Twenty-year (2005-2025) SST and ocean-current analysis of the Gulf of Guinea, built for reproducible marine-science research.
# Gulf of Guinea Sea Surface Temperature (2005–2025)
**A twenty-year SST and ocean-current analysis of the Gulf of Guinea, built for reproducible marine-science research.**
*Animated GIF: annual-mean SST, Gulf of Guinea, 2005–2025 (NOAA OISST v2.1, 0.25° daily means). The cold-tongue signature along the equator and the basin-wide warming trend are both visible at a glance.*
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## Why this matters
The Gulf of Guinea hosts one of Africa's most productive marine ecosystems, yet it sits at the intersection of several powerful and competing physical processes: the **Atlantic Cold Tongue** that cools equatorial waters each boreal summer, the **coastal upwelling cell** off Côte d'Ivoire and Ghana that supports regional fisheries, and a **warming trend** that is eroding the productivity margin of both systems. For anyone studying shoreline change, coastal erosion, or fishery science along the Nigerian, Ghanaian, and Ivorian coasts, a rigorous, reproducible quantitative baseline of SST variability is the first building block.
This repository provides that baseline: daily-mean satellite SST from 1 January 2005 through 2025, analyzed through five linked notebooks that move from climatology to trends, upwelling, heatwaves, and an animated synthesis.
## Results at a glance
| Question | Finding |
| --- | --- |
| What does the seasonal cycle look like? | Basin-mean SST peaks in **April (~29.4 °C)**, collapses to a minimum in **August (~25.2 °C)** with cold-tongue onset, then recovers through November — a seasonal swing of ~4 °C. |
| Is the gulf warming? | Basin-mean annual SST rose by **0.31 °C per decade (2005–2025, R² = 0.49)**; the fastest-warming cell (4.6°N, 3.9°W — Côte d'Ivoire shelf) warmed at **+0.42 °C/decade** (p 100 MB) — rebuilt by pipeline
│ ├── raw/ # one NetCDF per year (built by download pipeline)
│ ├── gog_sst_stats.csv # annual basin means, MHW counts, upwelling Aug–Sep means
│ └── *.npy / *.npz # intermedi …