Dry Deposition in TM5
F.Dentener, M.Krol, L.Ganzeveld, G. Verver, A. Segers
M.v. Weele
•Calculate on 1x1 degree, then coarsen to required resolution
•Use as much as possible consistent ECMWF fields
•Reduce the amount of pre-processing
•Simplified a number of calculations.
TM5 meeting, De Bilt, 10.06.2003
module dry_deposition
!
! Purpose:
! -------!
! This module contains all subroutines needed for dry deposition calculations.
! The mean purpose is to perform on a high resolution of 1x1 degree:
!
! 1. read fields needed for further calculations in subroutines:
!
! 2. calculate the tracer independent friction velocity, aerodynamic and sub-laminar
resistance
!
! 3. calculate fields needed for resistance calculations
!
! 4. the tracer dependent surface resistance rsurf
!
! 5. coarsen the sum of vd = 1./(raero and rsurf)
!
! 6. apply the coarsened deposition velocities to concentration field rm
!
! Reference:
! --------! general documentationon ECMWF fields can be found on:
! http://www.ecmwf.int/research/ifsdocs/PHYSICS/
! --------! Authors:
! ------! original code by Laurens Ganzeveld and Ad Jeuken (1997)
! revised and adapted for use in TM5 and use of ECMWF data by F. Dentener and M. Krol
(2003)
TM5 meeting, De Bilt, 10.06.2003
Main subroutines:
dd_get_3_hourly_surface_fields
dd_calc_ustar_raero_rb
dd_calc_rstom_rahcan
dd_calc_inisurf
dd_calc_rs
dd_coarsen_vd
TM5 meeting, De Bilt, 10.06.2003
External fields required:
lsmlai.hdf (from Olson)
soilph.hdf ()
ECMWF fields,
•either 3 hourly or daily average
•every daily file contains all fields: easy restart.
•Not every field in surface file is actually used by dry_deposition.
Constant fields:
lsm (land-sea mask)
tv, cvl, cvh vegetation characteristics (at moment annual average)
TM5 meeting, De Bilt, 10.06.2003
Daily fields:
sr_ecm
ci
sd
swvl1
surface roughness
sea ice
snow depth
soil water volume
3 hourly fields
t2m
2 m temperature
d2m
2 m dew point temperature
u10,v10
10 m u and v component of wind speed
surfstress
surface stresss
src
skin reservoir content
ssr
solar radiation
sshf
surface sensible heat flux
slhf
surface latent heat flux
TM5 meeting, De Bilt, 10.06.2003
subroutine dd_calc_ustar_raero_rb
Method
! -----! uses the log normal wind profile information stored by
! ECMWF in 10 meter wind
! to estimate a local ustar over land
! uses Charnock equation over sea to estimate ustar
! aerodynamic resistance is calculated from heat fluxes and
! ustar using a constant reference height
! sub laminar resistance from ustar
•MUCH SIMPLER THAN PREVIOUS METHOD WHERE USTAR AND RAERO
WERE CALCULATED ITERATIVELY
TM5 meeting, De Bilt, 10.06.2003
subroutine dd_calc_rstom_rahcan
! ----------------------------! Purpose
!--------!
!
!
!
Calculate water vapour stomatal resistance from the PAR
(Photosythetically Active Radiation) which is 0.55 times
the net short wave radiation (ssr) at the surface.
Calculate rahcan from ustar and lai
•USE OF SSR IS IMPROVEMENT COMPARED TO TM3
WHICH USED MONTHLY AVERAGED FIELDS AND A
SCALING FACTOR
TM5 meeting, De Bilt, 10.06.2003
subroutine dd_calc_inisurf
! -----------------------! Purpose
!--------! Calculate some surface fields later
needed in the calculation
•CLOSE TO TMSCIA VERSION MVW, USES ALMOST
ENTIRELY ECMWF FIELDS
TM5 meeting, De Bilt, 10.06.2003
Consistency of data ….
forest
TM5 meeting, De Bilt, 10.06.2003
Raero on-line calculated monthly average
Raero preprocessing calculated monthly average
TM5 meeting, De Bilt, 10.06.2003
Ustar calculated on line January and July
Ustar preprocessing January and July
TM5 meeting, De Bilt, 10.06.2003
vdHNO3 TM5 January
and July, TM3 July
TM5 meeting, De Bilt, 10.06.2003
vdO3
TM5 meeting, De Bilt, 10.06.2003
vdSO2
TM5 meeting, De Bilt, 10.06.2003