To calculate integrated shortwave or longwave irradiance, or to simulate
satellite instrument channels, use
correlated_k type
to choose between the following types of correlated-k schemes:
- kato
- Kato et al. (1999) correlated-k distribution, shortwave; based on HITRAN 96. Please note that the
bands above 2.5 micrometer are not very reliable which, however, this has only little impact
on integrated shortwave radiation.
- kato2
- Kato et al. (1999), shortwave; optimized version (Seiji Kato, personal communication, 2003);
please note that kato2 only has 148 subbands (that is, calls to the rte_solver)
compared to 575 for kato which translates to a decrease in computational speed by
up to a factor of 4 with only little increase in uncertainty. The absorption data are
based on HITRAN 2000. Please note that the bands above 2.5 micrometer are not very reliable which,
however, this has only little impact on integrated shortwave radiation.
- kato2.96
- Kato et al. (1999), shortwave; optimized version (Seiji Kato, personal communication, 2003);
similar to kato2 but based on HITRAN96. Please note that the bands above 2.5 micrometer
are not very reliable which, however, has only little impact on integrated shortwave radiation.
- fu
- Fu and Liou (1993); Fu and Liou (1992), shortwave and longwave; fast parameterization, developed for climate models.
- avhrr_kratz
- Kratz and Varanasi (1995), AVHRR instrument channels
- lowtran
- Gas absorption parameterization from LOWTRAN; code adopted from SBDART (Ricchiazzi et al., 1998);
please see the section on "Spectral resolution".
- sbdart
- Identical to LOWTRAN.
If correlated_k kato/kato2/kato2.96/fu/avhrr_kratz is specified, the extraterrestrial
flux is taken from
internally defined files specific for each parameterization, not
from solar_file. The output is the integrated irradiance for
each band. To get e.g. integrated shortwave irradiance, simply add all
bands of the Kato et al. (1999) or the Fu and Liou (1993); Fu and Liou (1992)
parameterization. The five AVHRR channels are weighted sums of the
libRadtran output. Examples how to integrate the output in the
avhrr_kratz case are included in the uvspec self check
which is initiated with
make check.
Arve Kylling
2010-03-10