id summary reporter owner description type status priority milestone component version resolution keywords cc 382 Observation Impact, OBS_IMPACT_SPLIT arango arango "The observation impact operator for '''W4DPSAS''' and '''W4DVAR''' was further developed to additionally compute the contributions due to initial conditions, surface forcing, and boundary conditions. A new C-preprocessing option, '''OBS_IMPACT_SPLIT''', is introduced to achieve this. It requires additional integrations of the tangent linear model. This option needs to be used at the same time with '''OBS_IMPACT''' and '''W4DPSAS_SENSITIVITY''' or '''W4DVAR_SENSITIVITY'''. If '''OBS_IMPACT_SPLIT''' is defined as well, then the contribution to the observation sensitivities for the increments in the initial conditions, surface forcing, and boundary conditions are all computed separately. This is a very nice feature and is very revealing. Many thanks to Andy Moore for coding and testing this new option." upgrade closed major Adjoint Based Algorithms Adjoint 3.3 Done