[Proj] proj4 definition for transverse mercator projection from RegCM3 model for North America

[Hailey Eckstrand]

Hello all,
I am trying to create the proj4 string for a netcdf file with the following
coordinate information:

variables:
        char Transverse_Mercator ;
                Transverse_Mercator:grid_mapping_name =
"transverse_mercator" ;
                Transverse_Mercator:longitude_of_central_meridian = -97. ;
                Transverse_Mercator:latitude_of_projection_origin = 47.5 ;
                Transverse_Mercator:scale_factor_at_central_meridian = 1. ;
                Transverse_Mercator:false_easting = 3925000. ;
                Transverse_Mercator:false_northing = 3175000. ;
        double lat(yc, xc) ;
                lat:units = "degrees_north" ;
                lat:long_name = "latitude" ;
                lat:standard_name = "latitude" ;
                lat:axis = "Y" ;
        double lon(yc, xc) ;
                lon:units = "degrees_east" ;
                lon:long_name = "longitude" ;
                lon:standard_name = "longitude" ;
                lon:axis = "X" ;
        double xc(xc) ;
                xc:long_name = "x-coordinate in Cartesian system" ;
                xc:standard_name = "projection_x_coordinate" ;
                xc:units = "m" ;
                xc:axis = "X" ;
        double yc(yc) ;
                yc:long_name = "y-coordinate in Cartesian system" ;
                yc:standard_name = "projection_y_coordinate" ;
                yc:units = "m" ;
                yc:axis = "Y" ;


The file gives the coordinates in their native projected coordinates as well
as the lat & lon coordinates.