Data Set Overview : The Ames Mars General Circulation Model is a three dimensional model based on the primitive equations of meteorology. It includes the radiative effects of dust and carbon dioxide as well as other features such as large-scale topography (see [POLLACKETAL1990]; [BARNESETAL1993]; and [HABERLEETAL1993]).  The model has 25 latitude bins (7.5 degree resolution), 40 longitude bins (9.0 degree resolution) and 13 vertical layers. The spacing between each layer varies. The following array defines the layer spacing from the tropopause to the surface in mbars:  0.005779, 0.009511, 0.01568, 0.02585, 0.04263, 0.07025, 0.1159, 0.1544, 0.1586, 0.1364, 0.1223, 0.09270, 0.05000.  The model spins up from a resting isothermal state with the global temperature equal to 200K. The spin up starts with hour equal to 0. The model saves data every 1.5 hours for a total of 16 hour bins per day.  Some other initial conditions that are set when the model spins up:  INITIAL SURFACE PRESSURE : 7.60 mbars TROPOPAUSE PRESSURE : 0.06699 mbars DUST OPTICAL DEPTH : 0.3 (for periods where Ls < 200) DUST OPTICAL DEPTH : 1.0 (for periods where Ls > 200) ICE CLOUD OPTICAL DEPTH : 0.00 TIME STEP : 9.25 minutes RICHARDSON NUMBER TIME SCALE : 200000000. seconds SCALE HEIGHT FOR DUST PROFILE : 0.03000 TIME CONSTANT FOR RAYLEIGH FRICTION : 2.0000 days  This data set is composed of 20 to 30 day averages of the data resulting from model runs simulating martian conditions for four Ls periods during 1977 (Ls 10-24, 94-103, 202-220, and 267-286).  Native start time : 10.15 AREOCENTRIC LON, EARTH YEAR 1977 Native stop time : 286.09 AREOCENTRIC LON, EARTH YEAR 1977  The latitude-pressure data set contains the time and zonally averaged values for several first order, heating, eddy, phase and amplitude variables. The data are given as a function of latitude and vertical pressure. The calculations were done in the pi or uv coordinate system. Pi coordinates are located at the intersection points of a set of evenly spaced latitude circles and a set of evenly spaced longitude circles. UV grid points lie midway between PI grid points. All data are given in the pi coordinate system.  The data set is in the following configuration (listed as field followed by description):  LATITUDE Latitude, degrees  PRESSURE Vertical pressure coordinate, mbars  WINDS_MER Meridional wind velocity, m/sec  WINDS_VERT Vertical wind velocity, m/sec  WINDS_ZON Zonal wind velocity, m/sec  TEMP_VERT Vertical temperature profile, K  MASS_STRM Mass stream function, kg/sec  RES_MASS_STRM Residual mass stream function, kg/sec  TOT_NET_HEAT Total net heating, K/day  TOT_NET_ACC Total net acceleration, m/sec/day   Diabatic heating parameters --------------------------- RAD_HEAT Radiative heating, K/day  RF_HEAT Rayleigh friction heating, K/day  SOL_HEAT Solar heating, K/day  IR_HEAT Infrared heating, K/day  15_MIC_HEAT 15 micron band heating, K/day  OUT_15_MIC_HEAT Outside 15 micron band heating, K/day   Eddy variables -------------- GEO_HT_VAR RMS geopotential height variance, m  GEO_TEMP_VAR RMS geopotential temperature variance, K   Phase and amplitude parameters ------------------------------ TEMP_AMP_D Diurnal temperature amplitudes, K  TEMP_AMP_SD Semi-diurnal temperature amplitudes, K  TEMP_PHASE_D Diurnal temperature phase, hours   TEMP_PHASE_SD Semi-diurnal temperature phase, hours

Confidence Level Overview : The Ames Mars General Circulation Model is a three dimensional computer model based upon the primitive equations of meteorology. It includes the radiative effects of dust and carbon dioxide as well as other features such as large-scale topography. Model results are dependent upon the selected initial conditions and spatial and temporal resolution of the model, and may not fully incorporate the effects of some physical processes represented by paramaterizations made by the model.