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The global energy cycle of stationary and transient atmospheric waves: Results from ECMWF analyses 总被引：3，自引：0，他引：3
Summary The role of stationary (monthly mean) and transient (departure from monthly mean) waves within the atmospheric energy cycle is examined using global analyses from the European Centre for Medium Range Weather Forecasts (ECMWF) for the period 1980–1987. Only January and July averages are considered.It is confirmed that planetary stationary waves are basically baroclinic. Their contribution to the globally averaged energy cycle of the atmosphere is comparable to that of the transient waves. In January they contribute about 40% to the baroclinic conversion (CA) from zonal mean to eddy available potential energy. Local values for the northern hemisphere even show a predominant role of the stationary wave conversions over those originating from transient waves. Part of the available potential energy of stationary waves (A
SE) is converted to kinetic energy by warm air rising and cold air sinking. Nonlinear energy conversion, which can be interpreted as destruction of stationary temperature waves by transients, is the second sink forA
SE. The order of magnitude of these two processes is similar.Barotropic nonlinear conversions, though negligible in the global average, reveal large conversion rates between the mean positions of the polar and the subtropical jets. Their orientation is suggestive of a tendency to increase stationary wave kinetic energyK
SE at its local minimum between the jets at the expense of the synoptic scale transients.While all terms of the energy cycle related to stationary waves reveal a predominance of the planetary scale (zonal wave numbers 1–3) transient waves are governed by synoptic scale waves (zonal wave numbers 4–9) only with respect to the baroclinic and barotropic conversions: a significant amount of transient wave energy (50% for the global average ofA
TE) is due to planetary scale waves.With 15 Figures 相似文献
3.
云南暴雨涡散场动能转换函数的动态分析 总被引：1，自引：0，他引：1
对1996年云南主汛期（6－8月）逐日散度风动能和旋转风动能之间的转换函数C（KD,KR）特征进行深入研究,同时分析了C（KD,KR）各项Af、Az、B、C在动能转换函数中所起的作用。研究结果表明,对流层内C（KD,KR）＞0,同时对流层低层的C（K,KR）＞中高层的C（KD,KR）之和．极易出现暴雨过程;Af项在整个动能转换中起主要作用,71％的Af与C（KD,KR）具有相同的符号,Az项和B项在动能转换中起振荡作用,Az＋B控制着29％的动能转换方向。 相似文献
4.
The energetics process of offehore typhoon in three kinds of explosive enhancement (TEE) are ana lyzed using ECMWF data. The results are as follows: (a) During the explosive development process,the enhancement of the rotational kinetic enersy (KW) is mainly in the lower troposphere while that ofthe potential energy (PE) is in the upper troposphere. The magnitude of rotational kinetic energy islargely bigger than that of divergent enersy (KΧ). (b) The environmental energy advected into the typhoon was about 30% of the internal increment of typhoon energy. The magnitude of energy was an order larger than increment of typhoon energy. (c) Among those three kinds of explosively developed typhoon, the enersy transformation mechanisms are different. (d) The influence of environment fields onabrupt intensification of typhoons couldn't be overestimated. 相似文献
5.
大气分层扰动位能控制方程及其应用——南海夏季风活动的能量收支 总被引：1，自引：1，他引：0
针对局地环流能量转换问题,本文推导了分层扰动位能一阶矩 (LPPE1) 和动能 (KE) 的控制方程,分析了方程中各能量项的空间分布和季节变化特征,并以南海夏季风为例,诊断了夏季风活动各相位的能量收支特征.结果表明,850 hPa高度上在赤道辐合带、大部分季风区、风暴轴地区是LPPE1的源区,副热带的大洋东部和高纬度地区是LPPE1的汇区,强源、汇的中心与LPPE1的纬向偏差场的脊、槽分布对应较好.LPPE1向KE的转化项 (CK)取决于垂直速度和大气稳定度,是连接KE和LPPE1的纽带,在暖 (冷) 空气上升 (下沉) 时,转化项为正,LPPE1向KE转化能量,反之KE转化为LPPE1.在850 hPa 高度上CK的分布特征是在赤道辐合带以及大部分季风区有大值分布,北半球风暴轴和南半球西风带有连续分布的正值区.将这应用到南海夏季风活动的能量收支,在南海夏季风恢复相位,CK增大,在南海夏季风活跃相位,CK达到最大,且为边界输入能量的2~3倍,CK是南海夏季风恢复、活跃的最重要因素.探讨了南海夏季风活跃的条件,当LPPE1等于南海季风区的夏季气候平均值时,上升速度大于临界速度的情形,有利于南海夏季风由中断相位向活跃相位的转变. 相似文献
6.
在第(一)部分的基础上,进一步讨论辐散风动能和旋转风动能的收支以及这两种动能之间的转换过程。结果表明,尽管辐散风动能在总动能中所占比重很小,但它的变化与强对流天气过程的发生发展有着更为密切的关系。计算结果表明,在辐散风动能与旋转风动能的转换函数{KD,KR)中,B项(代表垂直运动与旋转风动能的垂直变化的耦合)是最大的转换项;在强对流区,反映涡管伸缩机制的A项也是一个很重要的转换项。就区域时间平均而言,有旋转风动能向辐散风动能(KR→KD)转换。 相似文献
7.
西伯利亚风暴轴的气候特征及其可能维持机制 总被引：2，自引：1，他引：1
基于1959—2014年NCEP/NCAR的逐日再分析资料,首先研究了西伯利亚风暴轴各季节的气候平均特征,然后以冬季为例,利用能量诊断方程,从能量学的角度对其的可能维持机制进行了探讨,并在上述分析过程中与北半球两大洋风暴轴的特征进行了对比。结果表明:(1)西伯利亚风暴轴一年四季都独立存在,虽强度要比两大洋风暴轴的强度弱很多且位置偏北,但可以定义为一个弱风暴轴。(2)比较来看,西伯利亚风暴轴强度的季节变化与北太平洋风暴轴的季节变化类似。与两大洋风暴轴位于急流东北侧不同,冬季西伯利亚风暴轴位于东亚温带急流的西侧。(3)进一步的能量分析结果表明,与两大洋风暴轴一样,斜压不稳定的能量转换(Ke4)也是西伯利亚风暴轴区域天气尺度扰动动能的主要来源;而扰动非地转位势通量散度项(Ke3)和时间平均气流对扰动动能的平流输送项(Ke1)也是风暴轴下游发展所需的扰动动能来源之一。 相似文献
8.
利用辐散风和旋转风的动能收支方程,对北方一次北上台风倒槽暴雨过程暴雨区内的涡散场能量收支和转换进行了计算.结果表明:暴雨区内动能的增加是暴雨增幅的一个主要原因.暴雨发展时,就旋转风动能(KR)而言,旋转风动能通量(HFR)辐合是主要能源,而旋转风的动能产生项(GR)是主要能汇;就辐散风动能(KD)而言,辐散风的动能产生项(GD)是主要能源,辐散风动能通量(HFD)辐散是主要能汇;总动能水平通量(HF)提供的辐合主要表现于对流层中、低层,这就使得低层辐合加强,上升运动加强,有利于暴雨的增幅.在暴雨过程中次网格尺度效应由能源转变为能汇,在暴雨发展之时能汇减小;能量的转换项C(KD,KR)总为正值,在转换项中,地转效应项的贡献很大.说明暴雨过程能量均由KD向KR转换,也就是说有效位能经KD向KR转换,充分说明了在整个暴雨过程中,尽管辐散风动能变化(∂KD/∂t)很小,但是它在其中充当“桥梁”作用,C(KD,KR)在暴雨发展时达到最大,此时能量转换最为旺盛;对流层低层辐散风动能向旋转风动能的转换是暴雨产生和发展的重要条件.此次暴雨过程,在暴雨区内表现为斜压不稳定和正压稳定共存的特征,其发展过程是系统斜压不稳定增长,正压稳定性减弱的过程,暴雨增幅的另一个重要原因就是暴雨区内低层斜压的发展. 相似文献
9.
Pavel Vargin 《大气与海洋》2015,53(1):29-41
AbstractThe 2009–10 Arctic stratospheric winter, in comparison with other recent winters, is mainly characterized by a major Sudden Stratospheric Warming (SSW) in late January associated with planetary wavenumber 1. This event led to a large increase in the temperature of the polar stratosphere and to the reversal of the zonal wind. Unlike other major SSW events in recent winters, after the major SSW in January 2010 the westerlies and polar vortex did not recover to their pre-SSW strength until the springtime transition. As a result, the depletion of the ozone layer inside the polar vortex over the entire winter was relatively small over the past 20 years. The other distinguishing feature of the 2010 winter was the splitting of the stratospheric polar vortex into two lobes in December. The vortex splitting was accompanied by an increase in the temperature of the polar stratosphere and a weakening of the westerlies but with no reversal. The splitting occurred when, in addition to the high-pressure system over northeastern Eurasia and the northern Pacific Ocean, the tropospheric anticyclone over Europe amplified and extended to the lower stratosphere. Analysis of wave activity in the extratropical troposphere revealed that two Rossby wave trains propagated eastward to the North Atlantic several days prior to the vortex splitting. The first wave train propagated from the subtropics and mid-latitudes of the eastern Pacific Ocean over North America and the second one propagated from the northern Pacific Ocean. These wave trains contributed to an intensification of the tropospheric anticyclone over Europe and to the splitting of the stratospheric polar vortex. 相似文献
10.
Based on the ERA5 reanalysis datasets during 1980–2019, a total of eleven zonal shear lines (ZSLs) that caused heavy precipitation and lasted more than 60 hours over the Tibetan Plateau in summer are selected for composite analysis. By decomposing the kinetic energy (K) near the ZSL into divergent and rotational kinetic energies (KD and KR) and the kinetic energy of interaction between the divergent wind and the rotational wind (KRD), the influence of the rotational and divergent winds on the evolution of the ZSL intensity is investigated from the perspective of KD and KR. The main results are as follows. The ZSL is a comprehensive reflection of rotation and convergence. The intensity evolution of ZSL is essentially synchronized with those of K, KR, and KRD but lags behind KD by about three hours. The enhancement of K is mainly contributed by KR, which is governed by the conversion from KD to KR. Furthermore, the increase in the conversion from KD to KR is controlled by the geostrophic effect term Af, which is determined by the joint enhancement of the zonal rotational and meridional divergent wind components (uR and vD). Therefore, the joint enhancement of uR and vD controls the increase of the ZSL intensity, leading to increased precipitation. 相似文献
11.
V. B. Rao M. B. Rosa J. P. Bonatti S. H. Franchito 《Meteorology and Atmospheric Physics》2003,83(1-2):35-49
Summary. Using 9 years (1985–1993) data, final stratospheric warmings in the Southern Hemisphere are studied. Interannual variations
in the onset date and the temperatures are noted. In 1985 the stratosphere was colder by about 5 K and the wave activity was
less. This year the final warming got delayed. In contrast in 1988 the final warming occurred earlier when compared with the
mean picture and the wave activity was more. An examination of Eliassen-Palm fluxes showed the important role of planetary
waves in the wave-mean flow interaction. In the energetics the most spectacular change is the reduction of zonal kinetic energy.
Before the warming the energy exchanges were Pz → Pe → Ke → Kz ← Pz and after the warming they were Pz ← Pe ← Ke → Kz ← Pz. The dramatic reduction of zonal kinetic energy seems to be due to two effects: the reduction in Ke → Kz conversion and the weakening of direct meridional circulation.
Received October 3, 2001; revised June 5, 2002 相似文献
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The profound impact of solar irradiance variations on the decadal variability of Earth' s climate has been investigated by previous studies.However,it remains a challenge to quantify the energetic particle precipitation(EPP) influence on the surface climate,which is an emerging research topic.The solar wind is a source of magnetospheric EPP,and the total energy input from the solar wind into Earth' s magnetosphere(E_(in)) shows remarkable interdecadal and interannual variability.B ased on the new E_(in) index,this study reveals a significant interannual relationship between the annual mean E_(in)and Eurasian cold extremes in the subsequent winter.Less frequent cold events are observed over Eurasia(primarily north of 50°N) following the higher-than-normal E_(in) activity in the previous year,accompanied by more frequent cold events over northern Africa,and vice versa.This response pattern shows great resemblance to the first empirical orthogonal function of the variability of cold extremes over Eurasia,with a spatial correlation coefficient of 0.79.The pronounced intensification of the positive North Atlantic Oscillation events and poleward shift of the North Atlantic storm track associated with the anomalously higher E_(in) favor the anomalous extreme atmospheric circulation events,and thus less frequent extreme cold temperatures over northern Eurasia on the interannual time scale.It is further hypothesized that the wave-mean flow interaction in the stratosphere and troposphere is favorable for the connection of E_(in) signals to tropospheric circulation and climate in the following winter. 相似文献
14.
利用多年逐月海温距平和区风应力距平观测资料,运用线性回归和ＥＯＦ分析方法,分析了ＥＮＳＯ相联系的热带太平洋典型风应力异常场结构。结果显示,与ＥＮＳＯ线性相关的风应力异常场在时间尺度上表现为低频变化,在水平结构上主要表现为四个典型分布。 相似文献
15.
The spray content in the surface boundary layer above an air—water interface was determined by a series of measurements at various feteches and wind speeds in a laboratory facility. The droplet flux density N(z) can be described in terms of the scaling flux density N* and von Karman constant K throguh the equation, N(z)/N* = −(1/K) ln(z/z0d) where z is height above the mean water level and z0d is the droplet boundary layer thickness. N* is given by a unique relationship in terms of the roughness Reynolds number u*σ/ν where σ is the root-mean-square surface displacement. Spray inception occurred for u* 0.3. The dominant mode of spray generation in the present and most other laboratory tests, as well as in available field data, appears to be bubble bursting. 相似文献
16.
The Surface Energy Budget and Its Impact on the Freeze-thaw Processes of Active Layer in Permafrost Regions of the Qinghai-Tibetan Plateau 总被引：1，自引：0，他引：1
Junjie MA Ren LI Hongchao LIU Zhongwei HUANG Tonghua WU Guojie HU Yao XIAO Lin ZHAO Yizhen DU Shuhua YANG 《大气科学进展》2022,39(1):189-200
The surface energy budget is closely related to freeze-thaw processes and is also a key issue for land surface process research in permafrost regions.In this study,in situ data collected from 2005 to 2015 at the Tanggula site were used to analyze surface energy regimes,the interaction between surface energy budget and freeze-thaw processes.The results confirmed that surface energy flux in the permafrost region of the Qinghai-Tibetan Plateau exhibited obvious seasonal variations.Annual average net radiation(Rn)for 2010 was 86.5 W m-2,with the largest being in July and smallest in November.Surface soil heat flux(G0)was positive during warm seasons but negative in cold seasons with annual average value of 2.7 W m-2.Variations in Rn and G0 were closely related to freeze-thaw processes.Sensible heat flux(H)was the main energy budget component during cold seasons,whereas latent heat flux(LE)dominated surface energy distribution in warm seasons.Freeze-thaw processes,snow cover,precipitation,and surface conditions were important influence factors for surface energy flux.Albedo was strongly dependent on soil moisture content and ground surface state,increasing significantly when land surface was covered with deep snow,and exhibited negative correlation with surface soil moisture content.Energy variation was significantly related to active layer thaw depth.Soil heat balance coefficient K was>1 during the investigation time period,indicating the permafrost in the Tanggula area tended to degrade. 相似文献
17.
Summary The rate of oceanic heat storage of the upper 200m of the Arabian Sea is explained in terms of net air-sea heat flux (Q
F), heat change due to horizontal divergence and vertical motion (Q
V) and heat change due to lateral advection (Q
A). The analysis revealed that the heat storage of the Arabian Sea is mainly controlled byQ
V while the effect ofQ
A is much larger than expected. Parameterisation of summer cooling revealed that the depletion of energy from the mixed layer is mainly due to upwelling and horizontal advection though large amount of heat is accumulated due to net air-sea heat flux. The annual heat balance of the upper 200m of the Arabian Sea suggested large heat gain by air-sea exchange processes. About two third of this heat gain is compensated by horizontal advection and one third by vertical advection.With 4 Figures 相似文献
18.
On the basis of the budget equations for KR and KD, this paper presents the horizontal pattern of budget terms for two kinds of low level jets (LLJ) with and without heavy rain. The results show that the mechanisms for generating and maintaining LLJ are different, and especially, the direction of energy conversion is opposite. A positive conversion from KD to KR appears to be a necessary but not sufficient condition in the lower troposphere near the heavy rain area. The intensity and direction of energy conversion depends not only on the relative position of vorticity and divergence field, but also on the vertical profile of the jets directly. 相似文献
19.
K. Zeller 《Meteorology and Atmospheric Physics》1950,2(4):401-403
Zusammenfassung A. undE. Vassy haben in der Frage der Temperatur-abhängigkeit des Ozongehalts der Atmosphäre aus der Gleichung loge
n
–logJ
n
logK(T
n
) geschlossen, daß auch die Gleichung loge
n
logJ
n
+logK(T
n
) gültig sei. Es wird hier nun gezeigt, daß die bei der ersten Gleichung erlaubten Vernachlässigungen bei der zweiten zu großen Fehlern führen können und daß daher von A. undE. Vassy kein Beweis für die Richtigkeit der Beziehunge=J.K(T) erbracht ist.
Summary In the question of temperature dependence of ozone content of the atmosphere A. andE. Vassy have concluded from the equation loge n –logJ n logK(T n ) that also the formula loge n logJ n +logK(T n ) must be valid. In this paper it is proved that the neglections which may be admitted for the first equation, can conduct to great errors. Therefore A. andE. Vassy have not produced a proof for the correctness of the equatione=J.K(T).
Résumé A. etE. Vassy en étuidant le problème de la teneur de l'ozone atmosphérique en relation avec la température ont admis que l'équation loge n –logJ n logK(T n ) entraînait aussi la relation loge n logJ n +logK(T n ). On montre ici que les simplifications admises pour la première équation conduisent pour l'application de la seconde à de fortes erreurs, et que par conséquent ces auteurs n'ont pas fourni de preuve de la justesse de la relatione=J.K(T).相似文献
20.
欧亚北部冬季增雪“影响”我国夏季气候异常的机理研究:欧洲冬季增雪的重要作用 总被引：1，自引：0，他引：1
在作者前期研究(穆松宁和周广庆, 2012)的基础之上, 本文主要利用了EOF分析和相关分析, 对欧亚北部冬季新增雪盖面积(Total Fresh Snow Extent, 记为TFSE)与我国夏季气候异常之间"隔季相关"的机理进行了更进一步的探讨, 主要目的在于寻找TFSE气候效应的冬季增雪面积关键区。结果表明, 虽然欧洲中纬冬季增雪面积(文中均以TFSE-1表示)与我国夏季气候异常的关系不很显著, 但其变化维系了上述"隔季相关"的物理途径, 其变化对TFSE的气候效应而言起关键作用, 但是, 亚洲中纬冬季增雪面积(文中均以TFSE-2表示)的贡献尚不清楚;另外, 对TFSE的气候效应而言, 起作用的实际上是欧亚中纬冬季增雪面积(文中均以TFSE-1-2表示), 其不但与我国夏季气候异常具有更显著的"隔季相关", 而且这种"隔季相关"还具有和TFSE非常相似的、但更为清晰的物理途径, 因此, 在气候预测的意义上, TFSE-1-2可替代TFSE。 相似文献