Effects of vegetation, albedo, and solar radiation sheltering on the distribution of snow in the Valles Caldera, New Mexico

Abstract

The effects of radiation scattering and sheltering on snow distributions are poorly understood in montane regions of the southwestern United States. To examine this, we develop a single-layer, distributed snow model (DSM) that includes canopy interception, and radiation scattering and sheltering. In our simulations, we distinguish between local and remote controls on shortwave radiation. This allows us to vary the representation of the effective albedo of the surrounding terrain from a vegetated to a snow-covered landscape and examine the impact this has on snow accumulation and melt. The distributed model is applied to La Jara catchment in the Valles Caldera, New Mexico, during the 2004-2005 winter season. Results indicate that a landscape-scale albedo controlled by vegetation has little effect on local scale-processes, such as incoming shortwave radiation and maximum snow water equivalent (SWE). This implies that increases from scattered light are nearly equal to the losses of radiation from remote sheltering. In contrast, when landscape-scale albedo is controlled by snow cover or by a proposed dynamic method accounting for snow in the vegetation canopy, there are large deviations in the spatiotemporal distributions of shortwave radiation and SWE due to scattered radiation exceeding the sheltering effects of remote topography. Our study results indicate that remote interactions of radiation, vegetation and topography are critical to consider in snow ecohydrological studies in regions with high solar flux and rugged topography.

Mountain ecohydrology: quantifying the role of vegetation in the water balance of montane catchments

“…Rinehart et al (2008) present a model of snow-vegetation-topography interactions that describe how catchment-scale variability in albedo associated with forest vegetation modifies the energy balance and snow distribution throughout a watershed. In a series of modelling experiments, Rinehart et al show that reflected radiation from adjacent, snow-covered slopes greatly reduces both the amount and duration of winter snow cover.…”

Hydrological effects of Norway spruce and European beech on snow cover in a mid-mountain region of the Polana mts., Slovakia / Hydrologický vplyv smreka obyčajného a buka lesného na snehovú pokrývku v stredohorských polohách pohoria poľana na slovensku

“…Therefore, it is important to understand how particular types of forest stands perform within this context. Numerous research results Lyon et al, 2008;Mindas, 2003;Molotch et al, 2009;Pobedinskij and Krecmer, 1984;Rinehart et al, 2008;Veatch et al, 2009) point out that the accumulation and melting of snow depends on a large number of factors (geographic area, size of mountains, elevation, slope, exposition, stand age and canopy cover, oceanic/continental climate etc. ), hence, the obtained knowledge is not easy to interpret and generalize.…”

Modeling the distributed effects of forest thinning on the long-term water balance and streamflow extremes for a semi-arid basin in the southwestern US

“…Incoming solar radiation is reduced by vegetative shading according to the Beer-Lambert law (Brantley and Young, 2007;Marshall and Waring, 1986) (see Appendix B). Effects of distant landscape on the amount of incoming radiation are accounted through radiation scattering and sheltering functions that are controlled by landview factors and hillslope albedo (Rinehart et al, 2008). Surface latent (i.e.…”

“…evaporation and transpiration), sensible and ground heat fluxes are computed using meteorological conditions and soil moisture (Ivanov et al, 2004b). Snow processes are accounted for through a single-layer snow module with a coupled energy and mass balance approach that accounts for direct and diffuse solar (shortwave) and longwave radiation, snow interception and unloading, sublimation of intercepted and on-the-ground snow, accumulation and ablation of snow and infiltration of meltwater (Mahmood and Vivoni, 2013;Rinehart et al, 2008). Vegetation intercepts snow falling in solid form, based on its leaf area index, and unloads snow in relation to air temperature.…”