Cael, B.B., Bisson, K., Boss, E. et al. Global climate-change trends detected in indicators of ocean ecology. Nature (2023). https://doi.org/10.1038/s41586-023-06321-z
Figure: Map of locations where the ocean-colour trend SNR is higher than 2 for a 20-year annual time series. The intensity of the purple colour indicates the signal to noise ratio. Black stippling indicates regions with significant trends in Chl as well (12% of the ocean). MODIS-Aqua data from July 2002 to June 2022.
Climate change is altering the earth's oceans, specifically in marine ecosystems and it has been hypothosized that this could alter the ocean color. However, determining if this was occuring on a global scale has been difficult due to the lack of a long-term satellite data record, especially with intercalibration between different instruments being an issue. Having MODIS on Aqua for 20+ years has allowed for this type of study to take place, and for long term changes to be found.
A new study, published in Nature using Aqua MODIS reflectance data found that there are large areas of the global oceans where the color of the ocean has changed over the 20-year record and is becoming more green due to more phytoplantion. This change in ocean color is driven by climate change. This change is important because it alters the light environment of the oceans, which drive primary production and can lead to an overall change in the surface-ocean ecosystem, which could have potential effects on fisheries worldwide.
T.K. Westberry, et al., Atmospheric noursiment of global ocean ecysystems. Science 380, 515-519 (2023). DOI: 10.1126/science.abq5252
A new study by Westberry et al. published in Science titled, 'Atmospheric Nourishment of Global Ocean Ecoystems', detects the extent and magnitude of dust-deposition on the oceans globally. Dust-deposited on the ocean provides nutritents for phytoplankton. This new dataset was produced using Aqua MODIS data.
Dai, Y.,Yang, S., Zhao, D. et al. Coastal phytoplankton blooms expand and intensify in the 21st century. Nature 615, 280–284 (2023). https://doi.org/10.1038/s41586-023-05760-y
Figure: MODIS-dectected bloom count within certian years for several coastal regions with frequency reported blooms. The MODIS observational year is annotated within each panel, and overlaid points indicate in situ recorded harmful algal bloom events from the Harmful Algae Event Database (HAEDAT) within the same year. The lower right panel shows the locations of all the HAEDAT records that were used for algorithm validations in this study, which also demonstrates the increase in sampling effort in the most recent years.
A new study, published in Nature, found that globally coastal algae blooms are increasing in frequency and extent between 2003-2020. These blooms were detected by a algae bloom detection dataset, which was produced using 0.76 million MODIS-Aqua images. While some algae blooms are beneficial providing food to fisheries and the ecosystems worldwide, other blooms called 'Harmful Algae Blooms' are becoming more prevalaent and can put toxins in the food chain, affecting animals and humans, and can depelete the oxygen in areas creating 'Dead Zones' that can kill many species. This daily coastal phytoplanton bloom dataset is important because it can be used to inform future management and policy actions and provides locations and timing of these algae blooms.