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青藏高原地区一次深对流活动对平流层——对流层物质交换影响的模拟研究

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大气科学 2024年第4期48卷 1329-1344页

作者：刘迪田文寿雒佳丽张如华兰州大学大气科学学院/半干旱气候变化教育部重点实验室兰州730000

利用WRF-Chem模式分析了2010年8月12日发生在青藏高原东南部的一次深对流过程中的平流层—对流层物质交换(STE)过程及其影响机制。结果表明,此次深对流系统具备穿透性对流特征,强上升气流能够直接将近地面含高浓度CO和低浓度O_(3)的空... 详细信息

利用WRF-Chem模式分析了2010年8月12日发生在青藏高原东南部的一次深对流过程中的平流层—对流层物质交换(STE)过程及其影响机制。结果表明,此次深对流系统具备穿透性对流特征,强上升气流能够直接将近地面含高浓度CO和低浓度O_(3)的空气输送至低平流层,使低平流层CO浓度升高、O_(3)浓度降低。同时,深对流活动激发了较强的湍流混合过程,在深对流活动结束后的3~4小时内,湍流混合作用导致上对流层下平流层(UTLS)区域持续发生STE过程,将对流层的冰晶、CO和O_(3)输送至低平流层,但受凝结脱水作用影响,湍流过程向低平流层传输的水汽减少。

关键词：平流层—对流层物质交换(STE) 深对流青藏高原 WRF-Chem 模式

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Different Impact of Central Pacific and Eastern Pacific El Nio on the Duration of Sudden Stratospheric Warming

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Advances in Atmospheric Sciences 2017年第6期34卷 771-782页

作者： Yuanpu LI wenshou tian College of Atmospheric Science Lanzhou UniversityLanzhou 730000Chin

The NCEP-NCAR reanalysis dataset and the HadlSST dataset （1959-2014） are used to analyze the impact of two types of E1 Nino events, i.e., eastern Pacific E1 Nino （EP-E1 Nino） and central Pacific E1 Nino （CP-E1 Nino） events, on the duration of major and minor sudden stratospheric warmings （SSWs） in Northern Hemisphere winter （November to February）. Al- though the frequency of major and minor SSWs during different types of E1 Nino shows no distinct differences, the duration of both major and minor SSWs during CP-E1 Nino is shorter than that during EP-E1 Nino. The spatial distribution of geopo- tential height anomalies preceding major SSWs resembles the western Pacific （WP） teleconnection pattern, while the spatial distribution of geopotential height anomalies preceding minor SSWs bears similarity to the Pacific-North America （PNA） teleconnection pattern. An enhancement of the strength of both wavenumber 1 and wavenumber 2 is found before major SSWs. Before minor SSWs, wavenumber 1 is also strengthened, but wavenumber 2 is weakened. The analysis also reveals that EP-E1 Nino tends to induce positive phases of PNA and WP teleconnections, while CP-E1 Nino induces negative-phase WP teleconnection. As the positive phases of the PNA and WP teleconnections are related to the strengthening of wavenum- bet 1, EP-E1 Nino causes an enhancement of wavenumber 1 in the high-latitude upper troposphere and an enhancement of the upward wave flux in the high-latitude stratosphere, accompanied by a negative anomaly in Eliassen-Palm flux divergence in the subpolar stratosphere, which accounts for the longer SSW duration during EP-E1 Nino than during CP-E1 Nino.

关键词： SSW teleconnection E1 Nino

Treatment of LBCs in 2D Simulation of Convection over Hills

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Advances in Atmospheric Sciences 2004年第4期21卷 573-586页

作者： wenshou tian 郭振海宇如聪 The School of Environment University of Leeds UK State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 series of idealized model simulations are analyzed to determine the sensitivity of model results to different configurations of the lateral boundary conditions (LBCs) in simulating mesoscale shallow convection over hilly terrain. In the simulations with steady thermal forcing at the model surface a radiation condition at both boundaries is the best choice under high wind conditions and the best results are produced when both the normal velocities and the temperature are treated with the radiation scheme in which the phase speed is the same for different variables. When the background wind speed is reasonably small the LBC configuration with either the radiation or the zero gradient condition at both boundaries tends to make the numerical solution unstable. The choice of a constant condition at the inflow boundary and a radiation outflow boundary condition is appropriate in most cases. In the simulations with diurnal thermal forcing at the model surface different LBC schemes are combined together to reduce spurious signals induced by the outflow boundary. A specification inflow boundary condition in which the velocity fields at the inflow boundary are provided using the time-dependent results of a simulation with periodic LBCs over a flat domain is tested and the results indicate that the specification condition at the inflow boundary makes it possible to use a smaller model domain to obtain reasonable results. The model horizontal domain length should be greater than a critical length which depends on the domain depth H and the angle between gravity wave phase lines and the vertical. An estimate of minimum

A series of idealized model simulations are analyzed to determine the sensitivity of model results to different configurations of the lateral boundary conditions (LBCs) in simulating mesoscale shallow convection over hilly terrain. In the simulations with steady thermal forcing at the model surface, a radiation condition at both boundaries is the best choice under high wind conditions, and the best results are produced when both the normal velocities and the temperature are treated with the radiation scheme in which the phase speed is the same for different variables. When the background wind speed is reasonably small, the LBC configuration with either the radiation or the zero gradient condition at both boundaries tends to make the numerical solution unstable. The choice of a constant condition at the inflow boundary and a radiation outflow boundary condition is appropriate in most cases. In the simulations with diurnal thermal forcing at the model surface, different LBC schemes are combined together to reduce spurious signals induced by the outflow boundary. A specification inflow boundary condition, in which the velocity fields at the inflow boundary are provided using the time-dependent results of a simulation with periodic LBCs over a flat domain, is tested and the results indicate that the specification condition at the inflow boundary makes it possible to use a smaller model domain to obtain reasonable results. The model horizontal domain length should be greater than a critical length, which depends on the domain depth H and the angle between gravity wave phase lines and the vertical. An estimate of minimum domain length is given by , where N and U are the background stability and wind speed, respectively, Lx is the typical gravity wavelength scale, and Zi is the convective boundary layer (CBL) depth.

关键词： lateral boundary condition numerical simulation convection orography

Effect of Methane Emission Increases in East Asia on Atmospheric Circulation and Ozone

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Advances in Atmospheric Sciences 2015年第12期32卷 1617-1627页

作者： SHANG Lin LIU Yi tian wenshou ZHANG Yuli Shandong Province Climate Centre Key Laboratory of the Middle Atmosphere and Global Environmental Observation Institute of Atmospheric PhysicsChinese Academy of Sciences Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric SciencesLanzhou University

We used a fully coupled chemistry-climate model （version 3 of the Whole Atmosphere Community Climate Model, WACCM3） to investigate the effect of methane （CH4） emission increases, especially in East Asia and North America, on atmospheric temperature, circulation and ozone （03）. We show that CH4 emission increases strengthen westerly winds in the Northern Hemisphere midlatitudes, accelerate the Brewer-Dobson （BD） circulation, and cause an increase in the mass flux across the tropopause. However, the BD circulation in the tropics between 10°S and 10°N at 100 hPa weakens as CH4 emissions increase in East Asia and strengthens when CH4 emissions increase in North America. When CH4 emissions are increased by 50% in East Asia and 15% globally, the stratospheric temperature cools by up to 0.15 K, and the stratospheric 03 increases by 45 ppbv and 60 ppbv , respectively. A 50% increase of CH4 emissions in North America （with an amplitude of stratospheric 03 increases by 60 ppbv） has a greater influence on the stratospheric 03 than the same CH4 emissions increase in East Asia. CH4 emission increases in East Asia and North America reduce the concentration of tropospheric hydroxyl radicals （4% and 2%, respectively） and increase the concentration of mid-tropospheric 03 （5% and 4%, respectively） in the Northern Hemisphere midlatitudes. When CH4 emissions increase in East Asia, the increase in the tropospheric 03 concentration is largest in August. When CH4 emissions increase in North America, the increase in the 03 concentration is largest in July in the mid-troposphere, and in April in the upper troposphere.

关键词： CH4 temperature Brewer-Dobson circulation O3

A Differential Optical Absorption Spectroscopy Method for X_(CO_2) Retrieval from Ground-Based Fourier Transform Spectrometers Measurements of the Direct Solar Beam

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Advances in Atmospheric Sciences 2015年第8期32卷 1119-1128页

作者： HUO Yanfeng DUAN Minzheng tian wenshou MIN Qilong Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric Sciences Lanzhou University Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric Physics Chinese Academy of Sciences Wuhan University Atmospheric Science Research Center State University of New York

A differential optical absorption spectroscopy （DOAS）-like algorithm is developed to retrieve the column-averaged dry- air mole fraction of carbon dioxide from ground-based hyper-spectral measurements of the direct solar beam. Different to the spectral fitting method, which minimizes the difference between the observed and simulated spectra, the ratios of multiple channel-pairs--one weak and one strong absorption channel--are used to retrieve Xc02 from measurements of the shortwave infrared （SWIR） band. Based on sensitivity tests, a super channel-pair is carefully selected to reduce the effects of solar lines, water vapor, air temperature, pressure, instrument noise, and frequency shift on retrieval errors. The new algorithm reduces computational cost and the retrievals are le^s sensitive to temperature and H20 uncertainty than the spectral fitting method. Multi-day Total Carbon Column Observing Network （TCCON） measurements under clear-sky conditions at two sites （Tsukuba and Bremen） are used to derive Xc02 for the algorithm evaluation and validation. The DOAS-like results agree very well with those of the TCCON algorithm after correction of an airmass-dependent bias.

关键词： CO2 Retrieval ground-based measurement hyper-spectrum shortwave infrared band

Role of Stratospheric Processes in Climate Change: Advances and Challenges

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Advances in Atmospheric Sciences 2023年第8期40卷 1379-1400页

作者： wenshou tian Jinlong HUANG Jiankai ZHANG Fei XIE Wuke WANG Yifeng PENG College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China School of Systems Science Beijing Normal UniversityBeijing 100875China Department of Atmospheric Science China University of GeosciencesWuhan 430078China Centre for Severe Weather and Climate and Hydro-Geological Hazards Wuhan 430078China

In this review,instead of summarizing all the advances and progress achieved in stratospheric research,the main advances and new developments in stratosphere-troposphere coupling and stratospheric chemistry-climate interactions are summarized,and some outstanding issues and grand challenges are discussed.A consensus has been reached that the stratospheric state is an important source of improving the predictability of the troposphere on sub-seasonal to seasonal(S2S)time scales and ***,applying stratospheric signals in operational S2S forecast models remains a challenge because of model deficiencies and the complexities of the underlying mechanisms of stratosphere-troposphere *** chemistry,which controls the magnitude and distribution of many important climate-forcing agents,plays a critical role in global climate *** evidence has been found that stratospheric ozone depletion and recovery have caused significant tropospheric climate changes,and more recent studies have revealed that stratospheric ozone variations can even exert an impact on SSTs and sea *** climatic impacts of stratospheric aerosols and water vapor are also *** their quantitative contributions to radiative forcing have been reasonably well quantified,there still exist large uncertainties in their long-term impacts on *** advances and new levels of understanding presented in this review suggest that whole-atmosphere interactions need to be considered in future for a better and more thorough understanding of stratosphere-troposphere coupling and its role in climate change.

关键词： stratosphere the stratosphere-troposphere coupling stratospheric chemistry-climate interactions stratospheric ozone

Zonally Asymmetric Temperature Trends near the Northern Middle and High Latitude Stratopause during Winter

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Journal of Meteorological Research 2023年第4期37卷 441-453页

作者： Tao WANG wenshou tian Ruhua ZHANG Jiali LUO Wuhu FENG College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China National Centre for Atmospheric Science(NCAS) School of Earth and EnvironmentUniversity of LeedsLeeds LS29JTUK

The temperature trend near the stratopause is rarely evaluated owing to the limited long-term observations of global temperature. In this study, the spatial patterns of the temperature trends near the northern stratopause are investigated by using satellite and reanalysis datasets. Our analysis reveals a zonally asymmetric temperature trend pattern near the northern mid-to-high latitude stratopause during January, and this pattern underwent an evident transition around the 2000s. From 1980 to 2003, there was a cooling trend in the Western Hemisphere and a warming trend in the Eastern Hemisphere. In contrast, a reversed zonally asymmetric temperature trend pattern existed in the east–west direction from 2003 to 2020. Although the warming trends are statistically insignificant, they contrasted with the overall cooling trend in the upper stratosphere due to ozone depletion and an increase in well-mixed greenhouse gases in recent decades. The zonally asymmetric temperature trends were induced by the transition in the intensity of quasi-stationary planetary wavenumber 1(wave 1) near the stratopause. The increasing(decreasing) trend of the intensity of wave 1 enhanced(weakened) its meridional temperature advection near the stratopause before(after) the 2000s;consequently, a zonally asymmetric temperature trend pattern exists in the east–west direction near the stratopause. The transition in the intensity of the stratospheric wave 1 around the 2000s is most likely caused by the transition in the intensity of wave 1 activity in the troposphere.

关键词： stratospheric temperature trend zonally asymmetric temperature pattern quasi-stationary planetary wavenumber 1

Record Arctic Ozone Loss in Spring 2020 is Likely Caused by North Pacific Warm Sea Surface Temperature Anomalies

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Advances in Atmospheric Sciences 2021年第10期38卷 1723-1736页

作者： Yan XIA Yongyun HU Jiankai ZHANG Fei XIE wenshou tian College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China

Record ozone loss was observed in the Arctic stratosphere in spring *** study aims to determine what caused the extreme Arctic ozone *** and simulation results are examined in order to show that the extreme Arctic ozone loss was likely caused by record-high sea surface temperatures(SSTs)in the North *** is found that the record Arctic ozone loss was associated with the extremely cold and persistent stratospheric polar vortex over February-April,and the extremely cold vortex was a result of anomalously weak planetary wave *** analysis reveals that the weak wave activity can be traced to anomalously warm SSTs in the North *** observations and simulations show that warm SST anomalies in the North Pacific could have caused the weakening of wavenumber-1 wave activity,colder Arctic vortex,and lower Arctic *** results suggest that for the present-day level of ozone-depleting substances,severe Arctic ozone loss could form again,as long as certain dynamic conditions are satisfied.

关键词： Arctic ozone loss stratospheric polar vortex sea surface temperature planetary-scale wave climate change

Effects of Meridional Sea Surface Temperature Changes on Stratospheric Temperature and Circulation

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Advances in Atmospheric Sciences 2014年第4期31卷 888-900页

作者： HU Dingzhu tian wenshou XIE Fei SHU Jianchuan Sandip DHOMSE College of Atmospheric Sciences Lanzhou University Institute of Atmospheric Physics Chinese Academy of Sciences Institute of Plateau Meteorology China Meteorological Administration Institute for Climate and Atmospheric Science School of Earth and Environment University of Leeds UK

Using a state-of-the-art chemistry-climate model,we analyzed the atmospheric responses to increases in sea surface temperature （SST）.The results showed that increases in SST and the SST meridional gradient could intensify the subtropical westerly jets and significantly weaken the northern polar *** the model runs,global uniform SST increases produced a more significant impact on the southern stratosphere than the northern stratosphere,while SST gradient increases produced a more significant impact on the northern *** asymmetric responses of the northern and southern polar stratosphere to SST meridional gradient changes were found to be mainly due to different wave properties and transmissions in the northern and southern *** SST increases may give rise to stronger waves,the results showed that the effect of SST increases on the vertical propagation of tropospheric waves into the stratosphere will vary with height and latitude and be sensitive to SST meridional gradient *** uniform and non-uniform SST increases accelerated the large-scale Brewer-Dobson circulation （BDC）,but the gradient increases of SST between 60°S and 60°N resulted in younger mean age-of-air in the stratosphere and a larger increase in tropical upwelling,with a much higher tropopause than from a global uniform 1.0 K SST increase.

关键词： numerical simulation stratospheric temperature sea surface temperature Brewer-Dobson circulation