1. Hurricanes and Global Warming
By: Tiffany Katerndahl

2. Global Warming
The earth’s surface temp has risen about 1°F in last 100 yrs-from Environmental protection agency
The Earths sea surface temp has risen about
.5 ° C in the past 35 yrs in tropical ocean

3. Greenhouse Gasses Absorb radiation and emit it back to Earth
CO2 has increased 31% in past 250 yrs.
Methane has increased 150% in past 250 yrs.
Nitrous Oxide at highest levels in 1000 yrs.

4. Hurricanes Form in tropical waters
Sea surface temp must be at least 27° C
Saffir Simpson scale based on wind speed
Varies from a category 1, which is the weakest to a category 5.

5. Hurricane frequency and intensity
No increasing or decreasing trend in the frequency of hurricanes except in the North Atlantic
In N.A. the increase in frequency occurred simultaneously with a positive trend in sea surface temperature
No other basins show this increase

6. Intensity
Can determine this multiple ways….wind speed also by total power dissipated
Category 1 remains roughly constant decreases a little
Category 4 and 5 have almost doubled
These changes occur in all of the basins

7. Intensity
The total potential destructiveness of hurricanes can be based on the total dissipation of power after it is integrated over its lifetime
where:
CD is surface drag coefficient
p is the surface air density
[V] is the magnitude of the surface wind

8. You can simplify that equation to be the power dissipation index
V max is the maximum sustained wind speed

9. The power dissipation has more than doubled in 30 years in the Atlantic
In the west North Pacific it has increased by 75 percent

10. This is five to twelve percent stronger
If the sea surface temperature were to warm about 2.2 degrees Celsius, hurricane winds would be more intense by three to seven meters per second
This is five to twelve percent stronger
the central surface pressure would decrease by seven to twenty millibars. .

11. Conclusions Global Warming is increasing the sea surface temperature
This increase may or may not have an impact on frequency
Would have an increase in the intensity