The relative impact of meteorological observations in the Norwegian regional model as determined using an energy norm-based approach

The sensitivity of the forecasts to different observation groups is evaluated by comparing moist total energy norm-based cost functions within the HARMONIE/Norway regional model. We quantify the quality loss associated to each observation type. The use of a localisation operator has allowed us to obtain results for the whole domain and for the area of continental Norway only, as well as for different vertical sub-regions of the atmosphere. Results show a prominent role of in situ observations for short-range forecasts, while for medium-range forecasts microwave satellite observations result in the largest impact, especially the AMSU-A channels peaking within the troposphere. Copyright (C) 2010 Royal Meteorological Society