中国近海海温长期变化特征及其对沿岸气候的影响

发布时间：2018-01-16 14:30

  本文关键词：中国近海海温长期变化特征及其对沿岸气候的影响　出处：《中国气象科学研究院》2014年博士论文　论文类型：学位论文

  更多相关文章： 中国近海 海温长期变化 沿岸气候 “海效降水”

【摘要】：海-气相互作用是气候变化和变异研究的重要问题。海洋对大气以热力作用为主，而海温是海洋最重要的热力参数。本文分析探讨了中国近海地区海表水温长期变化及其对沿岸地带中尺度天气气候现象发生和演化的可能影响。首先利用英国Hadley中心近142年逐月全球海温资料集，分析了中国近海近142年海温气候学特征和长期变化特征及其可能原因；然后利用近51年山东省冬季逐日降水资料分析了山东半岛“海效降水”及其与近海海温和海冰的作用机理；最后采用沿岸自动站逐时风速、风向资料，初步分析了我国沿岸地带典型地点海陆风环流特征。本文得到以下主要结论： （1）近142年中国近海海温在各个海区均有显著增加趋势，其中以东海增暖最显著；增温主要从上世纪40年代开始，60-70年代变化较小，90年代增温最显著，但进入本世纪，增温趋势明显减弱；各海区最高温均发生在1998年，上世纪90年代和本世纪初是海温最高年代；与全球温度变化类似，中国近海海温在本世纪初开始（近10年）有变暖停滞现象；上世纪80年代中期海温在各海区均有突变。近142年不同海区变暖趋势最大的季节均在秋季（除了渤、黄海外），冬季次之；与其它海区相比，东海在四季均有最大增暖趋势。而近50年，比较各海区四个季节，均为冬季增暖最显著，东海增暖最显著。夏季我国南海西部、越南东南岸外存在一个相对低温区，近30年南海西部的冷水涌升作用有减弱趋势，这种减弱现象可能和西南夏季风减弱有关。 （2）近51年山东半岛共有1173个“海效降水”日，其中降雪日占73.7%，降雨日占16.1%，雨雪天占10.1%的“海效降水”日。不同等级降雪12月份发生的频率最高，雨天和雨雪天11月份发生的频率最高。降雪主要分布在以文登和成山头为中心的区域，降雨则主要分布在沿岸地区。 （3）渤海海表温度和850hPa气温差达到10℃以上时，山东半岛发生“海效降水”的概率最大，10-15℃时以小雪为主，15-20℃时以中小雪为主，20-25℃期间不同等级降雪发生概率类似，25℃以上时以暴雪为主；降雨和雨雪天也主要发生在海-气温差在10℃-20℃之间，随着海-气温差增加，，降水出现频率减小，但降水量增加；不管哪种类型的“海效降水”，海-气温差在15-20℃时发生频率都是最高的；山东半岛“海效降水”三种类型中，降雪和雨雪天降水强度与海冰面积呈弱的负相关。环流分析表明，不同类型“海效降水”500hPa高度场具有明显的差异。 （4）本文选取的14个沿岸代表站在2012年海陆风发生平均日数为92.5天，最多的站点达到140天，最少的站点为49天；所有代表站几乎每个月都有海陆风现象发生。
[Abstract]:The air-sea interaction is an important issue in the study of climate change and variation. The sea surface temperature (SST) is the most important thermodynamic parameter of the ocean. The long-term variation of SST and its possible influence on the occurrence and evolution of mesoscale weather and climate phenomena in the coastal zone of China are analyzed and discussed in this paper. The global SST data set of the adley Center is in the past 142 years. The characteristics of sea surface temperature and climatology in the last 142 years and its possible causes are analyzed. Then the daily precipitation data of Shandong Province in winter in recent 51 years are used to analyze the "sea effect precipitation" in Shandong Peninsula and its interaction mechanism with offshore sea and sea ice. Finally, by using the hourly wind speed and wind direction data of the coastal automatic station, the characteristics of sea-land wind circulation in typical locations along the coast of China are preliminarily analyzed. The main conclusions are as follows: (1) in the last 142 years, the sea surface temperature in China's coastal waters has a significant increasing trend, especially in the East China Sea. Since -60s, the change of temperature increase in the 60-70 's is the most obvious, but in this century, the increasing trend is obviously weakened. The maximum temperature of each sea area occurred in 1998, -10s and the beginning of this century was the highest SST. Similar to the global temperature changes, the sea surface temperature in China's coastal waters has been warming and stagnating since the beginning of this century (nearly 10 years). In the middle of -20s, the sea surface temperature had a sudden change in all sea areas. In recent 142 years, the largest warming season in different sea areas was in autumn (except the Bohai Sea, Yellow Sea, the second in winter); Compared with other sea areas, the East China Sea has the largest warming trend in the four seasons, and in the last 50 years, the four seasons in each sea area are the most significant in winter warming and the East China Sea warming is the most significant. There is a relatively low temperature area off the southeast coast of Vietnam. The cold water surge in the western part of the South China Sea tends to weaken in the past 30 years, which may be related to the weakening of the southwest summer monsoon. (2) in recent 51 years, there were 1173 "sea effect precipitation" days in Shandong Peninsula, of which the snowfall day accounted for 73.7%, and the rainfall day accounted for 16.1% days. Rainy and snowy days account for 10.1% days of "sea effect precipitation". The frequency of different grades of snow falls on December is the highest. The frequency of rain and snow on November is the highest. Snow is mainly distributed in the area with Wendeng and Chengshan as the center, while rainfall is mainly distributed along the coast. (3) when the difference between surface temperature and 850hPa temperature in the Bohai Sea reaches more than 10 鈩

本文编号：1433515