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Sub-seasonal to Seasonal Hindcasts of stratospheric Sudden Warming by BCC_CSM1.1(m):A Comparison with ECMWF

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Advances in Atmospheric Sciences 2019年第5期36卷 479-494页

作者： Jian RAO Rongcai REN Haishan CHEN Xiangwen LIU Yueyue YU Yang YANG Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and Technology State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Fredy and Nadine Herrmann Institute of Earth Sciences The Hebrew University of Jerusalem Edmond J.Safra Campus Climate Model Division National Climate Center China Meteorological Administration Institute of Urban Meteorology China Meteorological Administration

This study focuses on model predictive skill with respect to stratospheric sudden warming(SSW) events by comparing the hindcast results of BCC_CSM1.1(m) with those of the ECMWF's model under the sub-seasonal to seasonal prediction project of the World Weather Research Program and World Climate Research Program. When the hindcasts are initiated less than two weeks before SSW onset, BCC_CSM and ECMWF show comparable predictive skill in terms of the temporal evolution of the stratospheric circumpolar westerlies and polar temperature up to 30 days after SSW onset. However, with earlier hindcast initialization, the predictive skill of BCC_CSM gradually decreases, and the reproduced maximum circulation anomalies in the hindcasts initiated four weeks before SSW onset replicate only 10% of the circulation anomaly intensities in observations. The earliest successful prediction of the breakdown of the stratospheric polar vortex accompanying SSW onset for BCC_CSM(ECMWF) is the hindcast initiated two(three) weeks earlier. The predictive skills of both models during SSW winters are always higher than that during non-SSW winters, in relation to the successfully captured tropospheric precursors and the associated upward propagation of planetary waves by the model initializations. To narrow the gap in SSW predictive skill between BCC_CSM and ECMWF, ensemble forecasts and error corrections are performed with BCC_CSM. The SSW predictive skill in the ensemble hindcasts and the error corrections are improved compared with the previous control forecasts.

关键词： sub-seasonal to seasonal(S2S)hindcast stratospheric sudden warming BCC_CSM ensemble forecast error correction

The Spatial and Temporal Variability of Global stratospheric GravityWaves and Their Activity during Sudden stratosphericWarming Revealed by COSMIC Measurements

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Advances in Atmospheric Sciences 2018年第12期35卷 1533-1546页

作者： Xiaohua XU Daocheng YU Jia LUO School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan 430079China Collaborative Innovation Center for Geospatial Technology 129 Luoyu RoadWuhan 430079China Key Laboratory of Geospace Environment and Geodesy Ministry of Education129 Luoyu RoadWuhan 430079China

This study investigates the spatial and temporal variability of global stratospheric gravity waves(GWs) and the characteristics of GW activity during sudden stratospheric warming(SSW) using the GPS radio occultation measurements from the COSMIC mission during September 2006 to May 2013. Corresponding to the COSMIC RO observational window and analysis method,GW potential energy(Ep) with vertical scales no shorter than ～2 km is resolved. It is found that the distributions of GW Ep over 20-30 km and 30-38 km show similar spatial and seasonal variations. The variations of GW Ep with altitude and latitude along the westerly wind are identified in different seasons over 60°-80°W. In the middle and high latitudes,seasonal cycles are distinct in the time-latitude and time-altitude distributions of GW activities,which show larger Ep in winters when westerly wind dominates and smaller Ep in summers when easterly wind dominates. The influence of quasi-biennial oscillation on GW activity is recognized in the tropics. GW Ep enhances closely following the occurrence of minor SSW events; while during major events, GW Ep may not enhance, and sometimes may even weaken,in the regions where reversals of zonal wind occur, probably caused by the filtering impact of the 0 ms^(-1) wind level on the GWs.

关键词： stratospheric gravity waves GPS radio occultation COSMIC potential energy sudden stratospheric warming

Dynamical diagnosis of the breakup of the stratospheric polar vortex in the Northern Hemisphere

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Science China Earth Sciences 2007年第9期50卷 1369-1379页

作者： WEI Ke1,2, CHEN Wen1 & HUANG RongHui1 1 Center for Monsoon System Research, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100080, China 2 Graduate University of the Chinese Academy of Sciences, Beijing 100049, China 1. Center for Monsoon System Research Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100080 China 2. Graduate University of the Chinese Academy of Sciences Beijing 100049 China

The research on climate change in polar regions, especially on the role of polar in the global climate system, has gain unprecedented level of interest. It has been the key scientific issue of the International Polar Year program (IPY, 2007—2008). In this paper, we dealt with the debate upon the breakup time of the stratospheric polar vortex in boreal spring. An observational study of the relation between stratospheric polar vortex breakup and the extra-tropical circulation was performed. The mean breakup date—when the winter westerly at the core of polar jet turns to summer easterly—is about April 10. The breakup time has large interannual variation with a time span of about 2 months. It also has a long-term trend with the 1990s and 2000s witnessing more and more late breakups of polar vortex. Composite of wind speed at the core of polar jet for the extremely early and late breakup years shows that late years have two periods of westerly weakening while early breakup years have only one. The flrst weakening in the late years happens in middle January with wind speed dropping sharply from more than 40 m s^(-1) to about 15 m s^(-1). This is accompanied with anomalous activities of planetary waves in both stratosphere and troposphere; while the second weakening in the late breaking years is mainly the results of diabatic heating with very weak wave activities. In early breakup years, the transition from westerly to easterly is rapid with wind speed dropping from more than 30 m s^(-1) to less than -10 m s^(-1) within a month. This evolution is associated with a strong bidirectional dynamical coupling of the stratosphere and troposphere. The circulation anomalies at low troposphere are also analyzed in the extremely early and late breakup years. It shows that there are significant differences between the two kinds of extreme years in the geopotential height and temperature composite analysis, indicating the dynamical coupling of stratosphere and troposphere with the evo

关键词： stratospheric polar vortex, wave-flow interaction, diabatic heating, final breakup, stratosphere-troposphere coupling

The influence of tropical Indian Ocean warming on the Southern Hemispheric stratospheric polar vortex

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Science China Earth Sciences 2009年第3期52卷 323-332页

作者： LI ShuangLin Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

During the past decades, concurrent with global warming, most of global oceans, particularly the tropical Indian Ocean, have become warmer. Meanwhile, the Southern Hemispheric stratospheric polar vortex (SPV) exhibits a deepening trend. Although previous modeling studies reveal that radiative cooling effect of ozone depletion plays a dominant role in causing the deepening of SPV, the simulated ozone-depletion-induced SPV deepening is stronger than the observed. This suggests that there must be other factors canceling a fraction of the influence of the ozone depletion. Whether the tropical Indian Ocean warming (IOW) is such a factor is unclear. This issue is addressed by conducting ensemble atmospheric general circulation model (AGCM) experiments. And one idealized IOW with the amplitude as the observed is prescribed to force four AGCMs. The results show that the IOW tends to warm the southern polar stratosphere, and thus weakens SPV in austral spring to summer. Hence, it offsets a fraction of the effect of the ozone depletion. This implies that global warming will favor ozone recovery, since a warmer southern polar stratosphere is un-beneficial for the formation of polar stratospheric clouds (PSCs), which is a key factor to ozone depletion chemical reactions.

关键词： tropical Indian Ocean warming Southern Hemispheric stratospheric polar vortex atmospheric general circulation model ensemble experiments planetary wave

Analysis and Simulation of the stratospheric Quasi-zero Wind Layer over Korla, Xinjiang Province, China

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Advances in Atmospheric Sciences 2019年第10期36卷 1143-1155页

作者： Rui YANG Lingkun RAN Yuli ZHANG Yi LIU Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Guangzhou Meteorological Observatory Guangzhou 511430 China University of Chinese Academy of Sciences Beijing 100049 China

The stratospheric quasi-zero wind layer (QZWL) is a transition region with low zonal wind speeds in the lower stratosphere at an altitude of ~20 km. The zonal wind direction above the QZWL layer is opposite to that below the QZWL layer and the north –south wind component is small. The atmospheric wind field near the stratospheric QZWL is an important factor affecting the flight altitude and dynamic control of stratospheric airships. It is therefore necessary to study the stratospheric QZWL to provide better environmental information for these aircraft. High-resolution radiosonde data were used to analyze the characteristics of the stratospheric QZWL over Korla, Xinjiang Province, China. A weak wind layer in which the wind direction suddenly reversed from westerly to easterly was observed at ~20 km in the lower stratosphere, characteristic of the stratospheric QZWL. The Weather Research and Forecasting model was used to simulate the profiles of the horizontal wind speed and direction over Korla. The forcing effect of each diagnostic term in the equation on the zonal wind speed was analyzed. The results showed that the advection term was the dominant factor forcing the zonal wind speed. The wave term had a secondary forcing role, although the forcing effect of the wave term on the zonal wind speed was significant in some regions.

关键词： numerical simulation radiosonde stratospheric airships stratospheric quasi-zero wind layer

Trends of Lower- to Mid-stratospheric Water Vapor Simulated in Chemistry-Climate Models

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Atmospheric and Oceanic Science Letters 2015年第1期8卷 57-62页

作者： HU Ding-Zhu HAN Yuan-Yuan SANG Wen-Jun XIE Fei College of Atmospheric Sciences Lanzhou University College of Global Change and Earth System Science Beijing Normal University

Using the outputs from 16 chemistry-climate models(CCMs), the trends of lower- to mid-stratospheric water vapor(WV) during the period 1980–2005 were studied. Comparisons were made between the CCM results and European Centre for Medium-Range Weather Forecasts(ECMWF) Interim Reanalysis(ERA-Interim).The results of most of the CCMs, and those based on ERA-Interim, showed the trends of lower- to mid-stratospheric WV during the period 1980–2005 to be positive, with the extent of the trend increasing with altitude. The trend of lower- to mid-stratospheric WV in the ensemble mean of the CCMs was 0.03 ppmv per decade,which was about twice as large as that based on ERA-Interim. The authors also used a state-of-the-art general circulation model to evaluate the impacts of greenhouse gas(GHG) concentration increases and ozone depletion on stratospheric WV. The simulation results showed that the increases of lower- to mid-stratospheric WV affected by the combined effects of GHG and ozone changes happened mainly via warming of the tropopause and enhancement of the Brewer-Dobson circulation(BDC), with the former being the greater *** increase led to a higher and warmer tropopause with stronger BDC, which in turn led to more WV entering the stratosphere; while ozone depletion led to a higher and cooler tropopause, which caused the decreases of lowerto mid-stratospheric WV, despite also causing stronger BDC.

关键词： chemistry-climate model stratospheric wa ter vapor

THE MECHANISM OF SUDDEN stratospheric WARMING——INTERACTION OF stratospheric AND TROPOSPHERIC CIRCULATIONS

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Chinese Science Bulletin 1991年第4期36卷 309-313页

作者：李自强高由禧瞿章 Lanzhou Institute of Plateau Atmospheric Physics Academia Sinica Lanzhou 730000 PRC

Ⅰ. INTRODUCTIONMany observational data have demonstrated that the sudden stratospheric warming (SSW) play an essential role in stratospheric circulation and its seasonal variation. And SSW is usually accompanied by anomalous amplification of planetary wavenumbers 1 and/or 2 in the troposphere. Matsuno firstly proposed from dynamical point that SSW re-

关键词： sudden stratospheric warming blocking pattern interaction.

Simulation of the Madden-Julian Oscillation in Wintertime stratospheric Ozone over the Tibetan Plateau and East Asia: Results from the Specified Dynamics Version of the Whole Atmosphere Community Climate Model

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Atmospheric and Oceanic Science Letters 2015年第5期8卷 264-270页

作者： LIU Chuan-Xi LIU Yi ZHANG Yu-Li Key Laboratory of Middle Atmosphere and Global Environment Observation (LAGEO) Institute of Atmospheric Physics Chinese Academy of Sciences Joint Center for Global Change Studies (JCGCS) University of Chinese Academy of Sciences

The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2004 and 2010. Comparison with European Centre for Medium-Range Weather Forecasts Interim Reanalysis(ERA-Interim) data suggested that the model simulation represented well the three-dimensional structure of the MJO-related ozone anomalies in the upper troposphere and stratosphere(i.e., between 200 and 20 h Pa). The negative ozone anomalies were over the Tibetan Plateau and East Asia in MJO phases 3–7, when the MJO convective anomalies travelled from the equatorial Indian Ocean towards the equatorial western Pacific Ocean. Due to the different vertical structures of the MJO-related circulation anomalies, the MJO-related stratospheric ozone anomalies showed different vertical structure over the Tibetan Plateau(25–40°N, 75–105°E) and East Asia(25–40°N, 105–135°E). As a result of the positive bias in the model-calculated ozone in the upper troposphere and lower stratosphere, the amplitude of MJO-related stratospheric ozone column anomalies(10–16 Dobson Units(DU)) in the SD-WACCM simulation was slightly larger than that(8–14 DU) in the ERA-Interim reanalysis.

关键词： Madden-Julian Oscillation stratospheric ozone trop

Variation characteristics of stratospheric aerosols due to the Pinatubo eruption by SAGE Ⅱ data

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Chinese Science Bulletin 1995年第3期40卷 231-234页

作者：陈洪滨吕达仁许丽生 Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Chengdu Meteorological College Chengdu 610041 China

Both theoretical and observational studies reveal that the stratospheric volcanic aerosols have important impact on global climate change. The volcanic aerosols can also exert some influences on remote se(?)sing of the atmosphere-earth system . So it is necessary to monitor the aerosol variation in the stratosphere due to the volcanic eruption.

关键词： stratospheric volcanic aerosols Mt. Pinatubo eruption SAGE Ⅱ.