Groundwater impacts vegetation and the atmosphere via the soil-plant-atmosphere pathway.
Groundwater therefore contributes to the flows of water, energy and carbon between the land and the lower atmosphere and can influence local and regional air temperature and perhaps precipitation.
Understanding the potential impact of groundwater dynamics on climate extremes is an urgent topic of research given projections of more heatwaves and droughts in the future.
During heatwaves, groundwater reduces forest canopy temperatures by up to 5°C, where groundwater is shallow. However, the cooling effect is limited to the first two years of the multi-year droughts. The groundwater cools the forest canopy in heatwaves only 0.1~0.3 °C at the end droughts.