The role of winter sublimation in the Arctic moisture budget

In the Arctic, the simplest way to describe the winter surface moisture budget (in the absence of any net horizontal transport) is: snow-water-equivalent depth on the ground (D) equals precipitation (P) minus sublimation (S). D, P and S are the most fundamental components of the winter arctic hydrologic cycle and understanding them is essential to understanding arctic moisture-related processes. Unfortunately, accurate solid-precipitation (P) measurements have proven nearly impossible to achieve in the Arctic, because precipitation generally falls when it is windy. Gauge undercatch can range from 55–75% depending on the gauge type and wind conditions. The state of knowledge for winter sublimation (S) is even more limited. There are few actual measurements and most studies have used physical models to estimate this quantity. Moreover, fundamental questions concerning the boundary-layer physics of arctic winter sublimation remain unanswered. Resolving these is essential to closing local, regional, and pan-Arctic moisture budgets because some studies indicate sublimation may be as much as 50% of the total winter precipitation and 35% of the annual precipitation. This paper summarizes and analyzes the existing literature describing arctic sublimation.