but
            the algorithm has not changed


</PRE>
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<A NAME="NOTES">
<HR>
<H4>NOTES</H4>
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<PRE>

     A pseudo-program using the multistep algorithm:

         do atmospheric loop
             call gcm_vert_diff_down  
         end do

         call surface modules

         do atmospheric loop
             call gcm_vert_diff_up
         end do

</PRE>
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