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1.
康志明 《气象》2002,28(8):58-61
今年 5月 ,与常年同期相比 ,除东北大部、华北北部、华南东部、内蒙古东部和南疆大部等地降水明显偏少外 ,我国其余大部地区降水偏多或接近常年。本月全国大部地区气温接近常年或偏低 ,其中黄淮西部、江淮大部、西南地区东部、湖北和湖南北部等地的气温偏低 1~ 2℃ ,东北和华南东部沿海偏高 1~ 2℃。本月有一个热带风暴生成。1 天气概况5月份降水量 ,西南东部地区、黄淮大部及其以南地区在 10 0mm以上 ,其中江南及重庆大部、贵州大部、云南西南部、广西、广东中部等地一般有 2 0 0~ 330mm ,局部地区达 330~ 4 70mm ;东北、华北、…  相似文献   

2.
鲁中山区东北部丘陵地区霜冻特征分析   总被引:1,自引:0,他引:1  
利用临朐县1980-2008年29年间作物生育季节3—11月的所有“黑、白”霜观测记录,对鲁中山区东北部丘陵地区霜冻进行统计分析。结果表明,鲁中山区东北部丘陵地区霜冻有明显的地域特征,即霜冻危害较重的季节在3—4月份;霜冻类型以辐射霜冻为主;霜冻发生的气候特征与当地地形地貌密切相关;从而为鲁中山区东北部丘陵地区霜冻的预测预报提供可靠的依据。  相似文献   

3.
Fluctuations in the length of the growing season in Minnesota   总被引:3,自引:0,他引:3  
Fluctuations in growing season length and in the dates of the last spring freeze and first fall freeze between 1899 and 1982 were studied for five rural Minnesota stations with long, high quality records. A general increase in growing season length was found, but there was substantial variation in the pattern of fluctuations among the stations. The increase in growing season length is not clearly and uniformly related to changes in the dates of first and last freezes. The interannual variability of growing season duration is on the order of the increase in duration so that the change would not be readily apparent to a casual observer. Our results do not correspond well with certain other studies of growing season length nor with fluctuations in hemispheric mean temperature. We conclude that extreme care must be used in extrapolating results of growing season length studies in space and in relating them to mean temperature fluctuations.  相似文献   

4.
2002年夏季山东干旱成因分析   总被引:11,自引:4,他引:11  
顾润源  汤子东 《气象》2004,30(8):22-26
分析了山东省 2 0 0 2年夏季降水、气温特点和干旱情况 ,并从大气环流、北太平洋SST、气候背景等方面对少雨干旱气候的影响进行了分析 ,指出冬季大气环流、北太平洋SST对山东夏季旱涝趋势的预测具有重要的指示意义。  相似文献   

5.
主要用洛阳15 年冬季能见度资料对比,提出1994 年11 月—12 月出现多日大雾天气在历史上是少见的。通过分析1994 年几例典型大雾形成的具体特点和影响因素及天气形势。指出稳定层的存在,适宜的地面气压场是导致大雾的直接原因  相似文献   

6.
主要用洛阳15年冬季能见度资料对比,提出1994年11月-12月出现多日大雾天气在历史上是少见的.通过分析1994年几例典型大雾形成的具体特点和影响因素及天气形势.指出稳定层的存在,适宜的地面气压场是导致大雾的直接原因.  相似文献   

7.
本文利用常规资料及数值预报产品,对2014年12月1日牡丹江出现的暴雪天气过程进行诊断分析,结果表明:高空阶梯槽的形成和维持,为暴雪提供了有利的环流背景,中低空切变线和低压倒槽是主要影响系统,为暴雪产生提供强的辐合上升运动和水汽条件;冷平流的持续使近地面气温降至0℃以下,保证了降雪所需要的温度条件。  相似文献   

8.
Summary From a study of five cases of pronounced fronts in the upper troposphere, it is concluded that the waterspout model offers the most satisfactory solution to the problem of connecting frontal boundaries and tropopauses. Composite cross sections of temperature, potential temperature, normal wind component and potential vorticity are presented for the five cases. On the basis of the potential vorticity measurements it is suggested that the most likely explanation for the formation of the high-level front is a folding of the tropopause.
Zusammenfassung Auf Grund einer Untersuchung von fünf Fällen ausgesprochener Fronten in der höheren Troposphäre wird der Schluß gezogen, daß die Wasserhosen-Vorstellung am besten den Zusammenhang zwischen Fronten und Tropopausen darstellt. Kombinierte Querschnitte von Temperatur, potentieller Temperatur, normaler Windkomponente und potentieller Vorticity werden für die fünf Fälle vorgelegt. Auf Grund der Bestimmungen der potentiellen Vorticity wird dargelegt, daß die wahrscheinlichste Erklärung für die Entstehung einer Front in der Höhe in der Annahme einer Faltung der Tropopause besteht.

Résumé En se fondant sur cinq cas de fronts très nets de la haute troposphère, les auteurs concluent que le schéma de trombe constitue la meilleure solution pour représenter la liaison entre zones frontales et tropopause. Ils donnent des profils combinés de température, de température potentielle, de composantes normales du vent et de vorticity potentielle pour les cinq cas. Ils montrent à l'aide de mesures de la vorticity potentielle que l'explication la plus probable de la formation d'un front en altitude consiste à admettre un plissement de la tropopause.


With 11 Figures

Contribution No. 37, Department of Meteorology and Climatology. —The research reported in this article has been supported by the Geophysical Research Directorate, Air Force Cambridge Research Center, under Contract No. AF 19 (604)-1811.  相似文献   

9.
Presented are the results of mercury content measurements in the surface air layer in the Sea of Japan in the period from October 27 to November 11, 2010. It is revealed that the mercury content varied from 0.6 to 3.8 ng/m3. It is demonstrated that the mercury concentration distribution has geographical zoning and depends on the movement of air masses and on the closeness of anthropogenic sources. The maximum mercury concentration is detected in the central part of the sea at the southwestern and southern directions of the wind, that is associated with the industrial emissions of East Asia countries. The minimum mercury concentration corresponding to the concentration in the surface air layer of the Arctic, Atlantic Ocean (Northern Hemisphere), and the Sea of Okhotsk and Bering Sea was observed along the coast of Primorye at the northwestern wind direction.  相似文献   

10.
On the basis of long series of contemporary instrumental measurements, the dynamics of waters in the western boundary current of the Indian Ocean is studied. For the first time, the background (quasi-stationary) circulation is estimated, and summer and winter monsoon components of the velocity field are detected. It is shown that the features of water dynamics of the Somali Current pattern are caused by the intensification of circulation during the summer phase, when the background and monsoon velocity fields with the same sign of vorticity are superimposed on each other. During the winter phase, on the contrary, superposition of background and monsoon circulations, with the opposite signs, is associated with a weakening of the resultant velocity of the currents.  相似文献   

11.
2020年,长江三峡地区年平均气温17.2℃,接近常年;年平均降水量1530.8毫米,偏多29%,为1961年以来第二多,仅次于1998年.6月,7月降水量及年平均暴雨日数均为1961年以来第二多.平均风速较常年偏大;相对湿度略偏高;各月均无酸雨出现,近十余年酸雨强度呈现明显减弱趋势.2020年,三峡地区夏季暴雨洪涝灾...  相似文献   

12.
1998年洞庭湖流域特大暴雨的雨水情分析   总被引:2,自引:1,他引:1  
潘志祥  宁迈进 《气象》1999,25(9):11-14
应用1998 年汛期湖南省97 个气象站、200 多个水文站的雨量、水文资料,分析了同期洞庭湖流域特大暴雨洪涝的雨水情概况和基本特征。  相似文献   

13.
Summary Rainfall regimes are primarily unimodal in central and eastern Venezuela but bimodal (peaks in May–June and September-October-November with a minimum in July–August) in the northwest. There is a sharp transition across the Andes suggesting a topographic-circulation connection. However, a mid-summer minimum also occurs at other locations in Venezuela and Central America during individual years. This paper addresses the nature and control of the regimes including the role of large-scale circulation features and convection as indicated by outgoing longwave radiation data. Altitudinal characteristics of precipitation in the Andes and their spatial variability are also investigated. The development of the minimum within the rainy season annual cycle is shown to be related to the combined effects of the evolution of sea surface temperatures in the east Pacific warm pool and reinforced in the area of the Andes by enhanced easterlies during July and August.Abbreviations used in text ENSO El Nino-Southern Oscillation - EPWP East Pacific Warm Pool - ITCZ Inter-tropical Convergence Zone - MEI Multivariate ENSO Index - MSM Mid-Summer Minimum - NCEP National Centers for Environmental Prediction - OLR Outgoing Longwave Radiation - SOI Southern Oscillation Index - SST Sea Surface Temperature With 13 Figures  相似文献   

14.
海效应降雪的发生发展机制与内陆地区降雪有明显区别。中国渤海中东部、渤海海峡、黄海、东海海面及其沿海地区均可产生海效应降雪,以山东半岛的烟台和威海地区最为显著。从各海域海效应降雪的分布特征、渤海海效应暴雪的多尺度作用、地形对渤海海效应暴雪的影响、海效应降雪的研究资料、方法和数值预报检验等5个方面总结了近十年中国海效应降雪的主要研究进展,旨在进一步加深对海效应降雪的理解和认识。并针对当前预报业务难点和研究的薄弱环节提出了未来的研究重点。  相似文献   

15.
曾庆存  叶笃正 《大气科学》1980,4(4):379-393
关于旋转大气中运动的适应过程的各方面问题的研究,至今已获得了许多结果,本文试图作一全面的评述。全文分六个部分,本期发表前三部分,包括弓信、正压大气和斜压大气局地扰动的情况,讲述地转适应过程和演变过程的可区分性、小扰动线性化方程情况的地转适应过程和非线性完全适应过程、地转适应过程和演变过程的相互作用、多时间尺度现象、近赤道地区扰动演变的特点、初始场水平尺度和垂直结构的影响、科氏参数变化的影响、能量弥散过程以及静力平衡适应、热力因子和摩擦的影响等问题。其余三部分将在下期发表。  相似文献   

16.
The results are presented of hydrological studies in the coastal zone of the Sea of Japan in autumn in different years. It is revealed that the typical density stratification of water is formed there in autumn. The amplitudes are estimated of regular (with the periodicity of tidal harmonic M2) vertical displacements of isotherms in the intermediate layer and maximum values of flow velocity in the surface and bottom layers. It is demonstrated that temperature perturbations are induced at the shelf edge and propagate to the coastal zone with the velocity that is close to the velocity of the first mode of internal gravity waves with the frequency of the tidal harmonic M2.  相似文献   

17.
青藏高原近地面层微气象学特征   总被引:12,自引:3,他引:12  
利用1998年5月-7月在改则、当雄和昌都三测站获得的近地面层气象要素变化的观测资料,分析了青藏高原近地面层风速、温度和湿度日变化特征及廓线规律,发现高原近地面层微气象学特征具有自己的特点;同时还讨论了高原近地面层白天出现的逆湿现象。  相似文献   

18.
Summary ?This paper deals with variations and trends in some components of the water balance: the soil water content; evaporation loss from the soil (from the surface and underlying layers); transpiration; ground water recharge and runoff. These components are calculated by means of the Palmer procedure. This analysis is based on data from Osijek, Croatia from this century (1900–1995). Besides the meteorological input parameters necessary for the water balance calculations, i.e. precipitation, temperature and relative humidity, the pedological characteristics of this area have also been taken into account. Fluctuations have been considered by means of the 11-year binomial filtered series and linear trends were tested by means of the Mann-Kendall rank test. For a closer look on the trends of water balance components, a progressive analysis of the time series was performed, too. The results show a significant increase in potential evapotranspiration and evapotranspiration and decrease in runoff and soil water content has occurred during the century. Received February 22, 1999/Revised August 3, 1999  相似文献   

19.
流域水文模型是区域水资源评价的重要工具,基于普林斯顿全球气象驱动数据集和澜沧江-湄公河流域(简称:澜湄流域)八个水文站实测资料,分析了澜湄流域不同区间的水文特性,采用RCCC-WBM模型(Water Balance Model developed by Research Center for Climate Change,RCCC-WBM)开展了区间径流及水量平衡模拟研究。结果表明:1)澜湄流域不同区间气候水文差异显著,上游气温低且年内变幅大,下游气温高年内变幅小;尽管不同区间降水、径流的年内分配特征总体一致,但径流的年内分布峰值大多滞后降水峰值一个时段。2)RCCC-WBM模型能够较好地模拟出澜湄流域不同区间的径流过程,率定期和验证期的月径流模拟效率系数(Nash-Sutcliffe Efficiency,NSE)均在60%以上,总量模拟误差(Relative Error,RE)也均控制在±10%以内,模型具有较好的区域适应性。3)模拟的土壤含水量都具有先衰减后增加再衰减的年内分配特征;不同季节径流和蒸发耗散的水源不同,降水是汛期水分耗散的主要来源,而土壤含水量是非汛期径流和蒸发消耗的主要水源。  相似文献   

20.
盛夏亚洲和西太平洋地区除存在强大又稳定的太陆青藏高压外,西太平洋副热带高压也是对流层大气中深厚的高压实体. 这是两个既独立又有紧密联系的高压系统. 本文研究指出,它们之间的演变关系有两种情况:一种是整个环流调整,促使两个高压相向或相背而行,调整到一个位置或者分离在一定波长范围内;另一种是西太平洋副热带高压稳定存在,副热带地区环流作新的调整,大陆青藏高压东移与副高合并. 本文还分析太平洋中部槽与西太平洋副热带高压的关系,指出两者存在一定的对应关系.但其制约关系如何,有特进一步研究.  相似文献   

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