Satellite-observed greenness expansion across Antarctica

Polar ecosystems are reshaping rapidly in the 21st century, yet Antarctica's continent-wide terrestrial vegetation response remains unclear. Here, using 22 years (2002-2023) of daily MODIS products, we provide the first continent-wide, multi-decadal record of spectral greenness. The area of satellite product exhibiting greenness increased by more than 50%, from 7,356 to 11,219 km², and mean seasonal detection span lengthened from 22.6 to 32.4 days. Both trends were significant across all three major Antarctic regions. Water availability and ultraviolet radiation together account for 77% of modeled continental climate contributions, while temperature contributes less. Modeled regional contributions diverge sharply: water dominates in East Antarctica, ultraviolet-radiation on the Antarctic Peninsula, and ultraviolet-radiation and temperature jointly in West Antarctica. These results reveal shared spatial and seasonal greening across contrasting Antarctic changing environments.