Vegetation-climate coupling and vegetation sensitivity to climate extremes in growing seasons

Terrestrial vegetation is largely mediated by vegetation-climate coupling. Growing conditions control vegetation growth, which in turn feeds back to climate through changes in biophysical and biogeochemical properties and processes, such as canopy structure and carbon and water exchanges. The vegetation-climate coupling is thus highly variable in space and time. However, little is known on how the large-scale vegetation-climate coupling varies within growing season, and how vegetation responds to climate extremes. In this contribution, we present some recent findings on seasonal and intra-seasonal vegetation-climate coupling and vegetation sensitivity to droughts using multiple remote sensing products including MODIS EVI, GIMMS3g NDVI and VIP EVI2. We account for the differences in phenological stages of growing seasons affected by both climate and landscape heterogeneity. Based on a novel analytical framework incorporating meteorological and vegetation conditions to locally defined vegetation growing seasons, we analyse vegetation-climate couplings using both local climate conditions and teleconnection indices (e.g., Jet Latitude Index). In addition, vegetation sensitivity to droughts and post-drought vegetation changes are assessed. Our results highlight the importance of considering vegetation phenology in understanding sub-seasonal land-atmosphere interaction and vegetation dynamics. The developed analytical framework is suggested to be an effective approach for evaluating vegetation and climate dynamics simulated by Earth System Models.