ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 29,Issue 9,2003 Table of Contents
2003, 29(9):3-7.
DOI: 10.7519/j.issn.1000-0526.2003.9.001
Abstract:
A calculating method for the East Asia blocking high index is put forward.The index from 1951 to 2001 is calculated and analyzed. It shows that the rainfall pattern Ⅲ mostly follows the East Asia blocking high, and the flood of Yangtze valley only occurs under the specific blocking high condition. In comparison with the research done by others, this index describing the East Asia blocking high of recent 51 years is more properly.
A calculating method for the East Asia blocking high index is put forward.The index from 1951 to 2001 is calculated and analyzed. It shows that the rainfall pattern Ⅲ mostly follows the East Asia blocking high, and the flood of Yangtze valley only occurs under the specific blocking high condition. In comparison with the research done by others, this index describing the East Asia blocking high of recent 51 years is more properly.
2003, 29(9):8-12.
DOI: 10.7519/j.issn.1000-0526.2003.9.002
Abstract:
The snow-storm in the eastern part of Qinghai Plateau during 21-22,October 2002 was the heaviest process in the last 10 autumns. Based on infrared imagery,vapor image and some conventional observation,the synoptic diagnostic analysis of the snow-storm is made. The results show that there is a good corresponding relationship between Q-vector moist frontolysis function,Q-vector divergence,vapor flux divergence and the snow-storm region of the Qinghai Plateau,and this has a good implication for the snowfall forecast in the Qinghai Plateau.
The snow-storm in the eastern part of Qinghai Plateau during 21-22,October 2002 was the heaviest process in the last 10 autumns. Based on infrared imagery,vapor image and some conventional observation,the synoptic diagnostic analysis of the snow-storm is made. The results show that there is a good corresponding relationship between Q-vector moist frontolysis function,Q-vector divergence,vapor flux divergence and the snow-storm region of the Qinghai Plateau,and this has a good implication for the snowfall forecast in the Qinghai Plateau.
2003, 29(9):13-17.
DOI: 10.7519/j.issn.1000-0526.2003.9.003
Abstract:
Three cases are chosen to verify the MM5V3.5 model′s simulating capability for meso-scale system in the north of Shaanxi province. The results indicate that at 9km resolution and NCEP as the large scale background field, the model has the best ability of simulating the pattern of summer rainfall and evolution features except some deviation in the position and intensity of precipitation centers. Also, it has higher capability of imitating the trend of winter temperature. Meanwhile, it is poor of its performance in simulating the extreme local precipitation centers, and, there appear some dummy rainfall centers in precipitation′s simulation for large areas.
Three cases are chosen to verify the MM5V3.5 model′s simulating capability for meso-scale system in the north of Shaanxi province. The results indicate that at 9km resolution and NCEP as the large scale background field, the model has the best ability of simulating the pattern of summer rainfall and evolution features except some deviation in the position and intensity of precipitation centers. Also, it has higher capability of imitating the trend of winter temperature. Meanwhile, it is poor of its performance in simulating the extreme local precipitation centers, and, there appear some dummy rainfall centers in precipitation′s simulation for large areas.
2003, 29(9):18-22.
DOI: 10.7519/j.issn.1000-0526.2003.9.004
Abstract:
Based on normal meteorological observations, synoptic and diagnostic analysis of two typical severe sandstorm processes on March 19～21st 2002 and April 8～9th 2001 is made. The results show that the circulation patterns and sand source terrain of the two processes are nearly similar,but, their intensity,duration of cold wave and the position of Mongolian cyclone,as well as early climatic background are different.
Based on normal meteorological observations, synoptic and diagnostic analysis of two typical severe sandstorm processes on March 19～21st 2002 and April 8～9th 2001 is made. The results show that the circulation patterns and sand source terrain of the two processes are nearly similar,but, their intensity,duration of cold wave and the position of Mongolian cyclone,as well as early climatic background are different.
2003, 29(9):23-27.
DOI: 10.7519/j.issn.1000-0526.2003.9.005
Abstract:
The characteristics, including the distribution in a month and the duration of Beijing estival muggy weather, is gained here by analyzing the daily maximum and minimum temperature in summer season(June, July and August) from 1951 to 2000. It revealed that the occurrence probabilities of the hot and muggy weather during the summer in Beijing are, respectively,1/10 and 1/20, which indicates Beijing is a suitable city for the Summer Olympic Games. The hot weather mainly occurs in late June and the whole July, with two maximum frequencies in the period of 26 to 30 June and 21 to 25 July, respectively. The muggy weather mainly occurs in the middle of July and early August, with two maximum frequencies in the period of 26-31 July and 6-10 August, respectively. There are many hot weather days but few muggy weather days in June . And there are very few hot weather days but several muggy days in August. The hot weather lasting more than 2 days occurs at least once a year. The occurrence frequencies of the hot and muggy weather lasting more than 3 days are 0.84 times/ year and 0.88 times/year respectively. The average duration of the hot and muggy weather are both 3 days. In the middle and late August, the hot and muggy weather seldom occur. That time is a good period for holding the Olympic Games.
The characteristics, including the distribution in a month and the duration of Beijing estival muggy weather, is gained here by analyzing the daily maximum and minimum temperature in summer season(June, July and August) from 1951 to 2000. It revealed that the occurrence probabilities of the hot and muggy weather during the summer in Beijing are, respectively,1/10 and 1/20, which indicates Beijing is a suitable city for the Summer Olympic Games. The hot weather mainly occurs in late June and the whole July, with two maximum frequencies in the period of 26 to 30 June and 21 to 25 July, respectively. The muggy weather mainly occurs in the middle of July and early August, with two maximum frequencies in the period of 26-31 July and 6-10 August, respectively. There are many hot weather days but few muggy weather days in June . And there are very few hot weather days but several muggy days in August. The hot weather lasting more than 2 days occurs at least once a year. The occurrence frequencies of the hot and muggy weather lasting more than 3 days are 0.84 times/ year and 0.88 times/year respectively. The average duration of the hot and muggy weather are both 3 days. In the middle and late August, the hot and muggy weather seldom occur. That time is a good period for holding the Olympic Games.
2003, 29(9):28-33.
DOI: 10.7519/j.issn.1000-0526.2003.9.006
Abstract:
The extremely hot days during last 52 years(1951-2002) are investigated by means of statistical and wavelet analysis. The results show that extremely hot days mainly occur in the western, northern and southern Shandong province from May to August, mainly in June and July. They emerged frequently between 1950′s and the early 1970′s.In addition, the result of wavelet analysis indicates that the main period is about 4- and 10-years. The warm ridge in westerlies should be basically blamed for the most extremely hot days, and the subtropical high might play the second important role. Extremely hot day generally follows the previous hot days. And the warm center of 24℃ around Zhengzhou over 850hPa is a remarkable index for prediction of extremely hot days.
The extremely hot days during last 52 years(1951-2002) are investigated by means of statistical and wavelet analysis. The results show that extremely hot days mainly occur in the western, northern and southern Shandong province from May to August, mainly in June and July. They emerged frequently between 1950′s and the early 1970′s.In addition, the result of wavelet analysis indicates that the main period is about 4- and 10-years. The warm ridge in westerlies should be basically blamed for the most extremely hot days, and the subtropical high might play the second important role. Extremely hot day generally follows the previous hot days. And the warm center of 24℃ around Zhengzhou over 850hPa is a remarkable index for prediction of extremely hot days.
2003, 29(9):34-36.
DOI: 10.7519/j.issn.1000-0526.2003.9.007
Abstract:
The temporal-spatial distribution of drought index DH in late spring and early summer in the eastern Gansu Province is analyzed by EOF. The effect of drought on output of winter wheat and corn is also analyzed. Finally, a forecast model of drought index is developed with stepwise regression and it has better forecast results.
The temporal-spatial distribution of drought index DH in late spring and early summer in the eastern Gansu Province is analyzed by EOF. The effect of drought on output of winter wheat and corn is also analyzed. Finally, a forecast model of drought index is developed with stepwise regression and it has better forecast results.
2003, 29(9):37-41.
DOI: 10.7519/j.issn.1000-0526.2003.9.008
Abstract:
Based on the EOF analysis of summer precipitation of eight stations in the middle and lower reaches of the Changjiang River from 1961 to 2000, four patterns are named according to the first three eigenvectors. Moreover, the 500 hPa height departure in the same and preceding months are analyzed. Some useful relations for the summer precipitation prediction are obtained.
Based on the EOF analysis of summer precipitation of eight stations in the middle and lower reaches of the Changjiang River from 1961 to 2000, four patterns are named according to the first three eigenvectors. Moreover, the 500 hPa height departure in the same and preceding months are analyzed. Some useful relations for the summer precipitation prediction are obtained.
2003, 29(9):42-46.
DOI: 10.7519/j.issn.1000-0526.2003.9.009
Abstract:
Based on the date of the West Pacific Ocean subtropical high ridge carried to 25° N and monthly mean OLR data, the index of the subtropical high ridge and anomalous years are defined. And OLR features of the anomalous years are revealed. The results are as follows: (1) when OLR anomaly arranges in low( high ), high( low ), low( high ) on June in East Asia from middle latitude to low latitude,it is easy that subtropical high ridge carried to 25°N early( late ) than normal. (2) when diagnosis and analysis are being made, particular attention should be paid both to the last November information of Australia in Southern Hemisphere and to the current March information of convergence region over West Pacific Ocean.
Based on the date of the West Pacific Ocean subtropical high ridge carried to 25° N and monthly mean OLR data, the index of the subtropical high ridge and anomalous years are defined. And OLR features of the anomalous years are revealed. The results are as follows: (1) when OLR anomaly arranges in low( high ), high( low ), low( high ) on June in East Asia from middle latitude to low latitude,it is easy that subtropical high ridge carried to 25°N early( late ) than normal. (2) when diagnosis and analysis are being made, particular attention should be paid both to the last November information of Australia in Southern Hemisphere and to the current March information of convergence region over West Pacific Ocean.
2003, 29(9):47-49.
DOI: 10.7519/j.issn.1000-0526.2003.09.010
Abstract:
The severe tropical storm "Kammuri" brought severe disaster to southern Fujian and eastern Guangdong.Based on the synoptic situation,T213 numerical weather prediction product and local meteorological data,the severe tropical storm "Kammuri" are analyzed synthetically.The results indicate that the adjustment of steering flow and the air pumping action of upper divergence field resulted in the storm strengthening and the path changing.The conditions that the torrential rain took place and sustained at the tail of "Kammuri" include the low-level south-west jet stream,the continuous water vapor transportation,the strong upward vertical movement,and the extreme instability of atmospheric stratification.
The severe tropical storm "Kammuri" brought severe disaster to southern Fujian and eastern Guangdong.Based on the synoptic situation,T213 numerical weather prediction product and local meteorological data,the severe tropical storm "Kammuri" are analyzed synthetically.The results indicate that the adjustment of steering flow and the air pumping action of upper divergence field resulted in the storm strengthening and the path changing.The conditions that the torrential rain took place and sustained at the tail of "Kammuri" include the low-level south-west jet stream,the continuous water vapor transportation,the strong upward vertical movement,and the extreme instability of atmospheric stratification.
2003, 29(9):50-53.
DOI: 10.7519/j.issn.1000-0526.2003.9.011
Abstract:
Based on the proportion of monthly solar ultraviolet radiation and the total solar radiation in Lhasa and the climatological calculating method of solar radiation, a set of ultraviolet statistics-forecast method is proposed and verified by observation. The result shows that the method has fairly adaptability and accuracy.
Based on the proportion of monthly solar ultraviolet radiation and the total solar radiation in Lhasa and the climatological calculating method of solar radiation, a set of ultraviolet statistics-forecast method is proposed and verified by observation. The result shows that the method has fairly adaptability and accuracy.
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ISSN:1000-0526 CN:11-2282/P