Dynamics and connectivity of the Bonney Coast Upwelling on a daily scale using the Himawari-8 dataset

The Bonney Coast Upwelling (BCU) is a key ecological feature in the Australian marine regime; it helps contribute to the largest fin fish based fishery in Australian waters and is a feeding ground for the endangered blue whales. The BCU is a seasonal wind driven feature that operates intermittently (on the time scale of between a few days to a couple of weeks) throughout the Austral summer. Since its discovery in the late seventies, the region has been investigated using a range of physical oceanographic techniques, from shipboard sampling to modelling and remote sensing. The latter of which has, until recently, been limited by the temporal frequency of the MODIS and AVHRR passes over the Australasian region, (twice a day) making the data susceptible to cloud contamination. The geostationary Himawari-8 satellite, which became operational in late 2015, is an ideal platform to provide adequate temporal resolution to overcome the cloud contamination problem. This study generates sea surface temperature (SST) daily composites from hourly Himawari-8 images, during the period from November 2016 - March 2017. A topographical position index method is used to isolate the upwelling signatures in the Bonney Coast region from these daily images. With the BCU mapped on a daily basis, we are able to, for the first time, quantitatively investigate the spatial and temporal development of the BCU from onset to termination during an entire upwelling season. In addition, the study will also be able to investigate the connectivity between the BCU and other local upwelling features off Kangaroo Island and the Eyre Peninsula.

Presented at the 2017 Australian Marine Sciences Association (AMSA) Conference