Volume 33,Issue 1,2005 Table of Contents
2005, 33(1):1-6.
Abstract:
Recent progress in researches on tropical cyclone (TC) intensity and structure changes is reviewed. According to the maximum potential intensity (MPI) theory, at the given thermodynamic state of the atmosphere and ocean, there exists MPI. In fact, tropical cyclones' maximum intensity is generally less than that of MPI theory. There are many internal and external dynamic factors to prohibit TC intensification through structure changes. The changes of intensity and structure involve complex different-scale interactions. The recent researches show that the mesoscale processes resulting in TC asymmetry are crucial to the variation of both intensities and structures of TCs, including vortex Rossby waves, spiral rainbands, mesoscale vortices, environmental flow, and boundary layer processes. The external environment flow also influences the intensities and structures of TCs through these mesoscale processes over the eyewalls
Recent progress in researches on tropical cyclone (TC) intensity and structure changes is reviewed. According to the maximum potential intensity (MPI) theory, at the given thermodynamic state of the atmosphere and ocean, there exists MPI. In fact, tropical cyclones' maximum intensity is generally less than that of MPI theory. There are many internal and external dynamic factors to prohibit TC intensification through structure changes. The changes of intensity and structure involve complex different-scale interactions. The recent researches show that the mesoscale processes resulting in TC asymmetry are crucial to the variation of both intensities and structures of TCs, including vortex Rossby waves, spiral rainbands, mesoscale vortices, environmental flow, and boundary layer processes. The external environment flow also influences the intensities and structures of TCs through these mesoscale processes over the eyewalls
2005, 33(1):7.
Abstract:
Helicity denotes the conjunct intensity of rotation and the movement along the rotation, and it is conservative in isentropic fluid. Helicity is the basic physical pattern for the maintenance of atmospheric activities. Boundary layer fluids, turbulences, severe storms and tropical cyclones are highly helical in their structures. Severe storms often occur in highly helical environments. The stability of fluid is closely associated with helicity. High helicity prevents transient energy from leaping to other energy classes, thus has great importance for the maintenance of supercell. Z-helicity is a good indicator of heavy rainfall. The relative helicity of a storm has great importance in the evolution of the storm. The occurrence of a meso-cyclone is highly depended on the value of helicity. The relative helicity of a storm is also a good indicator of hail occurrence. It is difficult for the application of relative storm helicity in predicting storms for the uncertainty of storm velocity. There exists inherent relationship between atmospheric temperature and helicity, and the surface relative helicity can be used to measure the temperature advection caused by geostrophic flow.
Helicity denotes the conjunct intensity of rotation and the movement along the rotation, and it is conservative in isentropic fluid. Helicity is the basic physical pattern for the maintenance of atmospheric activities. Boundary layer fluids, turbulences, severe storms and tropical cyclones are highly helical in their structures. Severe storms often occur in highly helical environments. The stability of fluid is closely associated with helicity. High helicity prevents transient energy from leaping to other energy classes, thus has great importance for the maintenance of supercell. Z-helicity is a good indicator of heavy rainfall. The relative helicity of a storm has great importance in the evolution of the storm. The occurrence of a meso-cyclone is highly depended on the value of helicity. The relative helicity of a storm is also a good indicator of hail occurrence. It is difficult for the application of relative storm helicity in predicting storms for the uncertainty of storm velocity. There exists inherent relationship between atmospheric temperature and helicity, and the surface relative helicity can be used to measure the temperature advection caused by geostrophic flow.
3 Area Rainfall Forecast Method and Its Error Analysis Based on T213 Products and Water-Vapor Budget
2005, 33(1):12-16.
Abstract:
Based on T213 numerical prediction products and the equation of water-vapor budget, the method of predicting rainfall areas and their intensity is introduced. The area rainfall prediction in 6 hours was made. The method was applied in the flood season along the Huaihe River in 2003. The error analysis was made between prediction and observation. The results indicate that the method is useful and reliable.
Based on T213 numerical prediction products and the equation of water-vapor budget, the method of predicting rainfall areas and their intensity is introduced. The area rainfall prediction in 6 hours was made. The method was applied in the flood season along the Huaihe River in 2003. The error analysis was made between prediction and observation. The results indicate that the method is useful and reliable.
2005, 33(1):17-21.
Abstract:
In order to improve the single-station precipitation forecast accuracy, a case study was conducted on a strong precipitation event on 19 July 2003 in Hubei Province. Through diagnostic analysis, the causes of circulation formation were discussed. The results show that it was a typical large-scale heavy rain process resulted from a mid-latitude barocline system, and its formation mechanism can be explained by the quasi-geostrophic theory. For strong precipitation forecast, especially severe heavy rainfall forecasts within or at the edge of the raining area, secondary circulation must be diagnosed and analyzed. Only when the conditions of the secondary circulation are met, heavy rainfall will occur; or else there will be an absent forecast.
In order to improve the single-station precipitation forecast accuracy, a case study was conducted on a strong precipitation event on 19 July 2003 in Hubei Province. Through diagnostic analysis, the causes of circulation formation were discussed. The results show that it was a typical large-scale heavy rain process resulted from a mid-latitude barocline system, and its formation mechanism can be explained by the quasi-geostrophic theory. For strong precipitation forecast, especially severe heavy rainfall forecasts within or at the edge of the raining area, secondary circulation must be diagnosed and analyzed. Only when the conditions of the secondary circulation are met, heavy rainfall will occur; or else there will be an absent forecast.
2005, 33(1):22-24.
Abstract:
The commensurability indicates a certain order existing in natural phenomena. The commensurability (approximate periodicity) is the expansion of periodicity. In order to forecast the occurrence year of a landing typhoon in Zhejiang, a commensurable formula of three elements was used in arrangement and calculation. Thus the commensurable formula for several years in the future can be given, and the occurrence year of a landing typhoon can be judged according to the peak value of frequency of the commensurable formula. The long-term change process of a landing typhoon can be forecasted and analyzed by means of the principle and method of commensurability. The result is relatively good and is of practical significance for typhoon prevention and disaster reduction along the coast regions. Being able to reveal the interrelation of natural phenomena, the method has broad prospects in application.
The commensurability indicates a certain order existing in natural phenomena. The commensurability (approximate periodicity) is the expansion of periodicity. In order to forecast the occurrence year of a landing typhoon in Zhejiang, a commensurable formula of three elements was used in arrangement and calculation. Thus the commensurable formula for several years in the future can be given, and the occurrence year of a landing typhoon can be judged according to the peak value of frequency of the commensurable formula. The long-term change process of a landing typhoon can be forecasted and analyzed by means of the principle and method of commensurability. The result is relatively good and is of practical significance for typhoon prevention and disaster reduction along the coast regions. Being able to reveal the interrelation of natural phenomena, the method has broad prospects in application.
2005, 33(1):25-31.
Abstract:
A dust storm forecasting experiment was conducted with a dust storm integrated forecasting system in the spring of 2002. The system includes a regional atmospheric model, a land-surface model, a wind erosion model, and a dust transport and deposition model. Geographic information data, such as soil type, vegetation height, fractional vegetation cover and leaf-area index, were used in the integrated forecasting system. By means of the numerical products of the integrated forecasting system, two case studies were conducted through analyzing sand flux, dust flux, vertically integrated mass, and so on. The results were compared with surface observation data and satellite images. The test results show that the system is feasible as a dust storm operational model.
A dust storm forecasting experiment was conducted with a dust storm integrated forecasting system in the spring of 2002. The system includes a regional atmospheric model, a land-surface model, a wind erosion model, and a dust transport and deposition model. Geographic information data, such as soil type, vegetation height, fractional vegetation cover and leaf-area index, were used in the integrated forecasting system. By means of the numerical products of the integrated forecasting system, two case studies were conducted through analyzing sand flux, dust flux, vertically integrated mass, and so on. The results were compared with surface observation data and satellite images. The test results show that the system is feasible as a dust storm operational model.
2005, 33(1):32-36.
Abstract:
應用EOF—CCA方法對福建省前汛期(5～6月)降水量場進行試預測，預測因子選取關鍵區海溫場及13項物理量場，降水量場為35個地面氣象站降水資料。采用3種方案進行試預測，分別以關鍵區海溫場為因子，13項物理量場為因子，或兩者相結合。通過5年的獨立樣本預測檢驗表明，3種方案對福建省前汛期降水量場進行短期氣候預測均有一定的預報技巧，預報時效最佳的時期是前一年的11、12月分，以關鍵區海溫為因子的預測效果最好，12月份關鍵區海溫結合13項物理量場為因子預測穩定性最好，可用于日常預測業務中。
應用EOF—CCA方法對福建省前汛期(5～6月)降水量場進行試預測，預測因子選取關鍵區海溫場及13項物理量場，降水量場為35個地面氣象站降水資料。采用3種方案進行試預測，分別以關鍵區海溫場為因子，13項物理量場為因子，或兩者相結合。通過5年的獨立樣本預測檢驗表明，3種方案對福建省前汛期降水量場進行短期氣候預測均有一定的預報技巧，預報時效最佳的時期是前一年的11、12月分，以關鍵區海溫為因子的預測效果最好，12月份關鍵區海溫結合13項物理量場為因子預測穩定性最好，可用于日常預測業務中。
2005, 33(1):37.
Abstract:
Brief introduction of wavelet analysis and its application in atmospheric science is presented and the periodicity of 41 years (1960 to 2000) in the Chongqing precipitation time series (single station data) was diagnosed by the means of one-dimension Morlet wavelet transformation. The results show that there exists an obvious quasi 18-year period oscillation in Chongqing rainfall and less pronounced periods of 11, 3-5 and 8 years. It is found that the zero points of Morlet wavelet transformation coefficients correspond with the inflexions of the 40-year precipitation variation in Chongqing, and the zero-point positions of the of Morlet wavelet transformation coefficients correspond with the positions of the abrupt change points of the precipitation variation in Chongqing. Either over a large time scale or small scale, for summer and annual precipitation variations, Chongqing was in an obviously more-than-normal period, while for autumn precipitation, in an obviously less-than-normal period.
Brief introduction of wavelet analysis and its application in atmospheric science is presented and the periodicity of 41 years (1960 to 2000) in the Chongqing precipitation time series (single station data) was diagnosed by the means of one-dimension Morlet wavelet transformation. The results show that there exists an obvious quasi 18-year period oscillation in Chongqing rainfall and less pronounced periods of 11, 3-5 and 8 years. It is found that the zero points of Morlet wavelet transformation coefficients correspond with the inflexions of the 40-year precipitation variation in Chongqing, and the zero-point positions of the of Morlet wavelet transformation coefficients correspond with the positions of the abrupt change points of the precipitation variation in Chongqing. Either over a large time scale or small scale, for summer and annual precipitation variations, Chongqing was in an obviously more-than-normal period, while for autumn precipitation, in an obviously less-than-normal period.
2005, 33(1):41-44.
Abstract:
The characteristics of temporal and spatial distribution of hails over Yunnan Province were analyzed by using of the recent 40-year hail data, to reveal the variation regularities of hails and main influencing factors. The analysis shows that the seasonal distribution of hails was very complicated. The peak values usually occurred in spring and summer. The seasonal distribution of hails was related with elevation: generally in springtime hails happened more frequently at lower-elevation areas, and in summertime at high-elevation areas. The inter-annual change of the numbers of hailing days in the western Yunnan was more obvious than in the eastern Yunnan, while the inter-decadal change of hailing-day numbers was more obvious in the eastern Yunnan than in the western Yunnan. The numbers of hailing days in mountainous and high-elevation areas were greater than those in basin or plain areas and lower-elevation areas.
The characteristics of temporal and spatial distribution of hails over Yunnan Province were analyzed by using of the recent 40-year hail data, to reveal the variation regularities of hails and main influencing factors. The analysis shows that the seasonal distribution of hails was very complicated. The peak values usually occurred in spring and summer. The seasonal distribution of hails was related with elevation: generally in springtime hails happened more frequently at lower-elevation areas, and in summertime at high-elevation areas. The inter-annual change of the numbers of hailing days in the western Yunnan was more obvious than in the eastern Yunnan, while the inter-decadal change of hailing-day numbers was more obvious in the eastern Yunnan than in the western Yunnan. The numbers of hailing days in mountainous and high-elevation areas were greater than those in basin or plain areas and lower-elevation areas.
2005, 33(1):45.
Abstract:
By using the analyzed and 6-hour prediction data provided by the T213 model, the causes of a heavy rain and the energy and moisture conditions were analyzed. The dynamic trigger mechanism was studied through analyzing the features of helicity and Q* vectors. The result shows that the heavy rain was influenced mainly by the low vortex at 850 hPa and the surface cyclone; the convergence and ascending motion in the center of the vortex and north of the cyclone center triggered convective instability energy release, resulting in the heavy rain. The low-level Southwest Jet provided sufficient moisture and instability energy. The strong positive helicity and the intensive convergence of Q* vectors at the low level in the raining area indicate that there was superposition of mesoscale and synoptic-scale ascending motions. Differing from summer heavy rains, the systems in the westerly belt played a dominant role in spring heavy rain formation, but the subtropical systems are weaker and cool and warm air motions were very active before and after the heavy rain.
By using the analyzed and 6-hour prediction data provided by the T213 model, the causes of a heavy rain and the energy and moisture conditions were analyzed. The dynamic trigger mechanism was studied through analyzing the features of helicity and Q* vectors. The result shows that the heavy rain was influenced mainly by the low vortex at 850 hPa and the surface cyclone; the convergence and ascending motion in the center of the vortex and north of the cyclone center triggered convective instability energy release, resulting in the heavy rain. The low-level Southwest Jet provided sufficient moisture and instability energy. The strong positive helicity and the intensive convergence of Q* vectors at the low level in the raining area indicate that there was superposition of mesoscale and synoptic-scale ascending motions. Differing from summer heavy rains, the systems in the westerly belt played a dominant role in spring heavy rain formation, but the subtropical systems are weaker and cool and warm air motions were very active before and after the heavy rain.
2005, 33(1):50-52.
Abstract:
Through comparing forecast with observation, a forecasting failure is analyzed. On the basis of the analysis of the numerical forecasts and the meteorology elements, the predicting thoughts of the forecasters then are discussed. It is pointed out that the main physical mechanism inducing the sudden change of the weather system is the southward moving of the northwestly jet over the central Asia at 300 hPa. The changing high-level trough from backward to forward was unfavorable for the upward air motion. With the real time data, the reasons for forecasting failure are analyzed. The unexpected evolvement of the high level trough and the underestimated changing of the low-level path of the cold air as well as the amount of warm air are the main reasons for the forecast failure.
Through comparing forecast with observation, a forecasting failure is analyzed. On the basis of the analysis of the numerical forecasts and the meteorology elements, the predicting thoughts of the forecasters then are discussed. It is pointed out that the main physical mechanism inducing the sudden change of the weather system is the southward moving of the northwestly jet over the central Asia at 300 hPa. The changing high-level trough from backward to forward was unfavorable for the upward air motion. With the real time data, the reasons for forecasting failure are analyzed. The unexpected evolvement of the high level trough and the underestimated changing of the low-level path of the cold air as well as the amount of warm air are the main reasons for the forecast failure.
2005, 33(1):53-57.
Abstract:
通過對河西走廊1971～2000年3～5月大風和沙塵暴個例普查，運用相關法分析了河西走廊大風和沙塵暴天氣在時間上的分布差異和沙塵暴與沙源地區前期降水的關系，同時對“起沙風”也作了初步探討，結果表明：河西走廊地區在10min平均風速大于等于9m／s時，極易起沙；河西走廊的西部、中部、東部分別在南疆中東部、南疆東部內蒙西部河西西部、內蒙中西部出現5～8mm降水后5天才有可能出現沙塵暴。文中給出了河西走廊大風沙塵暴的幾種典型環流形勢及每一種環流形勢可引發沙塵暴的預報著眼點。
通過對河西走廊1971～2000年3～5月大風和沙塵暴個例普查，運用相關法分析了河西走廊大風和沙塵暴天氣在時間上的分布差異和沙塵暴與沙源地區前期降水的關系，同時對“起沙風”也作了初步探討，結果表明：河西走廊地區在10min平均風速大于等于9m／s時，極易起沙；河西走廊的西部、中部、東部分別在南疆中東部、南疆東部內蒙西部河西西部、內蒙中西部出現5～8mm降水后5天才有可能出現沙塵暴。文中給出了河西走廊大風沙塵暴的幾種典型環流形勢及每一種環流形勢可引發沙塵暴的預報著眼點。
2005, 33(1):58-62.
Abstract:
An analysis was made of observed data around the Qinghai Lake from 1961 to 2000, and the results show that the climatic tendencies of the annual and seasonal air temperature and surface evaporation and summer and winter precipitation change were all positive, while the climatic tendencies of spring and autumn precipitation change were negative. The tendencies of temperature rising and surface evaporation increasing were more significant, while the tendency of precipitation increasing was less obvious and its inter-annual change was slightly greater. The meteorological factors such as air temperature and surface evaporation shows the tendency of transiting toward warm and dry, which is the main cause of the falling water level of the Qinghai Lake.
An analysis was made of observed data around the Qinghai Lake from 1961 to 2000, and the results show that the climatic tendencies of the annual and seasonal air temperature and surface evaporation and summer and winter precipitation change were all positive, while the climatic tendencies of spring and autumn precipitation change were negative. The tendencies of temperature rising and surface evaporation increasing were more significant, while the tendency of precipitation increasing was less obvious and its inter-annual change was slightly greater. The meteorological factors such as air temperature and surface evaporation shows the tendency of transiting toward warm and dry, which is the main cause of the falling water level of the Qinghai Lake.
2005, 33(1):63-67.
Abstract:
On the basis of meteorological data from 1965 to 2001 around the Hunshandake sandy land, the characteristics of main climatic factors and their temporal and spatial variation regularities are analyzed. The research results indicate: there are obvious differences in main climatic factors along longitudes and less obvious along latitudes in the Hunshandake sandy land; from 1965 to 2001 in the most parts of the Hunshandake sandy land, the mean annual and seasonal temperatures had an evidently increasing tendency, and the mean annual wind velocity had an evidently decreasing tendency, especially in the spring; in the main part of the sandy land, the changing tendencies of annual and seasonal precipitation were not very clear, while there were slowly increasing tendencies in the annual dry/wet index, and not very clearly decreasing tendencies in annual evaporation.
On the basis of meteorological data from 1965 to 2001 around the Hunshandake sandy land, the characteristics of main climatic factors and their temporal and spatial variation regularities are analyzed. The research results indicate: there are obvious differences in main climatic factors along longitudes and less obvious along latitudes in the Hunshandake sandy land; from 1965 to 2001 in the most parts of the Hunshandake sandy land, the mean annual and seasonal temperatures had an evidently increasing tendency, and the mean annual wind velocity had an evidently decreasing tendency, especially in the spring; in the main part of the sandy land, the changing tendencies of annual and seasonal precipitation were not very clear, while there were slowly increasing tendencies in the annual dry/wet index, and not very clearly decreasing tendencies in annual evaporation.
2005, 33(1):68-72.
Abstract:
Based on winter wheat and summer corn growth regularities in Henan Province and application experiences in optimal irrigation techniques for winter wheat, as well as observed soil moisture data for winter wheat and summer corn from 1994 to 2000, a computer model of soil water prediction and optimal irrigation of winter wheat and summer corn was set up according to the soil water balance equation. The model results were verified by the observed data from wheat fields in Zhengzhou in 1998 and 1999. The relative errors of soil moisture for the next 10, 20, 30 days are -7.3% to 7.7%, -8.3% to 6.8%,-7.6% to 7.7%, respectively. It indicates that soil water can be predicted in one month ahead accurately with this model. Some irrigation suggestions with respect to different wheat and corn growth phases are given, aiming to obtain the maximum yield and the optimal economic benefits.
Based on winter wheat and summer corn growth regularities in Henan Province and application experiences in optimal irrigation techniques for winter wheat, as well as observed soil moisture data for winter wheat and summer corn from 1994 to 2000, a computer model of soil water prediction and optimal irrigation of winter wheat and summer corn was set up according to the soil water balance equation. The model results were verified by the observed data from wheat fields in Zhengzhou in 1998 and 1999. The relative errors of soil moisture for the next 10, 20, 30 days are -7.3% to 7.7%, -8.3% to 6.8%,-7.6% to 7.7%, respectively. It indicates that soil water can be predicted in one month ahead accurately with this model. Some irrigation suggestions with respect to different wheat and corn growth phases are given, aiming to obtain the maximum yield and the optimal economic benefits.
16 Impact of Climate Change and Natural Disasters on Grain Yields in Shandong Province in Past 40 Years
2005, 33(1):73.
Abstract:
根據山東省196l～2000年氣象與糧食產量資料，利用統計分析方法，分析了氣候變化、農業自然災害對糧食產量的影響。研究表明：①20世紀60年代以來，山東省氣候有變暖和變干的趨勢，各季節中，變暖趨勢最明顯的是冬季，變干表現最突出的是夏季；②氣溫和降水是造成山東省糧食產量波動的主要原因，在“暖干”氣候背景下，氣溫與氣候產量為負相關，降水量與氣候產量呈較顯著的正相關；③農業自然災害是造成糧食單產產生波動的主要原因之一。
根據山東省196l～2000年氣象與糧食產量資料，利用統計分析方法，分析了氣候變化、農業自然災害對糧食產量的影響。研究表明：①20世紀60年代以來，山東省氣候有變暖和變干的趨勢，各季節中，變暖趨勢最明顯的是冬季，變干表現最突出的是夏季；②氣溫和降水是造成山東省糧食產量波動的主要原因，在“暖干”氣候背景下，氣溫與氣候產量為負相關，降水量與氣候產量呈較顯著的正相關；③農業自然災害是造成糧食單產產生波動的主要原因之一。
2005, 33(1):77-80.
Abstract:
對2002年紅肉臍橙各物候期、落花落果數等觀測資料進行了分析，結果表明：紅肉臍橙春梢的生長量隨積溫的增加而增加，生長曲線符合指數規律。生理落花落果時間在4月30日至6月10日之間，著果率1．59％。果實膨大停止并達到商品成熟期為12月中下旬，成熟時間比國內最優臍橙紐荷爾晚30余天，大于等于10℃的積溫5685．5℃，降雨量1039．9mm，日照時數1416．9h，豐產性能好。生理落果期平均溫度22．6℃，平均相對濕度73％．落果率86．9％；平均溫度21．1℃，平均相對濕度82％，落果率96．9％。
對2002年紅肉臍橙各物候期、落花落果數等觀測資料進行了分析，結果表明：紅肉臍橙春梢的生長量隨積溫的增加而增加，生長曲線符合指數規律。生理落花落果時間在4月30日至6月10日之間，著果率1．59％。果實膨大停止并達到商品成熟期為12月中下旬，成熟時間比國內最優臍橙紐荷爾晚30余天，大于等于10℃的積溫5685．5℃，降雨量1039．9mm，日照時數1416．9h，豐產性能好。生理落果期平均溫度22．6℃，平均相對濕度73％．落果率86．9％；平均溫度21．1℃，平均相對濕度82％，落果率96．9％。
2005, 33(1):81-86.
Abstract:
綜合應用NOAA衛星AVHRR／3和FY-1極軌氣象衛星高分辨0．58～0．68μm可見光、1．58～1．64μm近紅外和10．3～11．3μm紅外多通道資料，充分考慮了云的厚度、云中粒子尺度和云頂亮溫的信息，給出了適宜飛機增雨作業云層的衛星遙感判據，建立了云層作業條件分析模型。實際應用表明，衛星遙感分析圖可以有效地監測、判識和分析云層的增雨作業條件，應用效果好，可作為飛機增雨航線設計、作業決策的重要依據。通過增雨個例的微波圖像特征分析，初步分析了AMSU—B微波圖像在人工增雨作業中的作用和應用前景。
綜合應用NOAA衛星AVHRR／3和FY-1極軌氣象衛星高分辨0．58～0．68μm可見光、1．58～1．64μm近紅外和10．3～11．3μm紅外多通道資料，充分考慮了云的厚度、云中粒子尺度和云頂亮溫的信息，給出了適宜飛機增雨作業云層的衛星遙感判據，建立了云層作業條件分析模型。實際應用表明，衛星遙感分析圖可以有效地監測、判識和分析云層的增雨作業條件，應用效果好，可作為飛機增雨航線設計、作業決策的重要依據。通過增雨個例的微波圖像特征分析，初步分析了AMSU—B微波圖像在人工增雨作業中的作用和應用前景。
2005, 33(1):87-90.
Abstract:
統計分析了陜西中北部1991～2001年4個711雷達站附近15個氣候觀測站日降雨量大于等于5mm降水過程的時空分布及雷達回波特征。陜西中部適宜人工增雨的時段為2月10日至11月15日，北部為2月25日至11月10日。陜西降雨性層狀云0℃層高度變化范圍為3．63～5．03km，平均高度為4．65km，融化層強回波區厚度為0．4～1．0km。冷云、暖云降雪(雨)量級較小，不適宜大范圍開展人工增雪(雨)作業。適宜人工增雨的穩定性層狀云雷達回波特征為：PPI回波結構密實，范圍大于30km，雷達回波強度大于等于30dBz，RHI顯示云頂高度大于等于5．8km或者融化層明顯，強度達30dBz以上。適宜人工增雨的混合性層狀云雷達回波特征為：PPI有明顯強回波中心，強度大于等于30dBz，15dB回波寬度大于等于25km，回波最大高度大于等于5km；或者融化層明顯，雷達觀測融化層下掛回波明顯傾斜或呈鋸齒型排列。
統計分析了陜西中北部1991～2001年4個711雷達站附近15個氣候觀測站日降雨量大于等于5mm降水過程的時空分布及雷達回波特征。陜西中部適宜人工增雨的時段為2月10日至11月15日，北部為2月25日至11月10日。陜西降雨性層狀云0℃層高度變化范圍為3．63～5．03km，平均高度為4．65km，融化層強回波區厚度為0．4～1．0km。冷云、暖云降雪(雨)量級較小，不適宜大范圍開展人工增雪(雨)作業。適宜人工增雨的穩定性層狀云雷達回波特征為：PPI回波結構密實，范圍大于30km，雷達回波強度大于等于30dBz，RHI顯示云頂高度大于等于5．8km或者融化層明顯，強度達30dBz以上。適宜人工增雨的混合性層狀云雷達回波特征為：PPI有明顯強回波中心，強度大于等于30dBz，15dB回波寬度大于等于25km，回波最大高度大于等于5km；或者融化層明顯，雷達觀測融化層下掛回波明顯傾斜或呈鋸齒型排列。
2005, 33(1):91-95.
Abstract:
After 15-year study, as the core program of the global change research, IGBP is evolving into the second phase. The advancement of IGBP is described, including the study of key processes in the earth system and the cross-program synthesis study. In future, the research directions of IGBP will change greatly: the synthesis study will be up to a higher level, adapt to the study of the global sustainable development,and realize the conversion from the academic study to practical application and the integration of global problems with the regional problems. Moreover, according to the structure of the earth system, the key issues of relative programs in future and the progress and prospects of IGBP researches in China are discussed.
After 15-year study, as the core program of the global change research, IGBP is evolving into the second phase. The advancement of IGBP is described, including the study of key processes in the earth system and the cross-program synthesis study. In future, the research directions of IGBP will change greatly: the synthesis study will be up to a higher level, adapt to the study of the global sustainable development,and realize the conversion from the academic study to practical application and the integration of global problems with the regional problems. Moreover, according to the structure of the earth system, the key issues of relative programs in future and the progress and prospects of IGBP researches in China are discussed.
2005, 33(1):96.
Abstract:
MTSAT衛星系列是日本運輸省和日本氣象廳合作投資的多功能(氣象觀測和飛行控制)衛星。第1顆衛星MTSAT-1在1999年11月發射，但由于火箭故障，星箭具毀，之后重新生產了MTSAT-1R，由于等待火箭的故障排除及改進，發射時間一再推延，直到2005年2月26日才發射，發射成功后約2～3個月播發圖像。
MTSAT衛星系列是日本運輸省和日本氣象廳合作投資的多功能(氣象觀測和飛行控制)衛星。第1顆衛星MTSAT-1在1999年11月發射，但由于火箭故障，星箭具毀，之后重新生產了MTSAT-1R，由于等待火箭的故障排除及改進，發射時間一再推延，直到2005年2月26日才發射，發射成功后約2～3個月播發圖像。
External LinksChina Meteorological AdministrationCMA Meteorological Observation CentreChinese Academy of Meteorological SciencesBeijing Meteorological ServiceNational Satellite Meteorological Center
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Supported by:Beijing E-Tiller Technology Development Co., Ltd.
Supported by:Beijing E-Tiller Technology Development Co., Ltd.