共查询到20条相似文献，搜索用时 826 毫秒
1.
Seasonal Transition of Summer Rainy Season over Indochina and Adjacent Monsoon Region 总被引：10，自引：0，他引：10
Jun MatsumotoDepartment of Geography University of Tokyo -- Hongo Bunkyo-ku Tokyo Japan 《大气科学进展》1997,(2)
ＳｅａｓｏｎａｌＴｒａｎｓｉｔｉｏｎｏｆＳｕｍｍｅｒＲａｉｎｙＳｅａｓｏｎｏｖｅｒＩｎｄｏｃｈｉｎａａｎｄＡｄｊａｃｅｎｔＭｏｎｓｏｏｎＲｅｇｉｏｎＪｕｎＭａｔｓｕｍｏｔｏＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｇｒａｐｈｙ，ＵｎｉｖｅｒｓｉｔｙｏｆＴｏｋｙｏ... 相似文献
2.
ＳｏｍｅＡｓｐｅｃｔｓｏｆｔｈｅＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＭｏｎｓｏｏｎＤｉｓｔｕｒｂａｎｃｅｓＵｓｉｎｇａＣｏｍｂｉｎｅｄＢａｒｏｔｒｏｐｉｃ－ＢａｒｏｃｌｉｎｉｃＭｏｄｅｌ￥Ｎ．Ｒ．ＰａｒｉｊａａｎｄＳ．Ｋ．Ｄａｓｈ（ＣｅｎｔｒｅｆｏｒＡ... 相似文献
3.
J.M. Pathan 《大气科学进展》1994,11(1):111-120
ＤｉｕｒｎａｌＶａｒｉａｔｉｏｎｏｆＳｏｕｔｈｗｅｓｔＭｏｎｓｏｏｎＲａｉｎｆａｌｌａｔＩｎｄｉａｎＳｔａｔｉｏｎｓＪ．Ｍ．Ｐａｔｈａｎ（ＩｎｄｉａｎＩｎｓｔｉｔｕｔｅｏｆＴｒｏｐｉｃａｌＭｅｔｅｏｒｏｌｏｇｙ，Ｐａｓｈａｎ，Ｐｕｎｅ－４１１００８，... 相似文献
4.
Wen Jingsong 《大气科学进展》1995,12(2):187-194
ＴｈｅＥｆｆｅｃｔｏｆＷｅａｋＳｈｅａｒ－ｉｎｄｕｃｅｄＭｏｔｉｏｎｏｎＢｒｏｗｎｉａｎＣｏａｇｕｌａｔｉｏｎｏｆＡｅｒｏｓｏｌＰａｒｔｉｃｌｅｓＷｉｎｊｉｎｇｓｏｎｓ（Ｃ．Ｓ．Ｗｉｎ）（温景嵩）（Ｄｅｐａｒｔｍｅｎｔｏｆｐｈｙｓｉｃｓ，Ｎａｎｋａｉ... 相似文献
5.
卫星测高实验室 (ＬＳＡ)是美国国家海洋资料中心 (ＮＯＤＣ)下属的一个部门 ,它担负着处理和分析所有来自目前测高卫星(Ｔｏｐｅｘ/Ｐｏｓｅｉｄｏｎ ,ＥＲＳ 2 ,ＧｅｏｓａｔＦｏｌｌｏｗ ｏｎ)以及过去卫星 (ＧＥＯＳ 3,Ｓｅａｓａｔ,Ｇｅｏｓａｔ,ＥＲＳ 1 )的测高资料。从欧洲空间局 (ＥＳＡ )的ＥＲＳ 1和ＥＲＳ 2卫星获得的资料是ＮＯＡＡ和其他机构在 6ｈ内可获得的惟一资料 ,为此ＮＯＡＡ有可能获得用于海洋分析和模式同化的准实时测高产品。第一颗欧洲遥感卫星ＥＲＳ 1于 1 991年8月发射 ,6个月后 ,ＬＳＡ开始常规处理高度计测试… 相似文献
6.
Ren Shuzhan 《大气科学进展》1994,11(3):291-295
ＳｙｍｍｅｔｒｉｃＳｔａｂｉｌｉｔｙｏｆＲｏｔａｔｉｏｎａｎｄＢｏｕｓｓｉｎｅｓｑＦｌｕｉｄｉｎＢｏｕｎｄｅｄＤｏｍａｉｎｂｙＵｓｉｎｇＮｏｒｍａｌＭｏｄｅＭｅｔｈｏｄ￥ＲｅｎＳｈｕｚｈａｎ（任舒展）（ＬＡＳＧ，ＩｎｓｔｉｔｕｔｅｏｆＡｔｍｏｓｐｈｅ... 相似文献
7.
Propagation of Envelope Solitons in Baroclinic Atmosphere 总被引：1，自引：0，他引：1
ＰｒｏｐａｇａｔｉｏｎｏｆＥｎｖｅｌｏｐｅＳｏｌｉｔｏｎｓｉｎＢａｒｏｃｌｉｎｉｃＡｔｍｏｓｐｈｅｒｅ￥ＴａｎＢｅｎｋｕｉ（谭本馗）（ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｐｈｙｓｉｃｓ，ＰｅｋｉｎｇＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊｉｎｇ１００８７１）ＹｉｎＤ... 相似文献
8.
Yong L. McHall 《大气科学进展》1994,11(2):251-251
ＡｎＩｎｔｒｏｄｕｃｔｉｏｎｔｏｔｈｅＮｅｗＢｏｏｋ－ＧＥＯＳＴＲＯＰＨＩＣＷＡＶＥＣＩＲＣＵＬＡＴＩＯＮＳ￥Ｙｏｎｇ．Ｌ．ＭｃＨａｌｌＤｅｐｔ．ｏｆＥａｒｔｈ，ＡｔｍｏｓｐｈｅｒｉｃａｎｄＰｌａｎｅｔａｒｙＳｃｉｅｎｃｅｓ，ＭＩＴＰｕｂｌｉｓｈｅｄ... 相似文献
9.
Monsoons over China 总被引：14，自引：0，他引：14
《大气科学进展》1994,(2)
ＭｏｎｓｏｏｎｓｏｖｅｒＣｈｉｎａ￥ｂｙＤｉｎｇＹｉｈｕｉ（ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＭｅｔｅｏｒｏｌｏｇｉｃａｌＳｃｉｅｎｃｅｓ，Ｂｅｉｇｕｇ，Ｃｈｉｎａ）ＡＴＭＯＳＰＨＥＲＩＣＳＣＩＥＮＣＥＳＬＩＢＲＡＲＹ，１６Ｔｈｅｍｏｎｓｏｏｎｏｖｅｒ... 相似文献
10.
ＳＨＯＲＴ－ＴＥＲＭＣＬＩＭＡＴＥＣＨＡＮＧＥＡＮＤＩＴＳＣＡＵＳＥＡＮＤＣＬＩＭＡＴＥＰＲＥＤＩＣＴＩＯＮＩＮＣＨＩＮＡ￥ＷｅｉＦｅｎｇｙｉｎｇ（魏凤英）（ＩｎｓｔｉｔｕｔｅｏｆＳｙｎｏｐｔｉｃａｎｄＤｙｎａｍｉｃＭｅｔｅｏｒｏｌｏｇｙ．）Ｂｅｉｊ... 相似文献
11.
为了研究大气污染对太行山中部地区地表风的影响,我们对阳泉、榆社(高山站),石家庄、邢台(平原站)4个站点1966~2005年间的能见度、近地面温度、近地面风速数据进行了统计计算与趋势分析。结果显示:在平原站能见度相对山坡站下降更加明显的背景下,平原站的近地面温度、近地面风速、850hPa风速都呈下降趋势;而山坡站的近地面温度、近地面风速呈上升趋势。分析表明:(1)由于气溶胶的辐射效应与冷却效应,抑制了垂直通量的上下传输,致使平原站下午的近地面气温呈下降趋势,平原站和高山站的地表风速呈相反的变化趋势。(2)平原站850hPa (与高山站高度相近)风速呈现下降趋势,印证了高山站的近地面风速增加是气溶胶的辐射效应减弱了垂直能量交换造成的。 相似文献
12.
设计基于GRAPES_Meso的不同试验模拟2014年3月28日-4月8日的广东前汛期降水过程,评估风廓线资料对同化和预报的影响。对资料同化后分析增量的分析表明:相比同化时仅使用自动气象站资料,风廓线雷达资料对1000 hPa到850 hPa纬向风增量均有贡献,在850 hPa,700 hPa高度以上贡献迅速减小。应用3个试验的预报结果计算探空站、风廓线雷达站预报值与观测值的11 d均方根误差发现,同化加入风廓线雷达资料对各预报要素的改善在850 hPa高度最明显,其中风速预报误差显著降低,为0.7 m·s-1。此外,风廓线雷达资料对700 hPa风速预报有一定改善,而在925 hPa高度模拟效果反而降低。通过对2014年3月30日12:00（世界时）的个例分析发现,同化加入风廓线雷达资料的风速预报均方根误差在大雨级别以上的降水落区更大,其原因还有待于进一步研究。 相似文献
13.
Using the monthly geopotential heights and winds for 700 and 200 hPa for India during July and August, and the weekly M-100 Soviet rocketsonde temperature and wind data for Thumba (8.5oN, 76.9oE) during the last week of June and the first week of September for the two contrasting summer monsoon years 1975 (a very strong monsoon year) and 1979 (a very weak monsoon year), a study has been made to examine the mean circulation features of the troposphere over India, and the structures of the temperatures and the winds of the middle atmosphere over Thumba. The study suggested that the axis of the monsoon trough (AMT) at 700 hPa shifted southward in 1975 and northward towards the foothills of the Himalayas in 1979, from its normal position. Superimposed on the low-pressure area (AMT) at 700 hPa, a well-defined divergence was noticed at 200 hPa over the northern India in 1975.The mean temperatures, at 25,50 and 60 km (middle atmosphere) over Thumba were cooler in 1975 than in 1979. While a cooling trend in 1975 and warming trend in 1979 were observed at 25 and 50 km, a reversed picture was noticed at 60 km. There was a weak easterly/ westerly (weak westerly phase) zonal wind in 1975 and a strong easterly zonal wind in 1979. A phase reversal of the zonal wind was observed at 50 km. A tentative physical mechanism was offered, in terms of upward propagation of the two equatorially trapped planetary waves i.e. the Kelvin and the mixed Rossby-gravity waves, to explain the occurrence of the two spells of strong warmings in the mesosphere in 1975. 相似文献
14.
2002—2010年我国高空探测系统逐步完成了由原来的59-701型探空系统升级为L波段雷达-电子探空仪系统的工作,湿度传感器由原来的肠衣更换为碳湿敏电阻。该文对全国98个高空站相对湿度探测值在换型前后的差异进行了统计分析。结果表明:探空系统换型后,相对湿度探测值较换型前显著降低,表现为明显的干偏差,且随着高度的增加而增大,200,500 hPa和850 hPa相对湿度分别偏低14.6%,8.3%和5.3%。受太阳辐射的影响,这种干偏差在白天甚于夜间;换型前后相对湿度的概率分布也发生了明显变化,整个对流层相对湿度低于20%的低值出现频率明显高于换型前,200 hPa相对湿度小于20%的出现频率由换型前的10%增加到换型后的53%。最明显的变化是相对湿度为3%以下的出现频率,换型前各高度层出现频率均接近于0,但换型后200,500 hPa和850 hPa出现频率分别达到16.2%,9.9%和2.2%。 相似文献
15.
L波段秒级探空资料在GRAPES同化系统中的应用研究 总被引：12，自引：7，他引：5
我国探空站的探空系统升级为L波段探空系统后,可以获取全国120个站点连续自动测定的高空温、压、湿、风等高垂直分辨率秒级和分钟级探空廓线数据。为了分析高垂直分辨率探空秒级资料水平和垂直结构特征,并将其应用于区域GRAPES-3DVAR变分同化预报系统中,文章比较秒/分钟级探空与传统探空资料使用对资料同化预报带来的影响。试验中使用2011年6—7月资料进行分析,结果发现:秒级探空资料具有水平分布均匀,垂直结构非常密集的特点;在850、500 hPa等层次上高度分析比传统探空分析更接近NCEP分析,显示出对分析场的改进效果;同时风场在200 hPa以上的高层分析中改进显著,表现出高分辨率资料使用在高层分析中对系统模拟更加准确的特征。由于模式预报初值的改进,降水预报评分有所提高,预报偏差明显变小。因此高垂直分辨率秒级探空资料的使用对数值模式分析初值及预报的改进有着积极的意义,这为进一步开发利用秒级探空资料打下基础。 相似文献
16.
S. K. Sinh D R. Talwalkar S. G. Narkhedkar P. L. Kulkarni S. Nair S. Rajamani 《大气科学进展》1990,7(4):491-501
In the present study objective analyses of relative humidity (RH) at surface and at the levels of 850,700 and 500 hPa have been made using Gandin’s (1963) optimum interpolation scheme. As the horizontal resolution of the radiosonde stations is rather inadequate for upper air humidity analysis, a scheme has been developed, following Rasmussen (1982) to estimate the upper air RH from the surface observations like surface RH, present weather and cloud cover. The relative humidities at the levels 850, 700 and 500 hPa were related to the surface observations through three separate regression relations. The RH values at 850, 700 and 500 hPa levels were estimated from the surface RH, cloud coverage and present weather using the above regression relations and subsequently the objective analyses at 00 GMT for the period from 4 July to 8 July 1979, were made using these estimated data along with the observed radiosonde data. Objective analyses were also made for the same period using only the radiosonde data for comparison to study the impact of those estimated data. Root mean square errors were computed for all the five days by interpolating RH at the observing stations from the objectively analysed field and comparing them with the actually observed RH to examine how best the analyses (with and without estimated data) fitted the observations. Lastly they were compared with satellite cloud pictures. This study shows that the estimated upper air RH values have positive impact on the analysis of upper air RH and could be used over radiosonde date sparse region and even over oceanic regions. 相似文献
17.
O. S. R. U. Bhanu Kumar S. Ramalingeswara Rao S. Ranganathan S. S. Raju 《Asia-Pacific Journal of Atmospheric Sciences》2010,46(1):21-28
Aim of this diagnostic study is to investigate the impact of intra-seasonal oscillations in terms of number, duration and intensity on rainfall during June through September, 1979–2006. Analysis of wavelet spectra for winds at 850 hPa field for monsoon period reveals number and duration of oscillations, which exercise profound influence on monsoon rainfall. Results indicate that four to six oscillations appear in normal rainfall or flood cases, while two or three oscillations are identified in the years of drought episodes. Though total duration of above oscillations is varied from 25 to 85 days, the duration is short (20 to 35 days) obviously in the years of less number of oscillations and also the number of oscillations are directly related to the monsoon rainfall. The coefficient of correlation between them is 0.56, which is significant at 1% level. To examine the strength of intra-seasonal oscillations in terms of different indices on seasonal rainfall is investigated. The Madden and Julian Oscillation Index shows an inverse relationship with rainfall, where as a direct relationship is noticed between Monsoon Shear Index and rainfall for the study period. Both results are significant at 5% level. To consolidate the above statistical relationships, seasonal circulation changes in the contrasting years of monsoon rainfall have been examined; present study reveals that anomaly negative outgoing longwave radiation is noticed over most of Arabian Sea, Indian sub-continent and the Bay of Bengal during June through September in flood year (1988). But opposite convective activity is true in drought year (2002). Similarly the spatial U-850 hPa field distribution showed much stronger monsoon winds in 1988, while zonal circulation was very weak in 2002. Such differences are observed in the anomaly zonal wind field at 200 hPa also. Over the monsoon region U-850 hPa field is almost a mirror image of U-200 hPa distribution of wind field. Finally annual cycles of U-850 and U-200 hPa fields reflect striking difference at 200 hPa level during the summer monsoon period in flood and drought years. 相似文献
18.
This paper describes the preparation of a preliminary set of maps of gradient‐level wind climate over Canada and some neighbouring regions of the United States. The data for this study were drawn from twice‐daily records of radiosonde ascents at a network of ten Canadian upper air stations. The period covered by the data was 1960–69, and this was supplemented by statistical information on upper level winds at fourteen points in the United States. The analysis and subsequent mapping were carried out for 300 and 500 m above ground level and were based on a number of statistical models: the bivariate Gaussian distribution of wind velocities characterized by the vector mean and standard vector deviation, monthly Weibull distributions of wind speed and a new model of extreme annual wind occurrences developed from a consideration of wind as a stochastic process. 相似文献
19.
《大气与海洋》2013,51(3):361-376
Abstract The goal of this study is to evaluate the impact of incorporating the marine surface winds retrieved from the ERS‐2 scatterometer in the Canadian three‐dimensional variational analysis system, (3D‐var). The aspects of the 3D‐var most relevant to the assimilation of surface ‐wind observations and a general method for resolving the directional ambiguity of the retrieved scatterometer ‐winds are first described. A comparison ‐with 6‐h forecasted winds is then made to demonstrate that these data are of high quality, but exhibit a speed bias that can be removed by increasing their amplitudes by about 5%. The analysis increment from a single scatterometer wind observation is calculated to illustrate the response of the 3D‐var to surface wind observations. As a consequence of the forecast error covariance model, the assimilation of surface wind observations produces meteorologically consistent increments for both the rotational and divergent wind components and the mass field. The results from a series of cross‐validation experiments using ship‐based wind data demonstrate a positive impact of assimilating scatterometer winds and the effectiveness of a simple method for estimating and removing the speed bias. The impact of assimilating scatterometer data within a short assimilation cycle is also evaluated. Overall, the results show that including scatterometer data in the analysis decreases the 6‐h forecast error of surface wind by 13%. Over the northern extra‐tropics the improvement is only 4% and for the southern extra‐tropics it is 16%. Results from a series of two‐day forecasts produced using the analyses from the assimilation cycles with and without retrieved scatterometer winds included are also presented. Using radiosonde observations at 850 hPa, 500 hPa, 250 hPa and 100 hPafor verification, the impact on the forecasts is nearly neutral in the northern hemisphere and the tropics. Conversely, a significant positive impact is found on both wind and mass fields in the southern hemisphere over the entire two‐day forecast. 相似文献
20.
对兰州单站探空资料７００ｈＰａ和５００ｈＰａ风向进行统计分析表明，兰州７００ｈＰａ风向既受复杂地形影响，又受天气系统影响。７００ｈＰａ的东北风和东南风与降水有较好的相关关系。７００ｈＰａ、５００ｈＰａ风向有机组合，其降水相关概率提高到７１％—８２％。 相似文献