Approximating snow surface temperature from standard temperature and humidity data: New possibilities for snow model and remote sensing evaluation

Here we test simple Ts approximations with standard height (2-4 m) air temperature (Ta), wet-bulb temperature (Tw), and dew point temperature (Td), which are more readily available than Ts. We used hourly measurements from seven sites to understand which Ts approximation is most robust and how Ts representation varies with climate, time of day, and atmospheric conditions (stability and radiation).

Td approximated Ts with the lowest overall bias, ranging from -2.3 to +2.6°C across sites and from -2.8 to 1.5°C across the diurnal cycle. Prior studies have approximated Ts with Ta, which was the least robust predictor of Ts at all sites. Approximation of Ts with Td was most reliable at night, at sites with infrequent clear sky conditions, and at windier sites (i.e., more frequent turbulent instability).