Assimilation satellite derived wind data (Ascat-a Ascat-b)

[jostersplus]

Hello everyone. I want assimilation wind data from sattelite in tradidtional format U V (or speed-dir). In that case all obsevrvation (each point) have itown time of observation. Do I understnad right, that 3DVar and 4DVar useless for me, becasue mesure moment's in 3DVar and 4DVar must be equal at all? Maybe the objective analysis fit to me more? May you have some tutorial about similar case, example assimilation rain from sat data. Thank you

 

[Jeffreystarks]

Hello,

If I understand correctly, you are looking for wind data from satellite observations in a traditional format such as U-V components (or speed-direction). You are wondering if 3DVar and 4DVar assimilation methods are suitable for your case because the measurement moments in these methods are assumed to be the same throughout. You're also interested in learning about objective analysis and whether it would be a better fit for assimilating rain data from satellite observations.

For your first question, if you have satellite observations with their respective times of observation, it is possible to assimilate them using 3DVar or 4DVar methods. In these methods, the assimilation system uses a time interpolation scheme to match the observations with the model's time grid. The observations and model background are then adjusted to find the best fit. MyHealthOnline


3DVar assimilates observations from a single time step, while 4DVar assimilates observations over a time window. Both methods can handle observations with different times of observation. The assimilation algorithms will account for the temporal mismatch by interpolating or extrapolating the observations to the model time grid. Therefore, the fact that the measurement moments are not exactly equal at all time steps does not render these methods useless for your case.