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Evaluation And Projection Of Surface Air Temperature In China By IPCC AR4 Coupled Climate Models And Downscaling Methods

Posted on:2009-09-16Degree:MasterType:Thesis
Country:ChinaCandidate:M LiuFull Text:PDF
GTID:2120360242996025Subject:Science of meteorology
Abstract/Summary:PDF Full Text Request
By using the daily mean temperature of 550 stations in China from 1961 to 2000 and the outputs of thirteen IPCC AR4 CGCMs,evaluated the models capabilities of simulating surface air temperature(SAT).Then do analysis on climate changes in China in the future 100 years under SRES A2,A1B and B1 greenhouse gas scenarios. In the central and eastern part of China,LMDZ GCM and SDSM downscaling methods were applied to investigate their abilities to evaluate and project SAT changes.The main results are:(1)The updated IPCC AR4 models have the capability of modeling the climatic average mode of SAT in China region.They all well revealed the annual variation and spatial distributions of the temperature.The spatial correlations all above 0.8.But in the simulated region models outputs are smaller than the observer in temperature.(2)Most IPCC AR4 models can simulate the linear trends of SAT,while have poor performance in simulating the inter-annual variability.For the linear trends,their simulations were a little weaker.(3)Whatever SRES A2,A1B or B1,the SAT in China has a warming tendency in 21st century.The range of temperature changes is from 1.6℃—5℃.Considering the effect of SRES A2,A1B and B1,the temperature in China would be increased by 5.3℃,4.3℃and 2.6℃respectively at the end of 21st century,the mean warming is 3.5℃.The largest range of warming is in the winter.The distributions of the mean temperature in China were analyzed in this paper.The results indicated that the warming over the northern part is greater than that in southern part of China.(4)The ensemble standard deviation of different models suggests that the uncertainty of the projected climate changes over China in the 21stcentury has been improved. (5)Using dynamical downscaling method to analyze,outputs show that,under SRES A2,SAT in Jianghuai basin would be increased by 1.3—1.9℃in 2050s.The warming over the southwest part is greater than that in the east part.The largest range of warming is in the winter.(6)Using statistical downscaling method to analyze,the results indicated that 5 stations would be increased by about 1.5℃in 2050s.By the end of 21st century the warming would be around 4℃.This conclusion is consistent with the dynamical downscaling method.
Keywords/Search Tags:China, surface air temperature, future climate change scenarios, IPCC AR4 Coupled Climate Model, downscale
PDF Full Text Request
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