POSTER SESSION 1
15:30–17:30, Monday, September 14
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1409 | POSTER 25
PERFORMANCE OF OC-CCI AND LAKES-CCI CHLOROPHYLL-A PRODUCTS OVER THE LAURENTIAN GREAT LAKES AND IMPLICATIONS FOR DETECTING TIPPING POINTS IN LAKE ECOLOGICAL STATUS
The Laurentian Great Lakes have undergone rapid ecological transformations over recent decades, driven by a combination of nutrient management, re-eutrophication, invasive species, and climate change. Effectively capturing the timing and magnitude of these changes using in situ datasets alone can be challenging. Merged multi-mission satellite datasets are therefore vital for reporting long-term trends in lake biogeochemistry and detecting regime shifts and tipping points in their ecological status. The European Space Agency-funded RESETlakes (REmote SEnsing of Tipping points in Lakes) project leverages satellite Earth observation data and numerical modeling to support the early detection of tipping points in lakes. The Climate Change Initiative Ocean Colour (OC-CCI) and Lake (Lakes-CCI) products aim to deliver stable, multi-decadal records of satellite-derived variables suitable for such temporal assessments. However, potential artifacts arising from different satellite sensors contributing to those datasets may affect the conclusions drawn from time-series analyses. An extensive in situ matchup dataset (1998-2024, N=2551 for OC-CCI; 2002-2023, N=1460 for Lakes-CCI) was used to assess CCI Chlorophyll-a (Chl-a) retrievals in the Great Lakes, allowing inter-annual and sensor-specific uncertainties to be quantified. Significant sensor-related bias in both OC-CCI and Lakes-CCI Chl-a products was documented. Locally Weighted Scatterplot Smoothing (LOWESS) with bootstrap resampling was used to generate sensor-specific bias corrections across a wide range of Chl-a concentrations. Bias-corrected CCI products were subsequently analyzed using Seasonal-Trend decomposition (STL) and Sequential T-test Analysis of Regime Shifts (STARS) to determine the impact of product discontinuities on regime shift detection in the Great Lakes across a range of trophic status.
Caren Binding, Environment and Climate Change Canada (ECCC), [email protected]
Varunan Theenathayalan, Environment and Climate Change Canada (ECCC), [email protected]
Daniel Odermatt, Eawag, [email protected]
Iestyn Woolway, Bangor University, [email protected]
Elisa Calamita, Universität Tübingen, [email protected]
Ann Scheliga, Eawag, [email protected]
Laura Boyall, Bangor University, [email protected]
Luiz Oliveira, Universität Tübingen, [email protected]
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