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1.
曹爽  何立富  沈晓琳  胡宁 《气象》2020,46(5):725-732
2020年2月大气环流的主要特征是北半球极涡呈偶极型分布且较常年同期明显偏强,欧亚地区中高纬环流呈三波型,环流呈纬向型,经向度较小。西太平洋副热带高压较常年偏强;下旬南支槽趋于活跃。2月,我国冷空气过程较常年偏少,出现今年首个全国型寒潮过程;全国平均气温为-0.1℃,较常年同期偏高1.6℃;全国平均降水量21.1 mm,较常年同期偏多18%。此外,前半月中东部多过程性雾 霾天气;西北地区出现今年首次沙尘天气过程。  相似文献   

2.
江琪  桂海林  徐冉 《气象》2020,46(4):575-580
2016年1月大气环流主要特征为:北半球极涡呈偶极型分布,东亚大槽位置较常年同期偏东偏北,强度偏弱。1月,全国平均降水量为23.3 mm,较常年同期(13.2 mm)偏多77%,为1961年以来历史同期第二多。1月,全国平均气温为-3.6℃,较常年同期(-5.0℃)偏高1.4℃,月内冷空气较弱,我国中东部雾 霾天气频发,共有三次大范围持续性雾 霾过程,分别为1月3—5日、16—18日和22—28日。此外,月内共有四次降水过程。  相似文献   

3.
2017年2月大气环流和天气分析   总被引:1,自引:1,他引:0  
毛旭  张涛 《气象》2017,43(5):634-640
2017年2月大气环流的主要特征是极涡偏强且呈单极偏心型分布,中高纬环流呈3波型,西太平洋副热带高压强度接近常年,南支槽强度较常年偏弱。2月全国平均气温0℃,较常年同期偏高1.7℃;全国平均降水量14.4 mm,比常年同期(17.4 mm)偏少17.1%。2月我国有两次强冷空气过程;3次降水过程,其中新疆出现了一次暴雪过程,日降水量打破历史极值;中东部出现两次雾 霾天气。  相似文献   

4.
2016年12月大气环流和天气分析   总被引:5,自引:4,他引:1  
刘超  马学款 《气象》2017,43(3):378-384
2016年12月大气环流主要特征如下:北半球极涡呈偶极型分布,中心气压较常年偏低,欧亚中高纬度环流呈两槽一脊型;南支槽强度偏弱,平均位置位于90°E附近,副热带高压较常年偏强。12月,全国平均降水量为11.5 mm,较常年同期偏多9.5%。全国平均气温为-0.7℃,较常年同期(-3.2℃)偏高2.5℃,为1961年以来历史同期最高值。月内,我国出现两次主要冷空气过程和两次主要降水过程以及3次雾 霾天气过程,其中16—21日雾 霾天气过程是2016年范围最广、持续时间最长、强度最强的雾 霾天气过程。  相似文献   

5.
2014年1月大气环流和天气分析   总被引:1,自引:0,他引:1       下载免费PDF全文
赖芬芬  马学款 《气象》2014,40(4):515-520
2014年1月大气环流主要特征如下:北半球极涡呈偶极型分布,位置较常年同期明显偏南;欧亚中高纬环流经向度较小;南支槽平均位置位于70°E附近,位置较常年同期明显偏西;同时,西太平洋副热带高压较常年同期略偏弱。1月,全国平均降水量为6.2 mm,较常年同期(13.2 mm)偏少53.0%。全国平均气温为-3.4℃,较常年同期(-5.0℃)偏高1.6℃。月内,我国出现1次主要冷空气过程和4次主要降水过程。北方冬麦区降水偏少,气象干旱持续;中东部地区出现大范围雾或霾天气;南方地区出现低温雨雪天气  相似文献   

6.
李晓兰  何立富 《气象》2019,45(5):738-744
2019年2月大气环流的主要特征是北半球极涡较常年同期偏强,中心偏向东半球,位置偏北;欧亚中高纬环流呈4波型,环流经向度总体较小。西太平洋副热带高压偏强;南支槽较常年偏弱、偏西。2月,我国冷空气活动较弱,仅出现一次大范围强冷空气和一次中等强度冷空气过程;全国平均气温为-1.3℃,较常年同期偏高0.4℃;东北地区北部气温异常偏高。月内,全国平均降水量为23.2 mm,较常年同期偏多33.3%;南方出现持续阴雨天气,青藏高原降雪明显偏多,青海东南部出现雪灾。另外,下旬我国中东部地区出现持续雾 霾天气。  相似文献   

7.
2017年1月大气环流和天气分析   总被引:1,自引:1,他引:0  
张楠  马学款 《气象》2017,43(4):508-512
2017年1月大气环流主要特征如下:北半球极涡呈绕极型分布,中心气压较常年偏低,欧亚中高纬度环流呈两槽一脊型;南支槽强度与常年接近,平均位置位于90°E以西附近,副热带高压较常年接近。1月,全国平均降水量为12.4 mm,较常年同期偏少6%。全国平均气温为-3.4℃,较常年同期(-5.0℃)偏高1.6℃,为1961年以来历史同期第三高值。月内,我国出现主要冷空气过程、主要降水过程以及雾 霾天气过程各2次,其中2016年12月30日至2017年1月6日雾 霾天气过程是1月范围最广、持续时间最长、强度最强的雾 霾天气过程。  相似文献   

8.
2018年10月大气环流和天气分析   总被引:1,自引:1,他引:0  
曹越男  高拴柱 《气象》2019,45(1):135-140
2018年10月大气环流主要特征如下:北半球极涡呈偶极型,中高纬地区西风带为4波型分布,西太平洋副热带高压较常年位置偏西。全国平均降水量为28.1 mm,较常年同期(35.8 mm)偏少21.6%。全国平均气温为9.9℃,较常年同期(10.3℃)偏低0.4℃,为近16年来同期最低。10月我国无大范围暴雨天气过程,江南及华南地区雨日较多。冷空气活动频繁,出现5次过程,较常年偏多。京津冀地区出现2次雾 霾天气过程,相对往年秋、冬季雾 霾偏轻。月内没有台风登陆我国。  相似文献   

9.
2019年12月大气环流和天气分析   总被引:2,自引:1,他引:2  
徐冉  桂海林  江琪  张天航 《气象》2020,46(3):441-448
2019年12月大气环流主要特征为:北半球极涡为偶极型分布,环流呈三波型,东亚槽略偏弱,南支槽偏强,且副热带高压位置偏西。12月,全国平均降水量为11.2 mm,较常年同期(10.5 mm)偏多6.7%;全国平均气温为-2.7℃,较常年同期(-3.2℃)偏高0.5℃。月内共出现3次较强降水过程和3次中等强度冷空气过程。另外,7—10日、20—26日我国中东部地区发生了两次持续性大范围雾-霾天气过程。  相似文献   

10.
胡海川 《气象》2013,39(1):123-128
2012年10月环流特征如下:北半球高纬度地区为单一极涡,强度较常年同期偏弱,中高纬环流呈现4波型,欧亚地区中高纬环流经向度较常年偏大,南支槽偏强,西太平洋副热带高压强度偏弱.10月,全国平均降水量为29.1 mm,比常年同期(36.9 mm)偏少18.9%,全国平均气温为10.3℃,与常年同期(10.3℃)持平.月内,冷空气活动频繁,先后有4次冷空气过程影响我国;受台风山神影响,我国华南地区出现一次强降水过程;西南地区阴雨寡照天气及华南秋旱天气持续,在中下旬均有所好转;我国中东部大部地区出现雾霾天气;个别地区出现低温冰冻、局地洪涝及风雹灾害.  相似文献   

11.
Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.  相似文献   

12.
The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.  相似文献   

13.
The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.  相似文献   

14.
正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment.  相似文献   

15.
Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.  相似文献   

16.
The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o.  相似文献   

17.
正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on  相似文献   

18.
Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d.  相似文献   

19.
Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region.  相似文献   

20.
Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms.  相似文献   

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