摘要
过去的研究结果指出 ,青藏高原东北侧的伏旱是在副高控制下的干旱 ,其干旱的典型环流呈上下一致的正压结构。为进一步研究青藏高原东北侧伏旱环流的维持机制 ,利用一个带有强迫和耗散的球面无辐散准地转正压涡度方程谱模式和经过严格挑选的五个实际典型伏旱个例 (共 48d)环流场 ,通过求解平衡方程得到了伏旱环流强迫场 ,再用该强迫场分别在有强迫和无强迫情形下进行了 8d的数值试验。结果表明 :伏旱环流的平均维持时间在一周左右 ,影响和维持它的外界强迫主要来自青藏高原北侧 。
The previous results show that the midsummer drought on the northeast side of Qinghai Xizang Plateau is a drought controled by the subtropical latitude high, and the structure of drought circulation displayes a barotropic state. In order to study the maintaining mechanism of the drought circulation, the resultant circulation of 5 typical midsummer drought cases and its forcing field were calculated, and the numerical experiment utilizing a spherical, nondivergent, quasigeostrophic, barotropic vorticity equation spectral model with forcing and dissipation termes was made. The results show that the mean duration of maintenance of drought circulation is about a week or so, the existence of drougt flow forcing source regions is critical for the maintenance of the drought circulation. The main forcing source region is in the North of Qinghai Xizang Plateau.
出处
《高原气象》
CSCD
北大核心
2001年第1期52-57,共6页
Plateau Meteorology
基金
甘肃省气象局"青年科技开发基金"
"98-2-2"项目资助
