Biomass, thermal inertia, and radiative freeze occurrence in leafless forests

Using field measurements of air temperature, wind, and relative humidity from a clearcut site and two wooded sites in northern Wisconsin, we used a radiative transfer model to simulate temperatures on seven calm, clear nights similar to those on which freezes typically occur. Each night was simulated twice for the wooded sites. One simulation ignored the presence of vegetation, the other approximated the vegetationʹs heat storage capacity and its influence on air temperatures. The simulations including biomass heat storage showed smaller mean absolute temperature errors and decreased magnitude of systematic model error when compared with the simulations ignoring vegetation. The results suggest that the thermal inertia of forest biomass may play a significant role in controlling forest temperatures on calm, clear nights and, hence, in controlling freeze occurrence.