本文選題：熱帶氣旋 + 東太型El��； 參考：《中國海洋大學(xué)》2014年碩士論文

【摘要】：本文利用JTWC熱帶氣旋資料、HadISST以及NCEP大氣資料分季節(jié)討論了不同El Ni(?)o事件時西北太平洋熱帶氣旋活動的差異以及引起差異的原因。文章首先分夏季和秋季討論了東太型El Ni(?)o與中太型El Ni(?)o對熱帶氣旋生成地和強(qiáng)度的影響的不同。然后，以是否同時發(fā)生正IOD事件為標(biāo)準(zhǔn)，將中太型El Ni(?)o事件分成純中太型El Ni(?)o事件（p-CPEN）、與IOD同時發(fā)生的事件（CPEN-IOD），并比較了兩類事件發(fā)生時，西北太平洋秋季熱帶氣旋生成地的差異。 東太型El Ni(?)o年夏季，熱帶氣旋生成頻數(shù)在西北太平洋西北區(qū)域減小、東南增大，正負(fù)異常呈長條狀偶極子分布。西北區(qū)域SSTA呈現(xiàn)顯著負(fù)異常、低層渦度減小、中層相對濕度較小是該區(qū)域熱帶氣旋生成受到抑制的主要原因，東南區(qū)域熱帶氣旋生成活躍的主因是低層渦度增大、垂直風(fēng)切變減小、相對濕度增大。中太型El Ni(?)o年夏季，熱帶氣旋生成頻數(shù)增大的區(qū)域較東太型El Ni(?)o年向西北方向延伸，產(chǎn)生這種差異的主要原因是中太型El Ni(?)o夏季，西北區(qū)域低層渦度增大、垂直風(fēng)切變減小。東太型El Ni(?)o年秋季，位于東南區(qū)域的熱帶氣旋生成活躍區(qū)較夏季東退大約20個經(jīng)度，發(fā)生這種季節(jié)變化的主要原因是秋季負(fù)渦度異常中心南移，同時垂直風(fēng)切變增大的區(qū)域向東向北擴(kuò)張、干空氣在南側(cè)的擴(kuò)張。中太型El Ni(?)o夏季熱帶氣旋生成向西北擴(kuò)張的趨勢在秋季被截斷，菲律賓以東區(qū)域熱帶氣旋生成受抑制區(qū)域擴(kuò)大，造成這種季節(jié)差異的主要原因是在這些區(qū)域垂直風(fēng)切變增大、相對濕度減小。 熱帶氣旋累積能量（ACE）被用來考查兩類事件對熱帶氣旋強(qiáng)度的影響。東太型El Ni(?)o指數(shù)Ni(?)o3以及中太型El Ni(?)o指數(shù)EMI在夏秋兩季都與ACE呈正相關(guān)，但Ni(?)o3與ACE的相關(guān)性在秋季不顯著。夏季時，ACE與Ni(?)o3的相關(guān)系數(shù)大于ACE與EMI的相關(guān)系數(shù)，而秋季時兩者的大小關(guān)系正好相反。東太型El Ni(?)o夏季與中太型El Ni(?)o夏季相比，前者強(qiáng)度較大的熱帶氣旋生成頻數(shù)比后者的多，同時前者熱帶氣旋累積持續(xù)時間更長，所以前者的ACE比后者的大。秋季，強(qiáng)度最強(qiáng)的CAT4、CAT5的生成頻數(shù)在中太型El Ni(?)o時要比在東太型El Ni(?)o時多，同時，前者熱帶氣旋累積持續(xù)時間也比后者大，最終使得中太型El Ni(?)o的ACE大于東太型El Ni(?)o的。 CPEN-IOD秋季熱帶氣旋生成地較p-CPEN秋季東伸20°。CPEN-IOD秋季西北太平洋暖SSTA位置較p-CPEN秋季時偏東，同時西側(cè)冷異常也更顯著，從而導(dǎo)致CPEN-IOD秋季赤道區(qū)域西風(fēng)異常場明顯強(qiáng)于p-CPEN秋季，西風(fēng)異常東伸的也更遠(yuǎn)；這進(jìn)一步使得CPEN-IOD秋季季風(fēng)槽明顯偏東。由于大部分熱帶氣旋都是生成于季風(fēng)槽內(nèi)，所以CPEN-IOD秋季熱帶氣旋生成地也延伸的更東。同時，CPEN-IOD時期，垂直風(fēng)切變的正負(fù)異常較p-CPEN都要大，且前者的正異常區(qū)較后者明顯偏東，使得前者適合熱帶氣旋生成的區(qū)域明顯東移，這也是熱帶氣旋生成地偏東的原因。
[Abstract]:Based on the JTWC tropical cyclone data HadISST and NCEP atmospheric data, the seasonal differences of tropical cyclone activities in the Northwest Pacific Ocean and the causes of the differences are discussed in this paper. In this paper, we first discuss the difference between the East Pacific type El Nianzao and the middle Pacific type El Nianzao on the ground and intensity of the tropical cyclone in summer and autumn. Then, based on the criterion of whether or not the positive IOD events occur at the same time, this paper classifies the middle and Pacific type El Niadao events into pure center-Pacific type El Nianzao events, and compares the two types of events when they occur simultaneously with the IOD events, which occur at the same time as the CPEN-IOD events. In summer, the frequency of tropical cyclone formation in the Northwest Pacific decreases in the Northwest Pacific region and increases in the southeast, and the positive and negative anomalies show a long strip dipole distribution. In the northwest region, the SSTA showed significant negative anomalies, the vorticity of the lower layer decreased, and the relative humidity of the middle layer decreased. The main reason for the suppression of tropical cyclone formation in the southeast region was the increase of the vorticity of the lower layer, the main reason for the active formation of the tropical cyclone was the increase of the vorticity of the lower layer. The vertical wind shear decreases and the relative humidity increases. The increasing frequency of tropical cyclones extends northwestward than that of east-Pacific El Nianzao in summer. The main reason for this difference is that in summer, the vorticity of the lower layer increases and the vertical wind shear decreases in the northwest region of the northwestern region, the main reason for this difference is that in the summer of the mid-Pacific type El Nianzhuo, the vertical wind shear is decreased with the increase of the vorticity of the lower layer in the northwestern region. In autumn, the active tropical cyclones in the southeastern region retreated about 20 degrees of longitude than that in summer. The main reason for this seasonal variation is the southward shift of the anomalous center of the autumn negative vorticity. At the same time, the area with vertical wind shear increases to the east and north, and the dry air expands to the south. The trend of tropical cyclones spreading northwestward in summer was cut off in autumn, and the restrained area of tropical cyclones in the east of the Philippines was enlarged. The main reason for this seasonal difference was the increase of vertical windshear in these areas. The cumulative energy of tropical cyclones (ACEE) is used to study the effects of two types of events on the intensity of tropical cyclones. The EMI of EST and EMI were positively correlated with ACE in summer and autumn, but the correlation between EMI and ACE was not significant in autumn. In summer, the correlation coefficient between ACE and Nijiao _ 3 is higher than that between ACE and EMI, but the relationship between ACE and EMI is opposite in autumn. Compared with the east-Pacific type El Nianzao in summer, the intensity of the former is higher than that of the latter, and the accumulative duration of the former is longer, so the ACE of the former is larger than that of the latter. In autumn, the most intense CAT4 / CAT5 has more frequency of formation than that of east-type El Nianzao, and the accumulative duration of the former tropical cyclone is also larger than that of the latter, and the intensity of CAT4 / CAT5 is higher than that of the east-Pacific type of El Nianzao in autumn, and the cumulative duration of the former is larger than that of the latter. As a result, the ACE of the mid-Pacific type El Nianzao is larger than that of the East Pacific type El Nianzao. The tropical cyclones of CPEN-IOD in autumn are more eastward than those of p-CPEN in autumn when the tropical cyclones extend 20 擄eastward. CPEN-IOD shows that the position of warm SSTA in the Northwest Pacific Ocean in autumn is more easterly than that in the autumn of p-CPEN, and the cold anomaly in the western side is also more significant than that in the autumn of p-CPEN. As a result, the westerly anomaly field in the equatorial region in autumn is obviously stronger than that in the p-CPEN autumn, and the westerly anomaly extends further eastward, which makes the monsoon trough of CPEN-IOD obviously eastward in autumn. Since most tropical cyclones occur in monsoon trough, CPEN-IOD also extends eastward in autumn. In the CPEN-IOD period, the positive and negative anomalies of vertical wind shear are larger than that of p-CPEN, and the positive anomalous regions of the former are obviously eastward than those of the latter, which makes the former suitable for the eastward movement of the region where the tropical cyclones are formed, which is also the reason for the eastward formation of the tropical cyclones.
【學(xué)位授予單位】：中國海洋大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：P732

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳光華;黃榮輝;;西北太平洋熱帶氣旋和臺風(fēng)活動若干氣候問題的研究[J];地球科學(xué)進(jìn)展;2006年06期

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本文編號：2000552