我国北方陆–气耦合特征

Characteristics of Land-Atmosphere Coupling in Northern China

摘要: 陆–气相互作用是在陆地表面发生的一系列复杂过程，是影响天气以及气候演变的重要途径。本文选取了纬度33˚N~45˚N，经度100˚E~125˚E的区域，将中国北方分为东北区，内蒙古高原区，黄土高原区，华北区和西北区五个区域，并进一步使用土壤湿度、气温、降水等资料，研究我国北方土壤湿度与气温和降水的相互作用的时空分布特点以及土壤湿度–气温和土壤湿度–降水相关系数，探究我国北方陆–气耦合特征，得到的主要结论如下：1) 我国北方土壤湿度和降水强度在不同季节均表现为从西北到东南逐渐增加，季节平均气温表现为整体上从北到南逐渐增大。2) 土壤湿度–气温强的正耦合区域位于西北区、华北区东部和东北区；强的负耦合区域位于华北区北部。土壤湿度–降水强的正耦合区域位于华北区北部和内蒙古高原区西部；强的负耦合区域位于华北区南部和内蒙古高原区中部。我国北方陆–气耦合季节差异明显，夏季耦合强度强于冬季。3) 在土壤湿度0.3到0.4时，存在强的正负土壤湿度–气温耦合强度。在气温较低时，存在强的正耦合；在气温较高时，存在强的负耦合。土壤湿度–降水耦合强度随土壤湿度变化不明显。在降水量较小时，土壤湿度–降水耦合强度绝对值较大；在降水量较大时，存在强的负耦合。

Abstract: Land-air interaction is a series of complex processes that occur on the surface of land and is an important way to affect weather and climate evolution. In this paper, the areas in latitude of 33˚N~45˚N and longitude of 100˚E~125˚E are selected, and the northern part of China is divided into five regions: Northeast China, Inner Mongolia Plateau, Loess Plateau, North China and Northwest China, and further use soil moisture, temperature, precipitation and other data to study the spatio-temporal distribution characteristics of the interaction between soil moisture and air temperature and precipitation in northern China, as well as the correlation coefficients of soil moisture, temperature and soil moisture and precipitation, and explore the characteristics of land-air coupling in northern China. The main conclusions are as follows: 1) The soil moisture and precipitation intensity in northern China gradually increase from northwest to southeast in different seasons, and the average seasonal temperature gradually increases from north to south as a whole. 2) The positive coupling area of soil moisture-temperature is located in the northwest region, the eastern and northeastern regions of north China; The strong negative coupling region is located in the northern part of North China. The positive coupling area of soil moisture-precipitation intensity is located in the northern part of North China and the western part of Inner Mongolia Plateau; and the strong negative coupling region is located in the south of north China and the middle of Inner Mongolia Plateau. The seasonal difference of land-atmosphere coupling in northern China is obvious, and the coupling intensity in summer is stronger than that in winter. 3) When the soil moisture is 0.3 to 0.4, there is a strong positive and negative soil moisture-temperature coupling intensity. At lower temperatures, there is a strong positive coupling; At higher temperatures, there is strong negative coupling. The soil moisture-precipitation coupling intensity does not change significantly with soil moisture. When the precipitation is small, the absolute value of soil mois-ture-precipitation coupling intensity is relatively large; There is strong negative coupling when precipitation is high.