Remote Sensing

Main Image Real Time Observations. Designed by Frank O'Reilly.

Remote Sensing Overview

Remote sensing allows to obtain measurements of different properties of seawater from sensors attached to satellites orbiting the Earth. It is possible to estimate sea surface temperature (SST) by measuring the electromagnetic radiation emmited by the ocean in the infrared and microwave wavelengths. Such measurements have been collected since the 1980's and it is now possible to study climate change from this 40-year database by calculating anomalies and determining the occurrence and intensity of marine heat waves. On the other hand, electromagnetic radiation in the visible light wavelength can be used to study the presence and concentration of pigments in the surface ocean, such as those that microalgae use for photosynthesis. These wavelengths are thus used to determine chlorophyll-a concentration and estimate phytoplankton growth and primary production. Have a look at the different remote sensing products available below for Irish waters.

Sea Surface Temperature
Sea Surface Temperature
Maps of sea surface temperature in the Irish EEZ from the Operational Sea Surface Temperature and Ice Analysis system run by the UK's Met Office and delivered by IFREMER. Data accessible from 1982 until present.
Sea Surface Temperature Anomaly
Sea Surface Temperature Anomaly
Maps of sea surface temperature anomaly from a 30-year (1993-2022) climatology, showing areas that are cooler or warmer than usual.
Marine Heat Waves
Marine Heat Waves
Maps of marine heat wave occurrence and intensity in the Irish EEZ. Due to global warming, the frequency, duration and intensity of marine heat waves have been increasing during the last decades.
Surface Temperature Historical
Surface Temperature Historical
A tool to obtain SST time series (1982 - present) at a specific site of your choice, together with analysis of marine heat wave and cold spell occurrence. In addition, in-situ seawater temperature observations from the Irish Marine Data Buoy Observation Network, Mace Head and Deenish Island buoys are provided. Observations are downloadable as CSV files.
Chlorophyll-a Concentration
Chlorophyll-a Concentration
Last week's maps of surface chlorophyll-a in Irish coastal waters from satellite observations. Maps of chlorophyll-a anomalies are provided too. These provide information on phytoplankton growth and primary production.
Red Band Difference
Red Band Difference
The Red Band Difference (RBD) algorithm is used as a proxy of relative chlorophyll-a fluorescence and is calculated as the difference between two red bands. As described by Amin et al. (2009) and tested in Irish waters by Jordan et al. (2021), the RBD algorithm is less sensitive to coloured dissolved organic matter, suspended particulate matter and atmospheric corrections, which makes it useful in both open and coastal waters.