the PMIP models (Bonfils et al. 1998)
PMIP Documentation for MSU
Moscow State University, Department
of Meteorology and Climatology: Model MSU (10x15L3), Version of the 1989
Mr. Alexsandre Kislov, Dep.of Meteorology and Climatology, Moscow State
University, Geographical Faculty, Moscow, Russia, 119899, Phone: 095 9392942,
Fax: 095 9328836, email: firstname.lastname@example.org
MSU (10x15L3) 1994
Model Identification for PMIP
0fix, 6fix, 21fix
JJA and DJF ('perpetual' conditions)
The MSU model was developed in 1989 for climate applications. The latest
version of this model is significantly differ from first version:
a) it is used the simulation with seasonal resolution
b) it is used the limited area model nested in global model (so called
MSU & LAMBLS )
c) it is used more comprechensive surface scheme (looks like as Sib,
but using subgrid information about vegetation cover within each grid box),
including explicit description of the thermal regime of the large lakes
d) it is used more comprechensive parameterization of the snow cower
the Russian magazines: 1) Izvestiya, Atmospheric and Oceanic Physics 2)
Meteorology & Hydrology, N 3 were translated in English and they can
be accessible. I do not represent the information about pages of the article
because the pages of the translated text are differ from pages of the Russian
Kislov A.V. (1991), Three-dimensional model of atmospheric circulation
with complete description of physical processes and simplified dynamics,
Izvestiya, Atmospheric and Oceanic Physics, Vol.27, N 4 /English Translation/
secondary reference(s) :
Kislov A.V. (1993), A simulation of the climate of Holocene's optimum,
Izvestiya, Atmospheric and Oceanic Physics, Vol.29, N 2 /English Translation/
Kislov A.V. (1993) Investigation of genesis of cold ivents during late
glaciation (using Dryas-3 as an example) Izvestiya, Atmospheric and Oceanic
Physics, Vol.29, N 2 /English Translation/
Kislov A.V. (1993), Character of monsoon circulation during some periods
of paleotime. Meteorology & Hydrology, N 3
Kislov A.V. (1994), Study of forming factors in the warm climates of
Holocene based on simplified general circulation model simulations, Izvestiya,
Atmospheric and Oceanic Physics, Vol.30, 353-361 /English Translation/
Kislov A.V. (1994) Study of the genesis of the global climate fluctuations
during postglaciation, Izvestiya, Atmospheric and Oceanic Physics, Vol.30,
353-361 /English Translation/
Kislov A.V., G.V.Surcova (1997), The use of a limited area model for
the estimation of variation in evaporation minus precipitation from the
Caspian Sea during the Holocene Izvestiya, Atmospheric and Oceanic Physics,
Vol.33, N 1 /English Translation/
Kislov A.V., G.V.Surcova (1998), The simulation of the Caspian Sea level
changes during last 20,000 years. In Palaeohydrology and the Hydrological
Sciences, Edited by G.Benito, V.R.Baker and K.J.Gregory, John Wiley &
Sons,Ltd. /To be published/
The finite difference mesh of the model has a spacing between grid points
of 10 latitude and 15 longitude.
10 x 15 degrees latitude-longitude.
Surface to 100 hPa. Pressure of lowest atmospheric level is 900 hPa when
surface pressure is 1000 hPa.
The model has 3 levels in the vertical direction. The model uses P-coordinate.
There are the following levels: 900, 600, 250 hPa.
Computer / Operating System
The PMIP simulation was run on PC-486.
For the PMIP, 0.1 minutes PC-486 computation time per simulation 1 day.
The model was started from a intial conditions based on dry, unmoveable
atmosphere. Snow cover boundary are prescribed based on climate scenario
(the present day, 6 or 21 ka). Temperature of the deepest soil level are
Time Integration Scheme(s)
A implicit time integration scheme is used. The time step is 24 hours for
all dynamics and physics fields.
Orography is represented on grid-poin mesh 10x15 deg. Negative values of
atmospheric specific humidity (which arise because of numerical errors
in the discretized moisture equation) are made slightly positive by borrowing
moisture (where possible) from other layers in the same column. If column
moisture is insufficient, a nominal minimum bound is imposed, the moisture
deficit is accumulated over all atmospheric points, and the global specific
humidity is reduced proportionally.
I have the output without sampling procedure.
A simlified (a quasigeostrophic scheme similar to Sellers (1983)) equations
are expressed in terms of temperature, specific humidity and wind components.
Effects of synoptic-scale eddies on transfer of the energy, moisture and
momentum have been parameterized. Divergence are calculated based on geostrophic
vorticity (Gill, 1982).
Horizontal diffusion follows the scale-dependent eddy viscosity. Second-order
vertical diffusion of moisture and heat operates within the boundary layer
depends on stability and the vertical shear of the wind, following standard
mixing-length theory. Diffusivity for moisture is taken to be the same
as that for heat.
Gravity Wave Drag
Gravity wawes are excluded by geostrophic approach.
Radiative Boundary Conditions
The solar constant is 1367 W/(m2). The orbital parameters and
seasonal insolation's distribution are calculated after PMIP recommendations.
'Perpetual' JJA and DJF are simulated.
The carbon dioxide concentration is the prescribed value of 300, 280 and
180 ppm for 0fix, 6fix 21fix run, respectively. A monthly globally averaged
ozone distribution is specified. Radiative effects of water vapor also
are treated. Radiative effects of aerosols are treated for solar fluxes
Upward/downward shortwave irradiance profiles are evaluated using integral
function of transmittance (Feigelson, 1978) taking into account clouds,
aerosols and gases. Shortwave/longwave optical properties of the clouds
is expected can be parameterized in terms of air temperature and precipitation
Upward/downward longwave radiation profiles are evaluated using integral
function of transmittance (Feigelson, 1970) taking into account clouds
and gases. Clouds at the middle and low levels are treated as blackbodies.
Clouds at the high level are treated as graybodies, with emissivity depending
on optical depth.
A moist convective adjustment procedure is applied on pairs of vertical
layers whenever the model atmosphere is conditionally unstable. Convective
instability occurs when the local thermal lapse rate exceeds a critical
value, which is determined from a weighted linear combination of dry and
moist adiabatic lapse rates, where the weighting factor is a function of
the local relative humidity. Convective instability may occur in association
with condensation of moisture under supersaturated conditions, and the
release of precipitation and associated latent heat.
The fractional cloud cover in a vertical layer is computed from a linear
function of the relative humidity of the air (Smagorinsky's relations).
Clouds at the high level is expected to appear if moist convection is realized
(typically for ITCZ conditions) or if wind speed at this level excess above
a threshold value. The threshold allows to take into account the fact that
in extratropical regions the fields of cirrus clouds are formed near the
Precipitation is simulated whenever supersaturation is indicated by the
prognostic equation for water vapor. There are two types of precipitation:
large-scale precipitation and convective precipitation. Part of precipitation
can be evaporated in situ.
Planetary Boundary Layer
The depth of the PBL is not explicitly determined, but in general is assumed
that it centered at the lowest prognostic vertical level (980 hPa). Within
the PBL convective adjustment takes place, which simulates boundary-layer
mixing of heat and moisture, and by enhanced vertical diffusivities. Within
the PBL the surface boundary layer is situated, its temperature and moisture
required for calculation of surface fluxes are calculated using standard
Orographic heights with a resolution of 1 deg. on a latitude/longitude
grid are smoothed by linear averaging over 10x15 degree grid boxes.
It was used the same spatial land/sea distribution for the run at 0k
and 21k , but at 21k the height of the ice sheets took into account it
was added to orography height for 0k.
I used the ice sheet reconstructions of Peltier et al. (1994).
Ocean Surface Boundary Conditions
For 0fix: monthly averaged modern climatological SSTs based on : NOAA Atlas
NESDIS 4, World Ocean Atlas 1994, Volume 4: Temperature, Washington, D.C.,
U.S. Dept.of Commerce, S.Levitus, T.P.Boyer.
For 6 fix: same as for 0fix.
For 21 fix: The CLIMAP (Last Glacial Maximum) data was used.
Sea ice distribution was prescribed corresponding on modern data (0fix,6fix)
and CLIMAP (21 fix). The surface temperature of the ice is a prognostic
function of the surface heat balance and of a heat flux from the ocean
Snow cover was prescribed field. Snow cover affects the surface albedo
of land and of sea ice, as well as the heat capacity of the soil.
The 5 x 7.5-deg. data on natural zones types are used to determine surfase
parameters (albedo, thermal conductivity, thermal diffusivity, depth of
the active layer of the soil (in permafrost region), moisture availability
factor). The local land albedo also depends on the fractional snow cover
the resulting albedo is a linear weighted combination of snow-covered and
snow-free albedos. Over the oceans, latitude-dependent albedos cover the
range between 0.06 and 0.17. The longwave emissivity is prescribed as unity
for all surfaces.
The surface solar absorption is determined from surface albedos. The surface
turbulent eddy fluxes of heat and moisture are expressed as bulk formulae
following Monin-Obukhov theory. The fluxes of latent and sensible heat
is a product of a neutral transfer coefficient, the surface wind speed,
the difference in temperatures (or specific humidity) between the surface
and that of the top surface boundary layer. Formulae for latent heat flux
over land includes the moisture availability factor.
Land Surface Processes
Soil heat storage is determined as a residual of the surface heat fluxes.
Soil temperature is computed from this heat storage in a single layer,
following the method of Kislov (1991). The soil parameters in each grid
box is computed as a function of natural zone type, soil moisture, and
snow cover. Soil moisture in 'perpetual' experiments is prescribed.
Last update November 9, 1998. For further information, contact: Céline