During periods of greater Atlantic hurricane activity, a protective barrier of vertical wind shear and cooler ocean temperatures forms along the U.S. East Coast, weakening storms as they approach land, according to a new study by NCEI scientist, Jim Kossin. In his paper, “Hurricane Intensification along United States Coast Suppressed during Active Hurricane Periods (link is external),” published in Nature, Kossin identifies this “buffer zone” and describes its relationship with both active and inactive periods of Atlantic hurricane activity.
During periods of greater Atlantic hurricane activity, a protective barrier of vertical wind shear and cooler ocean temperatures forms along the U.S. East Coast, weakening storms as they approach land, according to a new study by NCEI scientist, Jim Kossin. In his paper, “Hurricane Intensification along United States Coast Suppressed during Active Hurricane Periods (link is external),” published in Nature, Kossin identifies this “buffer zone” and describes its relationship with both active and inactive periods of Atlantic hurricane activity.
Hurricanes depend on warm sea surface temperatures to power their warm cores with heat and moisture. But, vertical wind shear—changes in wind speed and direction from the surface to the top of the troposphere—removes the heat and moisture from a storm’s center, potentially breaking it apart completely. In the tropical Atlantic, where hurricanes develop, sea surface temperatures and vertical wind shear act together to either enhance or hinder hurricane intensification.
“During periods of greater hurricane activity, the sea surface temperatures are warmer and the wind shear is weaker in the tropical Atlantic,” says Kossin. “Likewise, during periods of low activity, the sea surface temperatures are cooler and the wind shear is stronger there. But, the opposite is true when we look near the U.S. coast. When conditions in the tropical Atlantic are good for hurricane intensification, they are bad for it near the coast and vice versa.”
Continue reading at NOAA.
Photo via NOAA.
