Based on the comprehensive ground observation and the remote sensing data of Fengyun-4 satellite of a typical sand-dust weather process in the eastern part of the Qinghai-Tibet Plateau from November 26 to 27,2018,the ...Based on the comprehensive ground observation and the remote sensing data of Fengyun-4 satellite of a typical sand-dust weather process in the eastern part of the Qinghai-Tibet Plateau from November 26 to 27,2018,the weather situation,air mass trajectory,meteorological conditions,and pollution characteristics of this process were analyzed.The results show that the floating dust process was caused by the transmission of the northwest cold air flow in the Tarim Desert area,which caused dust and sand mixed with the Qaidam Desert particles to be transported to Xining.The wind field change caused by the difference of ground heat in the eastern plateau was a potential factor for dust transmission,and tropospheric subsidence,temperature inversion conditions,and the decrease in wind speed over Xining Station were the direct factors leading to the daily change of pollutant concentration in this process.展开更多
The actual situation of two sand and dust weather processes with heavy pollution in Ulanqab City in 2021 was analyzed from the aspects of air quality,visibility,PM_(2.5)and PM_(10),and the causes of the sand and dust ...The actual situation of two sand and dust weather processes with heavy pollution in Ulanqab City in 2021 was analyzed from the aspects of air quality,visibility,PM_(2.5)and PM_(10),and the causes of the sand and dust weather with heavy pollution were discussed.The differences between the two processes in transport characteristics of sand and dust were studied,and the roles of high-and low-altitude weather systems and their impact on sand and dust transport were explored.展开更多
The DERF2.0 model of China National Climate Center and NCEP (National Centers for Environmental Prediction) data were used in this paper. Using the knowledge of synoptic principles, the process of dust weather in most...The DERF2.0 model of China National Climate Center and NCEP (National Centers for Environmental Prediction) data were used in this paper. Using the knowledge of synoptic principles, the process of dust weather in most parts of China from January 11 to 16, 2021 was analyzed. The results show that: 1) Compared with previous years, this process has a large impact scope and appears earlier. 2) The continuous cold air caused the dust weather process. 3) The surface cold front is conducive to the development of dust. 4) Surface cyclone is conducive to the transport and diffusion of dust.展开更多
The relationship between dust weather frequency (DWF), which denotes the number of days of dust weather events, over Beijing and the East Asian Monsoon (EAM) was studied using DWF data for Beijing during the period 19...The relationship between dust weather frequency (DWF), which denotes the number of days of dust weather events, over Beijing and the East Asian Monsoon (EAM) was studied using DWF data for Beijing during the period 1951-2006. Results show that, during this period, the blowing-dust weather frequency (BDWF), as well as the indices of East Asian winter monsoon (EAWM) and East Asian summer monsoon (EASM), all decreased considerably, with a t-test confidence level of 99%. The correlation coeffcients between the chosen EAWM index and BDWF over Beijing in winter and the following spring were 0.34 and 0.33, respectively, with significance levels of 0.01 and 0.02, respectively. For the chosen EASM index and BDWF, these correlation coeffcients were 0.51 and 0.45, respectively, with both at a confidence level exceeding 99.9%. With the linear trends removed, the values (in the same order as above) were 0.14, 0.14, -0.12, and -0.09, all not significant at the 95% confidence level. Clearly, the EAM relates mainly to DWF over long timescales. To a certain extent, the EAM might have some impact on DWF by affecting the associated surface air temperature and precipitation during the corresponding time period in sand-dust source regions at the interannual scale. A stronger (weaker) EAWM might advance (suppress) the occurrence of DWF, and the opposite for the EASM.展开更多
近几十年,我国北方春季沙尘的频次的线性趋势下降,但去掉线性趋势后,发现我国北方春季沙尘频次在1966–2014期间有两段沙尘频次的多发年,前一段是1966–1979(P1),后一段是2000–2014(P2)。认识这两段高频沙尘发生的主要特点和可能原因...近几十年,我国北方春季沙尘的频次的线性趋势下降,但去掉线性趋势后,发现我国北方春季沙尘频次在1966–2014期间有两段沙尘频次的多发年,前一段是1966–1979(P1),后一段是2000–2014(P2)。认识这两段高频沙尘发生的主要特点和可能原因将进一步理解不同年代际背景下沙尘年际变异机理,为沙尘的气候预测提供依据。研究表明前一阶段沙尘的强度是高于后一阶段,沙尘中心分布在南疆和北方中部(华北、河套和内蒙)。主要的原因是北大西洋和北太平洋海温异常不同造成。前者主要受北大西洋副热带海温异常的影响,后者受北大西洋高纬海温异常的影响。前一阶段200 h Pa高层环流出现经向的大气遥相关,导致40–45°N东亚急流加强一方面有利于动量下传造成蒙古气旋活跃,另一方面有利于新疆和蒙古的沙尘输送到我国北方中部区域。后一阶段从北大西洋高纬到东亚呈现纬向波列,导致蒙古气旋南部西风气流加强,沙尘从新疆输送到我国北方。与后一阶段比较,前一阶段的两极冷空气更为活跃,沙尘发生动力条件更强。展开更多
[Objective]The study aimed to discuss the effects of dust weather on air quality in Lanzhou City.[Method]Under the influence of a strong sandstorm during March 8-15,2013 on air quality in Gansu Province,the changes of...[Objective]The study aimed to discuss the effects of dust weather on air quality in Lanzhou City.[Method]Under the influence of a strong sandstorm during March 8-15,2013 on air quality in Gansu Province,the changes of wind speed,atmospheric visibility and PM_(10)concentration as well as air pollution in Lanzhou were analyzed.[Result]The dust weather during March 8-15,2013 affected Lanzhou City for the longest time in recent 10 years,and the city suffered medium pollution on March 8 and heavy pollution during March 9-15 under the influence of the dust weather,while PM_(10)was the primary pollutant.[Conclusion]The research could provide the corresponding technical support for the prevention and control of environmental pollution in Lanzhou City.展开更多
Sand-dust weather has become an international social-environmental issue of common concern, and constitutes a serious threat to human lives and economic development. In order to explore the responses of natural desert...Sand-dust weather has become an international social-environmental issue of common concern, and constitutes a serious threat to human lives and economic development. In order to explore the responses of natural desert sand and dust to the dynamics of water in desertification, we extracted long-term monitoring data related to precipitation, soil water, groundwater, and sand-dust weather. These data originated from the test stations for desertification control in desert areas of the middle reaches of the Heihe River. We used an algorithm of characteristic parameters, correlations, and multiple regression analysis to establish a regression model for the duration of sand-dust weather. The response characteristics of the natural desert sand and dust and changes of the water inter-annual and annual variance were also examined. Our results showed:(1) From 2006 to 2014 the frequency, duration, and volatility trends of sand-dust weather obviously increased, but the change amplitudes of precipitation, soil water, and groundwater level grew smaller.(2) In the vegetative growth seasons from March to November, the annual variance rates of the soil moisture content in each of four studied layers of soil samples were similar, and the changes in the frequency and duration of sand-dust weather were similar.(3) Our new regression equation for the duration of sand-dust weather passed the R test, F test, and t test. By this regression model we could predict the duration of sand-dust weather with an accuracy of 42.9%. This study can thus provide technological support and reference data for water resource management and research regarding sand-dust weather mechanisms.展开更多
Based on the observation data of PM 10 mass concentration, ground meteorological elements and solar radiation in Dunhuang and Jiuquan , the changing trends of PM 10 mass concentration and solar total radiation in the ...Based on the observation data of PM 10 mass concentration, ground meteorological elements and solar radiation in Dunhuang and Jiuquan , the changing trends of PM 10 mass concentration and solar total radiation in the west of the Hexi Corridor in the spring of 2014 (from March to May) were studied, and the relationship between solar total radiation and net radiation in different pollution situations was analyzed. Moreover, the changes of solar radiation and PM 10 mass concentration in a typical dust process in April 2014, as well as the responses of ground meteorological elements were also analyzed. The results showed that in the west of the Hexi Corridor, solar total radiation and PM 10 mass concentration showed an increasing trend with fluctuation, and there was inverse correlation between them. The correlation was particularly obvious in dust days. The dust weather led to the increase of PM 10 mass concentration, so that the total radiation decreased. The net radiation declined in the daytime and rose at night. Dust weather is a major factor affecting air quality and total radiation.展开更多
[Objective] The research aimed to study new characteristics of the dust weather in northern Shaanxi in recent 10 years and correlation between dust weather and meteorological factor. [Method] Based on observation data...[Objective] The research aimed to study new characteristics of the dust weather in northern Shaanxi in recent 10 years and correlation between dust weather and meteorological factor. [Method] Based on observation data of 3 national basic meteorological stations (Yuyang District, Dingbian and Yanan) during 2001-2010, the newest fact characteristics of temporal-spatial evolution for sand storm, sand blowing and floating dust in northern Shaanxi during 2001-2010 were illustrated. Correlation between dust weather and meteorological factor (gale, precipitation and temperature) was analyzed. [Result] Compared with the 1990s, dust days in northern Shaanxi during 2001-2010 still continued to decrease. There was no sand storm in Yanan. Sand storm days in northern region of north Shaanxi in most years was 1.0-2.0 d. Sand blowing was main characteristics of the dust weather in northern Shaanxi, and proportion of the sand blowing days to dust days was 80%-90%. Dust days in Dingbian had good correlation with gale days, but gale days was smaller than dust days. That is to say, smaller wind force could induce dust weather. Decrease of the dust days presented inverse correlations with precipitaion and temperature. Precipitation increase and temperature rise could inhibit occurrence of the dust weather. Although total dust days decreased, sand storm in Yuyang District had increase tendency. [Conclusion] The research had scientific, objective and practical significance for prediction of the climate change tendency in northern Shaanxi.展开更多
It is of great social and scientific importance and also very difficult to make reliable prediction for dust weather frequency (DWF) in North China. In this paper, the correlation between spring DWF in Beijing and Tia...It is of great social and scientific importance and also very difficult to make reliable prediction for dust weather frequency (DWF) in North China. In this paper, the correlation between spring DWF in Beijing and Tianjin observation stations, taken as examples in North China, and seasonally averaged surface air temperature, precipitation, Arctic Oscillation, Antarctic Oscillation, South Oscillation, near surface meridional wind and Eurasian westerly index is respectively calculated so as to construct a prediction model for spring DWF in North China by using these climatic factors. Two prediction models, i.e. model-I and model-II, are then set up respectively based on observed climate data and the 32-year (1970 -2001) extra-seasonal hindcast experiment data as reproduced by the nine-level Atmospheric General Circulation Model developed at the Institute of Atmospheric Physics (IAP9L-AGCM). It is indicated that the correlation coefficient between the observed and predicted DWF reaches 0.933 in the model-I, suggesting a high prediction skill one season ahead. The corresponding value is high up to 0.948 for the subsequent model-II, which involves synchronous spring climate data reproduced by the IAP9L-AGCM relative to the model-I. The model-II can not only make more precise prediction but also can bring forward the lead time of real-time prediction from the model-I’s one season to half year. At last, the real-time predictability of the two models is evaluated. It follows that both the models display high prediction skill for both the interannual variation and linear trend of spring DWF in North China, and each is also featured by different advantages. As for the model-II, the prediction skill is much higher than that of original approach by use of the IAP9L-AGCM alone. Therefore, the prediction idea put forward here should be popularized in other regions in China where dust weather occurs frequently.展开更多
In this paper, seasonal prediction of spring dust weather frequency (DWF) in Beijing during 1982-2008 has been performed. First, correlation analyses are conducted to identify antecedent climate signals during last wi...In this paper, seasonal prediction of spring dust weather frequency (DWF) in Beijing during 1982-2008 has been performed. First, correlation analyses are conducted to identify antecedent climate signals during last winter that are statistically significantly related to spring DWF in Beijing. Then, a seasonal prediction model of spring DWF in Beijing is established through multivariate linear regression analysis, in which the systematic error between the result of original prediction model and the observation, averaged over the last 10 years, is corrected. In addition, it is found that climate signals occurring synchronously with spring dust weather, particularly meridional wind at 850 hPa over western Mongolian Plateau, are also linked closely to spring DWF in Beijing. As such, statistical and dynamic prediction approaches should be combined to include these synchronous predictors into the prediction model in the real-time operational prediction, so as to further improve the prediction accuracy of spring DWF in Beijing, even over North China. However, realizing such a prediction idea in practice depends essentially on the ability of climate models in predicting key climate signals associated with spring DWF in Beijing.展开更多
The different height mass concentrations of dust aerosol data from the atmosphere environment observation station(Tazhong Station)was continuously observed by instruments of Grimm 1.108,Thermo RP 1400a and TSP from Ja...The different height mass concentrations of dust aerosol data from the atmosphere environment observation station(Tazhong Station)was continuously observed by instruments of Grimm 1.108,Thermo RP 1400a and TSP from January of2009 to February of 2010 in the Taklimakan Desert hinterland.Results show that:(1)The mass concentration value of 80m PM10was higher,but PM2.5and PM1.0concentrations at 80 m was obviously lower than 4 m PM10,and the value of 80 m PM1.0mass concentration was the lowest.(2)The PM mass concentrations gradually decreased from night to sunrise,with the lowest concentration at 08:00,with the mass concentration gradually increased,up to the highest concentration around18:00,and then decreased again.It was exactly the same with the changes of wind speed.(3)The high monthly average mass concentration of TSP mainly appeared from March to September,and the highest concentration was in April and May,subsequently gradually decreased.Also,March–September was a period with high value area of PM monthly average mass concentration,with the highest monthly average mass concentration of 846.0μg/m3for 4 m PM10appeared in May.The concentration of PM10was much higher than those of PM2.5and PM1.0at 80 m.There is a small difference between the concentration of PM2.5and PM1.0.Dust weather was the main factor which influenced the concentration content of the different diameter dust aerosol,and the more dust weather days,the higher content of coarse particle,conversely,fine particle was more.(4)The mass concentration of different diameter aerosols had the following sequence during dust weather:clear day<blowing dust<floating and blowing dust<sandstorm.In different dust weather,the value of PM10/TSP in fine weather was higher than that in floating weather,and much higher than those in blowing dust and sandstorm weather.(5)During the dust weather process,dust aerosol concentration gradually decreased with particle size decreasing.The dust aerosol mass concentration at different heights and diameter would have a peak value area every 3–4days according to the strengthening process of dust weather.展开更多
基金the Applied Basic Research Project of Department of Science and Technology of Qinghai Province"Formation Mechanism of Salt Dust Storm in Qaidam Basin"(2018-ZJ-723).
文摘Based on the comprehensive ground observation and the remote sensing data of Fengyun-4 satellite of a typical sand-dust weather process in the eastern part of the Qinghai-Tibet Plateau from November 26 to 27,2018,the weather situation,air mass trajectory,meteorological conditions,and pollution characteristics of this process were analyzed.The results show that the floating dust process was caused by the transmission of the northwest cold air flow in the Tarim Desert area,which caused dust and sand mixed with the Qaidam Desert particles to be transported to Xining.The wind field change caused by the difference of ground heat in the eastern plateau was a potential factor for dust transmission,and tropospheric subsidence,temperature inversion conditions,and the decrease in wind speed over Xining Station were the direct factors leading to the daily change of pollutant concentration in this process.
文摘The actual situation of two sand and dust weather processes with heavy pollution in Ulanqab City in 2021 was analyzed from the aspects of air quality,visibility,PM_(2.5)and PM_(10),and the causes of the sand and dust weather with heavy pollution were discussed.The differences between the two processes in transport characteristics of sand and dust were studied,and the roles of high-and low-altitude weather systems and their impact on sand and dust transport were explored.
文摘The DERF2.0 model of China National Climate Center and NCEP (National Centers for Environmental Prediction) data were used in this paper. Using the knowledge of synoptic principles, the process of dust weather in most parts of China from January 11 to 16, 2021 was analyzed. The results show that: 1) Compared with previous years, this process has a large impact scope and appears earlier. 2) The continuous cold air caused the dust weather process. 3) The surface cold front is conducive to the development of dust. 4) Surface cyclone is conducive to the transport and diffusion of dust.
基金supported by the Pilot Project of Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-Q11-03)the National Basic Research Program of China(No. 2010CB428503)
文摘The relationship between dust weather frequency (DWF), which denotes the number of days of dust weather events, over Beijing and the East Asian Monsoon (EAM) was studied using DWF data for Beijing during the period 1951-2006. Results show that, during this period, the blowing-dust weather frequency (BDWF), as well as the indices of East Asian winter monsoon (EAWM) and East Asian summer monsoon (EASM), all decreased considerably, with a t-test confidence level of 99%. The correlation coeffcients between the chosen EAWM index and BDWF over Beijing in winter and the following spring were 0.34 and 0.33, respectively, with significance levels of 0.01 and 0.02, respectively. For the chosen EASM index and BDWF, these correlation coeffcients were 0.51 and 0.45, respectively, with both at a confidence level exceeding 99.9%. With the linear trends removed, the values (in the same order as above) were 0.14, 0.14, -0.12, and -0.09, all not significant at the 95% confidence level. Clearly, the EAM relates mainly to DWF over long timescales. To a certain extent, the EAM might have some impact on DWF by affecting the associated surface air temperature and precipitation during the corresponding time period in sand-dust source regions at the interannual scale. A stronger (weaker) EAWM might advance (suppress) the occurrence of DWF, and the opposite for the EASM.
基金supported by the National Natural Science Foundation of China[grant numbers 41325018,41575079,41421004]
文摘近几十年,我国北方春季沙尘的频次的线性趋势下降,但去掉线性趋势后,发现我国北方春季沙尘频次在1966–2014期间有两段沙尘频次的多发年,前一段是1966–1979(P1),后一段是2000–2014(P2)。认识这两段高频沙尘发生的主要特点和可能原因将进一步理解不同年代际背景下沙尘年际变异机理,为沙尘的气候预测提供依据。研究表明前一阶段沙尘的强度是高于后一阶段,沙尘中心分布在南疆和北方中部(华北、河套和内蒙)。主要的原因是北大西洋和北太平洋海温异常不同造成。前者主要受北大西洋副热带海温异常的影响,后者受北大西洋高纬海温异常的影响。前一阶段200 h Pa高层环流出现经向的大气遥相关,导致40–45°N东亚急流加强一方面有利于动量下传造成蒙古气旋活跃,另一方面有利于新疆和蒙古的沙尘输送到我国北方中部区域。后一阶段从北大西洋高纬到东亚呈现纬向波列,导致蒙古气旋南部西风气流加强,沙尘从新疆输送到我国北方。与后一阶段比较,前一阶段的两极冷空气更为活跃,沙尘发生动力条件更强。
文摘[Objective]The study aimed to discuss the effects of dust weather on air quality in Lanzhou City.[Method]Under the influence of a strong sandstorm during March 8-15,2013 on air quality in Gansu Province,the changes of wind speed,atmospheric visibility and PM_(10)concentration as well as air pollution in Lanzhou were analyzed.[Result]The dust weather during March 8-15,2013 affected Lanzhou City for the longest time in recent 10 years,and the city suffered medium pollution on March 8 and heavy pollution during March 9-15 under the influence of the dust weather,while PM_(10)was the primary pollutant.[Conclusion]The research could provide the corresponding technical support for the prevention and control of environmental pollution in Lanzhou City.
基金supported by the Science and Technology Innovation Service Platform of Qilian mountains in Gansu Province (No. 144JTCG254)the Innovation Groups of Basic Research of Gansu Province (No. 145RJIG337)the National Natural Science Foundation of China (No. 41461004)
文摘Sand-dust weather has become an international social-environmental issue of common concern, and constitutes a serious threat to human lives and economic development. In order to explore the responses of natural desert sand and dust to the dynamics of water in desertification, we extracted long-term monitoring data related to precipitation, soil water, groundwater, and sand-dust weather. These data originated from the test stations for desertification control in desert areas of the middle reaches of the Heihe River. We used an algorithm of characteristic parameters, correlations, and multiple regression analysis to establish a regression model for the duration of sand-dust weather. The response characteristics of the natural desert sand and dust and changes of the water inter-annual and annual variance were also examined. Our results showed:(1) From 2006 to 2014 the frequency, duration, and volatility trends of sand-dust weather obviously increased, but the change amplitudes of precipitation, soil water, and groundwater level grew smaller.(2) In the vegetative growth seasons from March to November, the annual variance rates of the soil moisture content in each of four studied layers of soil samples were similar, and the changes in the frequency and duration of sand-dust weather were similar.(3) Our new regression equation for the duration of sand-dust weather passed the R test, F test, and t test. By this regression model we could predict the duration of sand-dust weather with an accuracy of 42.9%. This study can thus provide technological support and reference data for water resource management and research regarding sand-dust weather mechanisms.
文摘Based on the observation data of PM 10 mass concentration, ground meteorological elements and solar radiation in Dunhuang and Jiuquan , the changing trends of PM 10 mass concentration and solar total radiation in the west of the Hexi Corridor in the spring of 2014 (from March to May) were studied, and the relationship between solar total radiation and net radiation in different pollution situations was analyzed. Moreover, the changes of solar radiation and PM 10 mass concentration in a typical dust process in April 2014, as well as the responses of ground meteorological elements were also analyzed. The results showed that in the west of the Hexi Corridor, solar total radiation and PM 10 mass concentration showed an increasing trend with fluctuation, and there was inverse correlation between them. The correlation was particularly obvious in dust days. The dust weather led to the increase of PM 10 mass concentration, so that the total radiation decreased. The net radiation declined in the daytime and rose at night. Dust weather is a major factor affecting air quality and total radiation.
文摘[Objective] The research aimed to study new characteristics of the dust weather in northern Shaanxi in recent 10 years and correlation between dust weather and meteorological factor. [Method] Based on observation data of 3 national basic meteorological stations (Yuyang District, Dingbian and Yanan) during 2001-2010, the newest fact characteristics of temporal-spatial evolution for sand storm, sand blowing and floating dust in northern Shaanxi during 2001-2010 were illustrated. Correlation between dust weather and meteorological factor (gale, precipitation and temperature) was analyzed. [Result] Compared with the 1990s, dust days in northern Shaanxi during 2001-2010 still continued to decrease. There was no sand storm in Yanan. Sand storm days in northern region of north Shaanxi in most years was 1.0-2.0 d. Sand blowing was main characteristics of the dust weather in northern Shaanxi, and proportion of the sand blowing days to dust days was 80%-90%. Dust days in Dingbian had good correlation with gale days, but gale days was smaller than dust days. That is to say, smaller wind force could induce dust weather. Decrease of the dust days presented inverse correlations with precipitaion and temperature. Precipitation increase and temperature rise could inhibit occurrence of the dust weather. Although total dust days decreased, sand storm in Yuyang District had increase tendency. [Conclusion] The research had scientific, objective and practical significance for prediction of the climate change tendency in northern Shaanxi.
基金the National Natural Science Foundation of China (Grant Nos. 40631005, 40620130113 and 40505017)
文摘It is of great social and scientific importance and also very difficult to make reliable prediction for dust weather frequency (DWF) in North China. In this paper, the correlation between spring DWF in Beijing and Tianjin observation stations, taken as examples in North China, and seasonally averaged surface air temperature, precipitation, Arctic Oscillation, Antarctic Oscillation, South Oscillation, near surface meridional wind and Eurasian westerly index is respectively calculated so as to construct a prediction model for spring DWF in North China by using these climatic factors. Two prediction models, i.e. model-I and model-II, are then set up respectively based on observed climate data and the 32-year (1970 -2001) extra-seasonal hindcast experiment data as reproduced by the nine-level Atmospheric General Circulation Model developed at the Institute of Atmospheric Physics (IAP9L-AGCM). It is indicated that the correlation coefficient between the observed and predicted DWF reaches 0.933 in the model-I, suggesting a high prediction skill one season ahead. The corresponding value is high up to 0.948 for the subsequent model-II, which involves synchronous spring climate data reproduced by the IAP9L-AGCM relative to the model-I. The model-II can not only make more precise prediction but also can bring forward the lead time of real-time prediction from the model-I’s one season to half year. At last, the real-time predictability of the two models is evaluated. It follows that both the models display high prediction skill for both the interannual variation and linear trend of spring DWF in North China, and each is also featured by different advantages. As for the model-II, the prediction skill is much higher than that of original approach by use of the IAP9L-AGCM alone. Therefore, the prediction idea put forward here should be popularized in other regions in China where dust weather occurs frequently.
基金Supported by the Knowledge Innovation Project of the Chinese Academy of Sciences(KZCX2-YW-Q03-3)National Basic Research Program of China(2009CB421406)Special Public Welfare Research Fund of China for Meteorological Profession (GYHY200906018)
文摘In this paper, seasonal prediction of spring dust weather frequency (DWF) in Beijing during 1982-2008 has been performed. First, correlation analyses are conducted to identify antecedent climate signals during last winter that are statistically significantly related to spring DWF in Beijing. Then, a seasonal prediction model of spring DWF in Beijing is established through multivariate linear regression analysis, in which the systematic error between the result of original prediction model and the observation, averaged over the last 10 years, is corrected. In addition, it is found that climate signals occurring synchronously with spring dust weather, particularly meridional wind at 850 hPa over western Mongolian Plateau, are also linked closely to spring DWF in Beijing. As such, statistical and dynamic prediction approaches should be combined to include these synchronous predictors into the prediction model in the real-time operational prediction, so as to further improve the prediction accuracy of spring DWF in Beijing, even over North China. However, realizing such a prediction idea in practice depends essentially on the ability of climate models in predicting key climate signals associated with spring DWF in Beijing.
基金supported by Natural Science Founda-tion of China(Nos.41375162,41175017,41175140)China Special Fund for Meteorological Research in the Public Interest(Nos.GYHY201006012,GYHY201106025)
文摘The different height mass concentrations of dust aerosol data from the atmosphere environment observation station(Tazhong Station)was continuously observed by instruments of Grimm 1.108,Thermo RP 1400a and TSP from January of2009 to February of 2010 in the Taklimakan Desert hinterland.Results show that:(1)The mass concentration value of 80m PM10was higher,but PM2.5and PM1.0concentrations at 80 m was obviously lower than 4 m PM10,and the value of 80 m PM1.0mass concentration was the lowest.(2)The PM mass concentrations gradually decreased from night to sunrise,with the lowest concentration at 08:00,with the mass concentration gradually increased,up to the highest concentration around18:00,and then decreased again.It was exactly the same with the changes of wind speed.(3)The high monthly average mass concentration of TSP mainly appeared from March to September,and the highest concentration was in April and May,subsequently gradually decreased.Also,March–September was a period with high value area of PM monthly average mass concentration,with the highest monthly average mass concentration of 846.0μg/m3for 4 m PM10appeared in May.The concentration of PM10was much higher than those of PM2.5and PM1.0at 80 m.There is a small difference between the concentration of PM2.5and PM1.0.Dust weather was the main factor which influenced the concentration content of the different diameter dust aerosol,and the more dust weather days,the higher content of coarse particle,conversely,fine particle was more.(4)The mass concentration of different diameter aerosols had the following sequence during dust weather:clear day<blowing dust<floating and blowing dust<sandstorm.In different dust weather,the value of PM10/TSP in fine weather was higher than that in floating weather,and much higher than those in blowing dust and sandstorm weather.(5)During the dust weather process,dust aerosol concentration gradually decreased with particle size decreasing.The dust aerosol mass concentration at different heights and diameter would have a peak value area every 3–4days according to the strengthening process of dust weather.
