论文标题
热带涡流和平均动量通量的年度周期和纵向结构
Annual cycle and longitudinal structure of tropical eddy and mean momentum fluxes
论文作者
论文摘要
研究了热带上层对流层中平均子午线和涡流动量通量的纵向结构和年度周期。以区域为单位，这两个术语相互反对，在印度夏季季风期间互相反对。这个区域平均特征源于丰富的纵向结构，该结构通过将地球划分为三个区域，即亚太地区太平洋（AWP），中太平洋西部大西洋（CP-WA）和非洲部门。平均收敛项在所有三个区域均具有凝聚力，在北方夏季都有一个峰，并且始终起作用可减速区域流量。 Helmholtz的分解表明，在局部跨赤道细胞中发散的子午风的绝对涡度对流负责所有部门平均收敛的一致性。 另一方面，涡流的融合从非洲地区的小且季节性不变到AWP（CP-WA）领域的季节性最大值（Minima）的一个季节性最大化（减速），该区域加速（减速）区域平均流量。 AWP和CP-WA区域中的涡流通量不同的性质在冬季，分别是由于波浪的热带和热带引起的。在夏季，AWP地区几乎占所有涡流融合。实际上，旋转区域 - 分歧的子午成分在区域平均涡流中的主要作用在单个扇区中不存在。最后，在整年中，CP-WA区域是局部倾覆细胞受涡流活动强烈影响的地方。
The longitudinal structure and annual cycle of mean meridional and eddy momentum fluxes in the tropical upper troposphere are studied. In zonal mean, these two terms oppose each other and peak during the Indian summer monsoon. This zonal mean character arises from a rich longitudinal structure that is revealed by splitting the globe into three zones, namely, the Asia-West Pacific (AWP), central Pacific-West Atlantic (CP-WA) and African sectors. The mean convergence term is cohesive across all three regions, has a single peak in the boreal summer and always acts to decelerate the zonal flow. A Helmholtz decomposition shows that the advection of absolute vorticity by the divergent meridional wind in localized cross-equatorial cells is responsible for the coherent nature of the mean convergence across all sectors. On the other hand, the eddy convergence goes from being small and seasonally invariant in the African region to one with large seasonal maxima (minima) in AWP (CP-WA) sector that accelerate (decelerate) the zonal mean flow. The disparate nature the eddy flux in the AWP and CP-WA regions is in the winter season and is due to the tropical and extratropical origin of waves, respectively. In summer, the AWP region accounts for almost all of the eddy flux convergence. In fact, the leading role of the rotational zonal - divergent meridional component in the zonal mean eddy flux does not hold in individual sectors. Finally, through the year, the CP-WA region is where the local overturning cell is strongly influenced by eddy activity.
