Parameterization of snow vertical structure and representation of the corresponding snow properties

1
Parameterization of snow vertical structure and
representation of the corresponding snow
properties in local climate modeling

• Andrey B. Shmakin
• (Institute of Geography,
• Russian Academy of Sciences)
• Sergey A. Sokratov
• (Moscow State University)

2
INTAS-funded project 03-51-5296 Influence of
snow vertical structure on hydrothermal regime
and snow-related economical aspects in Northern
Eurasia
- Technical University, Vienna - Institute of
Geography, Moscow- Moscow State University-
Hydrometeorological Center of Russia, Moscow -
Charles University, Prague - Swiss Federal
Institute for Snow and Avalanches Research,
Davos - Institute of Geology and Geophysics,
Tashkent, Uzbekistan - Institute of Hydrology,
Slovakia
3
(No Transcript)
4

• RESEARCH OBJECTIVES
• Creation of a data set of snow stratigraphy in
  Northern Eurasia
• Development of classification of the snow cover
  and its effective properties for Northern
  Eurasia
• Development of parameterization schemes of the
  snow cover stratigraphy for climate and
  hydrological models, and their testing against
  the observed data
• Estimation of the influence of the snow cover
  stratigraphy on hydrothermal regime in the
  Northern Eurasia and extreme events
• - Estimation of the economic effect of the snow
  cover spatial and temporal variability in the
  Northern Eurasia, and its projection for certain
  future climate change scenarios.

5
Changes in time of the snow vertical structure
(from SNOWPACK model and observations),
Weissfluhjoch, February April, 1999. The colors
correspond to different types of snow crystals
with certain surface curvature and other
characteristics. Basically, each type carries a
set of effective parameters (density, thermal
conductivity, liquid water holding capacity,
etc.). Then, integral effective parameters for
the entire snow profile are calculated and used
in local model of energy/water exchange on the
land.
6
The heat conductivity evaluation combining
continuity of flux and energy conservation at the
surface
Previously, data on internal geometry of the snow
crystals were unavailable, and there was no the
equation combining the porous media with
anisotropic matter.
At the next stage, liquid water holding capacity
of the snow will be modified according to the
crystal type. Also, possibility of multiple snow
layers will be allowed in the model.
7
(No Transcript)
8
Testing site Dukant, Uzbekistan (4109N,
7004E, 2000 and 2250 m a.s.l.), Jan. Apr.
1990 (Courtesy of Dr.Maxim Petrov and his team
from the INTAS project)
9
The atmospheric forcing parameters also
include - wind speed, - air humidity, - daily
range of air temperature.
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
Conclusions - Parameterization of the snow heat
conductivity is developed, based on the structure
of snow crystals, their density and temperature.
Information of main types of the snow (fluffy,
small-grain, depth hoar, etc.) fit to the
procedure. - Snow depth can be sensitive to the
method of snow heat conductivity evaluation,
depending on the weather conditions. At Dukant,
it provides higher accuracy in modeling of the
snow depth dynamics. Climate modeling with the
new snow scheme is expected to benefit from the
new procedure. - The new method results in more
accurate soil surface temperature calculation.
This will allow better evaluation of snow-related
processes (soil thermal regime, hydrology, etc.)
in the project.
14
FURTHER DEVELOPMENT OF THE PROJECT At the next
stage, the snow types recognition will be
formalized according to the evolution of
atmospheric conditions during winter season, and
landscape features (presence of tall vegetation,
etc.).   Then, the heat/water exchange blocks of
SPONSOR model will be interactively incorporated
in global climate models as parameterization
schemes. The snow cover vertical structure will
appear as a result of weather variations, and
influence them in turn.   A series of numerical
experiments will be carried out for contemporary
climate conditions and some future scenarios. The
results will be analyzed from the viewpoint of
both average regime and extreme events.
Projections of the economical effects in
Northern Eurasia due to climate change and
corresponding snow properties change will be
made.
15
Thank you!