Response of Freezing/Thawing Indexes to the Wetting Trend under Warming Climate Conditions over the Qinghai -Tibetan Plateau during 1961–2010: A Numerical Simulation

Abstract Since the 1990s, Qinghai-Tibetan Plateau (QTP) has experienced a strikingly warming and wetter climate that alters thermal hydrological properties of frozen ground. A positive correlation between degradation in permafrost or seasonally ground (SFG) long been recognized. Still, predictive relationship historical wetting under conditions not yet well demonstrated, despite expectation it will become even more important because precipitation over QTP projected to increase continuously near future. This study investigates response regime both SFG areas examines their relationships separately using Community Land Surface Model version 4.5. Results show before 1990s across mainly cooled body arid semiarid zones, with significant coefficients 0.60 0.48, respectively. Precipitation increased continually at rate 6.16 mm decade −1 zone after but had contrasting effect on through shortening thawing duration within active layer. However, diminished rainfall humid also significantly extended SFG. The index was negatively correlated (−0.75). dual effects dynamics are becoming critical increases future precipitation.