区域气候对土地类型变化的敏感性分析

Sensitivity Analysis of Regional Climate to Land-Use and Land-Cover Change

评估土地利用和土地覆盖变化(LUCC)对区域气候的影响对理解陆、气相互作用和设计气候适应、解决策略至关重要。文章选取85~135°E,20~50°N为研究区域,通过设置两组实验分别进行三年的气候模拟。实验结果指出:LUCC对我国气候变化有显著影响。其中,冬季青藏高原和东北北部地区积雪增加,使得大气层顶净辐射通量呈现显著的负变化。夏季东部地区是近大气层顶的净辐射通量幅度较大的区域,且正、负变化相邻。我国全年降温区域比增温区域出现得多,并且东部地区的增温在冬季较夏季强。受LUCC影响,东北地区降水显著增加,沿30~35°N从青藏高原到山东半岛及其环渤海东海地区,有一条降水增加的雨带;华南地区降水减少较为显著。降水变化与云的短波辐射强迫变化有较好的对应关系,降水增加的地方云的短波辐射强迫减少,反之亦然。另外,降水和夏季的温度变化也有较好的对应关系。环流场为降水的发生提供有利条件,冬季高度场在我国东北地区和青藏高原为负变高中心,与冬季积雪覆盖区相吻合。夏季高度场在华南地区有正变高,有利于副热带高压的西伸和西南气流向华北输送水汽,最终导致华南地区降水减少。

Assessing the impact of land use and land cover change(LUCC)on regional climate is critical to understanding land air interaction and designing climate adaptation and resolution strategies.In this paper,85~135°E and 20~50°N are selected as the study area,and two groups of experiments are set up to simulate the climate for three years.The results showed that LUCC has a significant impact on climate change in China.Among them,the increase of snow cover on the Qinghai Tibet Plateau and the northern part of Northeast China in winter makes the net radiation flux at the top of the atmosphere show a significant negative change.In summer,the net radiation flux near the top of the atmosphere in the eastern region has a large range,and the positive and negative changes are adjacent.There are more cooling regions than warming regions throughout the year in China,and the warming in the eastern region is stronger in winter than in summer.Under the influence of LUCC,the precipitation in Northeast China has increased significantly.Along 30~35°N,there is a rain belt with increased precipitation from the Qinghai Tibet Plateau to the Shandong Peninsula and the East China Sea area around the Bohai Sea;The precipitation in South China has decreased significantly.There is a good correspondence between the change of precipitation and the change of cloud shortwave radiative forcing.Where precipitation increases,cloud shortwave radiative forcing decreases,and vice versa.In addition,there is a good corresponding relationship between precipitation and temperature change in summer.The circulation field provides favorable conditions for the occurrence of precipitation.The winter height field is a negative height center in Northeast China and the Qinghai Tibet Plateau,which is consistent with the winter snow cover area.In summer,the height field in South China has a positive change,which is conducive to the westward extension of the subtropical high and the south-west flow to transport water vapor to North China,and ultimately leads to the reduction of precipitation in South China.