Lagged feedback of peak season photosynthetic activities on local surface temperature in Inner Mongolia, China

Wendu Rina; Yuhai Bao; Enliang Guo; Siqin Tong; Xiaojun Huang; Shan Yin

doi:10.1016/j.envres.2023.116643

Lagged feedback of peak season photosynthetic activities on local surface temperature in Inner Mongolia, China

Environ Res. 2023 Nov 1;236(Pt 1):116643. doi: 10.1016/j.envres.2023.116643. Epub 2023 Jul 12.

Authors

Wendu Rina¹, Yuhai Bao², Enliang Guo³, Siqin Tong¹, Xiaojun Huang¹, Shan Yin¹

Affiliations

¹ College of Geographical Science, Inner Mongolia Normal University, Hohhot, 010022, China; Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Hohhot, 010022, China.
² College of Geographical Science, Inner Mongolia Normal University, Hohhot, 010022, China; Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Hohhot, 010022, China. Electronic address: baoyuhai@imnu.edu.cn.
³ College of Geographical Science, Inner Mongolia Normal University, Hohhot, 010022, China; Inner Mongolia Key Laboratory of Disaster and Ecological Security on the Mongolian Plateau, Inner Mongolia Normal University, Hohhot, 010022, China.

PMID: 37442253
DOI: 10.1016/j.envres.2023.116643

Abstract

Increased vegetation peak growth and phenological shifts toward spring have been observed in response to climate warming in the temperate regions. Such changes have the potential to modify warming by perturbing land‒atmosphere energy exchanges; however, the signs and magnitudes of biophysical feedback on surface temperature in different biomes are largely unknown. Here, we synthesized information from vegetation growth proxies, land surface temperature (LST), and surface energy balance factors (surface evapotranspiration (ET), albedo, and broadband emissivity (BBE)) to investigate the variations in timing (PPT) and productivity (PP_max) of seasonal peak photosynthesis and their time-lagged biophysical feedbacks to the post-season LST in Inner Mongolia (IM) during 2001-2020. We found that increased PP_max, rather than advanced PPT, exhibited a significant impact on LST, with divergent signs and magnitudes across diurnal periods and among different biomes. In the grassland biome, increased PP_max cooled both LST during daytime (LST_day) and nighttime (LST_night) throughout the post-season period, with a more pronounced response during daytime and diminishing gradually from July to September. This cooling effect on LST was primarily attributed to enhanced ET, as evidenced by the greater effect of ET cooling than that of albedo warming and BBE cooling based on a structural equation model (SEM). In the forest biome, increased PP_max led to a symmetrical warming effect on LST_day and LST_night, and none of the surface energy balance factors were identified as significant intermediate explanatory factors for the observed warming effect. Moreover, the responses of average LST (LST_mean) and diurnal temperature range of LST (LST_DTR) to variations in PP_max were consistent with those of LST_day at two biomes. The observations above elucidate the divergent feedback mechanisms of vegetation peak growth on LST among different biomes and diurnal cycles, which could facilitate the improvement of the realistic parameterization of surface processes in global climate models.

Keywords: Cooling effect; Evapotranspiration; Land surface temperature; Peak season photosynthetic activities; Structural equation model; Warming effect.