Journal
Journal of Geo-Information Science
Class
accumlated temperature
Paper Keyword
regional area change,starting time,ending time,trend analysis,interval period for different accumulated temperature,Northern Xinjiang,Qinghai-Tibet Plateau,Northeast China
Abstract
Accumulated Temperature (AT) could affect plants' phonological period and crops' yield and spatial distribution. AT is usually obtained by extrapolation of surface observations. However, AT would have greater spatial uncertainties in regions where the surface observations are sparsely distributed with complex terrain. In recent years, there have been some gridded meteorological data with well spatial representation. If studies used these high spatial resolution gridded meteorological data to directly calculate AT, the problem mentioned above would be solved. This study used the gridded dataset (CN05.1) with high spatial resolution and long term time series from 1961- 2018 to analyze the spatiotemporal changes of the four Accumulated Temperatures (ATs) in mainland China with the thresholds of 0 ℃, 5 ℃, 10 ℃, and 15 ℃, respectively. The gridded dataset wasmade using more than 2400 surface meteorological stations across mainland China and was well extrapolated by the plate spline method. The main conclusions are summarized as follows: ① In mainland China, the four ATs(up0 ℃, up5 ℃, up10 ℃ and up15 ℃) have low-value areas in the Qinghai-Tibet Plateau, Tianshan Mountains inXinjiang, and Northeast China, but high-value areas in South China. Their spatial patterns are similar to those ofthe 2-m air temperature. ② All four ATs show significant increasing trends, especially in Inner Mongolia andNortheast China. ③ Due to changes in the AT spatial trends, the area of tropical and subtropical regions,identified by a threshold of 10 ℃, have a significant increase. In contrast, the area of mid-temperate and coldtemperate regions have a significant decrease. ④ During 1961-2018, starting time of four ATs had significantly
