August 2025
Greener green and bluer blue: Ocean poleward greening over the past two decades
- Haipeng Zhao et al., Greener green and bluer blue: Ocean poleward greening overe the past two decades. Science, 388, 1337-1340 (2025). https://www.science.org/doi/10.1126/science.adr9715
This study used 20 years of Aqua data, specifically the ocean color data product from MODIS which shows the Chlorphyll a concentrations, to assess the change in ocean color due to climate change. They found that the oceans were becomming greener at higher latitudes, and bluer near the equator. This is caused by warming ocean temperatures where the ideal temperatures for primary production (chlorophyll a) have moved north from the equator. This change in ocean color and chrlophyll a concentrations in our global oceans have a large impact on the fisheries and economies of coastal nations.
Figure Caption: Global distribution and latitudinal trends of surface Chl at 2° resolution.
(A) Climatological mean Chl between 60°S and 60°N (2003–2022) and north of 60°N (2003–2020). Coastal regions and areas south of 60°S are excluded. (B) Median of the climatological Chl (thick line) and the 10th and 90th percentiles (thin lines) as a function of latitude. (C) Annual Sen’s slope of the climatological Chl with Mann-Kendall (MK) test significance (°P < 0.1, *P < 0.05, **P < 0.01, ***P < 0.001) indicated. Color represents R2 (coefficient of determination) values.
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