Years Significant EventsTC Chair/Vice Chair1968UN ESCAP at its 24th Session at Canberra in April 1968,WMO Executive Committee at its 20th Session in 1968 endorsed the establishment of the Typhoon Committee in accordan...Years Significant EventsTC Chair/Vice Chair1968UN ESCAP at its 24th Session at Canberra in April 1968,WMO Executive Committee at its 20th Session in 1968 endorsed the establishment of the Typhoon Committee in accordance with the Statute.The Typhoon Committee was organized by the Governments of China;Hong Kong,China;Japan;Republic of Korea;Laos;the Philippines and Thailand as 7 founder Members,with ESCAP and WMO as ex-officio Members.Vice-Adm Sanit Vesa Rajananda,Thailand/Dr.Roman L.Kintanar Philippines.展开更多
This paper reviews the major achievements of the Working Group on Meteorology(WGM) of ESCAP/WMO Typhoon Committee since its establishment in 2004, especially in tropical cyclone observational research and scientific e...This paper reviews the major achievements of the Working Group on Meteorology(WGM) of ESCAP/WMO Typhoon Committee since its establishment in 2004, especially in tropical cyclone observational research and scientific experiments, tropical cyclone monitoring and forecasting technologies, seasonal prediction and climate change assessment for the past decade. The progress illustrates the great value of the Committee and WGM in monitoring and forecasting of tropical cyclones in the region and the improvement of disaster prevention and reduction capabilities.展开更多
Hydrological Component has been one of three essential parts of ESCAP/WMO Typhoon Committee.The Working Group on Hydrology(WGH)established at TC 33rd Session in 2000 is the first working group among three basic compon...Hydrological Component has been one of three essential parts of ESCAP/WMO Typhoon Committee.The Working Group on Hydrology(WGH)established at TC 33rd Session in 2000 is the first working group among three basic components of the Committee,which has been repeatedly recognized as the most active component in the Committee who has integrated conducted successfully a number of cooperation projects and integrated actions among Members.In the past decade,WGH has implemented wide range activities under the framework of Strategic Plan of the Committee.The achievement of those cooperation projects played very important roles in promoting the capacity building on hydrological monitoring,forecasting and early warning among Members.This paper introduced the Term of Reference for WGH and its high priorities,and summarized the activities conducted in recent decade.The paper also reviewed the progresses in TC Members on hydrological observation and monitoring network,hydrological data collection and transmission,hydrological information and forecasting,and establishment of flood forecasting system.The paper also pointed out the development direction and the area to be enhanced for hydrological component in future,including:(1)application of QPE/QPF in flood forecasting and establishment of the coupled hydro-meteorological modeling;(2)development of impact-based,risk-based and community-based flood forecasting and warning system,including storm surge,urban flood,sediment disaster(flash flood,landslide and mudflow);and(3)application of internet of things(IOT),big data,cloud computing,and mobile internet in flood monitoring,forecasting and early warning,and better response,particularly in flood inundation mapping and QPE/QPF products application.展开更多
The ESCAP/WMO Typhoon Committee(TC) is an intergovernmental regional organization, established by Governments of ESCAP Member Countries(or Member Territory) under the joint auspices of ESCAP and WMO in 1968 to minimiz...The ESCAP/WMO Typhoon Committee(TC) is an intergovernmental regional organization, established by Governments of ESCAP Member Countries(or Member Territory) under the joint auspices of ESCAP and WMO in 1968 to minimize the typhoon-related disaster risk reduction and damage mitigation in the region and to facilities closer regional and international cooperation. As of 2017, there are 14 Members. The Typhoon Committee has been repeatedly recognized as an outstanding regional body who has integrated the actions and plans of the meteorological, hydrological, and disaster risk reduction(DRR) components to produce meaningful results. Its work is primarily centered on reduction the damage caused by typhoons and floods, and focus on the following: 1) review the progress made in the various fields of typhoon damage prevention; 2) recommend the participating governments on plans and measures the improvement of community preparedness and disaster prevention; 3) promote the interested Governments and other interested organization for the coordination of research on typhoons; and 4) provide financial and technical support for plans and programs upon request. The paper reviewed the development of the Committee in the past 50 years in the aspects of establishment; membership, secretariat and programme components; strategic plan; and cooperative mechanism. The paper also states the areas of technical activities to be enhanced in the region and the proposals to enhance the Typhoon Committee's regional and international collaboration mechanism on typhoon-related disaster risk reduction and damage mitigation.展开更多
The inter-annual variability of rainfall onset and crop replanting in East Africa (EA) was assessed using daily estimated rainfall data from climate hazard group infrared precipitation (CHIRPS Ver2.0) and monthly Sea ...The inter-annual variability of rainfall onset and crop replanting in East Africa (EA) was assessed using daily estimated rainfall data from climate hazard group infrared precipitation (CHIRPS Ver2.0) and monthly Sea Surface Temperature (SST) indices [Indian Ocean Dipole (IOD) and El-Ni?o Southern Oscillation (ENSO) at NINO3.4 region] from the National Center for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR). The data covered a period of 40 years from1981 to 2020. The methods of cumulative of daily mean rainfall, percentage of onset date departure (PODD), Mann-Kendall (MK) trend test, student t-test, and correlation were applied in the analysis. The results showed that early onset with dry spell (WDS) consideration frequently occurs in Uganda between the first and second dekads of September, while late rainfall onset WDS occurs in the first and second dekads of December over central and Northern Kenya as well as in the Northeastern highlands, parts of the northern coast and unimodal regions in Tanzania. Rainfall onset with no dry spell (WnDS) portrayed an average of 10 days before the occurrence of true onset WDS, with maximum onset departure days (ODD) above 30 days across the Rift Valley area in Kenya and the Northeastern highlands in Tanzania. The high chance of minimum ODD is seen over entire Uganda and the area around Lake Victoria. However, few regions, such as Nakuru (Kenya) Gulu and Kibale (Uganda), and Gitega (Burundi), revealed a slight positive linear trend while others showed negative trend. Significant positive patterns for correlation between onset WDS and SST indices (IOD and NINO 3.4) were discovered in Northern and Northeastern Kenya, as well as areas along the Indian Ocean (over Tanzania’s Northern Coast). Inter-annual relationship between onset dates WDS and IOD (NINO3.4) indices exhibits a high correlation coefficient r = 0.23 (r = 0.48) in Uganda and r = 0.44 (r = 0.36) in Kenya. On the other hand, a negative correlation was revealed over Burundi and Tanzania (over a unimodal region). A high percentage of PODD was observed, ranging from 40% to 70% over the Rift Valley in Kenya and at the Northeastern highlands in Tanzania. However, a strong PODD above 70% was observed over Tanga and the Northern Pwani Region in Tanzania. These findings will help farmers to understand the appropriate time for crop planting, as well as help other socio-economic activities that strongly depend on rainfall.展开更多
NCEP GFS(Global Forecast System)analytical data(available 4 times per day),satellite cloud image data and real-time observations of path and intensity of Typhoon Morakot are employed to investigate the variation of sy...NCEP GFS(Global Forecast System)analytical data(available 4 times per day),satellite cloud image data and real-time observations of path and intensity of Typhoon Morakot are employed to investigate the variation of synoptic dynamics in its intensity and structure before and after the landing.This study intends to offer some hints for the forecast of intensity and structure of typhoons.Results show that in the tangential direction,the averaged asymmetry amplitude of wind on the radius of a large-value center of the low-level wind can be used as an important parameter for diagnosing the intensity of typhoons.Besides,the maximum of the upper dry potential vorticity in Morakot’s center tends to extend downward along the intensive gradient of tangential wind situated on the inner side of a large-value center of the low-level tangential wind.Additionally,the radial advection of the tangential wind determines the variation of tangential wind in conjunction with the vertical transmission of the tangential wind,the inertial centrifugal force and the Coriolis force.These four items are dominant in the motion equation of tangential wind based on a cylindrical coordinate without the effects of friction and turbulence.Moreover,the low-level convergence center of the typhoon has a tendency of shifting and developing along the intensive gradient of the tangential wind in the tangential direction.展开更多
Our blue planet is made of atmosphere,hydrosphere,lithosphere and biosphere,these four layers are interdependence and interaction,which effect the environment and life on the planet.In these four layers,the hydrospher...Our blue planet is made of atmosphere,hydrosphere,lithosphere and biosphere,these four layers are interdependence and interaction,which effect the environment and life on the planet.In these four layers,the hydrosphere is mainly associated with the ocean which is crucial to the human survival and development,due to the difference heat capacities be-展开更多
A regional climate model coupled with an aerosol model is employed to numerically simulate the direct climate effects of the anthropogenic aerosol emitted in South Asia and China in the East Asian summer monsoon durin...A regional climate model coupled with an aerosol model is employed to numerically simulate the direct climate effects of the anthropogenic aerosol emitted in South Asia and China in the East Asian summer monsoon during1988 to 2009.Based on the data of the numerical simulation,composite analysis and correlation analysis are used to make diagnostic study of climate dynamics.Results show that the month of maximum emission of the mean column burden of the anthropogenic aerosol in the main emission areas of South Asia is opposite in phase to that in China.Summer is the season of maximum emission amount in China,but the emission amounts are more in South Asia in spring and winter.On the whole,the mean column burden of the anthropogenic aerosol in China is relatively high compared with that in South Asia.The trend of distribution of aerosol is SW-NE in China,and Sichuan Basin is the emission center of aerosol.The effect of negative short wave radiative forcing alters the gradient of pressure between land and sea,weakening the development of East Asian summer monsoon over the northern part of Yangtze-Huaihe River Basin.We also discuss the feedback effect of East-Asian summer monsoon which is changed by the anthropogenic aerosol on the concentration and distribution of aerosol in China.展开更多
In this paper, using the daily grid data (2.5 × 2.5) of the ECMWF / WMO, we have computed respectively the three-dimensional wave activity flux in the stages of pre-onset, prevailing and post ending of Meiyu from...In this paper, using the daily grid data (2.5 × 2.5) of the ECMWF / WMO, we have computed respectively the three-dimensional wave activity flux in the stages of pre-onset, prevailing and post ending of Meiyu from 1 to 31 July 1982. The potential vorticity field is taken as the physical quantity relating the wave activity flux to the variation of the subtropical high over the Western Pacific. It is found that the three-dimensional wave activity flux is a powerful means for diagnosis of the variation of the subtropical high over the Western Pacific: The region of the subtropical high is just the confluence area of wave energy, whose changes in intensity and range decide the variation of the subtropical high. The confluence of wave energy comes from the monsoon flow in low latitudes, the Meiyu rain belts in middle latitudes and the heating fields on the eastern side of the Qinghai-Xizang Plateau. The relation between these sources and the subtropical high displays the self-adjusting mechanism among members of East-Asia summer monsoon.展开更多
Three sampling cross sections along the south path starting from the Tropics through the vapor passage in the Yunnan-Guizhou Plateau to the middle-low reaches of the Yangtze River, the north path from West China, via ...Three sampling cross sections along the south path starting from the Tropics through the vapor passage in the Yunnan-Guizhou Plateau to the middle-low reaches of the Yangtze River, the north path from West China, via North China, to Japan under the westerlies, and the plateau path from South Asia over the Himalayas to the northern Tibetan Plateau, are set up, based on the IAEA (International Atomic Energy Agency)/WMO global survey network and sampling sites on the Tibetan Plateau. The variations, and the relationship with precipitation and temperature, of the δ18 O in precipitation along the three cross sections are analyzed and compared. Along the south path, the seasonal differences of mean δ18O in precipitation are small at the stations located in the Tropics, but increase markedly from Bangkok towards the north, with the δ18O in the rainy season smaller than in,the dry season. The δ18O values in precipitation fluctuate on the whole, which shows that there are different vapor sources. Along the north path, the seasonal differences of the mean δ18O in precipitation for the stations in the west of Zhengzhou are all greater than in the east of Zhengzhou. During the cold half of the year, the mean δ18O in precipitation reaches its minimum at Urumqi with the lowest temperature due to the wide, cold high pressure over Mongolia, then increases gradually with longitude, and remains at roughly the same level at the stations eastward from Zhengzhou. During the warm half of the year, the δ18O values in precipitation are lower in the east than in the west, markedly influenced by the summer monsoon over East Asia. Along the plateau path, the mean δ18O values in precipitation in the rainy season are correspondingly high in the southern parts of the Indian subcontinent, and then decrease gradually with latitude. A sharp depletion of the stable isotopic compositions in precipitation takes place due to the very strong rainout of the stable isotopic compositions in vapor in the process of lifting over the southern slope of the Himalayas. The low level of the δ18O in precipitation is from Nyalam to the Tanggula Mountains during the rainy season, but δ18O increases persistently with increasing latitude from the Tanggula Mountains to the northern Tibetan Plateau because of the replenishment of vapor with relatively heavy stable isotopic compositions originating from the inner plateau. During the dry season, the mean δ18O values in precipitation basically decrease along the path from the south to the north. Generally, the mean δ18O in precipitation during the rainy season is lower than in the dry season for the regions controlled by the monsoons over South Asia or the plateau, and opposite for the regions without a monsoon or with a weak monsoon.展开更多
文摘Years Significant EventsTC Chair/Vice Chair1968UN ESCAP at its 24th Session at Canberra in April 1968,WMO Executive Committee at its 20th Session in 1968 endorsed the establishment of the Typhoon Committee in accordance with the Statute.The Typhoon Committee was organized by the Governments of China;Hong Kong,China;Japan;Republic of Korea;Laos;the Philippines and Thailand as 7 founder Members,with ESCAP and WMO as ex-officio Members.Vice-Adm Sanit Vesa Rajananda,Thailand/Dr.Roman L.Kintanar Philippines.
文摘This paper reviews the major achievements of the Working Group on Meteorology(WGM) of ESCAP/WMO Typhoon Committee since its establishment in 2004, especially in tropical cyclone observational research and scientific experiments, tropical cyclone monitoring and forecasting technologies, seasonal prediction and climate change assessment for the past decade. The progress illustrates the great value of the Committee and WGM in monitoring and forecasting of tropical cyclones in the region and the improvement of disaster prevention and reduction capabilities.
文摘Hydrological Component has been one of three essential parts of ESCAP/WMO Typhoon Committee.The Working Group on Hydrology(WGH)established at TC 33rd Session in 2000 is the first working group among three basic components of the Committee,which has been repeatedly recognized as the most active component in the Committee who has integrated conducted successfully a number of cooperation projects and integrated actions among Members.In the past decade,WGH has implemented wide range activities under the framework of Strategic Plan of the Committee.The achievement of those cooperation projects played very important roles in promoting the capacity building on hydrological monitoring,forecasting and early warning among Members.This paper introduced the Term of Reference for WGH and its high priorities,and summarized the activities conducted in recent decade.The paper also reviewed the progresses in TC Members on hydrological observation and monitoring network,hydrological data collection and transmission,hydrological information and forecasting,and establishment of flood forecasting system.The paper also pointed out the development direction and the area to be enhanced for hydrological component in future,including:(1)application of QPE/QPF in flood forecasting and establishment of the coupled hydro-meteorological modeling;(2)development of impact-based,risk-based and community-based flood forecasting and warning system,including storm surge,urban flood,sediment disaster(flash flood,landslide and mudflow);and(3)application of internet of things(IOT),big data,cloud computing,and mobile internet in flood monitoring,forecasting and early warning,and better response,particularly in flood inundation mapping and QPE/QPF products application.
文摘The ESCAP/WMO Typhoon Committee(TC) is an intergovernmental regional organization, established by Governments of ESCAP Member Countries(or Member Territory) under the joint auspices of ESCAP and WMO in 1968 to minimize the typhoon-related disaster risk reduction and damage mitigation in the region and to facilities closer regional and international cooperation. As of 2017, there are 14 Members. The Typhoon Committee has been repeatedly recognized as an outstanding regional body who has integrated the actions and plans of the meteorological, hydrological, and disaster risk reduction(DRR) components to produce meaningful results. Its work is primarily centered on reduction the damage caused by typhoons and floods, and focus on the following: 1) review the progress made in the various fields of typhoon damage prevention; 2) recommend the participating governments on plans and measures the improvement of community preparedness and disaster prevention; 3) promote the interested Governments and other interested organization for the coordination of research on typhoons; and 4) provide financial and technical support for plans and programs upon request. The paper reviewed the development of the Committee in the past 50 years in the aspects of establishment; membership, secretariat and programme components; strategic plan; and cooperative mechanism. The paper also states the areas of technical activities to be enhanced in the region and the proposals to enhance the Typhoon Committee's regional and international collaboration mechanism on typhoon-related disaster risk reduction and damage mitigation.
文摘The inter-annual variability of rainfall onset and crop replanting in East Africa (EA) was assessed using daily estimated rainfall data from climate hazard group infrared precipitation (CHIRPS Ver2.0) and monthly Sea Surface Temperature (SST) indices [Indian Ocean Dipole (IOD) and El-Ni?o Southern Oscillation (ENSO) at NINO3.4 region] from the National Center for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR). The data covered a period of 40 years from1981 to 2020. The methods of cumulative of daily mean rainfall, percentage of onset date departure (PODD), Mann-Kendall (MK) trend test, student t-test, and correlation were applied in the analysis. The results showed that early onset with dry spell (WDS) consideration frequently occurs in Uganda between the first and second dekads of September, while late rainfall onset WDS occurs in the first and second dekads of December over central and Northern Kenya as well as in the Northeastern highlands, parts of the northern coast and unimodal regions in Tanzania. Rainfall onset with no dry spell (WnDS) portrayed an average of 10 days before the occurrence of true onset WDS, with maximum onset departure days (ODD) above 30 days across the Rift Valley area in Kenya and the Northeastern highlands in Tanzania. The high chance of minimum ODD is seen over entire Uganda and the area around Lake Victoria. However, few regions, such as Nakuru (Kenya) Gulu and Kibale (Uganda), and Gitega (Burundi), revealed a slight positive linear trend while others showed negative trend. Significant positive patterns for correlation between onset WDS and SST indices (IOD and NINO 3.4) were discovered in Northern and Northeastern Kenya, as well as areas along the Indian Ocean (over Tanzania’s Northern Coast). Inter-annual relationship between onset dates WDS and IOD (NINO3.4) indices exhibits a high correlation coefficient r = 0.23 (r = 0.48) in Uganda and r = 0.44 (r = 0.36) in Kenya. On the other hand, a negative correlation was revealed over Burundi and Tanzania (over a unimodal region). A high percentage of PODD was observed, ranging from 40% to 70% over the Rift Valley in Kenya and at the Northeastern highlands in Tanzania. However, a strong PODD above 70% was observed over Tanga and the Northern Pwani Region in Tanzania. These findings will help farmers to understand the appropriate time for crop planting, as well as help other socio-economic activities that strongly depend on rainfall.
基金Natural Fundamental Research and Development Project"973"Program(2013CB430103)National Natural Science Foundation of China(41375058)Foundation of Science&Technology Innovation Team in Jiangsu Province
文摘NCEP GFS(Global Forecast System)analytical data(available 4 times per day),satellite cloud image data and real-time observations of path and intensity of Typhoon Morakot are employed to investigate the variation of synoptic dynamics in its intensity and structure before and after the landing.This study intends to offer some hints for the forecast of intensity and structure of typhoons.Results show that in the tangential direction,the averaged asymmetry amplitude of wind on the radius of a large-value center of the low-level wind can be used as an important parameter for diagnosing the intensity of typhoons.Besides,the maximum of the upper dry potential vorticity in Morakot’s center tends to extend downward along the intensive gradient of tangential wind situated on the inner side of a large-value center of the low-level tangential wind.Additionally,the radial advection of the tangential wind determines the variation of tangential wind in conjunction with the vertical transmission of the tangential wind,the inertial centrifugal force and the Coriolis force.These four items are dominant in the motion equation of tangential wind based on a cylindrical coordinate without the effects of friction and turbulence.Moreover,the low-level convergence center of the typhoon has a tendency of shifting and developing along the intensive gradient of the tangential wind in the tangential direction.
文摘Our blue planet is made of atmosphere,hydrosphere,lithosphere and biosphere,these four layers are interdependence and interaction,which effect the environment and life on the planet.In these four layers,the hydrosphere is mainly associated with the ocean which is crucial to the human survival and development,due to the difference heat capacities be-
基金National Key Fundamental Research Development and Planning 973 Project(2011CB403405)Natural Science Foundation of China(41075039+2 种基金41175065)Specialized Project of Public Welfare Industries(GYHY200806009)"Qing-lan"Project of Jiangsu Province(2009)
文摘A regional climate model coupled with an aerosol model is employed to numerically simulate the direct climate effects of the anthropogenic aerosol emitted in South Asia and China in the East Asian summer monsoon during1988 to 2009.Based on the data of the numerical simulation,composite analysis and correlation analysis are used to make diagnostic study of climate dynamics.Results show that the month of maximum emission of the mean column burden of the anthropogenic aerosol in the main emission areas of South Asia is opposite in phase to that in China.Summer is the season of maximum emission amount in China,but the emission amounts are more in South Asia in spring and winter.On the whole,the mean column burden of the anthropogenic aerosol in China is relatively high compared with that in South Asia.The trend of distribution of aerosol is SW-NE in China,and Sichuan Basin is the emission center of aerosol.The effect of negative short wave radiative forcing alters the gradient of pressure between land and sea,weakening the development of East Asian summer monsoon over the northern part of Yangtze-Huaihe River Basin.We also discuss the feedback effect of East-Asian summer monsoon which is changed by the anthropogenic aerosol on the concentration and distribution of aerosol in China.
文摘In this paper, using the daily grid data (2.5 × 2.5) of the ECMWF / WMO, we have computed respectively the three-dimensional wave activity flux in the stages of pre-onset, prevailing and post ending of Meiyu from 1 to 31 July 1982. The potential vorticity field is taken as the physical quantity relating the wave activity flux to the variation of the subtropical high over the Western Pacific. It is found that the three-dimensional wave activity flux is a powerful means for diagnosis of the variation of the subtropical high over the Western Pacific: The region of the subtropical high is just the confluence area of wave energy, whose changes in intensity and range decide the variation of the subtropical high. The confluence of wave energy comes from the monsoon flow in low latitudes, the Meiyu rain belts in middle latitudes and the heating fields on the eastern side of the Qinghai-Xizang Plateau. The relation between these sources and the subtropical high displays the self-adjusting mechanism among members of East-Asia summer monsoon.
基金This work was supported by the National High Technology Research and Development Program of China(863 Program,Grant No.2002AA135360)the National Natural Science Foundation of China(Grant Nos.40271025 and 90302006).
文摘Three sampling cross sections along the south path starting from the Tropics through the vapor passage in the Yunnan-Guizhou Plateau to the middle-low reaches of the Yangtze River, the north path from West China, via North China, to Japan under the westerlies, and the plateau path from South Asia over the Himalayas to the northern Tibetan Plateau, are set up, based on the IAEA (International Atomic Energy Agency)/WMO global survey network and sampling sites on the Tibetan Plateau. The variations, and the relationship with precipitation and temperature, of the δ18 O in precipitation along the three cross sections are analyzed and compared. Along the south path, the seasonal differences of mean δ18O in precipitation are small at the stations located in the Tropics, but increase markedly from Bangkok towards the north, with the δ18O in the rainy season smaller than in,the dry season. The δ18O values in precipitation fluctuate on the whole, which shows that there are different vapor sources. Along the north path, the seasonal differences of the mean δ18O in precipitation for the stations in the west of Zhengzhou are all greater than in the east of Zhengzhou. During the cold half of the year, the mean δ18O in precipitation reaches its minimum at Urumqi with the lowest temperature due to the wide, cold high pressure over Mongolia, then increases gradually with longitude, and remains at roughly the same level at the stations eastward from Zhengzhou. During the warm half of the year, the δ18O values in precipitation are lower in the east than in the west, markedly influenced by the summer monsoon over East Asia. Along the plateau path, the mean δ18O values in precipitation in the rainy season are correspondingly high in the southern parts of the Indian subcontinent, and then decrease gradually with latitude. A sharp depletion of the stable isotopic compositions in precipitation takes place due to the very strong rainout of the stable isotopic compositions in vapor in the process of lifting over the southern slope of the Himalayas. The low level of the δ18O in precipitation is from Nyalam to the Tanggula Mountains during the rainy season, but δ18O increases persistently with increasing latitude from the Tanggula Mountains to the northern Tibetan Plateau because of the replenishment of vapor with relatively heavy stable isotopic compositions originating from the inner plateau. During the dry season, the mean δ18O values in precipitation basically decrease along the path from the south to the north. Generally, the mean δ18O in precipitation during the rainy season is lower than in the dry season for the regions controlled by the monsoons over South Asia or the plateau, and opposite for the regions without a monsoon or with a weak monsoon.