On the relationship between ground temperature histories and meteorological records: a report on the Pomquet station

An experimental air-ground climate station is operating in Pomquet, Nova Sc otia, monitoring meteorological (surface air temperatures at three heights, wind velocity and direction, incoming solar radiation, precipitation, snow depth and relative humidity) and ground thermal variables (soil temperatur es at depths of 0, 5, 10, 20, 50 and 100 cm). Readings are taken every 30 s and 5 min averages are stored, in order to characterize the energy exchang es at the air ground interface. Here, I report on the first year of operati on. For spring, summer and fall, we find that soil temperatures track surfa ce air temperatures with amplitude attenuation and phase lag with depth con firming that heat conduction adequately describe the soil thermal field at the Pomquet site. For winter conditions, we find that heat transfer is domi nated by latent heat released during soil freezing and to a lesser extent b y the insulating affect of snow cover. A numerical model of heat conduction was used in order to estimate the magnitude of the heat released by freezi ng during the winter months. I also show that there is an inverse correlati on for the difference between soil (100 cm) and air temperatures and the in coming solar radiation at the site. (C) 2001 Elsevier Science B.V. All righ ts reserved.