Evaluation of an improved intermediate complexity snow scheme in the ORCHIDEE land surface model

Abstract

[1] Snow plays an important role in land surface models (LSM) for climate and hydrometeorological studies, but its current treatment as a single layer of constant density and thermal conductivity in ORCHIDEE (Organizing Carbon and Hydrology in Dynamic Ecosystems) induces significant deficiencies. The intermediate complexity snow scheme ISBA-ES (Interaction between Soil, Biosphere and Atmosphere-Explicit Snow) that includes key snow processes has been adapted and implemented into ORCHIDEE, referred to here as ORCHIDEE-ES. In this study, the adapted scheme is evaluated against the observations from the alpine site Col de Porte (CDP) with a continuous 18 year data set and from sites distributed in northern Eurasia. At CDP, the comparisons of snow depth, snow water equivalent, surface temperature, snow albedo, and snowmelt runoff reveal that the improved scheme in ORCHIDEE is capable of simulating the internal snow processes better than the original one. Preliminary sensitivity tests indicate that snow albedo parameterization is the main cause for the large difference in snow-related variables but not for soil temperature simulated by the two models. The ability of the ORCHIDEE-ES to better simulate snow thermal conductivity mainly results in differences in soil temperatures. These are confirmed by performing sensitivity analysis of ORCHIDEE-ES parameters using the Morris method. These features can enable us to more realistically investigate interactions between snow and soil thermal regimes (and related soil carbon decomposition). When the two models are compared over sites located in northern Eurasia from 1979 to 1993, snow-related variables and 20 cm soil temperature are better reproduced by ORCHIDEE-ES than ORCHIDEE, revealing a more accurate representation of spatio-temporal variability.Citation: Wang, T., C. Ottle´, A. Boone, P. Ciais, E. Brun, S. Morin, G. Krinner, S. Piao, and S. Peng (2013), Evaluation of an improved intermediate complexity snow scheme in the ORCHIDEE land surface model,

Temperature and Snow-Mediated Moisture Controls of Summer Photosynthetic Activity in Northern Terrestrial Ecosystems between 1982 and 2011

“…The result of the lagged coupling between vegetation and seasonal snow dynamics is consistent with the hypothesis that spring productivity gains from earlier thaw and extension of the growing season could potentially be offset by drought-induced productivity losses later in the season [4,16,21,35]. Since most Dynamic Global Vegetation Models (DGVMs) have only a limited ability to realistically simulate snowpack dynamics and feedbacks in forested regions [97,98], the sensitivity of the boreal forests to snow hydrology described in this empirical study may not be well captured in current simulations of the carbon cycle.…”

ORCHIDEE-MICT (v8.4.1), a land surface model for the high latitudes: model description and validation

“…3, its description of soil temperature and vertical water transport dynamics is based on coupled diffusion equations with identical vertical discretization (F. , and includes soil freezing, its effect on water infiltration, and phase change-induced heat sources and sinks in the soil column (Gouttevin et al, 2012a). The snow model described by Wang et al (2013) is incorporated into this version, where snow is discretized into three layers of variable thickness, conductivity and density, accounting for snow liquid water content (Boone and Etchevers, 2001). In terms of large-scale hydrology, a river routing scheme including floodplains and their dynamics (d'Orgeval et al, 2008;Guimberteau et al, 2012) is coupled to simulated grid-cell runoff (Sect.…”

“…Snowpack is represented by a three-layer snow model of intermediate complexity, as described in Wang et al (2013). This scheme was implemented to resolve the energy and water budgets inside the snowpack, accounting for thawing and refreezing of liquid water.…”

Assessing the uncertainty of glacier mass-balance simulations in the European Arctic based on variance decomposition

“…These sites are chosen to represent conditions in the accumulation and ablation area of the glacier, thus addressing different mass-and energybalance regimes. The snowpack model Crocus was originally developed and is still used for operational snow avalanche warnings Durand et al, 2009) and has been applied to various research studies, for example Brun et al (2013), Fréville et al (2014), Carmagnola et al (2013), Wang et al (2013), Phan et al (2014), Gallet et al (2014), Castebrunet et al (2014), and Vernay et al (2015). Vionnet et al (2012) provide a comprehensive review of Crocus and its implementation in SURFEX, which is an integrated platform for simulating earth surface processes.…”