Index Geophysics

Modeling the evolution of the structural anisotropy of snow

<p>The structural anisotropy of snow characterizes the spatially anisotropic distribution of the ice and air microstructure and is a key parameter for improving parameterizations of physical properties. To enable the use of the anisotropy in snowpack models as an internal variable, we propose a simple model based on a rate equation for the temporal evolution. The model is validated with a comprehensive set of anisotropy profiles and time series from X-ray microtomography (CT) and radar measurements. The model includes two effects, namely temperature gradient metamorphism and settling, and can be forced by any snowpack model that predicts temperature and density. First, we use CT time series from lab experiments to validate the proposed effect of temperature gradient metamorphism. Next, we use SNOWPACK simulations to calibrate the model with radar time series from the NoSREx campaigns in Sodankylä, Finland. Finally we compare the simulated anisotropy profiles against field-measured full-depth CT profiles. Our results confirm that the creation of vertical structures is mainly controlled by the vertical water vapor flux through the snow volume. Our results further indicate a yet undocumented effect of snow settling on the creation of horizontal structures. Overall the model is able to reproduce the characteristic anisotropy variations in radar time series of four different winter seasons with a very limited set of calibration parameters.</p>

S. Leinss

H. Löwe

M. Proksch

A. Kontu

Environmental sciences

GE1-350

Geology

QE1-996.5

Copernicus Publications

2020-01-01T00:00:00Z

article

10.5194/tc-14-51-2020

1994-0416

1994-0424

https://doaj.org/article/54db5f10bcde4af68488320abae2581c

The Cryosphere, Vol 14, Pp 51-75 (2020)

EN

https://www.the-cryosphere.net/14/51/2020/tc-14-51-2020.pdf

https://doaj.org/toc/1994-0416

https://doaj.org/toc/1994-0424

Journal Licence: CC BY