New-generation geostationary sensors, including the Advanced Baseline Imager (ABI) onboard GOES-16/17 and the Advanced Himawari Imager (AHI, a twin to ABI) onboard Himawari-8, capture infrared images with 2km nadir resolution every 10 or 15 minutes. This high temporal resolution is a unique feature of geostationary sensors, facilitating studies of SST diurnal variability.
A collated-in-time geostationary SST product developed for the NOAA Advanced Clear-Sky Processor for Oceans (ACSPO) SST system is able to exploit the temporal information in geostationary SST images by using the temporal context to separate the effects of faster moving clouds and other atmospheric formations from the slower evolution of the SST field. This significantly improves spatial coverage by using measurements from the nearest clear-sky looks in time, reduces the overall noise in the SST time series, and allows for a more accurate characterization of SST diurnal variability. Moreover, the data volume is significantly reduced by reporting at a reduced hourly temporal rate, which is sufficient to resolve the main features in the diurnal cycle.
We present an overview of the collation algorithm, sample validation data, and examples of ocean phenomena, such as thermal fronts, diurnal warming, and tidal motion, which have been observed by new-generation sensors. The improved spatial coverage and temporal resolution give us an unprecedented opportunity to investigate the sub-daily time evolution of these phenomena.