13 Jan 2026

Wave Information Study ERA5 Wind-Field Evaluation

Abstract: The Wave Information Study (WIS) provides continuous wave hindcasts along US coastlines, including the Great Lakes and US Territories. As wave modeling and wind-field technologies have advanced, WIS is now positioned to transition to the new long-term archived hindcast wind fields available from ERA5, the fifth-generation global atmospheric reanalysis from the European Centre for Medium-Range Weather Forecasts. Before adopting ERA5 operationally within the WIS hindcast, formal testing compared ERA5 wind-forced hindcasts to the existing WIS hindcasts using Nation Center for Atmospheric Research Reanalysis 1 (NCAR-R1) winds. Results were validated against collocated and concurrent point-source and altimeter-based wave measurements from 2015 to 2018. ERA5 showed a 53% improvement in significant wave-height bias in the Atlantic and 76%–77% improvements in the Pacific. While improvements in average wave period were less consistent, ERA5 still showed better correlation across all domains. Hawaii showed modest improvements, except for bias. ERA5 also outperformed NCAR-R1 in mean wave direction at peak frequency, with bias reductions of 5%–72%, most notably in Hawaii, where wave modeling is typically challenging. Overall, it was concluded that the ERA5 forced WIS estimates were more accurate than the NCAR forced WIS estimates, supporting the operational transition of WIS to ERA5.

5 Aug 2022

South Pole Station Snowdrift Model

Abstract: The elevated building at Scott-Amundsen South Pole Station was designed to mitigate the effects of windblown snow on it and the surrounding infrastructure. Because the elevation of the snow surface increases annually, the station is periodically lifted on its support columns to maintain its design height above the snow surface. To assist with planning these lifts, this effort developed a computational model to simulate snowdrift formation around the elevated building. The model uses computational fluid dynamics methods and synthetic wind record generation derived from statistical analysis of meteorological data. Simulations assessed the impact of several options for the lifting operation on drifts surrounding the elevated building. Simulation results indicate that raising the eastern-most building section (Pod A), or the entire station all at once, can reduce drift accumulation rates over the nearby arches structures. Long-term analyses, spanning 5–6 years, determine whether an equilibrium drift condition may be reached after a long period of undisturbed drift development. These simulations showed that after about 6 years, the rate of growth of the upwind drift slows, appearing to approach an equilibrium condition. However, the adjacent drifts were still increasing in depth at a roughly linear rate, indicating that equilibrium for those drifts was still several seasons away.

5 Aug 2022

SAGE-PEDD User Manual

Abstract: SAGE-PEDD is a computational model for estimating snowdrift shapes around buildings. The main inputs to the model are wind speed, wind direction, building geometry and initial ground or snow-surface topography. Though developed mainly for predicting snowdrift shapes, it has the flexibility to accept other soil types, though this manual addresses snow only. This manual provides detailed information for set up, running, and viewing the output of a SAGE-PEDD simulation.