Initialise the air-sea interaction module


INTERFACE:

   subroutine init_air_sea(namlst,lat,lon)
DESCRIPTION:

This routine initialises the air-sea module by reading various variables from the namelist airsea.nml and opens relevant files. These parameters are:

calc_fluxes .true.: Sensible, latent and back-radiation are calculated by
  means of bulk formulae. In this case, meteo_file must be
  given and hum_method must be specified.
  .false.: Surface fluxes and solar radiation are prescribed.
fluxes_method Select which parameterisation to use for latent and sensible fluxes:
  1: Kondo (1975)
  2: Fairall et al. (1996)
back_radiation_method Select which parameterisation to use:
  1: Clark et al. (1974)
  2: Hastenrath and Lamb (1978)
  3: Bignami et al. (1995)
  4: Berliandand Berliand (1952)
meteo_file file with meteo data (for calc_fluxes=.true.) with
  date: yyyy-mm-dd hh:mm:ss
  $ x$-component of wind (10 m) in ms$ ^{-1}$
  $ y$-component of wind (10 m) in ms$ ^{-1}$
  air pressure (2 m) in hectopascal
  dry air temperature (2 m) in Celsius
  rel. hum. in % or wet bulb temp. in C or dew point temp. in C
  cloud cover in 1/10
  Example:
  1998-01-01 00:00:00 6.87 10.95 1013.0 6.80 73.2 0.91
hum_method 1: relative humidity given as 7. column in meteo_file
  2: wet bulb temperature given as 7. column in meteo_file
  3: dew point temperature given as 7. column in meteo_file
heat_method 0: heat flux not prescribed
  1: constant value for short wave radiation (const_swr)
  and surface heat flux (const_qh)
  2: swr, heat are read from heatflux_file
rain_impact .true.: include sensible- and momentum-flux from precipitation
calc_evaporation .true.: calculate evaporation/condensation (m/s)
swr_method 1: constant value for short wave radiation (const_swr)
  2: read short wave radiation from file
  3: Solar radiation is calculated from time, longitude, latitude,
  and cloud cover.
const_swr constant value for short wave radiation in Wm$ ^{-2}$
  (always positive)
swr_file file with short wave radiation in Wm$ ^{-2}$
swr_factor scales data read from file to Wm$ ^{-2}$ - defaults to 1
const_heat constant value for surface heat flux in Wm$ ^{-2}$
  (negative for heat loss)
heatflux_file file with date and heat in Wm$ ^{-2}$
momentum_method 0: momentum flux not prescribed
  1: constant momentum fluxes const_tx, const_tx given
  2: surface momentum fluxes given from file momentumflux_file
const_tx $ x$-component of constant surface momentum flux in Nm$ ^{-2}$
const_ty $ y$-component of constant surface momentum flux in Nm$ ^{-2}$
momentumflux_file File with date, tx and ty given
precip_method 0: precipitation not included == precip=0.
  1: constant value for precipitation in ms$ ^{-1}$
  2: values for precipitation read from file precip_file
const_precip value for precip in ms$ ^{-1}$
precip_file file with date and precip in ms$ ^{-1}$
precip_factor scales data read from file to ms$ ^{-1}$ - defaults to 1
sst_method 0: no independent SST observation is read from file
  2: independent SST observation is read from file, only for output
sst_file file with date and SST (sea surface temperature) in Celsius
sss_method 0: no independent SSS observation is read from file
  2: independent SSS observation is read from file, only for output
sss_file file with date and SSS (sea surface salinity) in psu


USES:

   IMPLICIT NONE
INPUT PARAMETERS:
   integer, intent(in)                 :: namlst
   REALTYPE, intent(in)                :: lat,lon
REVISION HISTORY:
   Original author(s): Karsten Bolding

Karsten Bolding 2012-12-28