Preparations for the assessment and assimilation of npp data at ecmwf and the met office

Preparations are underway at ECMWF and the Met Office for the Cal/Val phase of the NPP Mission. Both centres aim to contribute to the assessment of instrument performance during this phase of the mission as well as assessing the impact of the data through observing system experiments. Despite the similarity of ATMS and CrIS sensors to previously flown instruments (AMSU and AIRS/IASI) additional efforts have been required in preparing to deal with the relatively high noise in the ATMS sensor. Independent data averaging schemes have been developed at both centres. Recent experience with China’s FY-3A Microwave Temperature Sounder sensor illustrates the value of NWP during Cal/Val in detecting a range of instrument biases and transient problems. Passband shifts, radiometer non-linearities as well as transient problems related to ground processing and solar storm events have been detected. In the case of passband shifts and non-linearities corrections have been developed and the data quality is significantly improved.