Disentangling the urbanization effect, multi-decadal variability, and secular trend in temperature in eastern China during 1909-2010

Abstract

Understanding surface air temperature (SAT) changes in China during the past 100 years is important; however, this is difficult because the impacts of multi-decadal variability (MDV), the urbanization effect, and other anthropogenic forcings are combined in instrumental records. The present study attempts to disentangle these factors recorded in observations in eastern China based on recently homogenized SAT data during 1909-2010. The estimated linear trend (secular nonlinear trend) in the data after deurbanization is 1.08 (1.74)°C (100 years)-1. The MDV has enhanced warming in the early 20th century and during the past 30 years, contributing approximately 30% to the latter period.