Monday, August 13, 2012

An Ominous Offshore Development

This summer has been warmer than usual in the New York Metro area, though that's nothing that the rest of the country hasn't experienced. However, the ocean waters off the New York and New Jersey waters is much warmer than usual.

In fact, the temperatures are running about 10 degrees warmer than they usually are. Warmer waters during the winter moderated temperatures along the coast, but during the summer that means that the shore breeze isn't cooling things down as much.

It's also meant some spectacular fishing opportunities and balmy waters for swimming, but there's a dark side.
Winter's lowest recorded ocean surface water temperature was about 40 degrees, according to the National Oceanic and Atmospheric Administration. The surface water temperature reached the mid-70s in June and the low 80s by July. A typical water temperature in June is in the mid-60s and in the mid-70s by July.

The surface isn't the only part of the ocean that is warmer; temperatures at the bottom of the sea also are above average in places. The boundary between colder bottom water and warmer surface water, known as a thermocline, near the New Jersey coast has seemingly blurred and weakened, according to data collected by an autonomous glider that has "flown" underwater for several weeks this summer.

"We're noticing that the thermoclines are much deeper and much weaker," said Bob Schuster, a state Department of Environmental Protection section chief who works with the glider program.

"(The warmth) is much more uniform throughout the water column."

The glider, which is about to be redeployed for another three-week mission, is a part of a joint program with the DEP, Rutgers and the U.S. Environmental Protection Agency to study the amount of oxygen in offshore water. However, the glider, which is a $108,000 torpedo-like device, also measures many other physical characteristics, including temperature profiles.

The warm winter also meant that the back bay waters never got very cold and warmed up quickly once the early spring arrived. Flounder have fled the bay shallows for deeper holes near inlets or have gone out into the ocean seeking cooler temperatures. Crabs began crawling out of the mud in the middle of March, weeks ahead of normal.

Bay temperatures have been in the upper 70s to low 80s in most places since early June, but in the grass flats of Barnegat Bay, the water temperature has been just below the threshold that causes heat-sensitive eel grass to die off, said Stockton College professor and sea grass researcher Jessie Jarvis.

Sampling trips so far this summer in Barnegat Bay have shown a typical seasonal decline of the grasses, but "it's too early to tell if water temperatures are resulting in a greater than normal decline," Jarvis said.

Warmer water also affects which species hang around offshore. Fish tales, whether about sharks or large game fish swimming much closer to shore than usual, abound among fishermen this summer.

Reports of large toothy sharks can be heard in bait shops, from fishing enthusiasts and even at shore bars, but Stockton College Marine Field Station manager Steve Evert said it's difficult to believe many of the stories of rarer shark species, such as bull sharks, in the area; none of the sightings has been confirmed.
The dark side? Hurricanes love warm waters. It's what they need to sustain and grow in power.

Last year, Hurricane Irene and Tropical Storm Lee hit in the New York metro area causing billions of dollars of damage in New Jersey alone. Hurricane Irene just missed a direct hit on New York City. Now, we've entered the height of hurricane season and a number of storms have already developed across the southern hurricane track into the Gulf of Mexico and Mexico, but as the season wears on, the tracks tend to run up the East Coast.

Storms generally wane in power as they head north away from the warmer waters. However, if a storm were to come up north this year, it would find waters conducive to maintaining strength. That could have dire repercussions should a storm track towards the region.

Last week, the NOAA increased its predictions for named storms in the Atlantic Basin, in part because of the warmer waters:
NOAA now expects 12 to 17 named storms and five to eight hurricanes, two or three of which are likely to be major hurricanes – categories 3, 4 or 5, with winds stronger than 111 mph. A normal hurricane season produces a dozen named storms and six hurricanes, three of which are major.

The change was made in part to reflect this year’s level of storm activity, NOAA said, as well as storm-conducive wind patterns and warmer-than-normal water surface temperatures in the Atlantic Ocean.

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