How Does Land Affect Atmospheric Processes at Diurnal to Seasonal Scales?

While the atmosphere drives land processes through its (radiation) energy and (precipitation) water fluxes, land also affects atmospheric processes at different time scales via different pathways. Here we will overview our recent work to illustrate some of these pathways.

First, we used in situ measurements and satellite remote sensing data to quantify the impact of morning land state (e.g., soil moisture, temperature) on afternoon rainfall in the warm season, and found that the impacts vary substantially, depending on larger-scale atmospheric water vapor convergence (Welty and Zeng 2018; Welty et al. 2019 in preparation).

Second, we used the theoretical insight gained from Zeng and Dickinson (1998) to improve the treatment of near-surface turbulence in land models, and demonstrated its impact on satellite remote sensing data assimilation and weather forecasting (Zeng et al. 2012; Zheng et al. 2012).

Finally, we used CFS ensemble seasonal forecasts to demonstrate the impact of snowpack initialization on seasonal forecasts. Furthermore, this impact is greater than that due to the uncertainties in the sea surface temperature initialization (Broxton et al. 2016; Zeng et al. 2018).