Opened 3 years ago

Last modified 3 years ago

#278 assigned

Diagnosis of global VAR inner loop convergence

Reported by: Jin Lee Owned by: Jin Lee
Priority: major Component: ACCESS model
Keywords: VAR 4DVAR convergence inner loop minimisation covariance PF adjoint Cc: Xingbao Wang, Xudong Sun, Peter Steinle, Monika Krysta


Xingbao Wang reported a case of a misbehaviour of VAR where the TC analysis he was running misplaced a TC vortex. In order to understand the cause of the problem I think we need to understand better the behaviour of the global 4DVAR during its inner loop minimisation as the global 4DVAR is scientifically more consistent than 4DVAR used in a higher resolution model: the background error covariance used better matches some of the characteristics of the actual covariance; the PF and its adjoint may be a better approximation than their use in a higher resolution model.

In this ticket I will explore VAR convergence using various diagnostics. Some of the diagnostics used are described in,

  • VTDP 21 - Outputting and Visualising VAR fields
  • VTDP 27 - Single Ob Tests with the VAR & AC Schemes

Change History (3)

comment:1 Changed 3 years ago by Jin Lee

comment:2 Changed 3 years ago by Jin Lee

Cc: Peter Steinle added

comment:3 Changed 3 years ago by Jin Lee

Cc: Monika Krysta added
Status: newassigned
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