Spatial correlation length of summer extreme heat stress over eastern China

Abstract

This study attempts to measure the spatial correlation length (SCL) of summer extreme heat stress in any location by using a characterized scale identification method. Daily datasets of multiple meteorological variables from 2,134 observation stations over eastern China during 1961–2010 were used. Three types of heat indexes (a total of seven indexes) were applied to characterize the heat stress. The first type used a single variable, that is, daily maximum temperature (Tmax) or daily minimum temperature (Tmin), while the second used mean temperature (T) and relative humidity, and the third used T, vapour pressure, and 10‐m wind speed. A 90th percentile of the climatology of local heat stress was applied to identify hot days. The SCLs of heat stress were analysed in three regions: North China (NC), the Yangtze River Valley (YRV), and South China (SC). Results showed that the trend changes in heat stress had obvious temporal and geographical characteristics, especially in NC and YRV. Generally, the SCLs of heat stress in NC were the largest, reaching more than 440 km for Tmax, with YRV second, about 350 km, and SC the smallest, only about 185 km. This phenomenon could be found for almost all indexes. Moreover, the SCLs of the first two types of heat indexes (except Tmin) for the three regions were greater than that of the third one, particularly in NC and YRV, which was related to inconsistent changes in the variables used and the primary role of which one characterized the heat stress. The spatial distributions of high SCLs for all indexes were in line with that of the major urban agglomeration in eastern China. The SCL of heat stress for a location was related not only to the changes themselves, but also to the surroundings, involving the number and spatial distribution of hot days.

Adaptability to High Temperature and Stay-Green Genotypes Associated With Variations in Antioxidant, Chlorophyll Metabolism, and γ-Aminobutyric Acid Accumulation in Creeping Bentgrass Species

“…Greenhouse or growth chamber test under controlled environment conditions provides relatively stable heat stress in day and night, but high temperature under summer stress is fluctuant in nature and is accompanied by other complex factors such as changes in wind, air humidity, and solar ultraviolet radiation (Gaffen and Ross, 1998;Wang and Gaffen, 2001;Zhou et al, 2021). Therefore, crops that have stronger tolerance to fluctuant high temperature in summer are of great practical value.…”

Persistent and nonpersistent regional extreme total, daytime, and night‐time precipitation events over southwest China (1961–2019)

“…The extreme precipitation intensity of this event of 295.3 mm mm·days −1 occurred in Kaizhou District (city of Chongqing) for TP, as reported by Zhou et al . (2021). The above analysis demonstrates that it is reasonable to use OITREE to extract PERPEs.…”

“…The PERPEs with duration of 5 days occurred mainly in May–September, similar to the details reported by Zhou et al . (2021). However, the PERPEs ranked first for comprehensive strength (July 29 to August 2 in 1983) and with extreme intensity (June 26, 1961; Mianyang: 306 mm) are different (Xiao et al ., 2017; Zhou et al ., 2021), which might be related to the different study areas (Zhou et al ., 2021) focused on the east of SWC.…”

“… Note : Relative parameters are consistent with those of Zhou et al . (2021), but the difference is that we define continuous precipitation as at least 3 days in time and at least 3 days in space. …”

“…(2012), Zou and Ren (2015), and Zhou et al . (2021), which are 0.18, 0.24, 0.21, 0.18, and 0.19, respectively.…”