Adjoint assimilation

{
  "id": "MLC-T-MET-003304",
  "term": "Adjoint assimilation",
  "field": "Meteorology and atmospheric science",
  "definition": "A four-dimensional variational (4D-Var) data assimilation method used in numerical weather prediction to find the optimal initial state of the atmosphere. It uses the adjoint of the forecast model to efficiently compute the gradient of a cost function, which measures the misfit between the model forecast and observations over a time window. This gradient is then used in an iterative minimization algorithm to adjust the initial conditions.",
  "see_also": [
    "adjoint sensitivity",
    "variational objective analysis"
  ],
  "url": "https://mlchart.com/terminology/meteorology/adjoint-assimilation/"
}