Article
Meteorology & Atmospheric Sciences
Jiankai Zhang, Chongyang Zhang, Siyi Zhao, Yixi Liu, Shihang Du, Wuke Wang, Jinlong Huang, Mian Xu
Summary: The impacts of changes in the Arctic stratospheric polar vortex (SPV) on frontogenesis in the middle latitudes of the Northern Hemisphere during winter are analyzed. We find that weak SPV years result in stronger and more frequent frontogenesis over West Russia, the Mongolian Plateau, the Mediterranean, and the southern North Atlantic compared to strong SPV years. Conversely, weaker and less frequent frontogenesis occurs over the northern parts of the North Atlantic and North Pacific Oceans during weak SPV years. These changes are attributed to alterations in the tropospheric circulation and temperature gradient associated with SPV changes.
ATMOSPHERIC RESEARCH
(2023)
Article
Meteorology & Atmospheric Sciences
Yonatan Givon, Chaim I. Garfinkel, Ian White
Summary: An intermediate complexity general circulation model is used to investigate the transient response of the NH winter stratosphere to modulated ultraviolet (UV) radiation by imposing an exaggerated UV perturbation. The enhanced UV radiation leads to immediate warming in the tropical upper stratosphere, spreading to the winter subtropics due to an accelerated Brewer-Dobson circulation. The study shows significant implications for observed stratospheric and tropospheric responses to solar variability on various time scales.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Yong-Cheol Jeong, Sang-Wook Yeh, Seungun Lee, Rokjin J. Park, Seok-Woo Son
Summary: This study found that in winter, the LINOZ-on experiment simulates lower surface temperatures over the Eurasian and Asian continents compared to the LINOZ-off experiment, due to the difference in ozone concentration in the upper troposphere and lower stratosphere. The climatological difference in ozone concentration leads to a weakened lower stratospheric zonal wind, which in turn affects surface temperatures.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Meteorology & Atmospheric Sciences
Linjie Fan, Shuangyan Yang
Summary: This study examines the impact of intraseasonal oscillation (ISO) over mid-high-latitude Eurasia on stratosphere sudden warming (SSW) events during boreal winter using NCEP-NCAR reanalysis data. The results show that the westward-propagating ISO from the Canadian Arctic Archipelago to western Europe plays a significant role in affecting SSW events by inducing sea ice loss and weakening westerly flow.
JOURNAL OF CLIMATE
(2023)
Article
Environmental Sciences
David D. Parrish, Richard G. Derwent, Ian C. Faloona, Charles A. Mims
Summary: A nonlinear change in baseline ozone concentrations has been observed at northern midlatitudes over the past few decades. Recent studies using linear trend analyses have reported relatively small trends, which are inconsistent with earlier findings. The COVID-19-related ozone changes based on linear analysis are shown to be significantly larger than recent long-term decreases in baseline ozone. The loss of lower stratospheric ozone in the 2020 springtime Arctic stratospheric ozone depletion event also contributed to anomalously low background ozone levels. Taken together, these factors suggest that the impact of COVID-19 restrictions on background tropospheric ozone in 2020 was smaller than previously reported. A consensus understanding of baseline ozone changes and their causes is crucial for developing effective policies to improve ozone air quality.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Meteorology & Atmospheric Sciences
Ruhua Zhang, Wen Zhou, Wenshou Tian, Yue Zhang, Zhenchen Liu, Paxson K. Y. Cheung
Summary: This study re-examines the impact of El Nino-Southern Oscillation (ENSO) on the winter stratospheric polar vortex intensity (PVI) and finds that the negative correlation between ENSO and PVI has weakened in recent decades and is no longer statistically significant. This weakening is associated with changes in wave-1 fluxes entering the stratosphere.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Hua Lu, Lesley J. Gray, Patrick Martineau, John C. King, Thomas J. Bracegirdle
Summary: A new regime index is constructed to capture the seasonal development of the stratospheric polar vortex in the northern winter, based on the standard deviation of Ertel's potential vorticity in the upper stratosphere in November-December. The study found that the narrow-jet flow regime and wide-jet flow regime exhibit significant differences in polar vortex characteristics and lower atmospheric circulation anomalies, potentially improving the accuracy of meteorological forecasts one to two months ahead.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Mian Xu, Wenshou Tian, Jiankai Zhang, Tao Wang, Kai Qie
Summary: The study shows that reduction of sea ice in the Barents-Kara Seas leads to a deepening of the East Asian trough in late winter, mainly through tropospheric and stratospheric pathways. Analysis using climate models and tracing models reveals that the climate system response to BKS sea ice reduction is primarily through the propagation of long Rossby waves and enhanced upward planetary waves to impact the East Asian trough.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Svenya Chripko, Rym Msadek, Emilia Sanchez-Gomez, Laurent Terray, Laurent Bessieres, Marie-Pierre Moine
Summary: The study found that the decrease in Arctic sea ice leads to a significant temperature increase in the Arctic region, with noticeable temperature anomalies in the midlatitudes - warming in North America and Europe, and cooling in Central Asia. The warming in North America and Europe can be explained by changes in atmospheric circulation and advection of warmer oceanic air, while the sea ice-induced cooling in Central Asia is solely due to dynamical changes.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Shuangze Han
Summary: This study finds a linkage between the wintertime atmospheric circulation in mid-latitude Eurasia and spring Asian snow cover. The primary atmospheric mode in mid-latitude Eurasia during winter is associated with positive snow cover anomalies in northern East Asia in the following spring. This mode leads to upward propagation of the zonal wavenumber-1 component in the stratosphere and creates abnormal stratospheric warming, leading to a weaker polar vortex and increased snowfall in the region. This connection can also be reproduced in historical simulations of CMIP6 coupled models and shows potential for predicting spring snow cover in northern East Asia.
ATMOSPHERIC RESEARCH
(2023)
Article
Meteorology & Atmospheric Sciences
Jian Rao, Chaim I. Garfinkel, Tongwen Wu, Yixiong Lu, Min Chu
Summary: Progress and persistent biases in the simulation of the stratospheric polar vortex from three generations of CMIPs are assessed. It is found that the stratospheric cold bias is largest in CMIP3, but is improved in CMIP5 and CMIP6. Furthermore, most models exhibit some common biases, with intermodel spread in some parameters highly correlated with the SST bias in northern tropical oceans.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Mengqi Zhang, Jianqi Sun
Summary: This study reveals that South China precipitation anomalies have persisted from winter to spring since the late 1990s, leading to prolonged droughts or floods in South China. The increased persistence is attributed to the interdecadal changes in El Nino-Southern Oscillation and central Asian snow cover. The study also demonstrates the weakened impact of ENSO on spring precipitation and the strengthened impact of central Asian snow cover on both winter and spring precipitation after the late 1990s.
JOURNAL OF CLIMATE
(2023)
Article
Environmental Sciences
Yan Xia, Fei Xie, Xiao Lu
Summary: Surface ozone in the Arctic was significantly enhanced during the 2020-2021 winter after the onset of sudden stratospheric warming (SSW). The enhanced ozone is primarily due to the strengthening of stratosphere-to-troposphere transport associated with SSW. The SSW also leads to positive anomalies in surface ozone in the northern midlatitudes, which are related to cold air outbreaks.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Yueyue Yu, Xueting Yu, Zhaoyong Guan, Dingzhu Hu, Chunhua Shi, Dong Guo, Jian Rao
Summary: This study categorizes the cold air outbreak (CAO) events over mid-latitudes of Eurasia (CAO_EA) and North America (CAO_NA) into those coupled with and those decoupled with stratospheric poleward warm airmass transport (PULSE) events. The findings show that the predictability of CAOs can be improved by predicting the stratospheric variability. In addition, a warm phase of the El Nino-Southern Oscillation (ENSO) in winter favors a higher coupling rate of CAO_NA and CAO_EA, while a phase transition of ENSO from the previous winter to the current winter is closely related to the interannual changes of the CAO coupling rate.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Environmental Sciences
Dong Guo, Zhuoqi Liang, Qiang Gui, Qian Lu, Qiong Zheng, Shuyang Yu
Summary: This study classifies the Arctic polar vortex into six regimes using the k-mean clustering algorithm and validates the classification with model data. The different regimes have distinct climate patterns and rainfall distributions in the Northern Hemisphere, which also impact the temperatures in mid-latitude regions.
