梅雨鋒面對(duì)流的動(dòng)力和微物理特征雷達(dá)觀測(cè)研究
發(fā)布時(shí)間：2018-09-07 11:01
【摘要】：梅雨鋒中國(guó)東部江淮地區(qū)夏季主要的天氣系統(tǒng),其產(chǎn)生的強(qiáng)降水常常引發(fā)城市內(nèi)澇等氣象災(zāi)害,并造成巨大的生命和經(jīng)濟(jì)損失。以往對(duì)梅雨鋒降水的對(duì)流特征等研究較多,但是對(duì)鋒面雨帶內(nèi)部對(duì)流的動(dòng)力和微物理特征的研究較少。2014年7月11日至12日,江淮地區(qū)發(fā)生一次典型的梅雨鋒降水過(guò)程,持續(xù)時(shí)間長(zhǎng),降水強(qiáng)度大,24小時(shí)累計(jì)降水量最大超過(guò)100mm。在此鋒面雨帶南北兩側(cè)存在不同特征的對(duì)流降水。本文利用南京大學(xué)C波段雙偏振多普勒天氣雷達(dá)和合肥雷達(dá)、定遠(yuǎn)C波段雙偏振雷達(dá)的觀測(cè)資料,結(jié)合先進(jìn)的雙多普勒雷達(dá)風(fēng)場(chǎng)反演技術(shù),對(duì)此梅雨期鋒面雨帶中對(duì)流的動(dòng)力和微物理特征進(jìn)行分析。首先,通過(guò)環(huán)境假相當(dāng)位溫將梅雨鋒面雨帶分為南北兩個(gè)部分,并利用雷達(dá)觀測(cè)識(shí)別出梅雨鋒面雨帶中的對(duì)流單體。對(duì)鋒面南北兩側(cè)對(duì)流進(jìn)行分析表明,鋒面南側(cè)對(duì)流主要由較強(qiáng)的對(duì)流單體和線狀對(duì)流組成的對(duì)流降水區(qū)域,對(duì)流降水強(qiáng)度較強(qiáng),四小時(shí)最大累積降水量達(dá)到60 mm,而鋒面北側(cè)為鑲嵌在層云降水區(qū)域內(nèi)的對(duì)流降水,對(duì)流發(fā)生頻數(shù)相對(duì)南側(cè)較少,四小時(shí)累積降水量最大值僅達(dá)20 mm。鋒面南側(cè)對(duì)流中上升速度較北側(cè)強(qiáng),最大值達(dá)到5 ms-1,對(duì)流發(fā)展高度高,回波強(qiáng)度強(qiáng),冰相過(guò)程強(qiáng);而鋒面北側(cè)對(duì)流發(fā)展高度和對(duì)流強(qiáng)度都相對(duì)南側(cè)較弱。由于鋒面南北兩側(cè)環(huán)境濕度和動(dòng)力結(jié)構(gòu)差異,使得南北兩側(cè)對(duì)流的微物理特征有著較大的差異。鋒面南側(cè)對(duì)流中冰相過(guò)程較強(qiáng),0℃層以上冰相降水粒子種類和數(shù)量較多,融化層以下降水粒子降落過(guò)程中增長(zhǎng)效率較大,低層降水粒子的ZDR主要分布在0～2.0 dB范圍內(nèi),最大值達(dá)到3 dB(粒徑約為2.3 mm),有較大降水粒子存在,但數(shù)量較少,鋒面南側(cè)對(duì)流中有著高濃度的小粒子;而鋒面北側(cè)對(duì)流中弱上升運(yùn)動(dòng)使得冰相過(guò)程較弱,冰相粒子含量較少,融化層以下降水粒子較小,尺度集中在0.3～1.5dB之間,最大粒徑約為1.8 mm。與日本梅雨鋒面對(duì)流降水相比,江淮梅雨鋒面對(duì)流降水的粒子粒徑偏小,粒子數(shù)濃度更高。鋒面南側(cè)對(duì)流中的冰水和液態(tài)水含量遠(yuǎn)大于鋒面北側(cè)。鋒面南側(cè)對(duì)流的降水效率為65.9%,高于鋒面北側(cè);盡管鋒面南側(cè)對(duì)流過(guò)程總降水和總水汽通量都比臺(tái)灣季風(fēng)中對(duì)流降水高,鋒面南側(cè)對(duì)流降水貢獻(xiàn)與臺(tái)灣地區(qū)接近。進(jìn)一步分析鋒面南側(cè)一孤立對(duì)流生命周期中不同階段動(dòng)力和微物理特征變化顯示,初生階段對(duì)流尺度較小,15 dBZ回波頂高僅達(dá)到10 km高度,以少量大粒子為主。在成熟階段,對(duì)流發(fā)展高度不斷增加,回波強(qiáng)度增強(qiáng),對(duì)流中小粒子數(shù)量不斷增加;初生、分裂和成熟階段對(duì)流中都有少量大粒子存在,ZDR都超過(guò)3 dB;成熟階段上升運(yùn)動(dòng)最強(qiáng),對(duì)流強(qiáng)度達(dá)到最強(qiáng),最大回波達(dá)到58 dBZ,回波頂高達(dá)到12 km。同時(shí)成熟階段的冰相過(guò)程也最強(qiáng),產(chǎn)生大量冰雹和霰粒子,冰水(≥4.0 gm-3)和液態(tài)水(～8.0 gm-3)含量達(dá)到最大,產(chǎn)生的強(qiáng)降水中存在大量小粒子和中等粒徑粒子;消散階段,上升運(yùn)動(dòng)較弱,對(duì)流強(qiáng)度開(kāi)始減弱,最大回波僅達(dá)46 dBZ,無(wú)大粒子存在,ZDR最大達(dá)到1.6 dB。同時(shí)由于環(huán)境較干,較小的雨滴被蒸發(fā),消散階段對(duì)流降水雨滴粒徑集中為中等粒徑的降水粒子。
[Abstract]:Meiyu front is the main synoptic system in the east of China in summer. The heavy precipitation produced by Meiyu front often leads to urban waterlogging and other meteorological disasters, and causes enormous life and economic losses. From July 11 to 12, 2000, a typical Meiyu front precipitation process occurred in the Yangtze-Huaihe region. It lasted a long time, the precipitation intensity was high, and the maximum cumulative precipitation was over 100 mm in 24 hours. The dynamic and microphysical characteristics of the convection in the front rain belt during the Meiyu period are analyzed by combining the observation data of the dual polarization radar and the advanced wind field inversion technique of the dual Doppler radar. Convective Monomer. The analysis of convection on the north and south sides of the front shows that the convection on the south side of the front is mainly composed of strong convective monomer and linear convection. The intensity of convective precipitation is strong, the maximum cumulative precipitation in four hours reaches 60 mm, while the convective precipitation on the north side of the front is embedded in the stratospheric precipitation area, and the frequency of convection occurs. Compared with the southern side, the maximum accumulated precipitation of four hours is only 20 mm. The southern side of the front is stronger than the northern side, and the maximum value is 5 ms-1. The convective development height is high, the echo intensity is strong, and the ice process is strong. The microphysical characteristics of convection on the south side of the front are different from those on the north side because of the difference of force structure. The value is 3 dB (particle size is about 2.3 mm), there are large precipitation particles, but the number is small, there are high concentration of small particles in the convection south of the front; and the weak upward motion in the convection north of the front makes the ice process weak, the content of ice particles is small, the precipitation particles below the melting layer is small, the scale concentrates between 0.3-1.5 dB, the maximum particle size is about 0.3-1.5 dB. Compared with the convective precipitation of the Meiyu front in Japan, the particle size of the convective precipitation of the Meiyu front in the Yangtze-Huaihe River is smaller and the concentration of the particles is higher. The total water vapor flux is higher than that of convective precipitation in the Taiwan monsoon, and the contribution of convective precipitation in the south of the front is close to that in the Taiwan area. In the mature stage, the height of convective development increases continuously, the echo intensity increases, and the number of small and medium particles in the convection increases continuously. In the primary, splitting and maturing stages, there are a small number of large particles in the convection, and ZDR exceeds 3 dB. In the mature stage, the ascending motion is the strongest, the convective intensity reaches the strongest, the maximum echo reaches 58 dBZ, and the echo top reaches 12 km. At the same time, the ice phase process in the mature stage is also the strongest, producing a large number of hail and graupel particles, ice water (> 4.0 gm-3) and liquid water (~ 8.0 gm-3) content reaches the maximum, resulting in a large number of small and medium-sized particles in heavy precipitation; at the dissipation stage, the ascending motion is weakened, the convective intensity begins to weaken, the maximum echo is only 46 dBZ, no large particles exist. The maximum of ZDR is 1.6 dB. At the same time, the smaller raindrops are evaporated because of the dry environment. In the dissipation stage, the convective raindrops are concentrated on the middle-sized particles.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：P412.25
本文編號(hào)：2228071
[Abstract]:Meiyu front is the main synoptic system in the east of China in summer. The heavy precipitation produced by Meiyu front often leads to urban waterlogging and other meteorological disasters, and causes enormous life and economic losses. From July 11 to 12, 2000, a typical Meiyu front precipitation process occurred in the Yangtze-Huaihe region. It lasted a long time, the precipitation intensity was high, and the maximum cumulative precipitation was over 100 mm in 24 hours. The dynamic and microphysical characteristics of the convection in the front rain belt during the Meiyu period are analyzed by combining the observation data of the dual polarization radar and the advanced wind field inversion technique of the dual Doppler radar. Convective Monomer. The analysis of convection on the north and south sides of the front shows that the convection on the south side of the front is mainly composed of strong convective monomer and linear convection. The intensity of convective precipitation is strong, the maximum cumulative precipitation in four hours reaches 60 mm, while the convective precipitation on the north side of the front is embedded in the stratospheric precipitation area, and the frequency of convection occurs. Compared with the southern side, the maximum accumulated precipitation of four hours is only 20 mm. The southern side of the front is stronger than the northern side, and the maximum value is 5 ms-1. The convective development height is high, the echo intensity is strong, and the ice process is strong. The microphysical characteristics of convection on the south side of the front are different from those on the north side because of the difference of force structure. The value is 3 dB (particle size is about 2.3 mm), there are large precipitation particles, but the number is small, there are high concentration of small particles in the convection south of the front; and the weak upward motion in the convection north of the front makes the ice process weak, the content of ice particles is small, the precipitation particles below the melting layer is small, the scale concentrates between 0.3-1.5 dB, the maximum particle size is about 0.3-1.5 dB. Compared with the convective precipitation of the Meiyu front in Japan, the particle size of the convective precipitation of the Meiyu front in the Yangtze-Huaihe River is smaller and the concentration of the particles is higher. The total water vapor flux is higher than that of convective precipitation in the Taiwan monsoon, and the contribution of convective precipitation in the south of the front is close to that in the Taiwan area. In the mature stage, the height of convective development increases continuously, the echo intensity increases, and the number of small and medium particles in the convection increases continuously. In the primary, splitting and maturing stages, there are a small number of large particles in the convection, and ZDR exceeds 3 dB. In the mature stage, the ascending motion is the strongest, the convective intensity reaches the strongest, the maximum echo reaches 58 dBZ, and the echo top reaches 12 km. At the same time, the ice phase process in the mature stage is also the strongest, producing a large number of hail and graupel particles, ice water (> 4.0 gm-3) and liquid water (~ 8.0 gm-3) content reaches the maximum, resulting in a large number of small and medium-sized particles in heavy precipitation; at the dissipation stage, the ascending motion is weakened, the convective intensity begins to weaken, the maximum echo is only 46 dBZ, no large particles exist. The maximum of ZDR is 1.6 dB. At the same time, the smaller raindrops are evaporated because of the dry environment. In the dissipation stage, the convective raindrops are concentrated on the middle-sized particles.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：P412.25
【參考文獻(xiàn)】
相關(guān)期刊論文 前7條
1 王曉芳;崔春光;;長(zhǎng)江中下游地區(qū)梅雨期線狀中尺度對(duì)流系統(tǒng)分析Ⅰ:組織類型特征[J];氣象學(xué)報(bào);2012年05期
2 趙坤;周仲島;胡東明;潘玉潔;;派比安臺(tái)風(fēng)(0606)登陸期間雨帶中尺度結(jié)構(gòu)的雙多普勒雷達(dá)分析[J];南京大學(xué)學(xué)報(bào)(自然科學(xué)版);2007年06期
3 周海光;郭富德;;梅雨鋒暴雨中尺度對(duì)流系統(tǒng)結(jié)構(gòu)模型的雙多普勒雷達(dá)研究[J];南京氣象學(xué)院學(xué)報(bào);2007年01期
4 倪允琪,周秀驥;中國(guó)長(zhǎng)江中下游梅雨鋒暴雨形成機(jī)理以及監(jiān)測(cè)與預(yù)測(cè)理論和方法研究[J];氣象學(xué)報(bào);2004年05期
5 張小玲,陶詩(shī)言,張順利;梅雨鋒上的三類暴雨[J];大氣科學(xué);2004年02期
6 周海光,王玉彬;一次梅雨鋒降水系統(tǒng)三維風(fēng)場(chǎng)雙、三雷達(dá)對(duì)比研究[J];氣象;2003年05期
7 馮定原;1991年江淮暴雨洪澇致災(zāi)因素及成災(zāi)規(guī)律[J];氣象;1992年08期
相關(guān)博士學(xué)位論文 前1條
1 汪會(huì);華南和江淮地區(qū)夏季風(fēng)期間降水和對(duì)流的一些統(tǒng)計(jì)特征和個(gè)例研究[D];中國(guó)氣象科學(xué)研究院;2014年
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