Comparison of NCEP/NCAR Reanalysis data with station data for the circum-polar coastal regime

Coastal dynamics in the circum-Arctic is being examined by a group of international researchers under the auspices of the Arctic Coastal Dynamics Project. In support of this effort, databases of environmental forcing parameters specific to Arctic coastal responses are being prepared based on the publicly available NCEP/NCAR Reanalysis. In order to validate the Reanalysis products in the coastal regions of the Arctic, they have been compared to coastal station data in the circum-polar region. This paper presents results of the comparison effort. Reanalysis wind field and temperature for the surface and upper air (500hPa) were compared with analogous observed parameters. In general, temperature data were well-correlated. Wind direction was well-correlated, except where stations were in mountainous or fjord regions. Direction correlation improved for higher wind speeds. This was attributed to a decrease in the influence of local effects at higher wind speeds. Wind speed correlation was moderate at low speeds, becoming poor at higher wind speeds. In very few instances was the Reanalysis data able to capture the magnitude of the corresponding observed wind speed during periods of stronger winds. This is similar to the experience of others who have examined the same parameters for other parts of the world. The nature of the wind speed relationship, however, did allow for automated corrections to be tested that brought the reanalysis speed data closer to observed. It is important to note that the timing of wind speed event peaks was well correlated even if magnitudes were not.