Role of Patchy Snow Cover on the Planetary Boundary Layer Structure during Late Winter Observed in the Central Tibetan Plateau

Abstract

The one-dimensional structure of a daytime planetary boundary layer (PBL) with shallow cloud development was captured by intensive sonde observation during the late winter season at the central Tibetan Plateau (TP), and its relationship to patchy snow cover conditions was revealed. The diurnal change of potential temperature was evident in the atmosphere up to 1 km above ground, indicating PBL development, and frequent cloud formation in the afternoon and night over the PBL was confirmed by the increase of relative humidity in the sonde data profile and abrupt decrease of brightness temperature in the satellite images. Day-to-day changes of PBL and nighttime stable layer developments were dependent on the speed of the sub-tropical jet stream prevailing 5 km Corresponding author: Kenichi UENO, Univ. Tsukuba, Nono-dai 1-1-1, Ibaraki 305-8572, Japan. E-mail: kenueno@sakura.cc.tsukuba.ac.jp 6 2012, Meteorological Society of Japan above the surface and the changing of snow cover conditions after snowfall events. Numerical simulations confirmed that the increase of land-surface albedo, imitating the continuous snow covers, could suppress the PBL and cloud development. The positive feedback of land-atmosphere interactions through the PBL development on patchy snow cover and re-distribution process of shallow and dry snow cover were discussed.

STEMMUS-UEB v1.0.0: integrated modeling of snowpack and soil water and energy transfer with three complexity levels of soil physical processes

“…For example, the wind blow effect and canopy snow interception, which have been recognized as important to the accurate simulation of snowpack dynamics (Mahat and Tarboton, 2014), are not taken into account in detail. Last but not least, the interpretation of surface albedo dynamics needs to be adapted to the specific site, especially regarding the shallow snow situations (Ueno et al, 2007(Ueno et al, , 2012Ding et al, 2017;Wang et al, 2017). The albedo of the underlying surface should also be properly accommodated to this Tibetan meadow system.…”

“…Many physically based models for the mass and energy balance in the snowpack have been developed for their coupling with hydrological models or atmospheric models. Boone and Etchevers (2001) divided these snow models into three main categories: (i) simple forcerestore schemes with the snow modeled as the composite snow-soil layer (Pitman et al, 1991;Douville et al, 1995;Yang et al, 1997) or a single explicit snow layer (Verseghy, 1991;Tarboton and Luce, 1996;Slater et al, 1998;Sud and Mocko, 1999;Dutra et al, 2010); (ii) detailed internal snow process schemes with multiple snow layers of fine vertical resolution (Jordan, 1991;Lehning et al, 1999;Vionnet et al, 2012;Leroux and Pomeroy, 2017); and (iii) intermediatecomplexity schemes with physics from the detailed schemes but with a limited number of layers, which are intended for coupling with atmospheric models (e.g., Sun et al, 1999;Boone and Etchevers, 2001). The intercomparison results of the abovementioned snow models at an alpine site indicated that all three types of schemes are capable of representing the basic features of the snow cover over the 2-year period but behaved differently on shorter timescales.…”

Coupled water-heat-carbon exchange processes in cold environments: observation and numerical modeling

“…For example, the wind blow effect and canopy snow interception, which have been recognized as important to the accurate simulation of snowpack dynamics , are not taken into account in detail. Last but not least, the interpretation of surface albedo dynamics needs to be adapted to the specific site, especially regarding the shallow snow situations (Ueno et al, 2007;Ueno et al, 2012;Ding et al, 2017;Wang et al, 2017b). The albedo of the underlying surface should also be properly accommodated to this Tibetan meadow system.…”