Transport of Snow by the Wind: A Comparison Between Observations in Adélie Land, Antarctica, and Simulations Made with the Regional Climate Model MAR

Abstract

For the first time a simulation of blowing snow events was validated in detail using one-month long observations (January 2010) made in Adélie Land, Antarctica. A regional climate model featuring a coupled atmosphere/blowing snow/snowpack model is forced laterally by meteorological re-analyses. The vertical grid spacing was 2 m from 2 to 20 m above the surface and the horizontal grid spacing was 5 km. The simulation was validated by comparing the occurrence of blowing snow events and other meteorological parameters at two automatic weather stations. The Nash test allowed us to compute efficiencies of the simulation. The regional climate model simulated the observed wind speed with a positive efficiency (0.69). Wind speeds higher than 12 m s −1 were underestimated. Positive efficiency of the simulated wind speed was a prerequisite for validating the blowing snow model. Temperatures were simulated with a slightly negative efficiency (−0.16) due to overestimation of the amplitude of the diurnal cycle during one week, probably because the cloud cover was underestimated at that location during the period concerned. Snowfall events were correctly simulated by our model, as confirmed by field reports. Because observations suggested that our instrument (an acoustic sounder) tends to overestimate the blowing snow flux, data were not sufficiently accurate to allow the complete validation of snow drift values. However, the simulation of blowing snow occurrence was in good agreement with the observations made during the first 20 days of January 2010, despite the fact that the blowing snow flux may be underestimated by the regional climate model during pure blowing snow events. We found that blowing snow occurs in Adélie Land only when the 30-min wind speed value at 2 m a.g.l. is >10 m s −1 . The validation for the last 10 days of January 2010 was less satisfactory because of complications introduced by surface melting and refreezing.

A Comparison of Antarctic Ice Sheet Surface Mass Balance from Atmospheric Climate Models and In Situ Observations

“…Based on RACMO2.1 and RACMO2.3 (Lenaerts et al 2012;van Wessem et al 2014a), drifting sublimation averaged over the ice sheet in magnitude accounts for ;10% of annual precipitated snow. This value is comparable to that derived from the MAR (Gallée et al 2013b). Nevertheless, according to the blowing snow flux comparison between simulation and observation (Gallée et al 2013a), it could actually be twice as large.…”

“…This value is comparable to that derived from the MAR (Gallée et al 2013b). Nevertheless, according to the blowing snow flux comparison between simulation and observation (Gallée et al 2013a), it could actually be twice as large. It is also clearly seen in Fig.…”

Evaluation of the FlowCapt Acoustic Sensor for the Aeolian Transport of Snow

“…It is a commercialized acoustic sensor able to quantify the horizontal snow flux with an accuracy given by the manufacturer of 65% (Chritin et al 1999). This instrument has been used in different research campaigns in the Swiss and French Alps (Lehning and Fierz 2008;Naaim-Bouvet et al 2010), in the Arctic region (Jaedicke 2002;Savelyev et al 2006), and in Antarctica (Scarchilli et al 2010;Gallée et al 2013). Two successive versions of FlowCapt exist: one, referred to as the firstgeneration FlowCapt, was sold until 2009; and the second one, referred to as the second-generation FlowCapt, has been sold since 2009.…”

Grand Challenges in Cryospheric Sciences: Toward Better Predictability of Glaciers, Snow and Sea Ice

“…While the most advanced models such as MAR (Gallee et al, 2013;Amory et al, 2015) or RACMO implement parameterizations of the complex snow processes, quantitative validation is challenging. The community agrees that potential calculation errors are large, and critically influence the modeled total mass balance.…”