Calculation of TH2M

[Liu-Jincan]

The TH2M calculation in the model is as follows:

WW3/model/src/w3iogomd.F90

Line 1681 in abc77b9

TH2M(JSEA,IK)= MOD ( 270. - RADE*0.5*ATAN2(ABY2(JSEA),AB2X(JSEA)) , 180. )

          ! These are the integrals with cos^2 and sin^2
          ABX2(JSEA) = ABX2(JSEA) + A(ITH,IK,JSEA)*EC2(ITH)
          ABY2(JSEA) = ABY2(JSEA) + A(ITH,IK,JSEA)*ES2(ITH)
          ! Using trig identities to represent cos2theta and sin2theta.
          AB2X(JSEA) = AB2X(JSEA) + A(ITH,IK,JSEA)*(2*EC2(ITH) - 1)
          AB2Y(JSEA) = AB2Y(JSEA) + A(ITH,IK,JSEA)*(2*ESC(ITH))
          ABYX(JSEA) = ABYX(JSEA) + A(ITH,IK,JSEA)*ESC(ITH)

The formula for TH2M as recorded in the manual is:

Is the use of AB2Y instead of ABY2 appropriate for calculating the TH2M variable, or does the formula require ABY2?

             TH2M(JSEA,IK)= MOD ( 270. - RADE*0.5*ATAN2(AB2Y(JSEA),AB2X(JSEA)) , 180. )

[Liu-Jincan]

The TH2M calculation in #114 ：

            TH2M(JSEA,IK)= MOD ( 270. - RADE*0.5*ATAN2(ABY2(JSEA),ABX2(JSEA)) , 180. )

! Using trig identities to represent cos2theta and sin2theta.
            ABX2(JSEA) = ABX2(JSEA) + A(ITH,IK,JSEA)*(2*EC2(ITH) - 1)
            ABY2(JSEA) = ABY2(JSEA) + A(ITH,IK,JSEA)*(2*ESC(ITH))
            ABYX(JSEA) = ABYX(JSEA) + A(ITH,IK,JSEA)*ESC(ITH)