Hilde Oliver
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hildeoliver.bsky.social
Hilde Oliver
@hildeoliver.bsky.social
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Assistant Scientist at WHOI, oceanographer / sea-going modeler 🌊 physical-biological interactions, polar and coastal systems 🇦🇶 Canadian-East Tennesseean

https://www2.whoi.edu/staff/holiver
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hildeoliver.bsky.social
This has major implications for our estimates of Antarctic coastal primary productivity, with large differences in NPP estimates for L2gen Chl products vs. those using an atmospheric correction less susceptible to adjacency (POLYMER, used by ESA OC-CCI). The effects are strongest in small polynyas.
Two subplots, showing the median and IQR Chl % difference and NPP % difference between the L2gen and POLYMER Chl products as a function of distance from the coastline. Both show an exponential decay from the coastline to ~100 km from the coast, with Chl being a factor of 600% different at the coast, and NPP being a factor of ~70% different. log-log scatterplot and linear regression showing the NPP% difference (using L2gen vs. POLYMER) vs. the mean open water area for each Antarctic coastal polynya. There is a strong linear relationship between polynya size and NPP % difference, with an R2 of 0.66.
September 6, 2025 at 11:40 PM
hildeoliver.bsky.social
🌊 I have a new paper out in L&O Letters! We show that ocean color-based estimates of chlorophyll concentrations within 100 km of the Antarctic coastline are severely underestimated when applying the standard NASA L2gen atmospheric processing. This is caused by adjacency effects from ice and snow.
Figure 1 from the paper, showing four subplots of maps of the west Antarctic shelf extending from the West Antarctic Peninsula to the Ross Sea. Figure caption: January 10-yr (2010–2019) mean (a) OBPG/L2gen Chl a (which shows low Chl near the coastline), (b) OBPG nFLH (which shows elevated nFLH near the coastline), (c) OC-CCI Chl a (which also shows high Chl near the coast, agreeing with the pattern in the nFLH), and (d) difference in Chl a products OC-CCI Chl a minus OBPG/L2gen Chl a, over the west Antarctic shelf (which shows a band of much higher Chl, ~5-10 ug/L, extending along the entire west Antarctic coastline).
September 6, 2025 at 11:40 PM