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1.
《气象》2007,33(6)
2007年4月500hPa环流指数、环流特征量资料国家气候中心气候系统诊断预测室环流指数西太平洋副热带高压东亚槽极涡平均月候平均123456积指数面度指数强伸脊点西线位置脊界位置北均位置平均强度平经中度心位纬置度强度亚欧地区IzI m1.120.701.180.541.160.870.780.721.040.591.010.931.540.54亚洲地区IzI m1.050.641.170.440.600.790.730.510.880.631.041.031.900.41245295141915418020°E85°N92007年4月亚洲地区逐日500hPa西风环流指数及副热带高压脊线(120°E、130°E、140°E)位置中央气象台中期预报科日12345678910111213141516171… 相似文献
2.
《气象》2007,33(2)
2006年12月500hPa环流指数、环流特征量资料国家气候中心气候系统诊断预测室环流指数西太平洋副热带高压东亚槽极涡平均月候平均123456积指数面度指数强伸脊点西线位置脊界位置北均位置平均强度平经中度心位纬置度强度亚欧地区IzI m1.650.751.450.811.700.621.850.521.860.661.410.881.631.01亚洲地区IzI m1.560.691.110.791.570.681.550.681.820.581.650.531.630.94256790162114110970°W75°N-22006年12月亚洲地区逐日500hPa西风环流指数及副热带高压脊线(120°E、130°E、140°E)位置中央气象台中期预报科日12345678910111213141516… 相似文献
3.
《气象》2007,33(7)
2007年5月500hPa环流指数、环流特征量资料国家气候中心气候系统诊断预测室环流指数西太平洋副热带高压东亚槽极涡平均月候平均123456积指数面度指数强伸脊点西线位置脊界位置北均位置平均强度平经中度心位纬置度强度亚欧地区IzI m1.430.451.520.651.570.171.480.311.470.491.480.391.050.68亚洲地区IzI m1.410.351.850.531.380.101.290.221.320.351.270.321.330.572552100162213726070°W70°N232007年5月亚洲地区逐日500hPa西风环流指数及副热带高压脊线(110°E、120°E、130°E)位置中央气象台中期预报科日123456789101112131415161… 相似文献
4.
《气象》2006,32(11):128-128
2006年9月500hPa环流指数、环流特征量资料国家气候中心气候预测室国家气候中心气候预测室环流指数西太平洋副热带高压东亚槽极涡平均月候平均123456积指数面度指数强伸脊点西线位置脊界位置北均位置平均强度平经中度心位纬置度强亚欧地区IZIM1.330.581.320.521.210.741.350.691.150.561.120.531.810.46亚洲地区IZIM1.480.531.250.581.140.901.690.511.280.431.290.392.200.343040952427132324110E85N12006年9月亚洲地区逐日500hPa西风环流指数及副热带高压脊线(120°E、130°E、140°E)位置中央气象台中2006年9月亚洲地区逐日500hPa… 相似文献
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2018年5月江苏极端降水事件发生前副热带高压异常及原因分析 总被引：1，自引：1，他引：0
本文利用NCEP/NCAR提供的2.5°×2.5°全球再分析数据,以2018年5月江苏两次极端降水事件发生前副高异常变化为研究对象,根据全型涡度方程定量计算了凝结潜热分布不均引起的涡源对副高迅速演变的诱发作用。研究发现,120°E处500 hPa 5月第1候副高脊线多年平均位置位于16°N附近,而2018年同期120°E的脊线则位于19°N附近,呈明显偏北的状态。2018年5月第1候东亚500 hPa位势高度距平场表现出南高北低的形态,有利于我国华东地区成为暖湿空气和干冷空气的交汇区,构成了江苏5月两次极端降水过程的有利环流背景。与对流层中层环流异常对应的是,同期115°~125°E之间850 hPa上8 g·kg-1等比湿线位于28°N附近,较多年气候态偏北15°,强降水区内同期850 hPa比湿较往年偏多2~4 g·kg-1,相应距平百分率可达50%~75%。且110°~120°E之间θse的340 K等值线5月第1候多年气候态位于13°N以南,但2018年同期却偏北至25°N附近,暖湿气团北进有利于强降水的发生。副高西伸北抬前,副高主体西侧和北侧均有凝结潜热加热区存在,说明潜热加热与副高演变关系密切。垂直剖面表明600 hPa为凝结潜热加热中心,向上加热率随高度减小,因此500 hPa处潜热加热率垂直梯度为负,使得500 hPa成为负涡源所在。因凝结潜热分布不均产生的负涡源,1~2 d便可形成与副高自身十分接近的负涡度值,足以诱发副高突变,该时间尺度与副高真实演变时间相符。负涡源中与凝结潜热垂直分布不均相关的部分起主要作用,而与凝结潜热水平分布不均相关的部分同时期产生的负涡度最多仅为前者的1/3左右,对副高突然西伸的作用较小。与凝结潜热相关的负涡源作为引发西太平洋副高异变的可能原因,其与副高的关系仍需进一步研究。 相似文献
6.
从大尺度环流形势场、西风环流指数、阻塞高压、副热带高压和南亚高压等方面,对2001年汛期强降水多发时段的中期天气特征进行了分析,结果表明①极涡由一个中心分裂为多个中心,北半球极涡呈偶极型或多极型,其中有一较强中心位于东半球偏于亚洲一侧;②亚欧中高纬环流形势为两脊一槽型,亚洲中部为一低压槽;③连续性强降水发生在西风环流指数由峰值向谷点过度的过程中;④鄂霍次克海阻塞高压的建立是造成我省连续性强降水的关键;⑤西太平洋副热带高压在短时间内迅速西伸北跳,140°E副高脊线位置位于30°N附近并稳定;⑥100 hPa南亚高压脊线北跳至33°N以北,且中心位置自西向东震荡并稳定于90°E以东地区. 相似文献
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从大尺度环流形势场、西风环流指数、阻塞高压、副热带高压和南亚高压等方面 ,对 2 0 0 1年汛期强降水多发时段的中期天气特征进行了分析 ,结果表明 :①极涡由一个中心分裂为多个中心 ,北半球极涡呈偶极型或多极型 ,其中有一较强中心位于东半球偏于亚洲一侧 ;②亚欧中高纬环流形势为两脊一槽型 ,亚洲中部为一低压槽 ;③连续性强降水发生在西风环流指数由峰值向谷点过度的过程中 ;④鄂霍次克海阻塞高压的建立是造成我省连续性强降水的关键 ;⑤西太平洋副热带高压在短时间内迅速西伸北跳 ,14 0°E副高脊线位置位于 30°N附近并稳定 ;⑥10 0hPa南亚高压脊线北跳至 33°N以北 ,且中心位置自西向东震荡并稳定于 90°E以东地区 相似文献
10.
《气象》2005,31(8)
2005年6月500hPa环流指数、环流特征量资料国家气候中心气候预测室环流指数西太平洋副热带高压东亚槽极涡月平均候平均123456中心位置经度纬度强度亚欧地区IZ IM0.920.441.050.310.520.710.790.361.270.521.050.330.860.38亚洲地区IZ IM0.900.410.850.330.350.661.000.331.480.461.080.290.640.362962115202565W65N37面积指数强度指数西伸脊点脊线位置2005年6月亚洲地区逐日500hPa西风环流指数及副热带高压脊线(120°E、130°E、140°E)位置中央气象台中期预报科日123456789101112131415161718192021222324252627282930数215191174138… 相似文献
11.
In this paper,the continuity and thermodynamic equations including moisture forcings were derived.Using these two equations and the basic momentum equation of local Cartesian coordinates,the budget equation of generalized moist potential vorticity(GMPV) was derived.The GMPV equation is a good generalization of the Ertel potential vorticity(PV) and moist potential vorticity(MPV) equations.The GMPV equation is conserved under adiabatic,frictionless,barotropic,or saturated atmospheric conditions,and it is closely associated with the horizontal frontogenesis and stability of the real atmosphere.A real case study indicates that term diabatic heating could be a useful diagnostic tool for heavy rainfall events. 相似文献
12.
Potential vorticity (PV) has been served as a powerful and useful dynamic tracer for the understanding of the large-scale dynamics and synoptic variations in the atmosphere and oceans. Significant progress has been made on the application of PV.
In recent decades there has been a substantial amount of work done on PV in a general moist atmosphere. In this paper PV and the generalized moist potential vorticity (GMPV) and their application in the tropical cyclones and mesoscale meteorological field are reviewed. The GMPV is derived for a real atmosphere (neither totally dry nor saturated) by introducing a generalized potential temperature instead of the potential temperature or equivalent potential temperature. Such a generalization can depict the moist effect on PV anomaly in the non-uniformly saturated atmosphere. A new convective vorticity vector (CVV) is introduced in connection with GMPV in order to diagnose the development of tropical deep convections. 相似文献
13.
青藏高原东北侧一次暴雪过程的湿位涡分析 总被引：4，自引：0，他引：4
利用NCEP（1°×1°）全球再分析格点资料,对青藏高原东北侧2002年10月18日一次暴雪天气进行诊断分析。结果表明：500 hPa北上的西南暖湿气流与东移南压的西北冷空气在36°N附近交汇形成的高原切变线是造成这次强降水的主要天气系统。暴雪发生在700 hPa湿位涡正压项MPV1正值密集带和湿位涡斜压项MPV2负值区中。由于等eθ线变得陡立密集,大气对流不稳定能量释放,MPV2绝对值增大,大气湿斜压性增强导致下滑倾斜涡度发展是形成此次暴雪的重要原因,它对暴雪预报有着很好的指示作用。 相似文献
14.
Dynamical and Thermal Problems in Vortex Development
and Movement. Part II: Generalized Slantwise
Vorticity Development 
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下载免费PDF全文 The development of vertical vorticity under adiabatic condition is investigated by virtue of the view of potential vorticity and potential temperature (PV-θ) and from a Lagrangian perspective. A new concept of generalized slantwise vorticity development (GSVD) is introduced for adiabatic condition. The GSVD is a coordinate independent framework of vorticity development (VD), which includes slantwise vorticity development (SVD) when a particle is sliding down the concave slope or up the convex slope of a sharply tilting isentropic surface under stable or unstable condition. The SVD is a special VD for studying the severe weather systems with rapid development of vertical vorticity. In addition, the GSVD clarifies VD and SVD. The criteria for VD and SVD demonstrate that the demand for SVD is much more restricted than the demand for VD. When an air parcel is moving down the concave slope or up the convex slope of a sharply tilting isentropic surface in a stable stratified atmosphere with its stability decreasing, or in an unstable atmosphere with its stability increasing, i.e., its stability θ z approaches zero, its vertical vorticity can develop rapidly if its C D is decreasing. The theoretical results are employed to analyze a Tibetan Plateau (TP) vortex (TPV), which appeared over the TP, then slid down and moved eastward in late July 2008, resulting in heavy rainfall in Sichuan Province and along the middle and lower reaches of the Yangtze River. The change of PV 2 contributed to the intensification of the TPV from 0000 to 0600 UTC 22 July 2008 when it slid upward on the upslope of the northeastern edge of the Sichuan basin, since the changes in both horizontal vorticity η s and baroclinity θ s have positive effects on the development of vertical vorticity. At 0600 UTC 22 July 2008, the criterion for SVD at 300 K isentropic surface is satisfied, meaning that SVD occurred and contributed significantly to the development of vertical vorticity. The appearance of the stronger signals concerning the VD and SVD surrounding the vortex indicates that the GSVD concept can serve as a useful tool for diagnosing the development of weather systems. 相似文献
15.
河北北部一次区域性暴雪过程的湿位涡分析 总被引：3，自引：0，他引：3
应用湿位涡理论及NCEP再分析资料(水平分辨率1°×1°),对2007年3月3—4日河北省北部出现的罕见区域性暴雪过程进行诊断分析。结果表明:500 hPa西来槽和地面气旋是造成大范围暴雪的主要天气系统。暴雪发生在700 hPa湿位涡正压项MPV1正值区和湿位涡斜压项MPV2负值区中。由于等θse线变得陡立密集,大气对流不稳定能量释放,MPV2绝对值增大,大气湿斜压性增强,导致下滑倾斜涡度发展,是形成此次暴雪的重要原因。湿位涡对暴雪预报有着很好的指示作用。 相似文献
16.
THE RELATIONSHIP BETWEEN HORIZONTAL VORTICITY INDUCED BY
VERTICAL SHEAR AND VERTICAL MOTION DURING A SQUALL LINE
PROCESS 总被引：2，自引：0，他引：2
The horizontal vorticity equation used in this study
was obtained using the equations of motion in the pressure
coordinate system without considering friction, to reveal its
relationship with vertical shear. By diagnostically analyzing
each term in the horizontal vorticity equation during a squall
line process that occurred on 19 June 2010, we found that the
non-thermal wind term had a negative contribution to the local
change of upward movement in the low-level atmosphere, and that
its impact changed gradually from negative to positive with
altitude, which could influence upward movement in the mid- and
upper-level atmosphere greatly. The contribution of upward
vertical transport to vertical movement was the largest in the
low-level atmosphere, but had negative contribution to the
upper-level atmosphere. These features were most evident in the
development stage of the squall line. Based on analysis of
convection cells along a squall line, we found that in the
process of cell development diabatic heating caused the
subsidence of constant potential temperature surface and non-
geostrophic motion, which then triggered strong convergence of
horizontal acceleration in the mid-level atmosphere and
divergence of horizontal acceleration in the upper-level
atmosphere. These changes of horizontal wind field could cause a
counterclockwise increment of the horizontal vorticity around
the warm cell, which then generated an increase of upward
movement. This was the main reason why the non-thermal wind term
had the largest contribution to the strengthening of upward
movement in the mid- and upper-level atmosphere. The vertical
transport of large value of horizontal vorticity was the key to
trigger convection in this squall line process. 相似文献
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对流涡度矢量在暴雨诊断分析中的应用研究 总被引：9，自引：5，他引：4
位涡在诊断分析中是一个常用且有效的物理量, 但在深对流系统中由于湿等熵面的倾斜变得较弱。因此, 本文利用高守亭等(2004)提出的新矢量——对流涡度矢量(简称CVV)来研究深对流系统, 并用对流涡度矢量诊断华北一次大范围的大到暴雨天气过程。结果表明, CVV垂直分量在中纬度对流性暴雨中有很好的指示性, 它的高值区与云中水凝物和地面降水有较好的对应关系, 暴雨区位于CVV垂直分量高值区附近及其北侧的梯度大值区内。CVV垂直分量是与云相联系的参数, 暴雨区垂直积分和区域平均的CVV垂直分量和云中水凝物混合比的相关系数为0.92, 与降水率的相关系数为0.71, 比湿位涡与云中水凝物的相关系数高很多。CVV垂直分量反映了水平涡度和水平相当位温梯度的相互作用, 可以把中纬度深对流系统中的中尺度动力过程和热力过程与云微物理过程密切联系起来, 有助于理解环流和云相互作用促使对流发展的机制, 可以很好地追踪暴雨系统的发展和演变。 相似文献
19.
On the Generalized Ertel--Rossby Invariant 总被引：1，自引：0，他引：1
A new invariant called the generalized Ertel-Rossby invariant(GER) was developed in this study.The new invariant is given by the dot product of the generalized vorticity and the generalized velocity.The generalized vorticity is the absolute vorticity minus the cross-product of the gradient of Lagrangian-time integrated temperature and the gradient of entropy.The generalized velocity is the absolute velocity minus the sum of the gradient of Lagrangian-time integrated kinetic potential and the Lagrangian-time integrated temperature multiplied by the gradient of entropy.In addition to the traditional potential vorticity,the GER invariant may provide another useful tool to study the atmospheric dynamic processes for weather phenomena ranging from large scales to small scales. 相似文献
20.
水平涡度与夏季风环流变化 总被引：1，自引：0，他引：1
在斜压涡度发展理论的基础上，讨论了大尺度大气运动中水平涡度向垂直涡度转化的情况，并用以刻划夏季风变动。将声坐标中涡度方程的有关项在2坐标中分离出水平涡度向垂直涡度转化的主要项，经尺度分析得出，在对流层中、高层，这些转化项中的水平分量是大尺度大气斜压性涡度发展的主要因子。通过对1998年4—8月的GAME(GEWEX Asian Monsoon Experiment，全球能量和水分循环试验(GEWEX)的子试验：亚洲季风试验，简称GAME)再分析资料进行实际计算发现，转化项在东亚夏季风上升支的600 hPa及以上层次对P坐标垂直涡度的局地变化贡献很大，不能忽略。同时发现水平涡度向垂直涡度的转化对南海季风爆发和江淮梅雨入梅及其发展过程均有指示性意义。南海季风爆发以后，在中国东南部地区，转化项的大小与夏季风的活跃和中断等活动吻合，转化项的变化反映了西太平洋副高在中国大陆的活动规律。 相似文献