Recent research indicates there has been a warming trend in Pacific Ocean temperatures over the last 50 years (IPCC, 2007). Nearshore regions along the North Pacific coast are particularly sensitive to this trend. In these nearshore regions, in situ SST measurements are typically made via buoys, but such measurements are irregular in both space and time. Satellite-based remote-sensing observations have the advantage of extensive spatial coverage and high repeatability that is not possible with field observations. The trade-off, however, is that satellite data generally have low spatial resolution compared with field measurements and therefore often cannot resolve smaller features important in coastal areas. Furthermore, high-resolution image products of large area often consist of an unmanageable amount of data, making them impractical for general use. However, a spatio-temporally continuous near-coastal SST dataset can be used to address questions about nearshore environments in ways that are not possible with offshore SST measurements. Therefore, for climate change research in coastal and estuarine environments, a moderate resolution SST product that covers the near-coastal area while keeping file size reasonable is needed.

To fill this nearshore SST data gap, a three-decade, moderate-resolution (4 km) SST dataset was generated for the nearshore areas of the North Pacific, from Baja, California to the East China Sea. This dataset is based on SST measurements from the Advanced Very High Resolution Radiometer (AVHRR) Pathfinder v. 5 data. The AVHRR data provide a consistent set of SST measurements, of a known quality, for nearshore environments in the North Pacific. The methods used to generate the data are described here. Our intent is to provide these data as a readily-available product for researchers who are addressing questions about the effects of variations in temperature on the distribution of nearshore organisms.