Event Detection — Each month, every block is compared to its own
same-calendar-month running mean and variance (Welford's algorithm). Blocks
deviating by more than 3σ are flagged — in net, SW, and LW independently.
Watch for El Niño (2015–16, 2023–24), La Niña (2010–12, 2020–22), Hunga Tonga
(Jan 2022, SW↑ LW↓), and Australian fires (2019–20, SW signature).
Event Detection Setup
Choose grid resolution, then start. Finer grids detect localized events
like Hunga Tonga more precisely; coarser grids run faster.
4°
~4,050 blocks · good balance of detail and speed
Detection: 3σ seasonal Welford · min 4 same-month samples · net + SW + LW