Pub Date : 2024-08-21DOI: 10.1038/s41612-024-00743-w
Hongxia Zhu, Shuping Yang, Hongwei Zhao, Yu Wang, Rui Li
An eight-year satellite observation dataset reveals that sulfate aerosols significantly influence the vertical structure of precipitation and latent heat (LH) in the Beijing-Tianjin-Hebei (BTH) region during summer. In this period, prevalent sulfate aerosols combine with warm, humid southerly winds and elevated convective available potential energy (CAPE), influencing precipitation dynamics. Under polluted conditions with specific CAPE and precipitation top temperature (PTT) ranges, precipitation particles experience accelerated growth within the mixed-phase layer, delineated by the −5 °C to 2 °C isotherms, compared to pristine environments. This results in a marked increase in both the intensity and height at which the maximum LH is released. Subsequent analysis reveals that hygroscopic sulfate aerosols, acting as cloud condensation nuclei (CCN), amplify the collision-coalescence process within the mixed layer amid high cloud water content, propelling rapid precipitation particle growth and elevating the PTT. This warming effect surpasses the cooling contribution from robust CAPE, culminating in a net elevation of PTT under polluted scenarios compared to pristine ones. Additionally, quantification of PTT sensitivity to both CAPE and aerosol optical depth (AOD) unveils a high consistency between satellite-detected PTT responses to CAPE and those predicted by cloud-resolving model simulations. The study deduces that the role of aerosols as CCN in either invigorating or diminishing the collision-coalescence process is contingent on the available cloud water.
八年的卫星观测数据集显示，硫酸盐气溶胶对京津冀（BTH）地区夏季降水和潜热（LH）的垂直结构有显著影响。在此期间，普遍存在的硫酸盐气溶胶与温暖潮湿的偏南风和升高的对流可用势能（CAPE）相结合，对降水动态产生影响。在具有特定 CAPE 和降水顶温 (PTT) 范围的污染条件下，降水颗粒在混合相层（由 -5 °C 至 2 °C 等温线划定）内的生长速度比原始环境要快。这导致释放最大 LH 的强度和高度明显增加。随后的分析表明，吸湿性硫酸盐气溶胶作为云凝结核（CCN），在云水含量较高的情况下放大了混合层内的碰撞-凝聚过程，推动了降水粒子的快速增长并提高了 PTT。这种升温效应超过了强劲的 CAPE 带来的降温效应，最终导致在污染情况下 PTT 比原始情况下净升高。此外，通过量化 PTT 对 CAPE 和气溶胶光学深度（AOD）的敏感性，发现卫星探测到的 PTT 对 CAPE 的响应与云解析模式模拟预测的响应高度一致。研究推断，气溶胶作为 CCN 在激活或减弱碰撞-凝聚过程中的作用取决于可用的云水。
{"title":"Complex interplay of sulfate aerosols and meteorology conditions on precipitation and latent heat vertical structure","authors":"Hongxia Zhu, Shuping Yang, Hongwei Zhao, Yu Wang, Rui Li","doi":"10.1038/s41612-024-00743-w","DOIUrl":"10.1038/s41612-024-00743-w","url":null,"abstract":"An eight-year satellite observation dataset reveals that sulfate aerosols significantly influence the vertical structure of precipitation and latent heat (LH) in the Beijing-Tianjin-Hebei (BTH) region during summer. In this period, prevalent sulfate aerosols combine with warm, humid southerly winds and elevated convective available potential energy (CAPE), influencing precipitation dynamics. Under polluted conditions with specific CAPE and precipitation top temperature (PTT) ranges, precipitation particles experience accelerated growth within the mixed-phase layer, delineated by the −5 °C to 2 °C isotherms, compared to pristine environments. This results in a marked increase in both the intensity and height at which the maximum LH is released. Subsequent analysis reveals that hygroscopic sulfate aerosols, acting as cloud condensation nuclei (CCN), amplify the collision-coalescence process within the mixed layer amid high cloud water content, propelling rapid precipitation particle growth and elevating the PTT. This warming effect surpasses the cooling contribution from robust CAPE, culminating in a net elevation of PTT under polluted scenarios compared to pristine ones. Additionally, quantification of PTT sensitivity to both CAPE and aerosol optical depth (AOD) unveils a high consistency between satellite-detected PTT responses to CAPE and those predicted by cloud-resolving model simulations. The study deduces that the role of aerosols as CCN in either invigorating or diminishing the collision-coalescence process is contingent on the available cloud water.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00743-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142022001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-20DOI: 10.1038/s41612-024-00733-y
Jing Wang, Lin Tang, Heng Lu
Snow cover on the Qinghai-Tibet Plateau significantly impacts the climate, hydrology, and ecology of China and East Asia. Current studies mainly use snow cover days to describe its duration, overlooking the snow’s discontinuous nature. This study analyzes snow phenology and the spatiotemporal distribution of continuous snow cover events on the Qinghai-Tibet Plateau from 1961 to 2019. The findings indicate that continuous snow cover days better capture the temporal discontinuity of snow cover compared to snow cover days. The contribution and continuity are lower than regions like North America, Europe, Northeast and Xinjiang in China, indicating poorer snow cover continuity on the Qinghai-Tibet Plateau. Additionally, we found that temperature and precipitation, especially autumn temperatures and spring and winter precipitation, significantly impact various snow indices. Wind speed also significantly impacts snow cover, particularly in autumn. Atmospheric circulation indirectly affects the snow cover discontinuity by influencing temperature and precipitation.
{"title":"The new indices to describe temporal discontinuity of snow cover on the Qinghai-Tibet Plateau","authors":"Jing Wang, Lin Tang, Heng Lu","doi":"10.1038/s41612-024-00733-y","DOIUrl":"10.1038/s41612-024-00733-y","url":null,"abstract":"Snow cover on the Qinghai-Tibet Plateau significantly impacts the climate, hydrology, and ecology of China and East Asia. Current studies mainly use snow cover days to describe its duration, overlooking the snow’s discontinuous nature. This study analyzes snow phenology and the spatiotemporal distribution of continuous snow cover events on the Qinghai-Tibet Plateau from 1961 to 2019. The findings indicate that continuous snow cover days better capture the temporal discontinuity of snow cover compared to snow cover days. The contribution and continuity are lower than regions like North America, Europe, Northeast and Xinjiang in China, indicating poorer snow cover continuity on the Qinghai-Tibet Plateau. Additionally, we found that temperature and precipitation, especially autumn temperatures and spring and winter precipitation, significantly impact various snow indices. Wind speed also significantly impacts snow cover, particularly in autumn. Atmospheric circulation indirectly affects the snow cover discontinuity by influencing temperature and precipitation.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00733-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142007577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-20DOI: 10.1038/s41612-024-00744-9
Mingjie Liang, Zhiwei Han, Jiawei Li, Yue Li, Lin Liang
This study explores aerosol direct, indirect, and feedback effects on meteorology and fine particulate matter during heat waves of August 2022 over eastern China by using an online coupled regional climate–chemistry–aerosol model. In this period, aerosols exerted mean direct (DRE) and indirect (IRE) radiative effects of −3.9 Wm−2 and −2.4 Wm−2 at TOA, which totally caused a decrease in average surface air temperature by 0.3 °C over east China, accompanied by decreases in PBLH (planetary boundary layer height) and precipitation and an increase in PM2.5 concentration. With the anthropogenic emission reduction from 2013 to 2022, DRE apparently decreased while IRE changed little, leading to a decrease in total aerosol radiative effect (TRE) by 27% at TOA. The weakened TRE resulted in increases in surface air temperature and precipitation by 0.14 °C and 2.7 mm, respectively, on average over east China, with the maximum warming exceeding 0.5 °C in BTH (Beijing–Tianjin–Hebei province). This study highlights a warming trend due to weakened TRE, which may exacerbate heat wave, and an increasing importance of aerosol IRE relative to DRE due to weak sensitivity of cloud properties to aerosol change during the emission reduction.
本研究利用区域气候-化学-气溶胶在线耦合模式，探讨了2022年8月中国东部热浪期间气溶胶对气象和细颗粒物的直接、间接和反馈效应。在此期间，气溶胶在TOA上的平均直接（DRE）和间接（IRE）辐射效应分别为-3.9 Wm-2和-2.4 Wm-2，共导致华东地区地表平均气温下降0.3 °C，同时伴有PBLH（行星边界层高度）和降水的减少以及PM2.5浓度的增加。随着2013年至2022年的人为减排，DRE明显下降，而IRE变化不大，导致TOA处气溶胶总辐射效应（TRE）下降了27%。气溶胶总辐射效应的减弱导致华东地区地表气温和降水量平均分别升高了 0.14 ℃ 和 2.7 毫米，其中京津冀地区的升温幅度最大，超过了 0.5 ℃。这项研究强调了由于 TRE 减弱而导致的变暖趋势，这可能会加剧热浪，同时由于减排期间云特性对气溶胶变化的敏感性较弱，气溶胶 IRE 相对于 DRE 的重要性日益增加。
{"title":"Aerosol effects during heat waves in summer 2022 and responses to emission change over China","authors":"Mingjie Liang, Zhiwei Han, Jiawei Li, Yue Li, Lin Liang","doi":"10.1038/s41612-024-00744-9","DOIUrl":"10.1038/s41612-024-00744-9","url":null,"abstract":"This study explores aerosol direct, indirect, and feedback effects on meteorology and fine particulate matter during heat waves of August 2022 over eastern China by using an online coupled regional climate–chemistry–aerosol model. In this period, aerosols exerted mean direct (DRE) and indirect (IRE) radiative effects of −3.9 Wm−2 and −2.4 Wm−2 at TOA, which totally caused a decrease in average surface air temperature by 0.3 °C over east China, accompanied by decreases in PBLH (planetary boundary layer height) and precipitation and an increase in PM2.5 concentration. With the anthropogenic emission reduction from 2013 to 2022, DRE apparently decreased while IRE changed little, leading to a decrease in total aerosol radiative effect (TRE) by 27% at TOA. The weakened TRE resulted in increases in surface air temperature and precipitation by 0.14 °C and 2.7 mm, respectively, on average over east China, with the maximum warming exceeding 0.5 °C in BTH (Beijing–Tianjin–Hebei province). This study highlights a warming trend due to weakened TRE, which may exacerbate heat wave, and an increasing importance of aerosol IRE relative to DRE due to weak sensitivity of cloud properties to aerosol change during the emission reduction.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00744-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142013753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-16DOI: 10.1038/s41612-024-00734-x
Reshmita Nath, Debashis Nath, Wen Chen
40% of global population, who resides in Asian monsoon region is at high risk from extreme hot summer events, which is expected to increase by 25%/30 years under RCP8.5 scenario. Using Community Earth System Model (CESM) Large-ensemble simulations we assess the relative contribution of external forcings and internal variability on hot extremes over South and East Asia. Climate change projects surface mean temperature to reach 2.0 °C and 5.0 °C by ~2050 and ~2100, respectively, making the region uninhabitable under exposed conditions. Internal variability will partly obscure anthropogenic warming over South and Southeast Asia; however, East Asia will experience a 4–6 fold rise in record breaking hot events in later periods. Nevertheless, beyond 2.35 °C warming internal variability will decrease over South Asia due to weaker albedo feedback on unforced internal variability. Our results contradict the existing hypothesis that warming will increase volatility in weather patterns everywhere, particularly the Asian monsoon regions.
{"title":"Projected changes in extreme hot summer events in Asian monsoon regions","authors":"Reshmita Nath, Debashis Nath, Wen Chen","doi":"10.1038/s41612-024-00734-x","DOIUrl":"10.1038/s41612-024-00734-x","url":null,"abstract":"40% of global population, who resides in Asian monsoon region is at high risk from extreme hot summer events, which is expected to increase by 25%/30 years under RCP8.5 scenario. Using Community Earth System Model (CESM) Large-ensemble simulations we assess the relative contribution of external forcings and internal variability on hot extremes over South and East Asia. Climate change projects surface mean temperature to reach 2.0 °C and 5.0 °C by ~2050 and ~2100, respectively, making the region uninhabitable under exposed conditions. Internal variability will partly obscure anthropogenic warming over South and Southeast Asia; however, East Asia will experience a 4–6 fold rise in record breaking hot events in later periods. Nevertheless, beyond 2.35 °C warming internal variability will decrease over South Asia due to weaker albedo feedback on unforced internal variability. Our results contradict the existing hypothesis that warming will increase volatility in weather patterns everywhere, particularly the Asian monsoon regions.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00734-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141994533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-15DOI: 10.1038/s41612-024-00737-8
Jiayuan Liao, Wei Zheng, Qiong Liao, Sheng Lu
Nitrous oxide (N2O) emissions are a serious global issue, with substantial evidence indicating that hydroclimate processes significantly contribute to these emissions. Forests, covering one-third of global land, are key in the water cycle and influence hydroclimate processes, which vary with climate, latitude, and forest types. The role of hydroclimate in regulating global forest N2O emission remains largely unknown. Our global analysis shows that hydroclimate factors dominate the latitudinal gradient of forest N2O fluxes, which decrease with latitude. N2O fluxes are highest in tropical forests, followed by temperate and boreal forests. Hydroclimate factors contribute 78.2% to N2O fluxes, while soil factors contribute 21.8%. Our results urgently call for future studies to investigate the relationship between N2O flux and hydroclimate factors like radiation, evapotranspiration, and vapor pressure deficits. Collectively, these findings highlight hydroclimate significant impact on N2O emissions and suggest incorporating these factors into predictive models for greater accuracy.
{"title":"Global latitudinal patterns in forest ecosystem nitrous oxide emissions are related to hydroclimate","authors":"Jiayuan Liao, Wei Zheng, Qiong Liao, Sheng Lu","doi":"10.1038/s41612-024-00737-8","DOIUrl":"10.1038/s41612-024-00737-8","url":null,"abstract":"Nitrous oxide (N2O) emissions are a serious global issue, with substantial evidence indicating that hydroclimate processes significantly contribute to these emissions. Forests, covering one-third of global land, are key in the water cycle and influence hydroclimate processes, which vary with climate, latitude, and forest types. The role of hydroclimate in regulating global forest N2O emission remains largely unknown. Our global analysis shows that hydroclimate factors dominate the latitudinal gradient of forest N2O fluxes, which decrease with latitude. N2O fluxes are highest in tropical forests, followed by temperate and boreal forests. Hydroclimate factors contribute 78.2% to N2O fluxes, while soil factors contribute 21.8%. Our results urgently call for future studies to investigate the relationship between N2O flux and hydroclimate factors like radiation, evapotranspiration, and vapor pressure deficits. Collectively, these findings highlight hydroclimate significant impact on N2O emissions and suggest incorporating these factors into predictive models for greater accuracy.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00737-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141986135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-10DOI: 10.1038/s41612-024-00732-z
Lingaona Zhu, Zhiwei Wu
The Antarctic ozone hole exerts a substantial impact on the climate of the Southern Hemisphere, yet research exploring its potential influence on the Northern Hemisphere climate is limited. This study unveils a significant positive relationship between interannual variations of Antarctic total column ozone (TCO) during September–October and East Asian precipitation in the subsequent boreal winter. Specifically, ~10% of the East Asian winter precipitation variability is attributed to Antarctic TCO during September–October. Both observational data and model results indicate that the increased Antarctic TCO during September–October triggers a simultaneous meridional southern Indian Ocean tripole sea surface temperature anomalies (SSTA) through the negative phase of the Southern Annular Mode. This SSTA pattern persists from September–November through the boreal winter, subsequently weakening the local-scale zonal-vertical circulation anomalies in the Indian Ocean. The process leads to positive outgoing longwave radiation (OLR) anomalies over the southern Marine Continent. As a result, the linear response of wind anomalies at 850 hPa over East Asia to the OLR-induced diabatic heating anomalies exhibits southwesterlies, as demonstrated by a linear baroclinic model. These anomalous winds facilitate the transport of abundant moisture from the tropics to East Asia, favoring the formation of winter precipitation. We employ the Specified-Chemistry version of the Whole Atmosphere Community Climate Model to validate that the increase of September–October Antarctic ozone substantially enhances East Asian precipitation during boreal winter. Importantly, the relationship between Antarctic ozone and East Asian winter precipitation is found to be independent of El Niño-Southern Oscillation and the Indian Ocean Dipole Mode. Our findings provide a fresh insight into the prediction of the East Asian winter precipitation.
{"title":"Climatic influence of the Antarctic ozone hole on the East Asian winter precipitation","authors":"Lingaona Zhu, Zhiwei Wu","doi":"10.1038/s41612-024-00732-z","DOIUrl":"10.1038/s41612-024-00732-z","url":null,"abstract":"The Antarctic ozone hole exerts a substantial impact on the climate of the Southern Hemisphere, yet research exploring its potential influence on the Northern Hemisphere climate is limited. This study unveils a significant positive relationship between interannual variations of Antarctic total column ozone (TCO) during September–October and East Asian precipitation in the subsequent boreal winter. Specifically, ~10% of the East Asian winter precipitation variability is attributed to Antarctic TCO during September–October. Both observational data and model results indicate that the increased Antarctic TCO during September–October triggers a simultaneous meridional southern Indian Ocean tripole sea surface temperature anomalies (SSTA) through the negative phase of the Southern Annular Mode. This SSTA pattern persists from September–November through the boreal winter, subsequently weakening the local-scale zonal-vertical circulation anomalies in the Indian Ocean. The process leads to positive outgoing longwave radiation (OLR) anomalies over the southern Marine Continent. As a result, the linear response of wind anomalies at 850 hPa over East Asia to the OLR-induced diabatic heating anomalies exhibits southwesterlies, as demonstrated by a linear baroclinic model. These anomalous winds facilitate the transport of abundant moisture from the tropics to East Asia, favoring the formation of winter precipitation. We employ the Specified-Chemistry version of the Whole Atmosphere Community Climate Model to validate that the increase of September–October Antarctic ozone substantially enhances East Asian precipitation during boreal winter. Importantly, the relationship between Antarctic ozone and East Asian winter precipitation is found to be independent of El Niño-Southern Oscillation and the Indian Ocean Dipole Mode. Our findings provide a fresh insight into the prediction of the East Asian winter precipitation.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00732-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141910439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-09DOI: 10.1038/s41612-024-00730-1
Fan Liu, Daniel Rosenfeld, Zengxin Pan, Lin Zang, Feiyue Mao
Climate models commonly overestimate warm rain frequency and underestimate its intensity over the ocean, primarily due to insufficient representation of the aerosol effects. This pertains to both fine aerosols (FA) and coarse sea spray aerosols (CSA), where the latter is mostly absent in the models. Here, our observations show that adding CSA enhances vertical warm rain structure, in contrast to the effect of FA. The magnitude of the effect of CSA is larger than the opposite effect of the FA. For rain with top heights of 2–3 km, the raindrop size, concentration, and rain rate can be increased by factors of 1.03, 1.47, and 1.60, respectively. These CSA-induced changes are larger for thicker clouds, reaching a maximum by factors of 1.12, 1.85, and 2.21, respectively. Therefore, the combined FA and CSA effects should be incorporated into climate models for accurately simulated precipitation microphysical processes.
气候模式通常会高估海洋上空暖雨的频率并低估其强度，这主要是由于气溶胶效应没有得到充分体现。这与细气溶胶（FA）和粗海雾气溶胶（CSA）都有关系，而后者在模型中大多不存在。在这里，我们的观测结果表明，加入 CSA 会增强垂直暖雨结构，这与 FA 的效应形成鲜明对比。CSA 的影响程度大于 FA 的相反影响。对于顶部高度为 2-3 千米的雨，雨滴大小、浓度和降雨率可分别增加 1.03、1.47 和 1.60 倍。对于较厚的云层，这些 CSA 引起的变化更大，最大变化系数分别为 1.12、1.85 和 2.21。因此，应将 FA 和 CSA 的综合效应纳入气候模式，以准确模拟降水微物理过程。
{"title":"Combined effects of fine and coarse marine aerosol on vertical raindrop size distribution","authors":"Fan Liu, Daniel Rosenfeld, Zengxin Pan, Lin Zang, Feiyue Mao","doi":"10.1038/s41612-024-00730-1","DOIUrl":"10.1038/s41612-024-00730-1","url":null,"abstract":"Climate models commonly overestimate warm rain frequency and underestimate its intensity over the ocean, primarily due to insufficient representation of the aerosol effects. This pertains to both fine aerosols (FA) and coarse sea spray aerosols (CSA), where the latter is mostly absent in the models. Here, our observations show that adding CSA enhances vertical warm rain structure, in contrast to the effect of FA. The magnitude of the effect of CSA is larger than the opposite effect of the FA. For rain with top heights of 2–3 km, the raindrop size, concentration, and rain rate can be increased by factors of 1.03, 1.47, and 1.60, respectively. These CSA-induced changes are larger for thicker clouds, reaching a maximum by factors of 1.12, 1.85, and 2.21, respectively. Therefore, the combined FA and CSA effects should be incorporated into climate models for accurately simulated precipitation microphysical processes.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00730-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141908967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-09DOI: 10.1038/s41612-024-00731-0
Guojian Wang, Wenju Cai, Agus Santoso, Kai Yang
The heat storage capacity of Southern Ocean (SO) buffers future atmospheric warming but differs vastly across climate models. Reducing its projection uncertainty is vital for understanding and evaluating future global sustainability. Using Coupled Model Intercomparison Project Phase 6, we show that the present-day SO high-latitude easterly wind anomalies induced by El Niño is an effective constraint for the projected increase in SO heat content. Models simulating weaker El Niño-induced easterlies generate more equatorward atmospheric teleconnection in the present day. Under global warming, these models have greater capacity in the poleward shift of atmospheric circulation, thus generate stronger future increase in El Niño-induced high-latitude easterlies, slowing the SO heat storage by weakening the northward Ekman transport that underpins the dynamical process for SO heat storage. However, most models overestimate the present-day El Niño-induced easterlies, implying that alleviating this bias would reduce future SO heat storage, thus exacerbating atmospheric warming.
南大洋（SO）的蓄热能力可缓冲未来大气变暖，但不同气候模式的蓄热能力却大相径庭。减少其预测的不确定性对于理解和评估未来全球可持续性至关重要。利用耦合模式相互比较项目第六阶段，我们表明厄尔尼诺现象引起的现今南大洋高纬度东风异常是预测南大洋热含量增加的有效约束条件。模拟较弱的厄尔尼诺现象引起的东风的模式会产生更多的赤道向大气遥联系。在全球变暖的情况下，这些模式在大气环流极向移动方面有更大的能力，从而使厄尔尼诺引起的高纬度东风在未来有更强的增长，通过减弱支撑SO热储存的动力过程的北向埃克曼输送来减缓SO热储存。然而，大多数模式都高估了现今厄尔尼诺引起的东风，这意味着减轻这种偏差会减少未来的 SO 储热，从而加剧大气变暖。
{"title":"Southern Ocean heat buffer constrained by present-day ENSO teleconnection","authors":"Guojian Wang, Wenju Cai, Agus Santoso, Kai Yang","doi":"10.1038/s41612-024-00731-0","DOIUrl":"10.1038/s41612-024-00731-0","url":null,"abstract":"The heat storage capacity of Southern Ocean (SO) buffers future atmospheric warming but differs vastly across climate models. Reducing its projection uncertainty is vital for understanding and evaluating future global sustainability. Using Coupled Model Intercomparison Project Phase 6, we show that the present-day SO high-latitude easterly wind anomalies induced by El Niño is an effective constraint for the projected increase in SO heat content. Models simulating weaker El Niño-induced easterlies generate more equatorward atmospheric teleconnection in the present day. Under global warming, these models have greater capacity in the poleward shift of atmospheric circulation, thus generate stronger future increase in El Niño-induced high-latitude easterlies, slowing the SO heat storage by weakening the northward Ekman transport that underpins the dynamical process for SO heat storage. However, most models overestimate the present-day El Niño-induced easterlies, implying that alleviating this bias would reduce future SO heat storage, thus exacerbating atmospheric warming.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00731-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141908968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-09DOI: 10.1038/s41612-024-00727-w
Nagaraju Chilukoti, Mahendra Nimmakanti, Jasti S. Chowdary
The analysis reveals that the occurrence of summer Monsoon Depressions (MDs) over the North Arabian Sea is doubling during 2001–2022 compared to the 1981–2000 period. This increase stems from changes in the region’s dynamic and thermodynamic conditions. The heightened genesis potential parameter with sea surface temperature and moisture flux transport and its convergence over the North Arabian Sea inducing MDs formation, contrasting to the Bay of Bengal. The dynamic processes involved in its formation, a combination of barotropic and dynamical instability, are leading to increased rainfall over northwestern India. Strong East Asian jet variability, with an anomalous anticyclone in the north and weak cyclonic anomalies in the south, induces prevailing easterly wind anomalies along the monsoon trough. This leads to a poleward shift (~1.13°) in the low-level jet, significantly altering dynamic and thermodynamic parameters in the northern Arabian Sea region leading to a notable increase in MDs.
{"title":"Recent two decades witness an uptick in monsoon depressions over the northern Arabian Sea","authors":"Nagaraju Chilukoti, Mahendra Nimmakanti, Jasti S. Chowdary","doi":"10.1038/s41612-024-00727-w","DOIUrl":"10.1038/s41612-024-00727-w","url":null,"abstract":"The analysis reveals that the occurrence of summer Monsoon Depressions (MDs) over the North Arabian Sea is doubling during 2001–2022 compared to the 1981–2000 period. This increase stems from changes in the region’s dynamic and thermodynamic conditions. The heightened genesis potential parameter with sea surface temperature and moisture flux transport and its convergence over the North Arabian Sea inducing MDs formation, contrasting to the Bay of Bengal. The dynamic processes involved in its formation, a combination of barotropic and dynamical instability, are leading to increased rainfall over northwestern India. Strong East Asian jet variability, with an anomalous anticyclone in the north and weak cyclonic anomalies in the south, induces prevailing easterly wind anomalies along the monsoon trough. This leads to a poleward shift (~1.13°) in the low-level jet, significantly altering dynamic and thermodynamic parameters in the northern Arabian Sea region leading to a notable increase in MDs.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00727-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141908974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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