Global warming and severe weather: hurricanes
Hurricanes and global warming More hurricanes – Warming SST’s (sea surface temperatures) suggest greater source of energy for hurricanes, hence they should be more frequent
N. Atlantic hurricane record best after 1944 with aircraft surveillance. SST ( )
Hurricanes and global warming Fewer hurricanes – Increased wind shear – Increasing atmospheric stability
La Nina Drawing
El Nino Drawing/animation
Southern Oscillation and global warming ENSO not caused by global warming ENSO is natural cycle More El Nino conditions under global warming
Source of uncertainties Small sample size (only a few hurricanes each year)
Early view of hurricane structure, 1946
Radar-based hurricane tracking, 1960
Source of uncertainties Difficult to separate natural and anthropogenic influences on the conditions leading to hurricane development
Source of uncertainties Different ways to quantify hurricane activity? – Strength? – Frequency? – Duration of season? – Tracks?