Slick Science: How Storms Spread Oil Spills

“The Deepwater Horizon explosion reopened debate on the role of synoptic weather features versus ocean currents in transporting the oil spill,” says Pat Fitzpatrick of Mississippi State Univ. in his abstract for a presentation in the upcoming AMS Annual Meeting.
This debate is a result of conflicting experiences with oil spills in windy storms. A storm notoriously expanded the Exxon Valdez oil slick in Prince William Sound in 1989, but on the other hand Hurricane Henri in 1979 basically had little effect on the plume of the Ixtoc spill and paradoxically cleaned up soiled Texas beaches.
We’ll know what chances this case has of settling the debate over how winds and storms move oil slicks around after seeing the data Fitzpatrick presents (Monday, 23 January, 4:30 p.m., Room 337) from the 2010 disaster in the Gulf of Mexico. For now, Fitzpatrick writes, “Lagrangian models generally assume oil concentrations travel largely proportional (80-100%) to ocean currents’ speed and direction, plus an additional 3% contribution from surface winds, diffused with each time step. However, cyclones are known to highly perturb water pollutants….”
Add another finding to this mix, however: A paper published this week in the Proceedings of the National Academy of Sciences confirms previous reports that most of the oil in the Deepwater Horizon disaster never made it to the surface. Of course, it makes sense that oil plumes from an undersea explosion might stay underwater. In this case, scientists say, the plumes consisted of microscopic particles of pollution–invisible to the naked eye (with or without a scuba mask). More than a third stayed deep in the Gulf; a quarter of the is unaccounted for. From the Sarasota Herald Tribune:

“The visible surface slick that people were riveted by during the months of the spill was really only 15 percent of the total mass,” said Thomas Ryerson, a research chemist with the National Oceanic and Atmospheric Administration who led the study.

It will be interesting to see if such varying conditions of oil releases from different disasters over the years will add up to a coherent understanding of the interaction of ocean and atmosphere that can be used to improve predictions of the movement and effects of the next big spill.

Science for Oysters…and Oysters for Scientists

One of the highlights of New Orleans is its distinctive, world-renowned cuisine. And indulging in that famous cuisine more often than not means enjoying the bounty of the Gulf of Mexico. AMS members will descend on New Orleans right at the high season for oysters, according to food critic Brett Anderson writing in the local paper, the Times-Picayune, right before Christmas:

Meteorologically speaking, it is an inconvenience that Louisiana oysters are never more delicious than they are right about now, just as we’re growing accustomed to the daily threat of something resembling winter. Wouldn’t it be nice if oysters were at their crispest in August instead, when they could provide cool relief from the blood-hot sun? Yes, that would be nice, but our reality is pretty sweet as well: oysters at their peak, tasting like clean ocean water, firm-fleshed and sitting pert on their shell. They’re perfectly sized, large enough to announce their presence, small enough to swallow whole. Get another dozen. It’s gift-giving season.

According to the reports from the restaurants, the local crop is back to the quality seen before the big BP Horizon oil spill of 2010. Prices and supplies have normalized.
So while you’re hunting for some Gulf oysters on the half-shell later this month at the AMS Annual Meeting, keep in mind that this delicacy is not only featured on your plates but, also, featured on scientific program. In particular, two presentations might ease concerns you have about subjecting your stomach to the raw variety (of food, not science, of course!). Gina Ylitalo (NOAA) and colleagues will present on “Oil Spills and Seafood Safety” (8:45 p.m., Tuesday, Room 333). They write

Thousands of seafood samples collected during reopening and surveillance in the Gulf, as well as those obtained dockside and in the marketplace have been analyzed using [advanced] analytical methods. While chemical compounds associated with the oil spill have been detected in seafood samples using these various analytical methods, none were present in edible tissues at levels that approached levels of concern for human consumers of seafood products from the Gulf.

Later in the same session on Tuesday, Jay Grimes (Univ. of Southern Mississippi) will talk about monitoring disease potential from raw seafood with satellite monitoring of ocean temperatures and salinity, in “Can You Really See Bacteria from Space?”.  Below is the latest bacteria estimate from their oceanographic monitoring website:

Space-based monitoring of a notorious bacteria in seafood that can cause illness in certain disease-prone diners. Right now threat levels are relatively low in the Gulf, which, presumably, means good times in New Orleans for oyster lovers.