In the boreal summer and autumn of 2023,the globe experienced an extremely hot period across both oceans and continents.The consecutive record-breaking mean surface temperature has caused many to speculate upon how th...In the boreal summer and autumn of 2023,the globe experienced an extremely hot period across both oceans and continents.The consecutive record-breaking mean surface temperature has caused many to speculate upon how the global temperature will evolve in the coming 2023/24 boreal winter.In this report,as shown in the multi-model ensemble mean(MME)prediction released by the Institute of Atmospheric Physics at the Chinese Academy of Sciences,a medium-to-strong eastern Pacific El Niño event will reach its mature phase in the following 2−3 months,which tends to excite an anomalous anticyclone over the western North Pacific and the Pacific-North American teleconnection,thus serving to modulate the winter climate in East Asia and North America.Despite some uncertainty due to unpredictable internal atmospheric variability,the global mean surface temperature(GMST)in the 2023/24 winter will likely be the warmest in recorded history as a consequence of both the El Niño event and the long-term global warming trend.Specifically,the middle and low latitudes of Eurasia are expected to experience an anomalously warm winter,and the surface air temperature anomaly in China will likely exceed 2.4 standard deviations above climatology and subsequently be recorded as the warmest winter since 1991.Moreover,the necessary early warnings are still reliable in the timely updated mediumterm numerical weather forecasts and sub-seasonal-to-seasonal prediction.展开更多
Understanding the response of the Earth system to varying concentrations of carbon dioxide(CO_(2))is critical for projecting possible future climate change and for providing insight into mitigation and adaptation stra...Understanding the response of the Earth system to varying concentrations of carbon dioxide(CO_(2))is critical for projecting possible future climate change and for providing insight into mitigation and adaptation strategies in the near future.In this study,we generate a dataset by conducting an experiment involving carbon dioxide removal(CDR)—a potential way to suppress global warming—using the Chinese Academy of Sciences Earth System Model version 2.0(CASESM2.0).A preliminary evaluation is provided.The model is integrated from 200–340 years as a 1%yr^(−1) CO_(2) concentration increase experiment,and then to~478 years as a carbon dioxide removal experiment until CO_(2) returns to its original value.Finally,another 80 years is integrated in which CO_(2) is kept constant.Changes in the 2-m temperature,precipitation,sea surface temperature,ocean temperature,Atlantic meridional overturning circulation(AMOC),and sea surface height are all analyzed.In the ramp-up period,the global mean 2-m temperature and precipitation both increase while the AMOC weakens.Values of all the above variables change in the opposite direction in the ramp-down period,with a delayed peak relative to the CO_(2) peak.After CO_(2) returns to its original value,the global mean 2-m temperature is still~1 K higher than in the original state,and precipitation is~0.07 mm d^(–1) higher.At the end of the simulation,there is a~0.5°C increase in ocean temperature and a 1 Sv weakening of the AMOC.Our model simulation produces similar results to those of comparable experiments previously reported in the literature.展开更多
Intracranial artery stenosis(ICAS)in youth is an under-explored condition.ICAS is one of the leading causes of stroke in young people worldwide and confers a higher risk of stroke recurrence,leading to a poor prognosi...Intracranial artery stenosis(ICAS)in youth is an under-explored condition.ICAS is one of the leading causes of stroke in young people worldwide and confers a higher risk of stroke recurrence,leading to a poor prognosis for individuals and a great burden to society.The etiology and risk factors of ICAS in youth differ from those of older patients,thus resulting in a difference in the progression and prognosis of the disease.Even though the diagnosis of ICAS is lumen-based,it is sometimes difficult to identify in young patients based on imaging alone.Notably,novel vessel wall imaging techniques play an important role in determining the cause of stenosis and screening patients at high risk of recurrence.Moreover,pharmacologic regimens and risk factor control goals for ICAS in young adults are largely consistent with those in older patients.Thus,considering the poor prognosis,there is an urgent need for high-quality studies in the young ICAS population to analyze the high-quality observational data collected.展开更多
基金the Key Research Program of Frontier Sciences,CAS(Grant No.ZDBS-LYDQC010)the National Natural Science Foundation of China(Grant No.42175045).
文摘In the boreal summer and autumn of 2023,the globe experienced an extremely hot period across both oceans and continents.The consecutive record-breaking mean surface temperature has caused many to speculate upon how the global temperature will evolve in the coming 2023/24 boreal winter.In this report,as shown in the multi-model ensemble mean(MME)prediction released by the Institute of Atmospheric Physics at the Chinese Academy of Sciences,a medium-to-strong eastern Pacific El Niño event will reach its mature phase in the following 2−3 months,which tends to excite an anomalous anticyclone over the western North Pacific and the Pacific-North American teleconnection,thus serving to modulate the winter climate in East Asia and North America.Despite some uncertainty due to unpredictable internal atmospheric variability,the global mean surface temperature(GMST)in the 2023/24 winter will likely be the warmest in recorded history as a consequence of both the El Niño event and the long-term global warming trend.Specifically,the middle and low latitudes of Eurasia are expected to experience an anomalously warm winter,and the surface air temperature anomaly in China will likely exceed 2.4 standard deviations above climatology and subsequently be recorded as the warmest winter since 1991.Moreover,the necessary early warnings are still reliable in the timely updated mediumterm numerical weather forecasts and sub-seasonal-to-seasonal prediction.
基金jointly supported by the National Key Research and Development Program of China (Grant No. 2022YFC3105000)the Youth Innovation Promotion Association of CAS (2022074)+3 种基金the National Natural Science Foundation of China (Grant Nos. 42005123, 42275173 and 41706028)the National Key Research and Development Program of China(2022YFE0106500)the 7th Youth Talent Support Project of Ningxia Hui Autonomous Region Association for Science and TechnologyNational Key Scientific and Technological Infrastructure project ‘‘Earth System Science Numerical Simulator Facility’’(EarthLab) for supporting the simulations in this study
文摘Understanding the response of the Earth system to varying concentrations of carbon dioxide(CO_(2))is critical for projecting possible future climate change and for providing insight into mitigation and adaptation strategies in the near future.In this study,we generate a dataset by conducting an experiment involving carbon dioxide removal(CDR)—a potential way to suppress global warming—using the Chinese Academy of Sciences Earth System Model version 2.0(CASESM2.0).A preliminary evaluation is provided.The model is integrated from 200–340 years as a 1%yr^(−1) CO_(2) concentration increase experiment,and then to~478 years as a carbon dioxide removal experiment until CO_(2) returns to its original value.Finally,another 80 years is integrated in which CO_(2) is kept constant.Changes in the 2-m temperature,precipitation,sea surface temperature,ocean temperature,Atlantic meridional overturning circulation(AMOC),and sea surface height are all analyzed.In the ramp-up period,the global mean 2-m temperature and precipitation both increase while the AMOC weakens.Values of all the above variables change in the opposite direction in the ramp-down period,with a delayed peak relative to the CO_(2) peak.After CO_(2) returns to its original value,the global mean 2-m temperature is still~1 K higher than in the original state,and precipitation is~0.07 mm d^(–1) higher.At the end of the simulation,there is a~0.5°C increase in ocean temperature and a 1 Sv weakening of the AMOC.Our model simulation produces similar results to those of comparable experiments previously reported in the literature.
基金supported by the National Natural Science Foundation of China(82071468,82271507).
文摘Intracranial artery stenosis(ICAS)in youth is an under-explored condition.ICAS is one of the leading causes of stroke in young people worldwide and confers a higher risk of stroke recurrence,leading to a poor prognosis for individuals and a great burden to society.The etiology and risk factors of ICAS in youth differ from those of older patients,thus resulting in a difference in the progression and prognosis of the disease.Even though the diagnosis of ICAS is lumen-based,it is sometimes difficult to identify in young patients based on imaging alone.Notably,novel vessel wall imaging techniques play an important role in determining the cause of stenosis and screening patients at high risk of recurrence.Moreover,pharmacologic regimens and risk factor control goals for ICAS in young adults are largely consistent with those in older patients.Thus,considering the poor prognosis,there is an urgent need for high-quality studies in the young ICAS population to analyze the high-quality observational data collected.
