March 5, 2020: Release_5_0
Added several new features and fixes:
- Two new cloud overlap options were added, exponential (
icld=4
) and exponential-random (icld=5
) that apply an exponential transition from maximum to random through model layers. Exponential applies this transition through all layers without regard to the cloud configuration and exponential-random applies this transition through adjacent cloudy layers while randomly correlating cloud layers separated by clear sky. Both methods require calling a new subroutine, get_alpha, to define alpha, the exponential transition parameter, prior to calling the McICA sub-column generator. Alpha requires the specification of a decorrelation length (in meters), and two methods for defining this value are available that are selected using a new input control variable, idcor, that allows the decorrelation length to be specified either as a constant or as a value that varies by latitude and day-of-year using the method of Oreopolous et al. (2012). See the filedoc/rrtmg_sw_instructions.txt
for more information. - The three NRLSSI2 solar source component coefficients (quiet sun, facular, and sunspot) added in v4.0 and updated in v4.1 were added to the optional netCDF input data file (/data/rrtmg_sw.nc), and the optional
source modulerrtmg_sw_read_nc.f90
was modified to input these data if the netCDF input option is selected in themakefile
. These data function in the same way as the identical NRLSSI2 solar source coefficients that are stored in the code by default in modulerrtmg_sw_k_g.f90
. - A fix was applied to source module
rrtmg_sw_read_nc.f90
, which optionally reads the input data coefficients fromdata/rrtmg_sw.nc
if that option is selected in themakefile
, to correct the loading of the water vapor foreign continuum data for the upper atmosphere into the model arrayforrefo
. This issue could impact surface downward shortwave fluxes by as much as five percent if the netCDF option was used. The default input coefficient data inrrtmg_sw_k_g.f90
were not affected. - Revised the calculation of
zwo
inrrtmg_sw_reftra.f90
to protect against unlikely, but possible divide by zero conditions.
Publicly released on AER RT web site in March 2020.