發(fā)布時間：2018-01-11 09:40

  本文關鍵詞：基于TRMM衛(wèi)星的亞洲穿透性對流及其對ENSO事件響應的研究　出處：《蘭州大學》2014年碩士論文　論文類型：學位論文

  更多相關文章： 穿透性對流 亞洲 雷達 閃電 微波亮溫 ENSO

【摘要】：穿透性對流(Overshooting Convections,簡稱OCs)不但常常伴隨暴雨、冰雹、大風、龍卷和閃電等災害性天氣事件,而且在對流層和平流層物質交換過程中也具有重要的作用。本論文利用TRMM衛(wèi)星的多傳感器觀測資料研究了亞洲地區(qū)OCs的時空分布和強度(雷達反射率、微波亮溫和閃電)特征及其對ENSO事件的響應,同時結合歐洲中心再分析資料(ERA-Interinn)分析了相應的環(huán)境氣象場分布特征,主要研究結果如下： 1.亞洲地區(qū)OCs占冷云系統(tǒng)(云頂紅外亮溫小于235K)總量的2.6%,其中陸地和海洋上分別占2.2%和3.0%。OCs主要分布在150N以南的熱帶地區(qū),約50%的OCs發(fā)生在夏季,其中八月最為活躍,兒乎每月海洋上OCs數(shù)目都高于陸地上,并且洋面上OCs的體積降水率和面積均高于陸地。無論是陸地和海洋,OCs的體積降水率均比非穿透性對流(NOCs)高一個數(shù)量級。對閃電頻數(shù)、微波亮溫和雷達回波頂高的分析表明,OCs的對流強度明顯比非穿透性對流(NOCs)強,其中陸地OCs強度又強于海洋。強OCs主要集中在青藏高原南麓、中國中東部和東南亞地區(qū),同時這些地區(qū)OCs的發(fā)生概率也很高。 2.OCs的空間分布規(guī)律與熱力、動力因子和水汽條件的分布呈現(xiàn)較好的對應關系。熱帶地區(qū)CAPE和比濕分別比副熱帶高約400J/kg和11g/kg、而垂直風切變比副熱帶約小15m/s(不包括青藏高原),為OCs的發(fā)生提供了適宜的環(huán)境條件；夏季青藏高原南麓地區(qū)CAPE和比濕都很高(CAPE大于500J/kg,比濕大于15g/kg),垂直風切變在3m/s左右,非常有利于強對流的發(fā)生和發(fā)展；中國中東部地區(qū)的OCs數(shù)目少但強度大,該區(qū)域夏季的比濕和CAPE比其他季節(jié)大、垂直風切變小(約5m/s),為強OCs的形成提供了有利的環(huán)境條件。 3. ENSO期間,絕大部分地方OCs的頻數(shù)變化與強度變化呈負相關關系。海洋性大陸和西北太平洋上OCs頻數(shù)變化最為顯著,表現(xiàn)為El Nino時期頻數(shù)減小,而La Nina時期頻數(shù)增大(除冬季西北太平洋)。OCs強度變化最明顯的區(qū)域發(fā)生在青藏高原及其南麓地區(qū),表現(xiàn)為El Ninno時期強度增強,La Ninna時期強度減弱。中國中東部除了La Nina夏季OCs頻數(shù)有所增大外,其他季節(jié)的頻數(shù)變化均不明顯,但強度變化比較顯著。El Nino時期,OCs的頻數(shù)變化與比濕和CAPE的變化相一致,但與垂直風切變的變化相反；La Nina時期除冬季外,OCs的頻數(shù)變化與環(huán)境場的對應關系均與El Nino時期相同。
[Abstract]:Penetrating convection overshooting Contractions (OCs) is often accompanied not only by heavy rain, hail, gale, tornado and lightning, but also by disastrous weather events. It also plays an important role in the process of material exchange between troposphere and stratosphere. In this paper, the temporal and spatial distribution and intensity of OCs in Asia are studied by using the multi-sensor observation data of TRMM satellite. Radar reflectivity. The characteristics of microwave light and lightning and its response to ENSO events are analyzed. The distribution characteristics of the corresponding environmental meteorological field are also analyzed by using ERA-Interinn reanalysis data from the European Center. The main findings are as follows: 1. OCs in Asia accounts for 2.6% of the total cold cloud system (the infrared bright temperature of the cloud top is less than 235K). Among them, 2.2% on land and 3.0 on ocean are mainly distributed in tropical areas south of 150N, about 50%% of OCs occur in summer, and most active in August. The number of OCs in the ocean is higher than that on land, and the volume precipitation rate and area of OCs on the ocean surface are higher than those on land, whether on land or sea. The volume precipitation rate of OCs is one order of magnitude higher than that of NOCs. The convection intensity of OCs is stronger than that of non-penetrating convection (NOCs), and the OCs intensity of land is stronger than that of ocean. The strong OCs is mainly concentrated in the southern foot of Qinghai-Xizang Plateau, central and eastern China and Southeast Asia. At the same time, the probability of occurrence of OCs in these areas is also very high. 2. The spatial distribution and thermal properties of OCs. The distribution of dynamic factors and water vapor conditions showed a good correspondence. The CAPE and specific humidity of tropical areas were about 400J / kg and 11g / kg higher than those of subtropics, respectively. The vertical wind shear is about 15m / s smaller than that of the subtropics (excluding the Qinghai-Tibet Plateau), which provides suitable environmental conditions for the occurrence of OCs. In summer, the CAPE and specific humidity in the southern foot of Qinghai-Xizang Plateau are very high, the Cape is more than 500J / kg, the specific humidity is more than 15g / kg / kg, and the vertical wind shear is about 3 m / s. It is very conducive to the occurrence and development of strong convection; In eastern and central China, where OCs is small but intense, summer specific humidity and CAPE are larger than other seasons and vertical windshear is smaller (about 5 m / s). It provides favorable environmental conditions for the formation of strong OCs. 3. During ENSO, there was a negative correlation between the frequency change of OCs and the intensity change in most places, and the OCs frequency in the oceanic continent and the Northwest Pacific Ocean was the most significant. The results show that the frequency of El Nino decreases, while the frequency of La Nina increases (except in winter, the most obvious change of intensity in the Northwest Pacific Ocean) occurs in the Qinghai-Xizang Plateau and its southern foothills. The intensity increases in El Ninno period and weakens in La Ninna period, except for the increase of OCs frequency in La Nina summer in the central and eastern part of China. The frequency change of other seasons is not obvious, but the intensity change is obvious. The frequency change of Nino is consistent with the change of specific humidity and CAPE, but the change of intensity is opposite to that of vertical wind shear. The corresponding relationship between the frequency variation and environmental field in La Nina period is the same as that in El Nino period except in winter.
【學位授予單位】：蘭州大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：P732;P412.27

【參考文獻】

相關期刊論文 前10條

1 徐華英,吉武勝,黃美元;風切變對積云發(fā)展影響的數(shù)值模擬研究[J];大氣科學;1988年04期

2 劉冬霞;郄秀書;馮桂力;;華北一次中尺度對流系統(tǒng)中的閃電活動特征及其與雷暴動力過程的關系研究[J];大氣科學;2010年01期

3 劉鵬;王雨;馮沙;李崇銀;傅云飛;;冬、夏季熱帶及副熱帶穿透性對流氣候特征分析[J];大氣科學;2012年03期

4 徐祥德,周明煜,陳家宜,卞林根,張光智,劉輝志,李詩明,張宏升,趙冀俊,索朗多吉,王繼志;青藏高原地-氣過程動力、熱力結構綜合物理圖象[J];中國科學(D輯:地球科學);2001年05期

5 周秀驥,羅超,李維亮,史久恩;中國地區(qū)臭氧總量變化與青藏高原低值中心[J];科學通報;1995年15期

6 黃榮輝，傅云飛，，臧曉云;亞洲季風與ENSO循環(huán)的相互作用[J];氣候與環(huán)境研究;1996年01期

7 傅云飛,宇如聰,徐幼平,肖慶農(nóng),劉國勝;TRMM測雨雷達和微波成像儀對兩個中尺度特大暴雨降水結構的觀測分析研究[J];氣象學報;2003年04期

8 吳國雄,毛江玉,段安民,張瓊;青藏高原影響亞洲夏季氣候研究的最新進展[J];氣象學報;2004年05期

9 周曉霞;丁一匯;王盤興;;夏季亞洲季風區(qū)的水汽輸送及其對中國降水的影響[J];氣象學報;2008年01期

10 陳丹;呂達仁;;臺風麥莎與赤道穿透對流云團的初步比較分析[J];氣象學報;2010年06期

本文編號：1409045