Spring Upgrade Solution to Allow Surface Temperatures To Be Turned Back On

• Limit the vertical influence of the surface temperature obs by analyzing these data independently with a 2DVar module

• Advantage: relatively easy to implement the 2DVar module without compromising 3DVar code etc

• Implementation:

• 1) use original 3dvar code to analyze all the observations except for surface temperature

• 2) at the end of the 3dvar, invoke the 2dvar module to analyze surface temperature

• 3) resulting 2dvar increments replace those from the 3dvar analysis at the appropriate vertical levels