Oil enters the Loop Current and is headed to the Florida Keys
Satellite imagery today from NASA's MODIS instrument confirms that a substantial tongue of oil has moved southeast from the Deepwater Horizon oil spill and entered the Gulf of Mexico's Loop Current. The Loop Current is an ocean current that transports warm Caribbean water through the Yucatan Channel between Cuba and Mexico. The current flows northward into the Gulf of Mexico, then loops southeastward just south of the Florida Keys (where it is called the Florida Current), and then along the west side of the western Bahamas. Here, the waters of the Loop Current flow northward along the U.S. coast and become the Gulf Stream. Once oil gets into the Loop Current, the 1 - 2 mph speed of the current should allow the oil to travel the 500 miles to the Florida Keys in 10 - 20 days. Portions of the Loop Current flow at speed up to 4 mph, so the transport could be just 4 - 5 days. It now appears likely that the first Florida beaches to see oil from the spill will be in the Lower Florida Keys, not in the Panhandle.
Figure 1. Satellite image of the oil spill taken at 12:40 EDT Monday May 17, 2010. The location of the Loop Current is superimposed. Image credit: University of Wisconsin and NASA.
Why is oil getting into the Loop Current?
The winds over the oil spill location are offshore out of the northwest today, and offshore winds will continue intermittently through Wednesday, which should allow a substantial amount of oil to enter the Loop Current. The major reason oil is moving southwards is because of the instability of the currents in the Gulf of Mexico. The Loop Current is not a stable feature, and tends to surge northwards and southwards in a chaotic fashion, and in response to changes in the prevailing winds. Over the past week, chaotic behavior of the Loop Current and a clockwise-rotating eddy just to its north, just south of the oil spill location, have combined to bring a current of southward-moving surface water to the oil spill location. As strong on-shore winds from the southeast slackened this past weekend, oil has been drawn southward into the Loop Current. The latest NOAA trajectory forecasts failed to anticipate the movement of the oil into the Loop Current. The latest surface current forecasts from NOAA's HYCOM model show that oil could continue pouring into the Loop Current for most of the rest of the week. It is highly uncertain how diluted the oil might get on its voyage to northwestern Cuba and the Florida Keys this week, but the possibility for a major ecological disaster in the fragile Keys ecosystem cannot be ruled out. Southeast to east winds of 10 - 15 knots are expected to develop late this week and extend into early next week, which may be strong enough to impose a surface current that will shut off the flow of oil into the Loop Current by Friday or Saturday.
Figure 2. Forecast made at 8pm EDT Sunday May 16, 2010, of the Gulf of Mexico currents by NOAA's HYCOM model. A persistent southward flowing surface current is predicted to occur this week between the oil spill location (red dot) and the Loop Current. Image credit: NOAA.
Likely areas of impact
Based on a study of 194 floating probes released into the Northeast Gulf of Mexico during a 1-year study in the 1990s (Figure 3), the west coast of Florida from Tampa Bay southwards to the Everglades is at minimal risk of receiving oil from surface currents. There is a "forbidden zone" off the southwest Florida coast where the shape of the coast, bottom configuration, and prevailing winds all act to create upwelling and surface currents that tend to take water away from the coast. This study implies that the greatest risk of land impacts by surface oil caught in the Loop Current is along the ocean side of the Florida Keys, and along the coast of Southeast Florida from Miami to West Palm Beach. Eddies breaking away from the Gulf Stream would also likely bring oil to northwest Cuba, the western Bahamas, and the U.S. East Coast as far north as Cape Hatteras, North Carolina, though at lesser concentrations. Southwest Florida cannot rest entirely, though--the "forbidden zone" is only true for surface waters, and there is onshore flow below the surface. Since recent ship measurements have detected substantial plumes of oil beneath the surface, southwest Florida might be at risk if one of these plumes gets entrained into the Loop Current. These subsurface plumes were also detected by current probes launched into the oil spill on May 8 by one of NOAA's hurricane hunter aircraft, according to one scientist I spoke to at last week's AMS hurricane conference. There are plans for the Hurricane Hunters to go out again tomorrow and drop more probes into the spill to attempt to get a better handle on where the oil is and where the currents are taking it.
Figure 3. Paths of 194 floating probes released into the yellow-outlined area in the northeast Gulf of Mexico between February 1996 and February 1997 as part of a study by the Mineral Management Service (MMS). The probes were all launched into waters with depth between 20 and 60 meters. Image credit: Yang, H., R.H. Weisberga, P.P. Niilerb, W. Sturgesc, and W. Johnson, 1999, Lagrangian circulation and forbidden zone on the West Florida Shelf, Continental Shelf Research Volume 19, Issue 9, July 1999, Pages 1221-1245 doi:10.1016/S0278-4343(99)00021-7
When will a Loop Current eddy break off?
Every 6 - 11 months, the looped portion of the Loop Current cuts off into a clockwise-rotating ring of water that then slowly drifts west-southwest towards Texas. When one of these rings breaks off at the peak of hurricane season, it provides a source of heat energy capable of providing fuel for rapid intensification of any hurricanes that might cross over. The Loop Current is not predicted to shed an ring over the next month, as predicted by the latest 1-month forecast from the U.S. Navy. However, the last eddy broke off in July of 2009, ten month ago, and it is unusual for the Loop Current to go more than eleven months without shedding an eddy. I expect we'll see the Loop Current shed an eddy in July or August, just in time to pose the maximum threat for hurricane season. According to an interesting February 2004 article published by offshore-engineer.com, reliable forecasts of these currents and eddies are not available yet. Keep in mind that surface currents are largely driven by winds, and wind forecasts are not reliable out more than about 10 days.
References
Yang, H., R.H. Weisberga, P.P. Niilerb, W. Sturgesc, and W. Johnson, 1999, Lagrangian circulation and forbidden zone on the West Florida Shelf, Continental Shelf Research Volume 19, Issue 9, July 1999, Pages 1221-1245 doi:10.1016/S0278-4343(99)00021-7.
Oil spill resources
NOAA trajectory forecasts
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Surface current forecasts from NOAA's HYCOM model
HYCOM ocean current forecasts from LSU
Jeff Masters
Reader Comments
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NEXSAT, Das Oil Plume
ok, the genesis of warm seclusion are the same for both phase though. I do not think this will be a warm seclusion.
.. also great post Dr. Masters!
Quoting JamesSA:
How do you interpret this "feature" streaming to the southeast from that oil spill?
It could be a thin rainbow sheen film on the surface reflecting the sun glint.
But, if you enlarge the photo and examine i closely, it appears to be showing an UNDERWATER plume of dispersant laden oil that has been picked up the loop current. That would be a much more serious development.
Any thoughts on this?
In looking at the image you posted and the links to much larger images of the same area posted by PAt (Thanks, Pat!) it sure doesn't look like "sheen", at least not at the SE portion of the plume...
It's not baroclinically driven when the surface low is stacked directly beneath the 500mb low.
Most of the cooler 850mb temps in the region are a reflection of the surface temps which are cooler due to cooler SSTs. Earlier maps, such as at 168 hours, show no such appearance of cold advection on the western side:
Careful! You might get misinterpreted! LOL
If you look at the Gulf Stream Loop......at the North end it would follow that SE turn as the picture shows look at the loop below...
Pfffttt...
The GFS convinces me of warm seclusion. The ECMWF is more subtropical in nature after looking over Levi's post in the previous blog. The surface low is vertically stacked under the 500mb low and the horizonal temperature gradient is neglible.
oh boy... Its total devestation.
Thanks, Doc.
The doc said 7-10 days 4-5 days at the least.
ok....By looking the rainfall patterns, isobar spacing and temperature contrast and wind profile, I do not think it will be a warm seclusion.
Could you discuss what the models are showing with the potential hybrid low?
Here is the "looking ahead" part of the latest San juan NWS discussion, I found it interesting and the last sentance even made me smile :
LOOKING AHEAD...STILL APPEARS THAT BRIEF OVERALL DRYING "MAY"
OCCUR FOR THE SECOND PART OF WEDNESDAY THROUGH EARLY THURSDAY...
BEFORE MOISTURE INCREASES AGAIN LATER THURSDAY THROUGH FRIDAY AND
BEYOND...WITH THE "POTENTIAL" FOR AT LEAST A COUPLE MORE DAYS OF
ACTIVE WEATHER AND "POTENTIAL" HEAVY RAINFALL AND FLOODING...
ESPECIALLY AS WE TRANSITION INTO LATE IN THE WEEK AND THE UPCOMING
WEEKEND. IT IS MAY IN THE NORTHEAST CARIBBEAN. STAY TUNED.
Promising. Things will need to be monitored for possible rain events.
Otherwise, bad news regarding the oil spill. Poor ecosystems (coral reefs, fishes, birds...)..nature is constently being hammered nowadays.. SAD!
yes i already fixed it to say 4-20
This does not look good for the FL Keys and East Coast....
Taco :o)
BP has got lotsa' splainin' to do!!
no worries, I wasnt sure you saw it.
Get used to saying that... especially this season...
or..
not talk about it at all
Yes, some of the blame goes on us for using the stuff, but BP and the other drillers putting these wells in with no plan "B" in the event that something like this would happen should be tried for crimes against humanity. What happens if/when the worst case scenario comes to pass and everything from Louisiana to South Carolina is covered light GOM crude? How long before this stuff is cleaned up, given that it can on such a tremendous scale?
Not too surprising...
CycloneOz is headed toward Clovis,NM to meet with TornadoDude's team. A joint chase to find severe weather outbreaks will ensue. Stay tuned to Xtremehurricanes.com around 6pm CDT / 7pm EST.
As an avid fishing person that owns a boat, i am really pissed right now.....really! I can't put into words how upset i am!
I wasnt joking, I live on the east coast of Florida. You are not the blog police.
Statement as of 2:13 PM EDT on May 17, 2010
This is a corrected message to revise a coordinate.
The National marine fisheries service announces a revised closed
area for all commercial and recreational fisheries in the portion of
the Gulf of Mexico affected by the Deepwater horizon oil spill... due
to the evolving nature of the oil spill. The revised closure is
effective may 17 2010 at 6 p.M. Eastern time and supersedes the
closed area announced on may 14 2010. The closed area coordinates
begin from the point where 30 degrees 01 minutes north latitude
intersects with the three nautical mile Louisiana state
boundary... proceeds southeast to 29 degrees 50 minutes north and 88
degrees 14 minutes west... then east to 29 degrees 50 minutes north
and 87 degrees 28 minutes west... then southeast to 29 degrees 27
minutes north and 86 degrees 31 minutes west... then southwest to 28
degrees 29 minutes north and 87 degrees 17 minutes west... then
southeast to 27 degrees 55 minutes north and 86 degrees 30 minutes
west... then southwest to 27 degrees 21 minutes north and 86 degrees
40 minutes west... then northwest to 27 degrees 48 minutes north and
88 degrees 48 minutes west... then northwest to 28 degrees 35 minutes
north and 89 degrees 35 minutes west... then west to 28 degrees 40
minutes north and 91 degrees 00 minutes west... then north to where
91 degrees 00 minutes west longitude intersects with the three
nautical mile Louisiana state boundary... then along the seaward
limit of Louisiana's waters. Questions should be directed to the
National marine fisheries service at 727-824-5305.
Simply put.......there is no way that all of this oil is coming from just that one pipe on video......NO WAY!
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