+ Effects of Climate Change on Ocean Storms Chloe Mawer

+ Why do we care? Specifically for this project: An increase in intensity causes increase in storm surges. If this occurs, ports will have to be able to withstand waters higher than that predicted with solely sea level rise and current surge levels. In general Damage is proportional to the cubed of hurricane intensity, wind speed. Category 3-5 storms account for only 24% of TCs, they account for 86% of damage.

+ Connection to Global Warming and what a hurricane is A tropical cyclone is more or less a Carnot Heat Engine. Entropy is usually produced to maintain thermal equilibrium. Usually this is done via mixing between moist and dry air, but vorticity prevents this. Thus entropy is produced via kinetic energy (wind). The warmer the water, the more entropy that needs to be produced to maintain equilibrium

+ Frequency Value of low-level relative vorticity Coriolis Parameter Weak vertical shear of horizontal winds High surface sea temperatures and a deep thermocline (where temperature changes more rapidly with depth than the layers around it). Conditional instability through the deep atmospheric layer Large values of relative humidity in the lower and middle troposphere.

+ Frequency Named Cyclones by YearAnnual Numer of Hurricanes and Named Hurricanes in Atlantic Average Cumulative Number of Systems per Year in the Atlantic Basin Average Cumulative Number of Systems per Year in the Eastern Pacific Basin

+ Frequency By the end of the century: Storms of category 4 or 5 (those with winds 134 mph or faster) will increase in frequency two-fold Storms with wind speeds greater than 145 mph will increase three-fold. The overall frequency of hurricanes will decrease, but given the increase frequency of intense storms, damage will still increase (Bender, Knutson et al. 2010). Average Number of Hurricanes per Decade for the Control and Warmed Climates and the Difference between the Two Storm Tracks for Control and Warmed Climate

+ Intensity Like damage, total power dissipation is also a function of the cubed wind speed. Emanuel shows that this index has notably increased since the 1970s. Emanuel not only finds that the index amplifies with time but also shows that the record of net power dissipation is proportional to the sea surface temperature (see Figure 3). (Emanuel 2005).

+ Future Resources

+ Conclusions Data based modeling shows that frequency of intense storms and the potential power destructiveness of storms is increasing, but it is hard to see statistical significance or predict from this. However, it does produce motivation. Models show frequency of intense storms will increase. Since are continually improving, we need to continue to look for improved predictions. More investigation needs to be done into the regional differences in projected frequency as this could have powerful effects on some ports. Research in this area should increase with improved models.