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Hurricanes are one of the most dramatic, damaging, and potentially deadly storm events that can occur in the U.S. These storms are products of the atmosphere and tropical ocean areas. Fueled by heat from the ocean, hurricanes are steered erratically by the easterly trade winds and the temperate westerly winds, as well as their own internal energy. As these storms move ashore, they bring with them storm surges of ocean water along the coastline, high winds, tornadoes, and torrential rains with flooding.
Each year an average of 10 tropical storms develop over the
Atlantic Ocean, Caribbean Sea, or the Gulf of Mexico. About six
of these storms will strengthen enough in intensity to become
hurricanes. Many of these hurricanes remain over the ocean
with little or no impact on the continental U.S., but an
average of five hurricanes strike the U.S. coastline every three
years. Of these five storms, two will be considered major hurricanes
(i.e., category 3 or higher per the Saffir-Simpson Scale).
These storms can ultimately cost the U.S. millions, if not billions,
of dollars in damages.
Onshore, hurricanes can damage or destroy homes, businesses, public
buildings, and infrastructure (e.g., roads, electric lines, telephone
lines) due to the locally produced high winds, storm surges,
and waves. Airborne debris breaks windows and doors in buildings
allowing high winds and rains inside the structure. Roads and
bridges can be washed away from flash flooding or can be blocked
by floating debris. In extreme storms, wind force alone can
cause tremendous devastation by toppling trees, power lines,
and marginal building structures. These storm impacts are
not limited to the coastline but can extend hundreds
of miles inland given the right weather conditions.
Offshore, hurricanes can have significant biological and physical impacts that can dramatically effect the condition of the coastline. Biological impacts include effects on the distribution and location of local fish and shellfish populations as well as algae and seagrasses. Physical impacts include changes in beach sedimentation patterns and bathymetry that may have catastrophic ocean navigation consequences. These coastal impacts can vary significantly depending upon storm intensity and ground track.
The capability to assess hurricane impacts depends greatly upon the ability to obtain and interpret storm damage information in an accurate and timely manner. With imagery derived from remote sensing instruments such as the Advanced Very High Resolution Radiometer (AVHRR), ocean turbidity and sea surface temperature information is readily available to emergency response personnel and coastal managers. Ocean water turbidity imagery may help identify specific coastal regions that may have undergone the highest storm-induced beach erosion, allowing disaster response officials to prioritize and respond quickly in the most affected coastal areas. In addition, ocean water turbidity imagery can potentially be used to derive estimates of the local total sediment concentration within the water column; this information can be used to estimate impacts on navigation channels and shoal areas as well as identify possible future beach renourishment locations. The imagery can also be used to predict regions that may experience significant biological changes to due increased sedimentation and nutrient concentrations.