Based on the high-and low-resolution Community Earth System Model, version 1(CESM1), and corresponding simulations from phase 6 of the Coupled Model Intercomparison Project(CMIP6), we compare the interannual variabili...Based on the high-and low-resolution Community Earth System Model, version 1(CESM1), and corresponding simulations from phase 6 of the Coupled Model Intercomparison Project(CMIP6), we compare the interannual variability of the East Asian summer monsoon(EASM). The EASM interannual variability is characterized by the anomalous western North Pacific anticyclone(WNPAC) circulation and the dipole rainfall pattern with a negative southern lobe over the western North Pacific and a positive northern lobe along the Meiyu–Baiu region, which is better reproduced by the highresolution models. The reason for the improvement in the high-resolution models has been attributed to the better simulation of the warm temperature advection from the wind anomalies on the climatological temperature gradient. Positive sea surface temperature(SST) anomalies over the tropical Indian Ocean are the key to the improved wind anomalies featuring a WNPAC in the high-resolution models. The warm SST anomalies over the tropical Indian Ocean strengthen the WNPAC by triggering a Kelvin-wave response to the enhanced heat release induced by the increased precipitation. Based on the mixed-layer heat budget analysis, the warm SST anomalies over the western Indian Ocean in the high-resolution CESM1 are tied to the anomalous easterly wind along the equator, which reduces surface evaporation and upwelling.Therefore, the better simulations of air–sea feedback and the oceanic mesoscale eddy over the western Indian Ocean are the key for the improved simulation of the EASM interannual variations in the high-resolution CESM1.展开更多
Urban environments lie at the confluence of social,cultural,and economic activities and have unique biophysical characteristics due to continued infrastructure development that generally replaces natural landscapes wi...Urban environments lie at the confluence of social,cultural,and economic activities and have unique biophysical characteristics due to continued infrastructure development that generally replaces natural landscapes with built-up structures.The vast majority of studies on urban perturbation of local weather and climate have been centered on the urban heat island(UHI)effect,referring to the higher temperature in cities compared to their natural surroundings.Besides the UHI effect and heat waves,urbanization also impacts atmospheric moisture,wind,boundary layer structure,cloud formation,dispersion of air pollutants,precipitation,and storms.In this review article,we first introduce the datasets and methods used in studying urban areas and their impacts through both observation and modeling and then summarize the scientific insights on the impact of urbanization on various aspects of regional climate and extreme weather based on more than 500 studies.We also highlight the major research gaps and challenges in our understanding of the impacts of urbanization and provide our perspective and recommendations for future research priorities and directions.展开更多
基金supported by the National Natural Science Foundation of China [Grant Nos.42275018 (L.D.) and 42175029 (F.S.)]the Shandong Provincial Natural Science Fund for Excellent Young Scientists Fund Program (Overseas) [Grant No.2022HWYQ-065 (L.D.)]+3 种基金the Taishan Scholars Program of Shandong Province [Grant No.tsqn202211068 (L.D.)]the Fund of Laoshan Laboratory [Grant Nos.LSKJ202202602 (L.D.) and LSKJ202202201 (F.S.)]financially supported by Laoshan Laboratory (Grant No.LSKJ202300302)supported by the Office of Science, U.S.Department of Energy (DOE) Biological and Environmental Research through the Water Cycle and Climate Extremes Modeling (WACCEM) scientific focus area funded by the Regional and Global Model Analysis program area。
文摘Based on the high-and low-resolution Community Earth System Model, version 1(CESM1), and corresponding simulations from phase 6 of the Coupled Model Intercomparison Project(CMIP6), we compare the interannual variability of the East Asian summer monsoon(EASM). The EASM interannual variability is characterized by the anomalous western North Pacific anticyclone(WNPAC) circulation and the dipole rainfall pattern with a negative southern lobe over the western North Pacific and a positive northern lobe along the Meiyu–Baiu region, which is better reproduced by the highresolution models. The reason for the improvement in the high-resolution models has been attributed to the better simulation of the warm temperature advection from the wind anomalies on the climatological temperature gradient. Positive sea surface temperature(SST) anomalies over the tropical Indian Ocean are the key to the improved wind anomalies featuring a WNPAC in the high-resolution models. The warm SST anomalies over the tropical Indian Ocean strengthen the WNPAC by triggering a Kelvin-wave response to the enhanced heat release induced by the increased precipitation. Based on the mixed-layer heat budget analysis, the warm SST anomalies over the western Indian Ocean in the high-resolution CESM1 are tied to the anomalous easterly wind along the equator, which reduces surface evaporation and upwelling.Therefore, the better simulations of air–sea feedback and the oceanic mesoscale eddy over the western Indian Ocean are the key for the improved simulation of the EASM interannual variations in the high-resolution CESM1.
基金supported by the US Department of Energy,Office of Science,Biological and Environmental Research program,as part of the Regional and Global Modeling and Analysis(RGMA)program,Multi-sector Dynamics Modeling(MSD)program,and Earth System Model Development(ESMD)program,through the collaborative,multiprogram Integrated Coastal Modeling(ICoM)project,HyperFACETS project,and COMPASS-GLM projectPacific Northwest National Laboratory is operated for the Department of Energy by Battelle Memorial Institute under contract DE-AC05-76RL01830.
文摘Urban environments lie at the confluence of social,cultural,and economic activities and have unique biophysical characteristics due to continued infrastructure development that generally replaces natural landscapes with built-up structures.The vast majority of studies on urban perturbation of local weather and climate have been centered on the urban heat island(UHI)effect,referring to the higher temperature in cities compared to their natural surroundings.Besides the UHI effect and heat waves,urbanization also impacts atmospheric moisture,wind,boundary layer structure,cloud formation,dispersion of air pollutants,precipitation,and storms.In this review article,we first introduce the datasets and methods used in studying urban areas and their impacts through both observation and modeling and then summarize the scientific insights on the impact of urbanization on various aspects of regional climate and extreme weather based on more than 500 studies.We also highlight the major research gaps and challenges in our understanding of the impacts of urbanization and provide our perspective and recommendations for future research priorities and directions.
