******************************************************************************* * USE OF THE RADIATIVE - CONVECTIVE EQUILIBRIUM ROUTINES * * * * 18 October 1997 * ******************************************************************************* The main FORTRAN 77 routine is contained in the file conrad.f, which includes the convection representation of Emanuel (JAS, 1991) and the radiation code developed by Chou et al. (J. Clim., 1991). It can find the radiative-convective equilibrium states with specified large-scale vertical velocity profiles, and with interactive or specified radiative transfer. With interactive radiation, the lower boundary temperature can be either specified, or calculated. In both cases the boundary is considered to be an ocean surface, and in the case of interactive boundary temperature, the sea is considered to be a shallow mixed layer, or "swamp", with a depth of 5 meters. The program rcsimp.f is identical to conrad.f except that the radiation code has been greatly simplified by Adam Sobel. It should not be used if quantitatively accurate results are desired. The main program reads two files: params.in and sounding.in. Both are ASCII files that can be directly modified. The former contains most of the modifiable parameters used by the model, while the latter contains the initial sounding, CO2 and O3 contents, sea surface temperature, and profiles of vertical velocity and radiative cooling of the atmosphere. The output file sounding.out is identical in format to the input file sounding.in, and can be used to restart the integration simply by changing its name to sounding.in. Running sounding.f allows one to automatically use one of several standard atmospheres for the initial sounding, CO2 content and O3 profile, and to specify the model vertical levels in the troposphere (the model structure of the stratosphere is specified automatically). The parameters specified in the file params.in (which can be created using parameter.f) are, for the most part, self-evident, and are described briefly in the file. They control the radiation, albedo, latitude, etc.; the vertical velocity profile, which may be arbitrarily specified in the file sounding.in or calculated from an assumed cubic polynomial; the pressure level above which the sounding can be fixed at its initial state (useful when specifying a mean subsidence profile), and parameters controlling the time integration. Output is in the form of four files: sounding.out, whose format is the same as soundiing.in; error.out, which contains some error information, if errors occur; and time.csv and profile.csv, which contain, respectively, time series and vertical profiles of various quantities. These are all ASCII files, and the last two are in "comma-separated" format so that they can be easily read by various commerical graphics packages. The rest of the output consists of graphics, which are made using NCAR routines. There are 11 graphs: 1. Precipitation (solid) and evaporation (dashed), in mm/day, as a function of time in days. 2. Surface air temperature (solid) and sea surface temperature (dashed), in degrees C, as a function of time in days. The following are produced from quantities averaged over a user-defined period at the end of the integration: 3. Contributions to the temperature tendency, in degrees C per day. These are: Convective tendency (solid), radiative tendency (dashed), surface fluxes and dry adiabatic adjustment (asterisks) and large-scale vertical advection (+'s). 4. Contributions to the specific humidity tendency, in grams per kilogram per day. These are: Detrainment from all convective drafts including the unsaturated downdraft, plus evaporation of rain (solid), subsidence drying associated with convection (dashed), surface fluxes and dry adiabatic adjustment (asterisks), and large-scale vertical advection (+'s). 5. The buoyancy of air lifted from the lowest grid point, in degrees C. (Only values greater than -4 are plotted.) 6. The relative humidity. 7. The moist static energy (solid) and saturated moist static energy (dashed), both divided by heat capacity, in Kelvins. (The magnitude of these quantities is not permitted to exceed the value of the surface saturated moist static energy in these graphs.) 8. The net upward mass fluxes, in kilograms m^(-2) s^(-1) multi- plied by 1000, due to all convective updrafts (solid), saturated (penetrative) downdrafts (dashed), and the unsaturated downdraft (asterisks). 9. The total detrainment (solid) and entrainment (dashed) of mass, in kilograms m^(-2) s^(-1), by all saturated convective drafts. This does not include the unsaturated downdraft. 10. The rain water content (solid) and the difference between the specific humidity of the unsaturated downdraft and its environ- ment (dashed), in grams per kilogram. The following is made using quantities at the last time step that the convection routine was called: 11. The mixing fraction of environmental air entrained at level i (horizontal axis) and detrained at level j (vertical axis). The file labelled "conradascii.f" contains the same code but without the NCAR graphics calls. You are requested to register as a user by sending an email message to emanuel@texmex.mit.edu. This will enable you to receive updates.