Asymmetric effects of soil moisture on mean daily maximum and minimum temperatures over eastern China

Abstract

This study statistically investigates the effects of soil moisture on mean daily maximum ( $$T_{\rm{max} }$$ ) and minimum temperatures ( $$T_{\rm{min} }$$ ) over eastern China in spring (from March to May), summer (from June to August) and fall (from September to November), using the Global Land Data Assimilation System (GLDAS) soil moisture and observational temperatures. The results show that soil moisture exerts asymmetric effects on $$T_{\rm{max} }$$ and $$T_{\rm{min} }$$ , thereby has substantial effects on the diurnal temperature range (DTR) in the three seasons. The soil moisture feedbacks on $$T_{\rm{max} }$$ , $$T_{\rm{min} }$$ , and DTR are found to evidently vary with season. In spring and summer, soil moisture exerts stronger negative forcing on $$T_{\rm{max} }$$ than $$T_{\rm{min} }$$ , and thus has negative effects on the DTR over many areas of northern China. In fall, soil moisture has much stronger positive effects on $$T_{\rm{min} }$$ than $$T_{\rm{max} }$$ , and thus has significant negative effects on the DTR over Northeast China and some areas of the climatic and ecological transition zone of northern China. The uncertainties in the employed data and method should be noted. Therefore, the results need to be further investigated by other data sets and methods in the future.