@misc{78757,
  keywords = {workshop, data assimilation, diagnostics, systems performance},
  author = {N. Zagar and J Tribbla and J.G. Anderson and K Raeder and D. Kleist and L. Isaksen and D. Tan},
  title = {Diagnosis of data assimilation systems by using normal modes},
  year = {2009},
  month = {2009},
  url = {https://www.ecmwf.int/node/15258},
  language = {eng},
}