CAJ | 학술논문

利用经验正交函数分解(EOF)、相关分析、小波分析等方法对低纬高原地区148站的气象观测数据进行分析，以揭示该区域冬、春季的降水时空分布及其环流背景差异，了解低纬高原干旱的原因。结果表明：冬、春季降水时空分布特征差异显著，春季降水量较大幅度高于冬季，差异最大区域位于低纬高原的西部和南部，呈“L”型区域分布；冬季降水在1985-1990年和2005年以后存在4～6a的振荡周期，1990年以后存在准2a和10a左右的振荡周期；春季降水在1995年以前存在较明显的4～6a振荡周期，2001年以后存在准2a的振荡周期。导致冬、春季降水差异显著的环流背景主要为：与冬季相比，春季青藏高原北侧的东亚大槽较弱；但高原南侧的南支槽活跃；海洋上的西太平洋副热带高压偏强偏西，沿着高压外围的气流更容易到达低纬高原，从而水汽输送更强；副高与南亚高压的两高辐合区向北延伸的范围更大，有利于低纬高原降水。进一步研究表明，低纬高原冬季降水主要与青藏高原南侧孟加拉湾附近区域的热力作用密切相关，春季降水则与该地区的比湿关系显著。
이용경험정교함수분해(EOF)、상관분석、소파분석등방법대저위고원지구148참적기상관측수거진행분석，이게시해구역동、춘계적강수시공분포급기배류배경차이，료해저위고원간한적원인。결과표명：동、춘계강수시공분포특정차이현저，춘계강수량교대폭도고우동계，차이최대구역위우저위고원적서부화남부，정“L”형구역분포；동계강수재1985-1990년화2005년이후존재4～6a적진탕주기，1990년이후존재준2a화10a좌우적진탕주기；춘계강수재1995년이전존재교명현적4～6a진탕주기，2001년이후존재준2a적진탕주기。도치동、춘계강수차이현저적배류배경주요위：여동계상비，춘계청장고원북측적동아대조교약；단고원남측적남지조활약；해양상적서태평양부열대고압편강편서，연착고압외위적기류경용역도체저위고원，종이수기수송경강；부고여남아고압적량고복합구향북연신적범위경대，유리우저위고원강수。진일보연구표명，저위고원동계강수주요여청장고원남측맹가랍만부근구역적열력작용밀절상관，춘계강수칙여해지구적비습관계현저。
In order to reveal the difference of temporal evolution and spatial distribution of rainfall and the corresponding circulation difference in winter and spring, and get the reason of drought in low-latitude highlands applied EOF, correlation analysis, wavelet analysis to analyze 148 stations’ observational precipitation. The results showed that there was a prominent difference between the winter and spring rainfall’s temporal evolution and spatial distribution. The spring rainfall was more than the winter's a lot, and the most different area was located in western and southern low-latitude highlands, which seemed to be a "L" pattern. The winter rainfall had a 4-6 years cycle during 1985-1990 and after 2005 and had quasi-2 years and around 10 years cycles after 1990.The spring rainfall had a 4-6 years cycle before 1995 and quasi-2 years cycle after 2001. The differences of circulation background accounted for the difference between the winter and spring rainfall. Compared to winter, the east Asian Trough to the north of the Tibetan Plateau was weaker and the southern branch trough to the south of the plateau was more active in spring; the subtropical high in the western pacific was more westward and stronger, then the flow along its flank was easier to reach to the low-latitude highlands with more water vapor input. The convergence area between the subtropical high and south high shifted more northward. Further studies indicated that the winter rainfall was very linked to the near-surface heating over around the bay of Bengal area, but the spring rainfall was closely related to the specific humidity.