El Nino: Phenomenon may bring more hurricanes
El Nino may bring more hurricanes
A shift of warming patterns in the Pacific Ocean, known as El Nino, may mean more seasons of increased hurricane activity in the Atlantic and more storms entering the oil-rich Gulf of Mexico, according to a study in the journal Science.
The warming of Pacific waters has been moving toward the central Pacific, meaning more storms will form in the Gulf and Caribbean, researchers at Georgia Institute of Technology said in the study.
Traditionally, when the eastern Pacific warms up, hurricane activity in the Atlantic falls.
“What this is saying is, if El Nino is changing its character, which we think it is, you are going to get less of the down years in the Atlantic Ocean,” said co-author Peter Webster, a professor at the Atlanta university’s School of Earth and Atmospheric Sciences.
The study shows central Pacific warming is happening at the expense of regular El Ninos, and the years that it occurs are as active as when the eastern Pacific is cool, a Bloomberg report said.
In addition, when the events occur, storms tend to follow paths to the Caribbean, the Gulf and the US East Coast.
The idea that increased activity in the Atlantic can occur when the central Pacific warms up makes sense to Colorado State University hurricane researcher Phil Klotzbach because El Nino “is what really squashes the Atlantic hurricane season.”
Klotzbach and William Gray draw up closely followed seasonal hurricane forecasts at the university in Fort Collins.
The number of years when the eastern Pacific is cold, called La Nina, has remained the same.
The Gulf of Mexico is home to about 26% of US oil production and 14% of gas.
El Nino brings low pressure over the eastern Pacific, which creates wind shear over the Atlantic that can keep storms from developing, said Josh Newhard, a meteorologist for AccuWeather.com in State College, Pennsylvania.
Webster, the study’s co-author, said when a warming system is moved about 2485 miles (4000 kilometres) west into the central Pacific, the entire dynamic changes.
“It’s not magic; if you move that heating more to the central Pacific you are not increasing the shear as much over the Atlantic Ocean,” said Webster, who wrote the paper with the school’s Hye-Mi Kim and Judith Curry. “So what you finish up with is a possibility of more storms occurring in the western Atlantic ocean.”
Warming in the central Pacific can also be misidentified as an El Nino, leading to forecasts that underestimate the number and intensity of Atlantic storms, according to the study.
All the major seasonal hurricane forecasts this year, including those from Colorado State and NOAA, cited El Nino as part of their reasons for calling for fewer storms.
Last month, Colorado State predicted the current Atlantic season, which runs from1 June to 30 November, would be “slightly below average” with 11 named storms, five of which would become hurricanes. NOAA forecast nine to 14 storms, fewer than last year’s above-average 16.
Currently, the US Climate Prediction Center, a branch of the National Weather Service, has issued an El Nino watch.
Webster said his team’s models suggest this El Nino will actually migrate and become another example of central Pacific warming.
If that holds up, the current hurricane season could see a greater number of late-season storms, he said.