performance of the LSBoost model, the downscaling of temperature (T) and precipitation (P) by the delta change factor (CF) method under three models ACCESS-ESM1-5, CanESM5 and MRI-ESM2-0 (scenarios SSP245-cov-fossil (SCF), SSP245-cov-modgreen (SCM) and SSP245-cov-strgreen (SCS)) was performed. The results showed that the monthly changes in the average T increases at all stations for all scenarios. Also, the average monthly change ratio of P increases in most stations and scenarios. In the next step, ETo forecasting under climate change for periods (2021–2050) was performed using the best model. Prediction results showed that ETo increases in all scenarios and stations in a pessimistic and optimistic state. In addition, the Monte Carlo method (MCM) showed that the lowest uncertainty is related to the Mianeh station in the MRI-ESM2-0 model and SCS scenario.
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Yang Y, Ren L, Wu M, Wang H, Song F, Leung LR, Hao X, Li J, Chen L, Li H, Zeng L, Zhou Y, Wang P, Liao H, Wang J, Zhou ZQ. Abrupt emissions reductions during COVID-19 contributed to record summer rainfall in China. Nat Commun 2022; 13:959. [PMID: 35181650 PMCID: PMC8857220 DOI: 10.1038/s41467-022-28537-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 01/26/2022] [Indexed: 11/09/2022] Open
Abstract
Record rainfall and severe flooding struck eastern China in the summer of 2020. The extreme summer rainfall occurred during the COVID-19 pandemic, which started in China in early 2020 and spread rapidly across the globe. By disrupting human activities, substantial reductions in anthropogenic emissions of greenhouse gases and aerosols might have affected regional precipitation in many ways. Here, we investigate such connections and show that the abrupt emissions reductions during the pandemic strengthened the summer atmospheric convection over eastern China, resulting in a positive sea level pressure anomaly over northwestern Pacific Ocean. The latter enhanced moisture convergence to eastern China and further intensified rainfall in that region. Modeling experiments show that the reduction in aerosols had a stronger impact on precipitation than the decrease of greenhouse gases did. We conclude that through abrupt emissions reductions, the COVID-19 pandemic contributed importantly to the 2020 extreme summer rainfall in eastern China.
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Affiliation(s)
- Yang Yang
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China.
| | - Lili Ren
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China
| | - Mingxuan Wu
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Hailong Wang
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA.
| | - Fengfei Song
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA.,Frontier Science Centre for Deep Ocean Multispheres and Earth System and Physical Oceanography Laboratory, Ocean University of China, Qingdao, China.,Qingdao National Laboratory for Marine Science and Technology (QNLM), Qingdao, China
| | - L Ruby Leung
- Qingdao National Laboratory for Marine Science and Technology (QNLM), Qingdao, China
| | - Xin Hao
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster, Ministry of Education, Nanjing University for Information Science and Technology, Nanjing, Jiangsu, China
| | - Jiandong Li
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China
| | - Lei Chen
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China
| | - Huimin Li
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China
| | - Liangying Zeng
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China
| | - Yang Zhou
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China
| | - Pinya Wang
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China
| | - Hong Liao
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China
| | - Jing Wang
- Tianjin Key Laboratory for Oceanic Meteorology, Tianjin Institute of Meteorological Science, Tianjin, China
| | - Zhen-Qiang Zhou
- Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences, Fudan University, Shanghai, China
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Kripalani R, Ha KJ, Ho CH, Oh JH, Preethi B, Mujumdar M, Prabhu A. Erratic Asian summer monsoon 2020: COVID-19 lockdown initiatives possible cause for these episodes? CLIMATE DYNAMICS 2022; 59:1339-1352. [PMID: 35095207 PMCID: PMC8784227 DOI: 10.1007/s00382-021-06042-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/05/2021] [Indexed: 06/14/2023]
Abstract
The summer (June through September) monsoon 2020 has been very erratic with episodes of heavy and devastating rains, landslides and catastrophic winds over South Asia (India, Pakistan, Nepal, Bangladesh), East Asia (China, Korea, and Japan), and Southeast Asia (Singapore, Thailand, Vietnam, Laos, Cambodia, Philippines, Indonesia). The withdrawal of the summer monsoon over India was delayed by 2 weeks. The monsoon season over East Asia has been the longest. China recorded a Dam burst in the twentieth century. Furthermore, the Korean Peninsula has experienced back-to-back severe tropical cyclones. Could the lockdown activities initiate to control the COVID-19 spread a possible cause for these major episodes? The strict enforcement of the lockdown regulations has led to a considerable reduction of air pollutants-dust and aerosols throughout the world. A recent study based on satellites and merged products has documented a statistically significant mean reduction of about 20, 8, and 50% in nitrogen dioxide, Aerosol Optical Depth (AOD) and PM2.5 concentrations, respectively over the megacities across the globe. Our analysis reveals a considerable reduction of about 20% in AOD over South as well as over East Asia, more-over East Asia than over South Asia. The reduced aerosols have impacted the strength of the incoming solar radiation as evidenced by enhanced warming, more-over the land than the oceans. The differential warming over the land and the ocean has resulted in the amplification of the meridional ocean-land thermal contrast and strengthening of the monsoon flow. These intense features have supported the surplus transport of moisture from the oceans towards the main lands. Some similarity between the anomalous rainfall pattern and the anomalous AOD pattern is discernable. In particular, the enhancement of rainfall, the reduction in AOD and the surface temperature warming match very well over two regions one over West-Central India and the other over the Yangzte River Valley. Results further reveal that the heavy rains over the Yangzte River Valley could be associated with the preceding reduced aerosols, while the heavy rains over West-Central India could be associated with reduced aerosols and also due to the surface temperature warming.
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Affiliation(s)
- Ramesh Kripalani
- Indian Institute of Tropical Meteorology, Pune, 411008 India
- Residence: B-303 Sai Royale Society, Wanowari, Pune 411040 India
| | - Kyung-Ja Ha
- Center for Climate Physics, Institute for Basic Science, Busan, South Korea
- Research Center for Climate Sciences and Department of Atmospheric Sciences, Pusan National University, Busan, South Korea
| | - Chang-Hoi Ho
- School of Earth and Atmospheric Sciences, Seoul National University, Seoul, South Korea
| | | | - B. Preethi
- Center for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, India
| | - Milind Mujumdar
- Center for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, India
| | - Amita Prabhu
- Radar and Satellite Meteorology Project, Indian Institute of Tropical Meteorology, Pune, India
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10
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Tibrewal K, Venkataraman C. COVID-19 lockdown closures of emissions sources in India: Lessons for air quality and climate policy. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 302:114079. [PMID: 34800767 PMCID: PMC8576099 DOI: 10.1016/j.jenvman.2021.114079] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 08/02/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
Reduced anthropogenic activities during the COVID-19 pandemic caused significant reductions in ambient fine particulate matter (PM2.5), SO2 and NOx concentrations across India. However, tropospheric O3 concentrations spiked over many urban regions. Moreover, reductions in SO2 and NOx (atmospheric cooling agents) emissions unmask heating exerted by warming forcers. Basing governmental guidelines, we model daily emissions reductions in CO2 and short-lived climate forcers (SLCFs) during different lockdown periods using bottom-up regional emission inventory. The transport sector, with maximum level of closure, followed by power plants and industry reduced nearly -50% to -75% emissions of CO2, primary PM2.5, SO2 and NOx, while warming SLCFs (black carbon, CH4, CO and non-methane VOCs) showed insignificant reduction from continuing activity in residential and agricultural sectors. Consequently, the analysis indicates that reduction in the emission ratio of NOx to NMVOC coincided spatially with observed increases in O3, consistent with reduced uptake of O3 from night-time NOx reactions. Also, similar reductions, occurring for longer timescales (say, a year), can potentially increase the annual warming rate over India from the positive regional temperature response, estimated using climate metric. Further, by linking ongoing policies to sectoral reductions during lockdown, this study shows that the relative pacing of implementation among policies is crucial to avoid counter-productive results. A key policy recommendation is introduction and improving efficacy of programs targeting reduction of NMVOC and warming SLCF emissions (shifts away from biomass cooking technologies, household electrification and curbing open burning of crop residues), must precede the strengthening of policies targeting NOx and SO2 dominated sectors.
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Affiliation(s)
- Kushal Tibrewal
- Interdisciplinary Program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Chandra Venkataraman
- Interdisciplinary Program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, India; Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India.
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11
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Christensen MW, Gettelman A, Cermak J, Dagan G, Diamond M, Douglas A, Feingold G, Glassmeier F, Goren T, Grosvenor DP, Gryspeerdt E, Kahn R, Li Z, Ma PL, Malavelle F, McCoy IL, McCoy DT, McFarquhar G, Mülmenstädt J, Pal S, Possner A, Povey A, Quaas J, Rosenfeld D, Schmidt A, Schrödner R, Sorooshian A, Stier P, Toll V, Watson-Parris D, Wood R, Yang M, Yuan T. Opportunistic experiments to constrain aerosol effective radiative forcing. ATMOSPHERIC CHEMISTRY AND PHYSICS 2022; 22:641-674. [PMID: 35136405 PMCID: PMC8819675 DOI: 10.5194/acp-22-641-2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Aerosol-cloud interactions (ACIs) are considered to be the most uncertain driver of present-day radiative forcing due to human activities. The nonlinearity of cloud-state changes to aerosol perturbations make it challenging to attribute causality in observed relationships of aerosol radiative forcing. Using correlations to infer causality can be challenging when meteorological variability also drives both aerosol and cloud changes independently. Natural and anthropogenic aerosol perturbations from well-defined sources provide "opportunistic experiments" (also known as natural experiments) to investigate ACI in cases where causality may be more confidently inferred. These perturbations cover a wide range of locations and spatiotemporal scales, including point sources such as volcanic eruptions or industrial sources, plumes from biomass burning or forest fires, and tracks from individual ships or shipping corridors. We review the different experimental conditions and conduct a synthesis of the available satellite datasets and field campaigns to place these opportunistic experiments on a common footing, facilitating new insights and a clearer understanding of key uncertainties in aerosol radiative forcing. Cloud albedo perturbations are strongly sensitive to background meteorological conditions. Strong liquid water path increases due to aerosol perturbations are largely ruled out by averaging across experiments. Opportunistic experiments have significantly improved process-level understanding of ACI, but it remains unclear how reliably the relationships found can be scaled to the global level, thus demonstrating a need for deeper investigation in order to improve assessments of aerosol radiative forcing and climate change.
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Affiliation(s)
- Matthew W. Christensen
- Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK
- Atmospheric Science & Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99354, Washington, USA
| | | | - Jan Cermak
- Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research, Karlsruhe, Germany
- Karlsruhe Institute of Technology (KIT), Institute of Photogrammetry and Remote Sensing, Karlsruhe, Germany
| | - Guy Dagan
- Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Michael Diamond
- Department of Atmospheric Sciences, University of Washington, Seattle, USA
- NOAA Chemical Sciences Laboratory (CSL), Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado, USA
| | - Alyson Douglas
- Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK
| | - Graham Feingold
- NOAA Chemical Sciences Laboratory (CSL), Boulder, Colorado, USA
| | - Franziska Glassmeier
- Department Geoscience and Remote Sensing, Delft University of Technology, P.O. Box 5048, 2600GA Delft, the Netherlands
| | - Tom Goren
- Institute for Meteorology, Universität Leipzig, Leipzig, Germany
| | - Daniel P. Grosvenor
- National Centre for Atmospheric Sciences, School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | - Edward Gryspeerdt
- Space and Atmospheric Physics Group, Imperial College London, London, UK
| | - Ralph Kahn
- Earth Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Zhanqing Li
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, USA
| | - Po-Lun Ma
- Atmospheric Science & Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99354, Washington, USA
| | - Florent Malavelle
- Met Office, Atmospheric Dispersion and Air Quality, Fitzroy Rd, Exeter, EX1 3PB, UK
| | - Isabel L. McCoy
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA
- Cooperative Programs for the Advancement of Earth System Science (CPAESS), University Corporation for Atmospheric Research, Boulder, CO, USA
| | - Daniel T. McCoy
- Department of Atmospheric Sciences, University of Wyoming, Laramie, USA
| | - Greg McFarquhar
- Cooperative Institute for Severe and High Impact Weather Research and Operations (CIWRO) and School of Meteorology, University of Oklahoma, Norman, OK, USA
- School of Meteorology, University of Oklahoma, Norman, OK, USA
| | - Johannes Mülmenstädt
- Atmospheric Science & Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99354, Washington, USA
| | - Sandip Pal
- Department of Geosciences, Texas Tech University, Lubbock, TX, USA
| | - Anna Possner
- Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Adam Povey
- Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK
- National Centre for Earth Observation, University of Oxford, Oxford, OX1 3PU, UK
| | - Johannes Quaas
- Institute for Meteorology, Universität Leipzig, Leipzig, Germany
| | - Daniel Rosenfeld
- Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Anja Schmidt
- Department of Geography, University of Cambridge, Cambridge, UK
- Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - Armin Sorooshian
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - Philip Stier
- Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK
| | - Velle Toll
- Institute of Physics, University of Tartu, Tartu, Estonia
| | - Duncan Watson-Parris
- Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK
| | - Robert Wood
- Department of Atmospheric Sciences, University of Washington, Seattle, USA
| | - Mingxi Yang
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK
| | - Tianle Yuan
- Joint Center for Earth Systems Technologies, University of Maryland, Baltimore County, Baltimore, MD, USA
- Earth Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, USA
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12
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Fiedler S, Wyser K, Rogelj J, van Noije T. Radiative effects of reduced aerosol emissions during the COVID-19 pandemic and the future recovery. ATMOSPHERIC RESEARCH 2021; 264:105866. [PMID: 34602689 PMCID: PMC8462062 DOI: 10.1016/j.atmosres.2021.105866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 09/06/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
The pandemic in 2020 caused an abrupt change in the emission of anthropogenic aerosols and their precursors. We estimate the associated change in the aerosol radiative forcing at the top of the atmosphere and the surface. To that end, we perform new simulations with the CMIP6 global climate model EC-Earth3. The simulations use the here newly created data for the anthropogenic aerosol optical properties and an associated effect on clouds from the simple plumes parameterization (MACv2-SP), based on revised SO2 and NH3 emission scenarios. Our results highlight the small impact of the pandemic on the global aerosol radiative forcing in 2020 compared to the CMIP6 scenario SSP2-4.5 of the order of +0.04 Wm-2, which is small compared to the natural year-to-year variability in the radiation budget. Natural variability also limits the ability to detect a meaningful regional difference in the anthropogenic aerosol radiative effects. We identify the best chances to find a significant change in radiation at the surface during cloud-free conditions for regions that were strongly polluted in the past years. The post-pandemic recovery scenarios indicate a spread in the aerosol forcing of -0.68 to -0.38 Wm-2 for 2050 relative to the pre-industrial, which translates to a difference of +0.05 to -0.25 Wm-2 compared to the 2050 baseline from SSP2-4.5. This spread falls within the present-day uncertainty in aerosol radiative forcing and the CMIP6 spread in aerosol forcing at the end of the 21st century. We release the new MACv2-SP data for studies on the climate response to the pandemic and the recovery scenarios. Our 2050 forcing estimates suggest that sustained aerosol emission reductions during the post-pandemic recovery cause a stronger climate response than in 2020, i.e., there is a delayed influence of the pandemic on climate.
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Affiliation(s)
- Stephanie Fiedler
- University of Cologne, Institute of Geophysics and Meteorology, Cologne, Germany
- Hans-Ertel-Centre for Weather Research, Climate Monitoring and Diagnostics, Bonn/Cologne, Germany
| | - Klaus Wyser
- Rossby Centre, Swedish Meteorological and Hydrological Institute, Sweden
| | - Joeri Rogelj
- Grantham Institute, Imperial College London, United Kingdom
- International Institute for Applied Systems Analysis, Laxenburg, Austria
| | - Twan van Noije
- Royal Netherlands Meteorological Institute, De Bilt, Netherlands
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13
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Lovenduski NS, Chatterjee A, Swart NC, Fyfe JC, Keeling RF, Schimel D. On the Detection of COVID-Driven Changes in Atmospheric Carbon Dioxide. GEOPHYSICAL RESEARCH LETTERS 2021; 48:e2021GL095396. [PMID: 34924639 PMCID: PMC8667626 DOI: 10.1029/2021gl095396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/25/2021] [Accepted: 11/07/2021] [Indexed: 06/14/2023]
Abstract
We assess the detectability of COVID-like emissions reductions in global atmospheric CO2 concentrations using a suite of large ensembles conducted with an Earth system model. We find a unique fingerprint of COVID in the simulated growth rate of CO2 sampled at the locations of surface measurement sites. Negative anomalies in growth rates persist from January 2020 through December 2021, reaching a maximum in February 2021. However, this fingerprint is not formally detectable unless we force the model with unrealistically large emissions reductions (2 or 4 times the observed reductions). Internal variability and carbon-concentration feedbacks obscure the detectability of short-term emission reductions in atmospheric CO2. COVID-driven changes in the simulated, column-averaged dry air mole fractions of CO2 are eclipsed by large internal variability. Carbon-concentration feedbacks begin to operate almost immediately after the emissions reduction; these feedbacks reduce the emissions-driven signal in the atmosphere carbon reservoir and further confound signal detection.
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Affiliation(s)
- Nicole S. Lovenduski
- Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine ResearchUniversity of ColoradoBoulderCOUSA
| | - Abhishek Chatterjee
- Carbon Cycle and Ecosystems GroupJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
- USRA/NASA Goddard Space Flight CenterGreenbeltMDUSA
| | - Neil C. Swart
- Canadian Centre for Climate Modelling and AnalysisEnvironment and Climate Change CanadaVictoriaBCCanada
| | - John C. Fyfe
- Canadian Centre for Climate Modelling and AnalysisEnvironment and Climate Change CanadaVictoriaBCCanada
| | - Ralph F. Keeling
- Scripps Institution of OceanographyUniversity of California San DiegoLa JollaCAUSA
| | - David Schimel
- Carbon Cycle and Ecosystems GroupJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
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14
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Khatri P, Hayasaka T, Holben B, Tripathi SN, Misra P, Patra PK, Hayashida S, Dumka UC. Aerosol Loading and Radiation Budget Perturbations in Densely Populated and Highly Polluted Indo-Gangetic Plain by COVID-19: Influences on Cloud Properties and Air Temperature. GEOPHYSICAL RESEARCH LETTERS 2021; 48:e2021GL093796. [PMID: 34924636 PMCID: PMC8667642 DOI: 10.1029/2021gl093796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/18/2021] [Accepted: 10/02/2021] [Indexed: 06/14/2023]
Abstract
Aerosols emitted in densely populated and industrialized Indo-Gangetic Plain, one of the most polluted regions in the world, modulate regional climate, monsoon, and Himalayan glacier retreat. Thus, this region is important for understanding aerosol perturbations and their resulting impacts on atmospheric changes during COVID-19 lockdown period, a natural experimental condition created by the pandemic. By analyzing 5 years (2016-2020) data of aerosols and performing a radiative transfer calculation, we found that columnar and near-surface aerosol loadings decreased, leading to reductions in radiative cooling at the surface and top of the atmosphere and atmospheric warming during lockdown period. Further, satellite data analyses showed increases in cloud optical thickness and cloud-particle effective radius and decrease in lower tropospheric air temperature during lockdown period. These results indicate critical influences of COVID-19 lockdown on regional climate and water cycle over Indo-Gangetic Plain, emphasizing need for further studies from modeling perspectives.
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Affiliation(s)
- P. Khatri
- Graduate School of ScienceCenter for Atmospheric and Oceanic StudiesTohoku UniversitySendaiJapan
- Research Institute for Humanity and NatureKyotoJapan
| | - T. Hayasaka
- Graduate School of ScienceCenter for Atmospheric and Oceanic StudiesTohoku UniversitySendaiJapan
| | - B. Holben
- National Aeronautics and Space AdministrationGoddard Space Flight CenterGreenbeltMDUSA
| | - S. N. Tripathi
- Department of Civil EngineeringIndian Institute of Technology KanpurKanpurIndia
| | - P. Misra
- Research Institute for Humanity and NatureKyotoJapan
| | - P. K. Patra
- Graduate School of ScienceCenter for Atmospheric and Oceanic StudiesTohoku UniversitySendaiJapan
- Research Institute for Humanity and NatureKyotoJapan
- Research Institute for Global ChangeJAMSTECYokohamaJapan
| | - S. Hayashida
- Research Institute for Humanity and NatureKyotoJapan
| | - U. C. Dumka
- Aryabhatta Research Institute of Observational Sciences (ARIES)NainitalIndia
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15
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Yusfiandika F, Lim SC, Gomes C, Chockalingam A, Cheng Pay L. Lightning Behaviour during the COVID-19 Pandemic. F1000Res 2021; 10:906. [PMID: 34804502 PMCID: PMC8573680 DOI: 10.12688/f1000research.70650.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/02/2021] [Indexed: 07/30/2023] Open
Abstract
Background COVID-19 has drastically dampened human activities since early 2020. Studies have shown that this has resulted in changes in air temperature and humidity. Since lightning activities are dependent on air temperature and humidity, this study is conducted to evaluate the correlation between the intensity of lightning activities with the atmospheric changes, and investigates the changes, in lightning activities due to atmospheric changes during the COVID-19 pandemic. Methods The hypothesis was tested through a t-test and Pearson's correlation study. The variation trend of lightning strikes count (LSC) in Europe and Oceania during the five months COVID-19 lockdown period (March - July) compared to the same period in the previous five years from 2015 to 2019 is investigated. Results Statistical analysis shows the LSC in Europe and Oceania during the lockdown period dropped significantly by more than 50% and 44% respectively compared to the same period in previous five years. Furthermore, LSC was found to be positively correlated with air temperature and relative humidity in Europe. However, in Oceania, LSC seems to be only positively correlated with air temperature but negatively correlated with relative humidity. Conclusions This study seems to suggest that lightning activities have significantly changed during this pandemic due to reduction in human activities.
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Affiliation(s)
- Fazandra Yusfiandika
- Faculty of Engineering, Multimedia University, Cyberjaya, Selangor, 63100, Malaysia
| | - Siow Chun Lim
- Faculty of Engineering, Multimedia University, Cyberjaya, Selangor, 63100, Malaysia
| | - Chandima Gomes
- School of Electrical & Information Engineering, University of the Witwatersrand, Johannesburg, South Africa
| | - Aravind Chockalingam
- School of Computer Science & Engineering, Taylor's University, Subang Jaya, Selangor, Malaysia
| | - Lee Cheng Pay
- Electrical Engineering, Duriane Professionals, Puchong, Selangor, Malaysia
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16
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Yusfiandika F, Lim SC, Gomes C, Chockalingam A, Cheng Pay L. Lightning Behaviour during the COVID-19 Pandemic. F1000Res 2021; 10:906. [PMID: 34804502 PMCID: PMC8573680 DOI: 10.12688/f1000research.70650.3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/01/2021] [Indexed: 08/01/2023] Open
Abstract
Background COVID-19 has drastically dampened human activities since early 2020. Studies have shown that this has resulted in changes in air temperature and humidity. Since lightning activities are dependent on air temperature and humidity, this study is conducted to evaluate the correlation between the intensity of lightning activities with the atmospheric changes, and investigates the changes, in lightning activities due to atmospheric changes during the COVID-19 pandemic. Methods The hypothesis was tested through a t-test and Pearson's correlation study. The variation trend of lightning strikes count (LSC) in Europe and Oceania during the five months COVID-19 lockdown period (March - July) compared to the same period in the previous five years from 2015 to 2019 is investigated. Results Statistical analysis shows the LSC in Europe and Oceania during the lockdown period dropped significantly by more than 50% and 44% respectively compared to the same period in previous five years. Furthermore, LSC was found to be positively correlated with air temperature and relative humidity in Europe. However, in Oceania, LSC seems to be only positively correlated with air temperature but negatively correlated with relative humidity. Conclusions This study seems to suggest that lightning activities have significantly changed during this pandemic due to reduction in human activities.
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Affiliation(s)
- Fazandra Yusfiandika
- Faculty of Engineering, Multimedia University, Cyberjaya, Selangor, 63100, Malaysia
| | - Siow Chun Lim
- Faculty of Engineering, Multimedia University, Cyberjaya, Selangor, 63100, Malaysia
| | - Chandima Gomes
- School of Electrical & Information Engineering, University of the Witwatersrand, Johannesburg, South Africa
| | - Aravind Chockalingam
- School of Computer Science & Engineering, Taylor's University, Subang Jaya, Selangor, Malaysia
| | - Lee Cheng Pay
- Electrical Engineering, Duriane Professionals, Puchong, Selangor, Malaysia
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17
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Yusfiandika F, Lim SC, Gomes C, Chockalingam A, Cheng Pay L. Lightning Behaviour during the COVID-19 Pandemic. F1000Res 2021; 10:906. [PMID: 34804502 PMCID: PMC8573680 DOI: 10.12688/f1000research.70650.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/06/2021] [Indexed: 12/03/2022] Open
Abstract
Background COVID-19 has drastically dampened human activities since early 2020. Studies have shown that this has resulted in changes in air temperature and humidity. Since lightning activities are dependent on air temperature and humidity, this study is conducted to evaluate the correlation between the intensity of lightning activities with the atmospheric changes, and investigates the changes, in lightning activities due to atmospheric changes during the COVID-19 pandemic. Methods The hypothesis was tested through a t-test and Pearson's correlation study. The variation trend of lightning strikes count (LSC) in Europe and Oceania during the five months COVID-19 lockdown period (March - July) compared to the same period in the previous five years from 2015 to 2019 is investigated. Results Statistical analysis shows the LSC in Europe and Oceania during the lockdown period dropped significantly by more than 50% and 44% respectively compared to the same period in previous five years. Furthermore, LSC was found to be positively correlated with air temperature and relative humidity in Europe. However, in Oceania, LSC seems to be only positively correlated with air temperature but negatively correlated with relative humidity. Conclusions This study seems to suggest that lightning activities have significantly changed during this pandemic due to reduction in human activities.
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Affiliation(s)
- Fazandra Yusfiandika
- Faculty of Engineering, Multimedia University, Cyberjaya, Selangor, 63100, Malaysia
| | - Siow Chun Lim
- Faculty of Engineering, Multimedia University, Cyberjaya, Selangor, 63100, Malaysia
| | - Chandima Gomes
- School of Electrical & Information Engineering, University of the Witwatersrand, Johannesburg, South Africa
| | - Aravind Chockalingam
- School of Computer Science & Engineering, Taylor's University, Subang Jaya, Selangor, Malaysia
| | - Lee Cheng Pay
- Electrical Engineering, Duriane Professionals, Puchong, Selangor, Malaysia
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18
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East Asian climate response to COVID-19 lockdown measures in China. Sci Rep 2021; 11:16852. [PMID: 34413343 PMCID: PMC8376968 DOI: 10.1038/s41598-021-96007-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/28/2021] [Indexed: 11/08/2022] Open
Abstract
The COVID-19 pandemic caused disruptions of public life and imposed lockdown measures in 2020 resulted in considerable reductions of anthropogenic aerosol emissions. It still remains unclear how the associated short-term changes in atmospheric chemistry influenced weather and climate on regional scales. To understand the underlying physical mechanisms, we conduct ensemble aerosol perturbation experiments with the Community Earth System Model, version 2. In the simulations reduced anthropogenic aerosol emissions in February generate anomalous surface warming and warm-moist air advection which promotes low-level cloud formation over China. Although the simulated response is weak, it is detectable in some areas, in qualitative agreement with the observations. The negative dynamical cloud feedback offsets the effect from reduced cloud condensation nuclei. Additional perturbation experiments with strongly amplified air pollution over China reveal a nonlinear sensitivity of regional atmospheric conditions to chemical/radiative perturbations. COVID-19-related changes in anthropogenic aerosol emissions provide an excellent testbed to elucidate the interaction between air pollution and climate.
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