University of Florida Homepage
College of Liberal Arts and Sciences

Geography
Make a Gift
Make a Gift

Assessing the Impacts of Falling Ice Radiative Effects on the Seasonal Variation of Land Surface Properties

Figure 3. The seasonal cycle of mean differences between NOS and SON CESM1-CAM5 sensitivity experiments is shown for (a) surface radiative fluxes, (b) land surface and air temperature and canopy ET, (c) soil moisture state and snow cover, and (d) vegetation properties, averaged over Eurasia (90°−120°E, 50°–65°N). The error bars show the ± one standard deviation in NOS minus SON across the region at each calendar month.

Kisembe, J., Li, J. L. F., Wen, Y., Lee, W. L., Qian, W., Li, Z., & Jiang, J. H. (2024). Assessing the impacts of falling ice radiative effects on the seasonal variation of land surface properties. Journal of Geophysical Research: Atmospheres, 129(15), e2024JD040991. DOI: https://doi.org/10.1029/2024JD040991

Article first published online: 05 August 2024 in JGR Atmospheres

ABSTRACT: The impacts of falling ice radiative effects (FIREs) on land-atmosphere feedback processes were examined, with a focus on the fidelity of land surface properties and their variability as inferred by global climate models (GCMs). We conducted a pair of sensitivity experiments using the National Center for Atmospheric Research (NCAR) Community Earth System Model Version 1 (CESM1) in fully coupled modes with FIREs turned on and off. This allowed us to investigate the seasonal response of land surface properties to changes in radiation fluxes and land surface temperature (LST) associated with FIREs across global land areas. Our findings indicate that during boreal winter, excluding FIREs results in less surface downward longwave and net flux (∼5–15 Wm−2), leading to a colder land surface (∼2–4 K) and air temperatures (∼1–4 K) at mid- and high latitudes. Consequently, the surface frozen soil layer and snow cover persist through spring, delaying snowmelt and thawing until summer. This delay reduces liquid soil moisture, thereby suppressing vegetation productivity in subsequent seasons. Conversely, tropical regions, exhibit contrasting responses, with a warmer land surface (∼0.5 K) and warmer air temperatures (∼0.1–0.5 K) due to increased surface downward shortwave and net flux (∼2–10 Wm−2). This enhancement in radiation fosters increased vegetation productivity throughout the seasonal cycle. These findings illustrate a local response of land surface properties to changes in the surface energy balance and LST, highlighting the significant role that FIREs play in land surface modeling within GCMs.

Read the full publication in JGR Atmospheres