Sentences with phrase «snow grains»

But Dumont and her colleagues have found that, since 2009, there has been a darkening that can not be explained by larger snow grain size alone.

Snow grains become rounded.

Scientists have generally attributed that darkening to larger, slightly less white snow grains caused by warmer temperatures.

Simulating the variation of the ice sheet's albedo using a regional climate model — Modèle Atmosphérique Régionale (MAR), which some members of the team helped develop — indicated that increasing temperatures and melting accompanied by snow grain growth and greater bare ice exposure account for about half the decline, the scientists report.

Smaller - sized graupels are generally referred to as snow grains.

Poorly characterized mechanisms driving both production and destruction of GEM in the interstitial air of snowpacks depend on environmental conditions (irradiation, temperature, and presence of water layer around snow grains) and the chemical composition of snow (e.g., presence of halogens or divalent mercury species as a consequence of surface deposition)(25).

Using satellite observations, they found lower albedos at elevations and at times of the year that are too cold for larger snow grains to form.

I have also studied, for example, the effects of snow grain shape on the reflection of solar radiation by snow, and the effects of subgrid - scale cloud features (clouds too small to be resolved by a climate model) on radiative transfer.

For example, regional climate models need to refine the modeling of snow grain size and exposure of bare ice and need to include impurities and biological activity in their albedo schemes.

Second, it includes contacts and bonding between the snow grains.

Third, it can explicitly account for the large displacements and rearrangement of the snow grains during deformation.

Two properties dominate reflectivity in dry snow — the size of snow grains, which become larger and more absorbent as they melt, and the presence of dark impurities that absorb the sun's energy, predominantly black carbon and mineral dust, which also cause the snow to melt faster.

«When snow first falls, snow grains are quite small, and as snowpack ages, and particularly for warmer snowpack, you get consolidation of those grains into larger clumps,» said Sarah Doherty, a researcher at the University of Washington who co-authored the paper.

snow albedo) was modified in the NorESM climate model, by replacing an approach based on spherical snow grains with an approach assuming nonspherical snow grains.

MODIS - based Mosaic of Antarctica (MOA) data sets: Continent - wide surface morphology and snow grain size.

Räisänen, P., Makkonen, R., Kirkevåg, A., and Debernard, J. B.: Effects of snow grain shape on climate simulations: sensitivity tests with the Norwegian Earth System Model, The Cryosphere, 11, 2919 - 2942, doi: 10.5194 / tc -11-2919-2017, 2017.