Version 5.0

March 5, 2020: Release_5_0

Added several new features:

• 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 file doc/rrtmg_lw_instructions.txt for more information.

Publicly released on AER RT web site in March 2020.