By dint of the summer precipitation data from 21 stations in the Dongting Lake region during 1960-2008 and the sea surface temperature(SST) data from NOAA,the spatial and temporal distributions of summer precipitation...By dint of the summer precipitation data from 21 stations in the Dongting Lake region during 1960-2008 and the sea surface temperature(SST) data from NOAA,the spatial and temporal distributions of summer precipitation and their correlations with SST are analyzed.The coupling relationship between the anomalous distribution in summer precipitation and the variation of SST has between studied with the Singular Value Decomposition(SVD) analysis.The increase or decrease of summer precipitation in the Dongting Lake region is closely associated with the SST anomalies in three key regions.The variation of SST in the three key regions has been proved to be a significant previous signal to anomaly of summer rainfall in Dongting region.展开更多
The precipitation in Shandong in July, August as well as the whole summer (JJA) and the corresponding 500 hPa geopotential height fields are analyzed by means of the SVD (singular value decomposition) methodology. It ...The precipitation in Shandong in July, August as well as the whole summer (JJA) and the corresponding 500 hPa geopotential height fields are analyzed by means of the SVD (singular value decomposition) methodology. It is found that the general circulations in East Asia and the Western Pacific underwent decadal changes around 1979. The geopotential height, in particular over key areas like the South China Sea and the Philippines, increased after 1979. Corresponding to the changes in the geopotential height, the rainfall in Shandong started to decrease around 1979. The synthesized analysis shows that when the geopotential height at 500hPa level decreases in the key areas, the Western Pacific subtropical high shifts northward and an anticyclonic anomalous cell enforces the southerly flow over Shandong-Korea-Japan, Shandong could experience a wet period. A dry period is likely to occur when the geopotential height increases in these key areas, the subtropical high moves southward or expands westward to a great distance, and a cyclonic anomalous cell controls Shandong. Respective conceptual models for the causative mechanism are obtained for the cases of July, August and the whole summer (JJA) .展开更多
Based on Arctic sea ice concentration data and NCEP／NCAR reanalysis data, relationship between sea ice anomaly over the sea of Okhotsk and its vicinage and northern Pacific storm track during winter is discussed by s...Based on Arctic sea ice concentration data and NCEP／NCAR reanalysis data, relationship between sea ice anomaly over the sea of Okhotsk and its vicinage and northern Pacific storm track during winter is discussed by statistic analysis methods. It is found that with northern Pacific SSTA, sea ice area anomaly over southwest of the sea of Okhotsk can except crucial influence on the variation in vigor and extension （contraction） from northwest to southeast of nor{hem Pacific storm track. But with tl^e influence of SSTA, sea ice area anomaly over northeast of the sea of Okhotsk and the gulf of SheUkhow works mainly on the strength and the south-north movement of the storm track.展开更多
Investigation is conducted of the interannual variability of the northern Pacific storm track and its concurrent association with 500 hPa height and Pacific sea surface temperature (SST) during winter. Evidence sugges...Investigation is conducted of the interannual variability of the northern Pacific storm track and its concurrent association with 500 hPa height and Pacific sea surface temperature (SST) during winter. Evidence suggests that during the studying period the center of the northern winter Pacific storm track experiences substantial interannual variability in the variation of its latitude, longitude and intensity. Singular value decomposition (SVD) of 15 winter 500 hPa filtered geopotential height variance over the storm track with the tropical and northern Pacific SST shows that the first coupled mode depicts the effect on the track of SSTA over the equatorial central and eastern Pacific, while the second one reflects the impact of Kuroshio SSTA on the track. Further Composite analysis indicates, moreover, that the SSTA over Kuroshio (equatorial central and eastern Pacific) during winter, which is relative to WP (PNA) teleconnection response pattern in 500 hPa height field, respectively, exerts crucial influence on the interannual variability in vigor and meridianal (zonal) displacement of the track over its central and western (eastern) part.展开更多
Synthesis analysis and singular value decomposition (SVD) methods were used to study the impact of surface air temperature (SAT) over Asian-Pacific region on the summertime northeastern Asian blocking high (NABH) with...Synthesis analysis and singular value decomposition (SVD) methods were used to study the impact of surface air temperature (SAT) over Asian-Pacific region on the summertime northeastern Asian blocking high (NABH) with NCEP/NCAR Reanalysis Data.The results showed that 500 hPa geopotential height and SAT fields over Asian-Pacific region shared the similar pattern of East Asian Pacific (EAP) wave train;there was steady remote response relationship between the EAP wave train in summer and the '+-+' pattern of tropical SAT in zonal direction from former winter to summer;there were two relative negative(positive) Walker circulations over the tropical Indian Ocean and Pacific when being more(less) summertime NABH. The influence of sea surface temperature anomaly (SSTA) on the summertime NABH was possibly as follows.The special distribution of SSTA in tropical zonal direction continuously forced the tropical convection and zonal circulation from former winter to summer,and led them to act anomaly.Finally the abnormal conditions were transported to middle-high latitudes through EAP wave train and yielded the advantageous or disadvantageous atmospheric circulation background for the summertime NABH.展开更多
We studied the structure of the Indian Ocean(IO)Meridional Overturning Circulation(MOC)by applying a nonlinear inertia theory and analyzed the coupled relationship between zonal wind stress and MOC anomalies.Our resul...We studied the structure of the Indian Ocean(IO)Meridional Overturning Circulation(MOC)by applying a nonlinear inertia theory and analyzed the coupled relationship between zonal wind stress and MOC anomalies.Our results show that the inertia theory can represent the main characteristics of the IO MOC:the subtropical cell(STC)and cross-equator cell(CEC).The stream function in equatorial and northern IO changes a sign from winter to summer.The anomalies of the zonal wind stress and stream function can be decomposed into summer monsoon mode,winter monsoon mode,and abnormal mode by using the singular vector decomposition(SVD)analysis.The first two modes correlate with the transport through 20°S and equator simultaneously whereas the relationship obscures between the third mode and transports across 20°S and equator,showing the complex air-sea interaction process.The transport experiences multi-time scale variability according to the continuous power spectrum analysis,with major periods in inter-annual and decadal scale.展开更多
基金Supported by The Special Foundation of Chinese Meteorological Bureau Climate Changes Program(200920)The Special Foundation of Hunan Major Scientific and Technological Research Program(2008FJ1006)~~
文摘By dint of the summer precipitation data from 21 stations in the Dongting Lake region during 1960-2008 and the sea surface temperature(SST) data from NOAA,the spatial and temporal distributions of summer precipitation and their correlations with SST are analyzed.The coupling relationship between the anomalous distribution in summer precipitation and the variation of SST has between studied with the Singular Value Decomposition(SVD) analysis.The increase or decrease of summer precipitation in the Dongting Lake region is closely associated with the SST anomalies in three key regions.The variation of SST in the three key regions has been proved to be a significant previous signal to anomaly of summer rainfall in Dongting region.
文摘The precipitation in Shandong in July, August as well as the whole summer (JJA) and the corresponding 500 hPa geopotential height fields are analyzed by means of the SVD (singular value decomposition) methodology. It is found that the general circulations in East Asia and the Western Pacific underwent decadal changes around 1979. The geopotential height, in particular over key areas like the South China Sea and the Philippines, increased after 1979. Corresponding to the changes in the geopotential height, the rainfall in Shandong started to decrease around 1979. The synthesized analysis shows that when the geopotential height at 500hPa level decreases in the key areas, the Western Pacific subtropical high shifts northward and an anticyclonic anomalous cell enforces the southerly flow over Shandong-Korea-Japan, Shandong could experience a wet period. A dry period is likely to occur when the geopotential height increases in these key areas, the subtropical high moves southward or expands westward to a great distance, and a cyclonic anomalous cell controls Shandong. Respective conceptual models for the causative mechanism are obtained for the cases of July, August and the whole summer (JJA) .
基金supported by the key project of Science and Technology Development Foundation of Regional Meteorological Center of Wuhan (No. QY-Z-200902)subsidized project of Key Laboratory of Meteorological Disaster of Jiangsu Province (KLME050202) subsidized project of "Qing-lan" for the Young and Middle-aged Academic Pathfinders in Colleges and Universities of Jiangsu province
文摘Based on Arctic sea ice concentration data and NCEP／NCAR reanalysis data, relationship between sea ice anomaly over the sea of Okhotsk and its vicinage and northern Pacific storm track during winter is discussed by statistic analysis methods. It is found that with northern Pacific SSTA, sea ice area anomaly over southwest of the sea of Okhotsk can except crucial influence on the variation in vigor and extension （contraction） from northwest to southeast of nor{hem Pacific storm track. But with tl^e influence of SSTA, sea ice area anomaly over northeast of the sea of Okhotsk and the gulf of SheUkhow works mainly on the strength and the south-north movement of the storm track.
基金Sponsored by the China National Key Fundamental Research and Development Program(G1998040901-3) and National Natural Science F
文摘Investigation is conducted of the interannual variability of the northern Pacific storm track and its concurrent association with 500 hPa height and Pacific sea surface temperature (SST) during winter. Evidence suggests that during the studying period the center of the northern winter Pacific storm track experiences substantial interannual variability in the variation of its latitude, longitude and intensity. Singular value decomposition (SVD) of 15 winter 500 hPa filtered geopotential height variance over the storm track with the tropical and northern Pacific SST shows that the first coupled mode depicts the effect on the track of SSTA over the equatorial central and eastern Pacific, while the second one reflects the impact of Kuroshio SSTA on the track. Further Composite analysis indicates, moreover, that the SSTA over Kuroshio (equatorial central and eastern Pacific) during winter, which is relative to WP (PNA) teleconnection response pattern in 500 hPa height field, respectively, exerts crucial influence on the interannual variability in vigor and meridianal (zonal) displacement of the track over its central and western (eastern) part.
基金supported by the National Natural Science Foundation of China under Grant of No.40233033 and No.40475040
文摘Synthesis analysis and singular value decomposition (SVD) methods were used to study the impact of surface air temperature (SAT) over Asian-Pacific region on the summertime northeastern Asian blocking high (NABH) with NCEP/NCAR Reanalysis Data.The results showed that 500 hPa geopotential height and SAT fields over Asian-Pacific region shared the similar pattern of East Asian Pacific (EAP) wave train;there was steady remote response relationship between the EAP wave train in summer and the '+-+' pattern of tropical SAT in zonal direction from former winter to summer;there were two relative negative(positive) Walker circulations over the tropical Indian Ocean and Pacific when being more(less) summertime NABH. The influence of sea surface temperature anomaly (SSTA) on the summertime NABH was possibly as follows.The special distribution of SSTA in tropical zonal direction continuously forced the tropical convection and zonal circulation from former winter to summer,and led them to act anomaly.Finally the abnormal conditions were transported to middle-high latitudes through EAP wave train and yielded the advantageous or disadvantageous atmospheric circulation background for the summertime NABH.
基金supported by the National Basic Research Program of China(Grant No.2010CB950300)
文摘We studied the structure of the Indian Ocean(IO)Meridional Overturning Circulation(MOC)by applying a nonlinear inertia theory and analyzed the coupled relationship between zonal wind stress and MOC anomalies.Our results show that the inertia theory can represent the main characteristics of the IO MOC:the subtropical cell(STC)and cross-equator cell(CEC).The stream function in equatorial and northern IO changes a sign from winter to summer.The anomalies of the zonal wind stress and stream function can be decomposed into summer monsoon mode,winter monsoon mode,and abnormal mode by using the singular vector decomposition(SVD)analysis.The first two modes correlate with the transport through 20°S and equator simultaneously whereas the relationship obscures between the third mode and transports across 20°S and equator,showing the complex air-sea interaction process.The transport experiences multi-time scale variability according to the continuous power spectrum analysis,with major periods in inter-annual and decadal scale.
