Published · Southern Hemisphere dynamics
How detection choices shape Southern Hemisphere atmospheric blocking
Southern Hemisphere blocking is especially sensitive to how a blocking event is defined. This project asks how much our assessment of climatology, model performance and future change depends on the detection framework itself.
Published paper · Geophysical Research Letters · 2026
Southern Hemispheric atmospheric blocking patterns in CESM-LENS2: Effects of Reversal versus Anomaly approaches
Shelke, P. B. & Renwick, J. A. (2026). Geophysical Research Letters, 53, e2025GL120428.
Read the published paper ↗Scientific question
How strongly does diagnosed Southern Hemisphere blocking depend on whether events are detected through flow reversal or geopotential-height anomaly approaches?
Approach
The study compares blocking behaviour across CESM-LENS2 and reanalysis using contrasting detection frameworks, allowing methodological sensitivity to be separated from model behaviour and internal variability.
Key contribution
Blocking climatology and apparent model bias can depend strongly on the chosen detection method. At the same time, parts of the projected response are more consistent across approaches, helping distinguish method-sensitive conclusions from more robust climate-change signals.
Why it matters
A model can appear to perform differently simply because the diagnostic emphasises a different expression of blocking. Treating detection uncertainty explicitly makes model evaluation and future-risk interpretation more physically transparent.
Where this leads next
This published work motivates my continuing research on hemisphere-aware blocking diagnostics, large-ensemble uncertainty, blocked temperature extremes and the circulation dynamics behind regional changes.