v8.3.1-2.33 Correct the equation of time (ufs-community#253)

* Correct the EOT

* Update README.md

---------

Co-authored-by: Dustin Swales <dustin.swales@noaa.gov>

Author: clark-evans

README.md

@@ -1,4 +1,4 @@
-MPAS-v8.3.1-2.32
+MPAS-v8.3.1-2.33
 ====
 
 The Model for Prediction Across Scales (MPAS) is a collaborative project for

src/core_atmosphere/physics/physics_wrf/module_ra_rrtmg_sw.F

@@ -10204,9 +10204,9 @@ subroutine rrtmg_swrad( &
        !    eot is based on the second equation at https://gml.noaa.gov/grad/solcalc/solareqns.PDF
        !    do not call rrtmg_sw is night-time:
        dorrsw = .true.
-       da=6.2831853071795862*(julian-1.)/365.
+       da=6.2831853071795862*(julian-0.5)/365.
        eot=(0.000075+0.001868*cos(da)-0.032077*sin(da) &
-            -0.014615*cos(2*da)-0.04089*sin(2*da))*(229.18)
+            -0.014615*cos(2*da)-0.040849*sin(2*da))*(229.18)
        xt24 = mod(xtime+radt*0.5,1440.)+eot
        tloctm = gmt + xt24/60. + xlong(i,j)/15.
        hrang = 15. * (tloctm-12.) * degrad