Hurricanes and Global Warming By Tiffany Katerndahl Global

Hurricanes and Global Warming By: Tiffany Katerndahl

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

Greenhouse Gasses • Absorb radiation and emit it back to Earth • CO 2 has increased 31% in past 250 yrs. • Methane has increased 150% in past 250 yrs. • Nitrous Oxide at highest levels in 1000 yrs.

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.

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

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

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

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

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

• 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.

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