中国东部地区城市化对极端温度及区域气候变化的影响

发布时间：2018-01-21 02:39

本文关键词： 均一化城市群 WRF模式长江三角洲极端温度区域气候　出处：《南京大学》2013年硕士论文　论文类型：学位论文

【摘要】：本文首先利用一套经均一化订正的中国东部312个国家级气象站1979-2008年夏季(六、七、八月)和冬季(十二、一、二月)具有连续观测的逐日最高气温、最低气温资料通过对各个极端温度指数进行空间滤波(滑动空间距平)来分析改革开放30年来中国东部城市化对极端温度的影响。然后再利用耦合了单层城市冠层模型UCM的中尺度模式WRF对长三角特大城市群夏季和冬季城市化效应进行的7年(2001-2007)高分辨数值模拟结果,通过对比长三角各个极端温度指数有城市(Urban)和无城市(NoUrban)两组试验结果,重点分析长三角城市化对极端温度的影响。接着通过对比夏季不同风向下有无城市两组试验中气温、气压以及水汽混合比的差异,从气候意义上对长三角城市化对夏季不同风向下区域气候的影响进行分析探讨。观测结果表明,近30年来,在中国东部京津冀、长三角和珠三角三个城市群中,夏季长三角城市群日最高气温的增温信号最为显著,冬季京津冀城市群日最低气温的增温信号最为显著；夏季长三角城市群的日较差表现出增大趋势,冬季京津冀城市群的日较差表现出减小趋势。城市化作用使得长三角城市群和珠三角城市群夏季高温日数表现出较强的增加趋势,并且长三角城市群夏季闷热日数的增加信号也最为显著,而京津冀城市群冬季冰冻日数和长三角城市群冬季霜冻日数表现出较强的减少趋势。同时城市化作用使得长三角城市群和珠三角城市群夏季高温热浪表现出较明显的增加信号,并且高温热浪的增加主要体现为重度热浪的增加。模式结果表明,WRF模式能较好地再现长三角2001-2007年7年平均夏季和冬季2m气温和降水的空间分布,比较成功地模拟出了2m气温和降水中心的位置和强度。夏季城市化作用造成在长江入海口附近形成以大城市群为中心的区域性热岛。和日最低气温相比,日最高气温的增温范围增大,但增温强度减小。而冬季的热岛效应非常微弱。城市化作用会造成长三角绝大部分地区夏季高温日数和闷热日数不同程度的增加,其中上海的日数增加最为明显,而城市化作用对长三角冬季冰冻日数和霜冻日数的影响非常微弱。同时城市化作用会造成长三角大部分地区夏季高温热浪不同程度的增加,其中上海的增加值最显著,并且高温热浪的增加也主要体现为重度热浪的增加。模式结果还表明,夏季城市化作用会造成以长三角城市群为中心,向下风方向扩散的区域性热岛。和静风时相比,有风时长三角城市群下风控制区的热岛加剧。并且有风时城市化作用对处于上风向的上海和杭州湾的增温强度较静风时减弱,而对处于下风向的宁镇扬的增温强度较静风时增强。城市热岛的存在导致局地上升运动,热岛发展强烈的区域上空存在明显的上升气流,下风附近则对应着下沉气流,形成热岛环流。城市热岛的作用造成长三角形成了以大城市群为中心,向下风方向扩散的低压区,有风时长三角城市群下风控制区热岛更为强烈的区域,地面气压减小程度更大。城市化作用造成了长三角城市群及其邻近地区近地面水汽的显著减小,有风时其下风控制区水汽减弱程度较静风时更强烈。干岛中心处存在较大的上升速度,因此在强烈的热力湍流作用下,由近地面向上输送的水汽量增多,造成了水汽混合比低层减少高层增加。
[Abstract]:This paper uses a set of homogeneity adjusted Chinese Eastern 312 national meteorological stations during 1979-2008 in summer (six, seven, August) and winter (twelve, February) with the continuous observation of daily maximum temperature, minimum temperature data through the spatial filtering of each extreme temperature index (moving spatial anomaly) to analyze the 30 years of reform and opening up the eastern city of China influence on extreme temperature. Then the coupling of the Yangtze River Delta city group in summer and winter city effect of mesoscale model WRF single city canopy model UCM 7 years (2001-2007) high resolution numerical simulation results, the extreme temperature index between all the Yangtze River Delta city (Urban) and city (NoUrban) of two groups of test results, focus on the analysis of influence on extreme temperature in the Yangtze River Delta city. Then through the comparison of different wind summer without the city two group The difference of middle temperature, air pressure and water vapor mixing ratio is analyzed and discussed from the climate sense to the influence of Yangtze River Delta urbanization on the regional climate under different summer wind directions.
The observation results show that over the past 30 years, China in eastern Beijing Hebei, Yangtze River Delta and Pearl River Delta city group in the summer of three, the Yangtze River Delta city group of the daily maximum temperature warming signal is the most significant, winter minimum temperature Group Tianjin city warming signal is most significant in summer; Delta city group, poor show the increasing trend in winter, Tianjin city group daily showed a decreasing trend. The role of the city city city groups in the Yangtze River Delta and Pearl River delta group of summer high temperature days showed strong increasing trend, and the signal increase in the Yangtze River Delta city group hot summer days are the most significant, and Beijing and Tianjin city group of freezing in winter the number of days and the Yangtze River Delta city group of winter frost days showed a decreasing trend. The strong effect at the same time the city heat waves in summer of city groups in the Yangtze River Delta and Pearl River Delta city group showed significantly increased The increase of the high temperature heat wave is mainly reflected by the increase of the severe heat wave.
The results show that the spatial distribution of the WRF model can successfully reproduce the Yangtze River Delta 2001-2007 7 years average temperature and precipitation in summer and winter 2m, successfully simulate position and 2m temperature and precipitation intensity. The summer city center due to the formation of regional heat island in the city group as the center in the vicinity of the Yangtze River Estuary. Compared with the daily minimum temperature, daily maximum temperature of the temperature range increases, but the increasing temperature strength decreases. And the heat island effect in winter is very weak. The role of city will make the most of the growth triangle area of summer high temperature days and hot days do not increase with the degree of the number of days in Shanghai, the most obvious increase, the effect of the Yangtze River Delta city of freezing in winter days and frost days is very weak. At the same time the city will build up heat waves in summer in most areas of delta increased in different degree, which The added value of the sea is the most significant, and the increase of the heat wave is mainly reflected in the increase of the severe heat wave.
Model results also show that the summer effect will cause the city in the Yangtze River Delta city group as the center, regional heat island spreads to leeward. Compared with the static wind, wind heat island in the Yangtze River Delta city group wind control region intensified. And when the wind weakened to the warming effect of city in Shanghai and the strength of the wind Hangzhou Bay is calm, and enhance the warming intensity on the downwind in Ningzhenyang than the static wind. There are city heat island leads to local ascending motion. The development of regional heat island over there was a strong updraft, the leeward of a downdraft, forming the heat island circulation. The city heat island effect by the Yangtze River delta formed a large city group as the center, low down wind direction diffusion, wind wind control of the Yangtze River Delta city group is more intense heat island area, the ground pressure decreases to a greater degree of urbanization. Due to reduce the Yangtze River Delta city group and its adjacent area near the ground water vapor, wind the wind control area of water vapor decreased less when the static wind more intense. At the center of the dry island there is a big rise in speed, so the thermal turbulence strongly, vapor transported by surface on the increase, resulting in the water vapor mixing ratio of low layer reduced high-rise increased.

【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P463.3

【相似文献】