检索结果-南通市图书馆

Anomalous changes of temperature and ozone QBOs in 2015−2017 from radiosonde observation and MERRA-2 reanalysis

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2021年第3期5卷 280-289页

作者： XiaoYan Bai KaiMing huang ShaoDong Zhang chunming huang Yun Gong School of Electronic Information Wuhan UniversityWuhan 430072China Key Laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan 430072China State Observatory for Atmospheric Remote Sensing Wuhan 430072China

Anomalous changes of zonal wind quasi-biennial oscillation(QBO)in winter 2015−2016 have received close *** radiosonde and satellite observations and reanalysis data,we investigate anomalous changes in temperature and ozone QBOs from the lower to middle *** wind shear direction is reversed due to unexpected changes of zonal wind QBO at about 24−30 km,the shortest cold phase at 21−27 km appears in temperature *** is different from the completely interrupted westward phase in zonal wind QBO,while the longest cold phase above almost 27 km lasts for 2−3 years from 2015 to 2017,owing to the absence of corresponding warm *** scale reduction of temperature QBO causes a small temperature anomaly,thus the thermal wind relationship looks seemingly different from that in the other regular QBO *** in the ozone mixing ratio anomaly shows a double-peak with inverse phase,and its phase below(above)30 km is in agreement with(opposite to)the phase of temperature QBO because of different control mechanisms of *** temperature QBO variation,QBO in the ozone mixing ratio anomaly exhibits a less positive phase at 20−30 km in 2016−2017,and a very long positive phase above 30 km from 2015 to *** in total column ozone shows a small peak in winter 2016−2017 since ozone is mainly concentrated at 20 to 30 *** changes of temperature and ozone QBOs due to unexpected QBO zonal wind variation can be well-explained according to thermal wind balance and thermodynamic balance.

关键词： QBO temperature anomaly ozone anomaly thermal wind balance

Nonlinear Interactions between the Quasi 5-day Wave and Tides Based on Meteor Radar Observations at Maui

在线全文

学校读者我要写书评

暂无评论

空间科学学报 2015年第4期35卷 445-452页

作者： GU Jingxiao huang chunming huang Kaiming School of Electronic Information Wuhan University Key Laboratory of Geospace Environment and Geodesy Ministry of Education State Observatory for Atmospheric Remote Sensing

Nonlinear interactions between the quasi 5-day wave and tides based on meteor radar observation in the Mesosphere and Lower Thermosphere(MLT) at Maui are studied in this *** sum interaction between quasi 5-day wave and diurnal tide,and evident difference interaction between quasi 5-day wave and semidiurnal tide are observed during the time of ***,their difference and sum counterparts are clearly *** secondary waves generated from those interactions beat with the tide and show intense modulation at the period of 5 days which confirms the existence of their ***,correlation coefficients among these waves are calculated to further explore their interactions and find that they can persist for several days although they are highly *** energy exchange among these waves can be reversible during the observational *** periods when the significant difference interaction between the quasi 5-day wave and semidiurnal tide occur are much shorter than those when the significant sum interaction between the quasi 5-day wave and diurnal tide ***,these two strong interactions can take place *** generally,this study provides the proof of nonlinear interactions between quasi 5-day wave and tides which were seldom reported before.

关键词： Quasi 5-day wave Tides Nonlinear interaction Mesos

Observations of gravity wave activity during stratospheric sudden warmings in the Northern Hemisphere

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第6期58卷 951-960页

作者： JIA Yue ZHANG ShaoDong YI Fan huang chunming huang KaiMing GAN Quan GONG Yun School of Electronic Information Wuhan University Key Laboratory of Geospace Environment and Geodesy Ministry of Education State Observatory for Atmospheric Remote Sensing State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing

Arctic stratospheric sudden warming(SSW) with polar vortex displacement and splitting occurred in 2008 and 2009, respectively. The temperature profiles derived from the Constellation Observing System for Meteorology, Ionosphere and Climate(COSMIC) along with NCEP/NCAR reanalysis are used to investigate the gravity wave(GW) variations during these SSW events. Some phenomena are characterized and possible mechanisms are discussed. The GW variations during both types of SSW events shared some similarities. During the warming events, enhanced zonal mean GW amplitudes are detected. The enhancements of GW amplitudes first appeared at higher altitudes and then progressed downward during the major warming events. The downward progressions correspond well with the height variations of the zonal wind reversal, and the enhancements seem to occur at the same time with the wind reversal. The spatial variations of GWs showed evident correlation to the polar vortex. Generally, GWs were enhanced at the edge of the polar vortex where the background wind was strong, whereas the areas with the largest GW amplitudes did not always correspond with those with the strongest background wind. The differences during the two types of SSW are also noticeable. In the 2008 major event, the magnitudes of the zonal mean GW enhancements during the downward progression were relatively stable, whereas in the 2009 major event, a clear reduction was detected as the GW enhancement was progressing downward. Also, the recovery time of the polar vortex was longer in 2009. These differences indicate that different types of SSWs may have different impacts on the GW.

关键词： stratospheric sudden warming gravity wave COSMIC

Diurnal variations of the planetary boundary layer height estimated from intensive radiosonde observations over Yichang, China

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2014年第11期57卷 2172-2176页

作者： ZHANG YeHui ZHANG ShaoDong huang chunming huang KaiMing GONG Yun GAN Quan Applied Hydrometeorological Research Institute Nanjing University of Information Science & Technology State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University School of Electronic Information Wuhan University

By using the eight-times-daily sampling data from an intensive radiosonde observation campaign at Yichang(111°18′E,30°42′N),China in August 2006 and January 2007,the diurnal variation of the planetary boundary layer height determined by using a bulk Richardson(Ri)number approach,was studied in this *** was found that the boundary layer heights in both summer and winter months showed diurnal changes and the daily cycle was deeper in summer,which agreed well with the previous studies;the monthly averaged height was 103–1112 m and 89–450 m in summer and winter,respectively;the morning rise began at 0700 LT/1000 LT in summer/winter and the evening transition occurred at 1900 LT in both seasons;the maximum height occurred in the afternoon for most cases,except some peaks found in the winter night;the surface temperature and relative humidity dominated the variations of summer height,while the diurnal variation shown in January 2007 might have some connections with the dynamical processes in the lower troposphere,besides the surface effects.

关键词： planetary boundary layer height bulk Richardson (Ri) number method intensive radiosonde observations diurnalvariation

Long-term variation of Arctic Sudden Stratospheric Warmings(SSW)and potential causes

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第5期8卷 742-752页

作者： QingRan Li ShaoDong Zhang KaiMing huang chunming huang Yun Gong WenTao Tang Zheng Ma School of Electronic Information Wuhan UniversityWuhan 430072China Guizhou Normal University Guiyang 550001China Key Laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan 430072China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan 430072China School of Electronic Information Engineering Jingchu University of TechnologyJingmen 448000China

Utilizing the European Centre for Medium-Range Weather Forecast(ECMWF)Reanalysis v5(ERA5),for the first time,we have confirmed close links among Sudden Stratospheric Warmings(SSWs)in the Northern Hemisphere(NH),the polar vortices,and stratospheric Planetary Waves(PWs)by analyzing and comparing their ***,within overall increasing trends,the duration and strength of SSWs exhibit increasing and decreasing trends before and after the winter of 2002,*** reveal possible physical mechanisms driving these trends,we analyzed the long-term trends of the winter(from December to February)polar vortices and of stratospheric PWs with zonal wave number ***,our results show that in all three time periods(the entire period of 41winters,1980 to 2020,and the two subperiods—1980-2002 and 2002-2020)enhancing SSWs were always accompanied by weakening winter polar vortices and strengthening polar PWs like Stationary Planetary Waves(SPWs)and 16-day waves,and vice *** is the first proof,based on ERA5 long-term trend data,that weakening polar vortices and enhancing stratospheric PWs(especially SPWs)could cause an increase in SSWs.

关键词： sudden stratospheric warmings stationary planetary waves 16-day waves polar vortrices long-term trend correlation coefficient

Comparison of stratospheric evolution during the major sudden stratospheric warming events in 2018 and 2019

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2020年第5期4卷 493-503页

作者： Zheng Ma Yun Gong ShaoDong Zhang JiaHui Luo QiHou Zhou chunming huang KaiMing huang School of Electronic Information Wuhan UniversityWuhan 430072China State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190China Key Laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan 430079China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China Electrical and Computer Engineering Department Miami UniversityOxfordOhio 45056USA

Using Modern-Era Retrospective analysis for Research and Applications,Version 2(MERRA-2)data in the northern hemisphere at the 10 hPa level,we compared the stratospheric evolution of temperature and geopotential height during two major sudden stratosphere warming events(SSWs)that occurred in the Arctic winter of 2018 and *** the prewarming period,poleward temperature-enhanced regions were mainly located around 120°E with a displaced vortex and around 120°E and 60°W with splitting *** evolution of geopotential height indicated that these temperature-enhanced regions were both on the western side of high-latitude *** the postwarming period,the polar vortex turned from splitting to displacement in the 2018 SSW but from displacement to splitting in the 2019 *** transitions were observed over the Atlantic region,which may have been caused by anticyclones moving through the polar *** findings revealed that the evolution of the anticyclone is important during SSWs and is closely related to temperature-enhanced regions in the prewarming periods and to transitions of the polar vortices in postwarming periods.

关键词： sudden stratosphere warming transitions of the polar vortex anticyclone Atlantic region

Climatology of global gravity wave activity and dissipation revealed by SABER/TIMED temperature observations

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2014年第5期57卷 998-1009页

作者： SHUAI Jing ZHANG ShaoDong huang chunming YI Fan huang KaiMing GAN Quan GONG Yun Electronic Information School Wuhan University Key Laboratory of Geospace Environment and Geodesy Ministry of Education State Observatory for Atmospheric Remote Sensing

Gravity wave activity and dissipation in the height range from the low stratosphere to the low thermosphere(25–115 km)covering latitudes between 50°S and 50°N are statistically studied by using 9-year(January 22,2002–December 31,2010)SABER/TIMED temperature *** propose a method to extract realistic gravity wave fluctuations from the temperature profiles and treat square temperature fluctuations as GW ***,the gravity wave activity generally increases with *** the equator(0°–10°),the gravity wave activity shows a quasi-biennial variation in the stratosphere(below 40 km)while from 20°to 30°,it exhibits an annual variation below 40 km;in low latitudes(0°–30°)between the upper stratosphere and the low thermosphere(40–115 km),the gravity wave activity shows a semi-annual *** middle latitudes(40°–50°),the gravity wave activity has a clear annual variation below 85 *** addition,we observe a four-monthly variation with peaks occurring usually in April,August,December in the northern hemisphere and in February,June,October in the southern hemisphere,respectively,above 85 km in middle latitudes,which has been seldom reported in gravity wave *** order to study the dissipation of gravity wave propagation,we calculate the gravity wave dissipation ratio,which is defined as the ratio of the gravity wave growth scale height to the atmosphere density scale *** height variation of the dissipation ratio indicates that strong gravity wave dissipation mainly concentrates in the three height regions:the stratosphere(30–60 km),the mesopause(around 85 km)and the low thermosphere(above 100 km).Besides,gravity wave energy enhancement can be also observed in the background atmosphere.

关键词： gravity wave dissipation climatology middle and high atmosphere TIMED/SABER

Characteristics of the quasi-16-day wave in the mesosphere and lower thermosphere region as revealed by meteor radar,Aura satellite,and MERRA2 reanalysis data from 2008 to 2017

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2020年第3期4卷 274-284页

作者： Yun Gong Zheng Ma Chun Li XieDong Lv ShaoDong Zhang QiHou Zhou chunming huang KaiMing huang You Yu GuoZhu Li School of Electronic Information Wuhan UniversityWuhan 430079China Key Laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan 430079China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China Electrical and Computer Engineering Department Miami UniversityOxfordOhioUSA Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

This study presents an analysis of the quasi-16-day wave(Q16DW)at three stations in the middle latitudes by using a meteor radar chain in conjunction with Aura Microwave Limb Sounder temperature data and MERRA2(Modern-Era Retrospective Analysis for Research and Applications,Version 2)reanalysis data from 2008 to *** radar chain consists of three meteor radar stations located at Mohe(MH,53.5°N,122.3°E),Beijing(BJ,40.3°N,116.2°E),and Wuhan(WH,30.5°N,114.6°E).The Q16DW wave exhibits similar seasonal variation in the neutral wind and temperature,and the Q16DW amplitude is generally strong during winter and weak around *** Q16DW at BJ was found to have secondary enhancement around September in the zonal wind,which is rarely reported at similar *** latitudinal variations of the Q16DW in the neutral wind and temperature are quite *** Q16DW at BJ is the most prominent in both neutral wind components among the three stations and the Q16DW amplitudes at MH and WH are comparable,whereas the wave amplitude in temperature decreases with decreasing *** quasi-geostrophic refractive index squared at the three stations in the period from 2008 to 2017 was *** results indicate that the Q16DW in the mesosphere and lower thermosphere(MLT)at MH has a limited contribution from the lower *** March and October,the Q16DW in the troposphere at BJ can propagate upward into the MLT region,whereas at WH,the contribution to the Q16DW in the MLT region is largely from the mesosphere.

关键词： quasi-16-day waves seasonal variations meteor radar winds Aura MLS temperature generation mechanisms

AN ITERATIVE RELIABILITY-BASED DECODING FOR LDPC CODED MODULATION SYSTEM

在线全文

学校读者我要写书评

暂无评论

Journal of Electronics(China) 2008年第3期25卷 289-293页

作者： huang Ping Zhao chunming Jiang Ming National Mobile Communication Research Lab Southeast University Nanjing 210095 China Electrical Engineering School Hohai University Nanjing 210098 China

In this paper, A Belief Propagation concatenated Orderd-Statistic Decoder (BP-OSD) based on accumulated Log-Likelihood Ratio (LLR) is proposed for medium and short lengths Low Density Parity-Check (LDPC) codes coded Bit-Interleaved Coded Modulation (BICM) systems. The accumulated soft output values delivered by every BP iteration are used as reliability values of Soft-Input Soft-Output OSD (SISO-OSD) decoder and the soft output of SISO-OSD is used as a priori probabilities of the demodulator for the next iteration. Simulation results show that this improved algorithm achieves noticeable performance gain with only modest increase in computation complexity.

关键词： Low-Density Parity-Check (LDPC) codes Bit-Interleaved Coded Modulation (BICM) Belief Propagation (BP) Soft-Input Soft-Output Ordered Statistics Decoding (SISO-OSD) Log- Likelihood Ratio (LLR)