Dynamical impact of parameterized turbulent orographic form drag on the simulation of winter precipitation over the western Tibetan Plateau
Dynamical impact of parameterized turbulent orographic form drag on the simulation of winter precipitation over the western Tibetan Plateau
复制标题
参数化湍流地形阻力对青藏高原西部冬季降水模拟的动力学影响
DOI：
10.1007/s00382-019-04628-0
复制
发表时间：
2019
期刊：
影响因子：
4.6
通讯作者：
Wang Yan
中科院分区：
文献类型：
--
作者：
Zhou Xu;Yang Kun;Beljaars Anton;Li Huidong;Lin Changgui;Huang Bo;Wang Yan
亚网格地形阻力直接作用于风，通过控制大气水汽输送影响区域水循环。TOFD模拟的风分量和大气环流的日循环与观测和ERA-Interim数据一致，而没有TOFD方案的模拟中存在较强的西风带。后者导致更多来自西部的纬向AWV输送，以及西部高原及其周边地区更多的降水。当使用两个基于观测的降水产品进行评估时，TOFD方案的实施减少了偏差。因此，该方案对区域大气补给具有明显的动力控制作用，模式中小尺度地形阻力的参数化有助于改善青藏高原西部地区冬季降水的预测。
Sub-grid orographic drag directly acts on wind and impacts the regional water cycle through control of atmospheric water vapor (AWV) transport. The effect of turbulent orographic form drag (TOFD) on wind and precipitation is investigated in this study using the WRF model for a winter month over the western Tibetan Plateau (TP), where solid precipitation supplies large amounts of water resources. The diurnal cycle of wind components and atmospheric circulation simulated with TOFD are consistent with observations and ERA-Interim data, whereas stronger westerlies exist in the simulation without the TOFD scheme. The latter results in more zonal AWV transport from the west and more precipitation over the western TP and surroundings. The implementation of the TOFD scheme leads to reduced biases, when evaluated with two observation-based precipitation products. It is therefore concluded that this scheme has a clear dynamical control on the regional atmospheric water recharge and thus the parameterization of the small-scale orographic drag in the model helps to improve the prediction of wintertime precipitation in the western TP region.