;+
; NAME:
;       parcel_thetae
;
; PURPOSE:
;       To calculate the equivalent potential temperature of a parcel of air
; CATEGORY:
;       Function
; CALLING SEQUENCE:
;
; INPUTS:
;
; OPTIONAL INPUTS:
;	
; KEYWORD PARAMETERS:
;
; OUTPUTS:
;
; OPTIONAL OUTPUTS:
;
; COMMON BLOCKS:
;
; SIDE EFFECTS:
;
; RESTRICTIONS:
;
; PROCEDURE:
;
; EXAMPLE:
;
; MODIFICATION HISTORY:
;       Written by:     Wayne F. Feltz, CIMSS/SSEC 
;
; $Date:$       May 10, 1998
; $Id:$
; $Log:$
;
;
;-

function parcel_thetae, p, t, td, p_surf

;  Calculate Equivalent Potential Temperature

theta=t*(p_surf/p)^0.28541
parcel_thetae=theta*exp(2481.9e-3*wvmr(p,t,td)/temp_at_lcl(t,td))

return,parcel_thetae
end