Downscaling

Alaska’s complex topography, with its extensive coastlines, dozens of islands, and mountain ranges that contain the tallest peaks in North America have a strong influence on temperature and precipitation. Accurate representations of that terrain can improve the quality of simulations of past and future climate conditions. In order for the state and federal decision-makers to adequately prepare for and adapt to changing conditions in Alaska high-resolution climate data is needed.

Downscaling is the process of increasing the resolution of globally available climate data which is typically too coarse (~80 to 100 km) to adequately detect local landscape features. Without this process these models aren’t useful for predicting future conditions in Alaska. Dynamical downscaling, a technique in which higher resolution weather forecasting models are used to provide local context to global-scale data is one method to improve model resolution and decision-relevance.

Modelers working with the Alaska CASC have been building capacity and expertise in climate model downscaling since the center’s inception.

Downscaling-focused work at the Alaska CASC over the past decade has included:

• Developing High Resolution Climate Data for Alaska
• Dynamical Downscaling for Southeast Alaska: Historical Climate and Future Projections
• Projections of Twenty-First-Century Climate Extremes for Alaska via Dynamical Downscaling and Quantile Mapping
• Downscaling of climate model output for Alaskan stakeholders
• Dynamical downscaling of ERA-Interim temperature and precipitation for Alaska
• Assessment of Alaska rain-on-snow events using dynamical downscaling

Much of the downscaled climate data developed in collaboration with the Alaska CASC is handled and delivered by the Scenarios Network for Alaska + Arctic Planning via web tools tailored for distinct audiences:

• northernclimatereports.org – Northern Climate Reports delivers summary reports of high resolution data at points or over areas of interest for planners, managers, and decision-makers.
• arcticeds.org – The Arctic-EDS delivers high resolution data at points in Alaska for engineers.
• arcticdatascience.org – The Arctic Data Collaborative provides summaries of high-resolution curated datasets by variable along with guidance on access and use for researchers.
• earthmaps.io – The Alaska + Arctic Geospatial Data API is a portal for direct query of downscaled climate data by programmers.