Study Of Relationship Between Land Surface Albedo And Elevation-dependent Temparature Changes On The Tibetan Plateau

In this paper,we studied the issue about there is a strong warming at high altitudes caused by global warming,which is also called elevation-dependent warming.We chose the Tibetan Plateau as the study area which is in high altitude and is the global warming responder.We studied whether the temperature changes in the Tibetan Plateau have elevation-dependent,analyzed the possible causes,and investigated whether the albedo is its influencing factor.Based on the MODIS surface temperature product and the digital elevation model,we analyzed the overall surface temperature variation trend of the Tibetan Plateau,and studied the relationship between the temperature change and the elevation in the area,and the temperature of different land types and seasons as a function of elevation.Whether there is an elevation-dependent on the annual temperature change in the Tibetan Plateau.The study found that the Tibetan Plateau has an elevation-dependent warming,but the elevation-related of each season is not obvious.And the elevation-dependent of grassland,shrubs,and snow and ice is significantly warmer.It is manifested that there is a increasing trend with annual warming rate increases below 5000 meters above sea level.But above 5,000 meters,there is a trend of declining warming rate,and the law of bare land changes is not obvious.Elevation-dependent warming is affected by many factors.This paper focuses on the analysis of the relationship between elevation-dependent warming and surface albedo over the Tibetan Plateau.The results of the study show that there is a positive correlation between the overall warming rate and the albedo over the Tibetan Plateau,indicating that the accelerated temperature increase in high altitude regions is related to albedo.In addition,we have selected two representative areas(inflow area of plateau and Lancang River basin)to analyze whether there is elevation dependence on the temperature change and its relationship with albedo.The study found that the elevation-dependent trends of different elevations in different regions are different:the altitude-increased plateau inflow zone shows a significant elevation dependence at an altitude of 3000-4800 meters,and the warming rate increases with the elevation;The altitudes of 2000-3000 meters and 3600-4800 meters of Lancang River Basin showed obvious elevation-dependent warming.Compared with the warming rate of the two typical areas,the warming rate of the two above 5,000 meters has obviously decreased.This conclusion is consistent with the overall elevation-dependent trend of the Tibetan Plateau.By analyzing the relationship between the warming rate and the surface albedo of the two typical areas,it is found that the albedo and warming rate in the plateau inflow area and Lancang River basin show a significant correlation,indicating that the warming rates of these two places are altitude-dependent.And the relationship between albedo and elevation-dependent warming of the Tibetan Plateau varies according to the geographic features of different study area.Therefore,it is necessary to analyze the different feature areas separately for the study of altitude dependence.