南岭同纬度带典型区域气候特征差异与成因分析

Analysis of Climatic Characteristics and Trend in Typical Regions with the Same Latitude as the Nanling Moutainous Area

基于91个气象站观测值和大气环流模型CCSM3,对南岭同纬度典型区域的气候特征参数进行分析,并对未来不同区域的温度和降水进行预测,进一步探索净初级生产力对温度和降水的敏感性,并分析导致南岭同纬度带典型区域气候差异的可能原因。结果表明:1)南岭和同纬度其它区域呈现不同的干旱期和湿润期,撒哈拉沙漠、阿拉伯半岛沙漠和塔尔沙漠仅存在干旱期,墨西哥荒漠和南岭均存在湿润期,但两者湿润期出现的季节有差异。南岭在植物生长的春季和夏季雨热同期,而墨西哥荒漠雨水充沛的季节多在秋季。墨西哥除湿润期外,一年有两次干旱期,其中冬旱持续的时间较长。2)撒哈拉沙漠、阿拉伯半岛沙漠和塔尔沙漠的潜在蒸散、风速和日照百分率均高于墨西哥荒漠和南岭,但降水正好相反。墨西哥荒漠干季的水汽压与撒哈拉沙漠和阿拉伯半岛沙漠接近,低于该区域湿季及塔尔沙漠与南岭的值。3)在B1气候情景下,对2000―2099年5个阶段(每20年为一个阶段)与1981―2010年的温度和降水数据进行T-test检验发现,南岭同纬度5个典型区域的未来温度均呈极显著上升趋势(P<0.001),降水总体呈增加趋势,然而在不同阶段和区域也存在不同比例的显著减少和显著增加情况。4)通过比较5个区域是否存在温度或降水成为潜在生产力限制因子发现,南岭及同纬度的其它区域均为降水限制因子区域。其中,撒哈拉沙漠和阿拉伯半岛沙漠对降水的敏感性显著高于墨西哥荒漠、塔尔沙漠和南岭。5)南岭与同纬度其它区域气候迥异的原因除气候变化外,还包括海陆位置、人类活动干扰的强弱、地形地貌特征等因素。

Based on the observations of 91 meteorological stations and an atmospheric circulation model （CCSM3）, the climatic characteristic parameters of typical regions with the same latitude as the Nanling mountainous area were analyzed, the temperature and precipitation in different regions were forecasted until 2099, and the sensitivity of net primary productivity to temperature and precipitation was explored. We further explored the possible causes of climate difference in typical regions with the same latitude as the Nanling moutainous area. It has showed that arid and humid periods had different patterns among the studied regions. The Sahara Desert, the Arabian Desert and the Thar Desert only had an arid period, whereas both the Mexican Dryland and Nanling had a wet （moist and even humid） period. However, the seasons in which wet periods appeared was different between these two regions; Nanling had a rainy season during the spring and summer during plant growth, while the rainy season occurred in autumn in the Mexican Dryland. The potential evapotranspiration, wind speed and sunshine fraction of the Sahara Desert, the Arabian Desert and the Thar Desert were higher than those of the Mexican Dryland and Nanling, but the precipitation showed the opposite pattern. The water vapor pressure in the dry season of the Mexican Dryland was close to those of the Sahara Desert and the Arabian Desert but lower than the values for the wet season in the Mexican Dryland and those of the Thar Desert and Nanling. In the B1 climate scenario, a t-test of the temperature and precipitation data for every 20 years during the period 2000-2099 and 1981-2010 showed a significant upward trend （P〈0.001） in the future temperature of the five typical regions. In contrast, precipitation showed a significant decrease or significant increase in different proportions in different stages and regions, even though there was an increasing trend overall. The sensitivity of the net primary productivity to temperature was zero in all five studied regions, indicating that the precipitation is a limiting factor for all studied regions. The deserts of the Sahara Desert and the Arabian Desert were significantly more sensitive to precipitation than the Mexican Dryland, the Thar Desert and Nanling. In addition to climate change, the reasons for different climatic conditions in Nanling moutainous area and other regions with same latitude include probably the spatial position of each region to the ocean and land, disturbance of human activities, and the roughness of topography.