The spatiotemporal patterns of climate asymmetric warming and vegetation activities in an arid and semiarid region

Authors: HENG, TONG - Shihezi University; Feng, Gary; OUYANG, YING - Us Forest Service (FS); HE, XINLIN - Shihezi University

Submitted to: Climate
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2020
Publication Date: 12/10/2020
Citation: Heng, T., Feng, G.G., Ouyang, Y., He, X. 2020. The spatiotemporal patterns of climate asymmetric warming and vegetation activities in an arid and semiarid region. Climate. 8:145. https://doi.org/10.3390/cli8120145.
DOI: https://doi.org/10.3390/cli8120145

Interpretive Summary: This study analyzed weather data and normalized difference vegetation index (NDVI) (2000-2020) in the arid and semiarid regions. The change trends of day and nighttime warming (DNW), seasonal warming, and the diurnal temperature range in northern Xinjiang (S1) and southern Xinjiang (S2) were determined. A second-order partial correlation analysis was employed to analyze the impacts of asymmetric warming and precipitation on vegetation activities. The findings indicated that the DNW rate showed a significant (p<0.01) upward trend, especially in winter. The nighttime warming rate (0.65°C (decade)-1) was faster than the daytime warming rate (0.4°C (decade)-1), and the temperature differences between daytime and nighttime exhibited a decreasing trend. The diurnal range was the highest in spring and the lowest in winter. Extreme values of the diurnal range appeared in autumn (48.6 °C) and winter (12.3 °C), and both extremes were located in S1. There were spatial inconsistencies in the DNW rate. The Tmin in S1 had a mutation trend in 2006-2017, the Tmax in S2 had a mutation trend in 2005-2011, and the probability of spatial mutation in S1 was higher than that in S2. The responses of vegetation activities to DNW in Xinjiang had significant spatial differences, especially between the Junggar Basin and the Gurbantünggüt Desert plain. The partial correlation between the NDVI and Tmin was significantly higher than that between the NDVI and Tmax in the area where the significance test passed; therefore, asymmetric nighttime warming had a greater impact on the NDVI than the asymmetric daytime warming.

Technical Abstract: analyze the impacts of asymmetric warming and precipitation on vegetation activities. The findings indicated that the DNW rate showed a significant (p<0.01) upward trend, especially in winter. The nighttime warming rate (0.65°C (decade)-1) was faster than the daytime warming rate (0.4°C (decade)-1), and the temperature differences between daytime and nighttime exhibited a decreasing trend. The diurnal range was the highest in spring and the lowest in winter. Extreme values of the diurnal range appeared in autumn (48.6 °C) and winter (12.3 °C), and both extremes were located in S1. There were spatial inconsistencies in the DNW rate. The Tmin in S1 had a mutation trend in 2006-2017, the Tmax in S2 had a mutation trend in 2005-2011, and the probability of spatial mutation in S1 was higher than that in S2. The responses of vegetation activities to DNW in Xinjiang had significant spatial differences, especially between the Junggar Basin and the Gurbantünggüt Desert plain. The partial correlation between the NDVI and Tmin was significantly higher than that between the NDVI and Tmax in the area where the significance test passed; therefore, asymmetric nighttime warming had a greater impact on the NDVI than the asymmetric daytime warming.