Near–surface air temperature and snow skin temperature comparison from CREST-SAFE station data with MODIS land surface temperature data
C. L. Pérez Díaz1, T. Lakhankar1, P. Romanov1, J. Muñoz2, R. Khanbilvardi1, and Y. Yu31National Oceanic and Atmospheric Administration-Cooperative Remote Sensing Science and Technology (NOAA-CREST) Center, The City College of New York, New York, NY 10031, USA 2Universidad de Puerto Rico, Recinto de Mayagüez, Recinto Universitario de Mayagüez, Universidad de Puerto Rico, Departamento de Ingeniería Civil y Agrimensura, Mayagüez, PR 00681, Puerto Rico 3NOAA-Satellite Applications and Research (STAR), 5830 University Research Court, College Park, MD 20740, USA
Received: 24 Jun 2015 – Accepted for review: 20 Jul 2015 – Discussion started: 10 Aug 2015
Abstract. Land Surface Temperature (LST) is a key variable (commonly studied to understand the hydrological cycle) that helps drive the energy balance and water exchange between the Earth's surface and its atmosphere. One observable constituent of much importance in the land surface water balance model is snow. Snow cover plays a critical role in the regional to global scale hydrological cycle because rain-on-snow with warm air temperatures accelerates rapid snow-melt, which is responsible for the majority of the spring floods. Accurate information on near-surface air temperature (T-air) and snow skin temperature (T-skin) helps us comprehend the energy and water balances in the Earth's hydrological cycle. T-skin is critical in estimating latent and sensible heat fluxes over snow covered areas because incoming and outgoing radiation fluxes from the snow mass and the air temperature above make it different from the average snowpack temperature.
This study investigates the correlation between MODerate resolution Imaging Spectroradiometer (MODIS) LST data and observed T-air and T-skin data from NOAA-CREST-Snow Analysis and Field Experiment (CREST-SAFE) for the winters of 2013 and 2014. LST satellite validation is imperative because high-latitude regions are significantly affected by climate warming and there is a need to aid existing meteorological station networks with the spatially continuous measurements provided by satellites. Results indicate that near-surface air temperature correlates better than snow skin temperature with MODIS LST data. Additional findings show that there is a negative trend demonstrating that the air minus snow skin temperature difference is inversely proportional to cloud cover. To a lesser extent, it will be examined whether the surface properties at the site are representative for the LST properties within the instrument field of view.
Pérez Díaz, C. L., Lakhankar, T., Romanov, P., Muñoz, J., Khanbilvardi, R., and Yu, Y.: Near–surface air temperature and snow skin temperature comparison from CREST-SAFE station data with MODIS land surface temperature data, Hydrol. Earth Syst. Sci. Discuss., 12, 7665-7687, doi:10.5194/hessd-12-7665-2015, 2015.