The Trend Analysis of Future Precipitation and Temperature in the Mountainous Regions of Heihe Mainstream Based on the CMIP6 Multi-Model

Abstract

The mountainous regions of Heihe mainstream in China， is one of the sensitive areas to response the climate change， however， there are few studies on analyzing the possible variation under different climate scenarios in this area.Based on the daily precipitation and mean temperature data from four national standard meteorological stations （which located in or around the study area） and seven climate model outputs from CMIP6， this paper assesses the ability of the CMIP6 Multi-Model ensemble average data in simulation of precipitation and temperature， which including bias correction and not.Furthermore， the predicted precipitation and temperature evolution trends of four SSPs scenarios at different time scales are analyzed by quantitative analysis method.The results show that： （1） The CMIP6 model data has different simulation deviations between precipitation and temperature， and overall， the performance of temperature simulation is better than that of precipitation.After bias correction by MBC， the CMIP6 Multi-Model ensemble mean data can accurately simulate the spatial-temporal characteristics and trends of actual precipitation and temperature.Therefore， it can be considered that the Multi-Model ensemble mean data of CMIP6 with MBC correction can reflect the future climate change trend in study area.（2） Existing differences vary among precipitation and temperature change in the mountainous regions of Heihe mainstream at different time scales.On the seasonal scale， precipitation increases significantly in winter and spring， and temperature increases in spring and autumn.On the annual scale， both future precipitation and temperature show an increasing trend with time， and the trend becomes more significant with increasing radiate forcing of the scenario.On the periods scale， annual precipitation and mean annual temperature increase less in the near to medium period， but more in the medium to far period.（3） At the spatial scale， both precipitation and temperature in the mountainous regions of Heihe mainstream present generally increasing trend from west to east and， there is more rain and higher temperature in the east area than west， so the phenomenon of warmer and wetter in spring will be more obvious in the eastern area than the west.As the climate continues to humidifier and warmer， the possibility of anomalous precipitation and temperature events are likely to increase in the future in the mountainous regions of Heihe mainstream.The extreme climate phenomenon， mainly characterized as the precipitation exploded and the temperature sharply fell， which show a spatial distribution of less in west and more in east.

Keywords

• the mountainous regions of heihe mainstream
• cmip6
• multi-model ensemble mean data
• precipitation and temperature changes