Antarctic sea-ice at 'mind-blowing' low alarms experts
Statistics & Probability
The sea-ice surrounding Antarctica is well below any previous recorded winter level, satellite data shows, a worrying new benchmark for a region that once seemed resistant to global warming. (BBC)
Where this idea comes from
Start here — this is the source that inspired this exploration.
Introduction
Satellite records of Antarctic winter sea-ice extent go back to 1979. The recent record low sits far outside the range that record has shown before. This exploration treats that shift as a statistics problem: characterise the normal range of past winters, then work out how unusual the new value is and whether the shift looks like a one-off or the start of a trend.
Guiding Questions
- Plot Antarctic winter sea-ice extent over the satellite record. How unusual is the recent low?
- Calculate the mean and standard deviation of past winters. How many standard deviations below is the new value?
- What is the probability of a value that low if nothing had changed? What does that suggest?
- Fit a trend and discuss: is this a freak year or part of a pattern? What further data would settle it?