TM5 meeting, De Bilt, 10.06.2003

Dry Deposition in TM5

F.Dentener, M.Krol, L.Ganzeveld, G. Verver, A. SegersM.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-laminarresistance!! 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

! dd_get_3_hourly_surface_fields! dd_calc_ustar_raero_rb! dd_calc_rstom_rahcan! dd_calc_inisurf! dd_calc_rs! dd_coarsen_vd

Main subroutines:

dd_get_3_hourly_surface_fieldsdd_calc_ustar_raero_rbdd_calc_rstom_rahcandd_calc_inisurfdd_calc_rsdd_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 surface roughnessci sea icesd snow depthswvl1 soil water volume

3 hourly fields t2m 2 m temperatured2m 2 m dew point temperatureu10,v10 10 m u and v component of wind speedsurfstress surface stressssrc skin reservoir contentssr solar radiationsshf surface sensible heat fluxslhf 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 TM3WHICH 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 Januaryand July, TM3 July

TM5 meeting, De Bilt, 10.06.2003

vdO3

TM5 meeting, De Bilt, 10.06.2003

vdSO2