Pattern-based downscaling of snowpack variability in the western United States

Abstract

The decline in snowpack across the western United States is one of the most pressing threats posed by climate change to regional economies and livelihoods. Earth system models are important tools for exploring past and future snowpack variability, yet their coarse spatial resolutions distort local topography and bias spatial patterns of accumulation and ablation. Here, we explore pattern-based statistical downscaling for spatially-continuous interannual snowpack estimates. We find that a few leading patterns capture the majority of snowpack variability across the western US in observations, reanalyses, and free-running simulations. Pattern-based downscaling methods yield accurate, high resolution maps that correct mean and variance biases in domain-wide simulated snowpack. Methods that use large-scale patterns as both predictors and predictands perform better than those that do not and all are superior to an interpolation-based “delta change” approach. These findings suggest that pattern-based methods are appropriate for downscaling interannual snowpack variability and that using physically meaningful large-scale patterns is more important than the details of any particular downscaling method.

Awareness levels of the dynamics of the climate change risk impacts

“…The mountain snowpack makes up a key component of surface water resources, provides crucial storage of winter precipitation and serves as necessary, regionally integrated indicators of climate variability and change (Stewart, 2009;Mote, Hamlet, Clark & Lettenmaier, 2005). Climate change has caused continued warming and increasingly higher elevations and results in declines in snowpack accumulation and melt that cannot be offset by winter precipitation increases and variations in dates of melt across different regions (Carroll, 2022;Gauthier, Anchukaitis & Coulthard, 2022;Evan & Eisenman, 2021).…”

“…Permafrost is the permanently frozen ground that underlies much of the Arctic land surface; hence, its melting is known as thawing permafrost (Van Huissteden, 2020). The past 20 years of research and interest in the thawing permafrost reveal that at least a quarter of some parts of nearby places arctic that has been continuous permafrost will degrade in the next fifty years and may completely disappear by the end of the 21st century (Gauthier, Anchukaitis & Coulthard, 2022). The extent of this thaw creates concern for the settlements nearby, especially for the industries, and the threatening sustainability of other activities due to ground instability (Street, 2020).…”