The Coupling Simulation Of Soil Water And Heat Based On WRF-Noah Land Surface Model In Mongolian Plateau

Global climate change and its prediction and simulation is one of the most important scientific issues in domestic and abroad.The interaction between land and atmosphere is an extremely critical component of the Earth's climate system.It is not only the key to control the exchange of energy and materials between the atmosphere and terrestrial ecosystems,but also one of the principal drivers of the Earth's climate system.However,soil moisture and soil temperature are determinants in the interaction between land and atmosphere.The Mongolian Plateau is a major component of the Eurasian steppe,and it is also one of the largest grassland ecosystems in the world with higher grassland species diversity.In recent decades,the ecological environment of the Mongolian Plateau has become more and more serious.In this paper,we use the WRF model to couple the Noah land surface model with NCEP_fnl global analysis data.Simulation of the 0-10 cm soil water and heat conditions during the growing season of the Mongolian Plateau from 2000 to 2015 at four-time periods(2000,2005,2010,2015).We focued on the soil hydrothermal characteristics of the Mongolian Plateau and its relationship with major land surface parameters and the response of the main vegetation types to changes in soil water and heat.The main conclusions are as follows:(1)The WRF-Noah land surface model is suitable for simulation of soil moisture and soil temperature in the Mongolian Plateau.(2)The temporal and spatial characteristics of 0-10 cm soil moisture in Mongolian Plateau during the growth period of 2000-2015:Soil moisture in the Mongolian Plateau has an obvious spatial distribution during the growing season-It's highest in the north and east,but the least in the southwest and gradually decreases from north to south and from east to west;In the past 16 years,soil moisture in the whole area has been increasing and the spatial distribution pattern has not changed;The seasonal fluctuation of soil moisture is more obvious.It gradually increased from May to August and gradually declined from September to October.(3)The temporal and spatial characteristics of 0-10 cm soil temperature in the Mongolian Plateau during the period of 2000-2015:The spatial distribution of soil temperature in the Mongolian Plateau during the growing season has obvious zonal patterns—The soil temperature gradually increased from north to south and east to west,and the soil temperature is highest in the southwest;In the past 16 years,the soil temperature in the entire area has slightly decreased.However,it didn't reach a significant level and the spatial distribution pattern has not changed;The seasonal fluctuation of soil temperature is more obvious.It's gradually increased from May to August and falling from September to October.(4)The coupling characteristics of 0-10 cm Soil Moisture and Soil Temperature in the Mongolian Plateau During the Period of 2000-2015:A large climate background is the deciding factor that affects soil moisture and temperature and have a comprehensive impact on land surface.Then underlying surface with a similar climatic background will have similar soil hydrothermal characteristics.(5)The response characteristics of vegetation to soil moisture and soil temperature change of 0-10 cm in the growth season of Mongolian plateau from 2000 to 2015:1)In the meadow steppe and typical steppe,the soil temperature is the main factor affecting NDVI.The rate of change was 0.0227 units/°C and 0.0075 units/°C.2)In the desert steppe,neither soil moisture nor soil temperature can have a significant effect on NDVI.