IFS#

Model description#

IFS-H is a hydrostatic spectral transform model with a semi-Lagrangian semi-implicit solution procedure, discretised on a cubic octahedral grid (Wedi 2014, Malardel et al. 2016). Here we used the single precision version of IFS (cycle 45r2). Information on IFS can be found at the IFS documentation. Note that cycle 45r2 differs from 45r1 only by a technical change in ecbuild and the change from double to single precision, thus 45r1 is still the relevant reference.

Contact#

Peter Dueben and Nils Wedi, European Centre for Medium-Range Weather Forecasts (ECMWF), UK

Data structure#

Horizontal#

Here we offer two runs with TCo1279 (~9km) (ECMWF’s operational configuration) and TCo2559 (~4km) following the Dyamond protocol.

Vertical#

The runs use 137 vertical levels (data provided from level 137 to level 25). The number of grid columns is 26 306 560 (4km) and 6 599 680 (9km). The vertical discretisation uses hybrid vertical levels defined as A(eta) + B(eta)*p_s, with A, B ixed defined parametersand where p_s is the provided surface pressure. Pressure on model levels needs to be calculated by the given formula.

Data#

gg_uv_mars_out_ml_vor_div_sh.*.grib, output interval: PT03h (levels 125-137)

Please ignore the dates indicated in these files and concentrate on step for time.

u

velocity u

v

velocity v

mars_out.*, output interval: PT01h

ci

sea ice area fraction

asn

snow albedo

rsn

snow density

sst

sea surface temperature

istl1

ice temperature layer 1

istl2

ice temperature layer 2

istl3

ice temperature layer 3

istl4

ice temperature layer 4

swvl1

volumetric soli water layer 1

swvl2

volumetric soli water layer 2

swvl3

volumetric soli water layer 3

swvl4

volumetric soli water layer 4

es

snow evaporation

smlt

snowmelt

dsrp

direct solar radiation

lspf

large-scale precipitation fraction

uvb

downward UV radiation at the surface

par

photosynthetically active radiation at the surface

cape

convective available potential energy

tclw

total column liquid water

tciw

total column cloud ice water

z

geopotential

tcw

total column water

tcwv

total column water vapour

stl1

soil temperature level 1

Sd

solar duration

lsp

large-scale precipitation

cp

convective precipitation

tp

total precipitation

sf

snowfall

bld

boundary layer dissipation

sshf

surface sensible heat flux

slhf

surface latent heat flux

chnk

Charnock

msl

mean sea level pressure

blh

boundary layer height

tcc

total cloud cover

10 u

10m zonal wind

10 v

10m meridional wind

2 t

2m temperature

2d

2 metre dewpoint temperature

ssrd

surface solar radiation downwards

stl2

soil temperature level 2

lsm

land sea mask

strd

surface thermal radiation downwards

ssr

sub-surface runoff

str

surface net thermal radiation

tsr

top net solar radiation

ttr

top net thermal radiation

ewss

eastward turbulent surface stress

nsss

northward turbulent surface stress

e

evaporation

stl3

soil temperature level 3

lcc

low cloud cover

mcc

medium cloud cover

hcc

high cloud cover

sund

sunshine duration

lgws

eastward gravity wave surface stress

mgws

northward gravity wave surface stress

gwd

gravity wave dissipation

src

skin reservoir content

ro

runoff

tsrc

top net solar radiation

ttrc

top net thermal radiation

ssrc

surface net solar radiation

strc

surface net thermal radiation

skt

skin temperature

stl4

soil temperature level 4

tsn

temperature of snow layer

fal

forecast albedo

fsr

forecast surface roughness

flsr

forecast logarithm of surface roughness for heat

iews

instantaneous eastward turbulent surface stress

inss

instantaneous northward turbulent surface stress

ishf

instantaneous surface sensible heat flux

ie

instantaneous moisture flux

vimd

vertically integrated moisture divergence

tisr

TOA incident solar radiation

sro

surface runoff

ssro

sub-surface runoff

tcrw

total column rain water

tcsw

total column snow water

cin

convective inhibition

kx

k index

totalx

total totals index

vis

visibility

i10fg

instantaneous 10 metre wind gust

pev

potential evaporation

fzra

accumulated freezing rain

ilspf

instantaneous large-scale surface precipitation fraction

crr

convective rain rate

lsrr

large scale rainfall rate

csfr

convective snowfall rate water equivalent

lssfr

large scale snowfall rate water equivalent

ptype

precipitation type

mars_out_ml_moist.*, output interval: PT03h

q

specific humidity

clwc

specific cloud liquid water content

ciwc

specific cloud ice water content

mars_out_pl_gg.*, output interval: Pt1h

w

vertical velocity m/s

r

relative humidity

mars_out_sfc_ps_orog_gg.*, output interval: Pt3h

lnsp

logarithm of surface pressure

geopotential

Topography stored as geopotential (z). Multiply with 1/g ? m

gg_mars_out_ml_upper_sh.*.grib, output interval: Pt3h (levels 125-137)

t

temperature

vertical velocity/omega in Pa/s

Initialisation and Boundary conditions#

Soil Initialisation#

Initial soil data from the ECMWF IFS model state at the initialisation date are time and spatially interpolated.

Input Data#

Input data are extracted from mars for the specified start date 2016080100.

Treatment of SST and Sea Ice#

Daily updated SST/CI from ECMWF analysis is used.

See also#