Greenhouse Gas Induced Changes in the Seasonal Cycle of the Amazon Basin in Coupled Climate-Vegetation Regional Model

Climate

Flavio Justino³  Frode Stordal¹  Edward K. Vizy²  Kerry H. Cook²  Marcos P. S. Pereira³ 

[1] Department of Geosciences, University of Oslo, PO Box 1047 Blindern, N-0316 Oslo, Norway;The University of Texas at Austin Department of Geological Sciences, University Station C1100, Austin, TX 78712, USA;Department of Agricultural and Environmental Engineering, Federal University of Viçosa (UFV), Av. P. H. Rolfs s/n Campus Universitário, Viçosa, MG 3670-900, Brazil;

关键词: Amazon rainforest;    harmonic analysis;    climate change;   

DOI  :  10.3390/cli4010003

来源: mdpi

【 摘 要 】

Previous work suggests that changes in seasonality could lead to a 70% reduction in the extent of the Amazon rainforest. The primary cause of the dieback of the rainforest is a lengthening of the dry season due to a weakening of the large-scale tropical circulation. Here we examine these changes in the seasonal cycle. Under present day conditions the Amazon climate is characterized by a zonal separation of the dominance of the annual and semi-annual seasonal cycles. This behavior is strongly modified under greenhouse warming conditions, with the annual cycle becoming dominant throughout the Amazon basin, increasing differences between the dry and wet seasons. In particular, there are substantial changes in the annual cycle of temperature due to the increase in the temperature of the warmest month, but the lengthening of the dry season is believed to be particularly important for vegetation-climate feedbacks. Harmonic analysis performed to regional climate model simulations yields results that differ from the global climate model that it is forced from, with the regional model being more sensitive to changes in the seasonal cycle.

【 授权许可】

CC BY   
© 2016 by the authors; licensee MDPI, Basel, Switzerland.