Estuarine and coastal primary production estimation using remote sensing data and radiative transfer modelling

Primary production is a key indicator of ecosystem health and carbon cycling and this can have a strong influence on the economic, social and physical health of the human population living in the estuarine and coastal zone. Making sufficient primary production measurements to understand aquatic ecosystems has always been difficult and expensive, but advances in airborne remote sensing technology allow us to use airborne images to produce maps of primary production in estuaries and coastal waters. Through this research we propose to develop and implement a data processing technique which will use images collected by the NERC Airborne Remote Sensing Facility to produce and disseminate primary production maps, improving our understanding of these ecosystems and allowing us to monitor them over time. We will produce lookup tables of spectra that would be seen by the aircraft under a variety of conditions, and these spectra will be compared with what the aircraft actually sees at each pixel of the image. This allows us to find the chlorophyll concentration (a measure of phytoplankton amount) and the photic depth (a measure of light availability) even in highly turbid waters such as are found in estuaries and coastal waters. Knowledge of these allows us to estimate primary production at each pixel and hence generate maps of primary production. Doing this for a succession of images allows us to build up a picture of how primary production changes over time.