Multiscale Evaluation of the Improvements in Surface Snow Simulation through Terrain Adjustments to Radiation
Open Access
- 1 February 2013
- journal article
- Published by American Meteorological Society in Journal of Hydrometeorology
- Vol. 14 (1), 220-232
- https://doi.org/10.1175/jhm-d-12-046.1
Abstract
The downwelling shortwave radiation on the earth’s land surface is affected by the terrain characteristics of slope and aspect. These adjustments, in turn, impact the evolution of snow over such terrain. This article presents a multiscale evaluation of the impact of terrain-based adjustments to incident shortwave radiation on snow simulations over two midlatitude regions using two versions of the Noah land surface model (LSM). The evaluation is performed by comparing the snow cover simulations against the 500-m Moderate Resolution Imaging Spectroradiometer (MODIS) snow cover product. The model simulations are evaluated using categorical measures, such as the probability of detection of “yes” events (PODy), which measure the fraction of snow cover presence that was correctly simulated, and false alarm ratio (FAR), which measures the fraction of no-snow events that was incorrectly simulated. The results indicate that the terrain-based correction of radiation leads to systematic improvements in the snow cover estimates in both domains and in both LSM versions (with roughly 12% overall improvement in PODy and 5% improvement in FAR), with larger improvements observed during snow accumulation and melt periods. Increased contribution to PODy and FAR improvements is observed over the north- and south-facing slopes, when the overall improvements are stratified to the four cardinal aspect categories. A two-dimensional discrete Haar wavelet analysis for the two study areas indicates that the PODy improvements in snow cover estimation drop to below 10% at scales coarser than 16 km, whereas the FAR improvements are below 10% at scales coarser than 4 km.Keywords
This publication has 39 references indexed in Scilit:
- Noah land surface model modifications to improve snowpack prediction in the Colorado Rocky MountainsJournal of Geophysical Research: Solid Earth, 2010
- Potential impacts of a warming climate on water availability in snow-dominated regionsNature, 2005
- A new intensity‐scale approach for the verification of spatial precipitation forecastsMeteorlogical Applications, 2004
- Implementation of Noah land surface model advances in the National Centers for Environmental Prediction operational mesoscale Eta modelJournal of Geophysical Research: Solid Earth, 2003
- Scaling issues in snow hydrologyHydrological Processes, 1999
- Eurasian snow cover variability and northern hemisphere climate predictabilityGeophysical Research Letters, 1999
- Discriminating clear sky from clouds with MODISJournal of Geophysical Research: Solid Earth, 1998
- Scale issues in hydrological modelling: A reviewHydrological Processes, 1995
- A Statistical-Topographic Model for Mapping Climatological Precipitation over Mountainous TerrainJournal of Applied Meteorology and Climatology, 1994
- The New Global Operational Analysis System at the National Meteorological CenterWeather and Forecasting, 1991