Physical controls on frost events in the central Andes of Peru using in situ observations and energy flux models

We successfully validated a numerical soil heat diffusion model with data from a field campaign in July 2010 and we used it, together with a radiative transfer model, to estimate the sensitivities of Tmin and LW↓ to atmospheric and soil variables. With these results we estimated the partial contributions of these variables to the overall day-to-day variability in Tmin and LW↓. We found that low cloud cover is the dominant factor, although specific humidity has a comparable role in the wet season. Lack of information on the cloud liquid water path is an important source of uncertainty. Enhanced soil moisture has a strong mitigating effect on frosts, although strong variability of soil moisture in the wet season could contribute substantially to the development of frosts.