Loop Current Eddy cuts off; oil danger to Keys now greatly reduced

By: Dr. Jeff Masters , 2:24 PM GMT on May 28, 2010

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A major ocean current re-alignment is underway the Gulf of Mexico right now, and the new configuration that is developing greatly reduces the threat of oil entering the Loop Current and affecting the Florida Keys and U.S. East Coast. As I explain in my Loop Current Primer, 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 past the western Bahamas. Here, the waters of the Loop Current flow northward along the U.S. coast and become the Gulf Stream. With current speeds of about 0.8 m/s, the Loop Current is one of the fastest currents in the Atlantic Ocean. Every 6 - 11 months, the top bulge of the Loop Current cuts off, forming a 250-mile diameter circular eddy in the middle of the Gulf of Mexico. This clockwise-spinning eddy is filled with warm water from the Loop Current, and is called a Loop Current Eddy. The main body of the Loop Current then takes a fairly direct eastward path from the Yucatan Channel to the Florida Keys.

Over the past two days, surface currents in the Gulf of Mexico have aligned to form a Loop Current Eddy, as seen in the analysis of surface currents done by the U.S. Navy (Figure 1, and see also a 30-day animation of the eddy forming.) It remains to be seen if the deep water currents have followed suit, and a stable Loop Current Eddy cannot exist until the deep water currents also cut off into a clockwise-rotating ring of water at depth. A NOAA Hurricane Hunter aircraft is out over the Gulf of Mexico today dropping expendable buoys and current probes to determine if a stable Loop Current Eddy has formed. Roffer's Ocean Fishing Forecast Service has a nice discussion on the Loop Current Eddy formation.


Figure 1. Comparison of surface currents in the Gulf of Mexico on May 19 (top) and May 27 (bottom) as simulated by the HYCOM model. On May 19, the Loop Current made a large northward loop into the Gulf, and was able to transport oil from the near the spill location southwards through the Keys. By May 27, this loop had cut off, and new oil moving southwards from the spill will now be trapped in the clockwise rotating Loop Current Eddy that is cut off from the Loop Current. Note on the west side of the Gulf of Mexico, off the coast of Texas, there is an old Loop Current Eddy that cut off from the Loop Current in July 2009. This eddy cut off in the same location as this week's eddy, and has drifted west-southwestward at 3 - 5 km per day over the past ten months. Image credit: U.S. Navy.

If the eddy does remain in place, it will greatly reduce the chances of oil making it to Cuba, the Florida Keys, and beyond. Any oil moving southwards from the spill location will now become entrained in the eddy, and will move in a 250 mile-wide clockwise circle in the east-central Gulf of Mexico. A small portion the oil will get shed away from the eddy's periphery and make it into the Loop Current and waters surrounding the eddy, but the concentrations of oil doing so will be small. Keep in mind, though, that during the first 1 - 2 months that a Loop Current Eddy forms, it is common for the eddy to exchange substantial amounts of water with the Loop Current, and in some cases get re-absorbed into the Loop Current. A 1-year animation of the Loop Current shows that the last Loop Current Eddy, which cut off in mid-July 2009, experienced a 2-week period in early August when it re-attached to the Loop Current. A significant portion of any oil entering the eddy during a period of re-attachment will be able to enter the Loop Current and flow past the Keys.

One bad result of the eddy breaking off is that now we have an extra source of heat energy for passing hurricanes during the upcoming hurricane season. Loop Current eddies have high-temperature water that extends to great depth, and hurricanes passing over such eddies often undergo rapid intensification. Hurricanes Katrina and Rita of 2005 both underwent rapid intensification as they passed over warm Loop Current eddies in 2005. The formation of a Loop Current Eddy during hurricane season means that a much greater portion of the Gulf of Mexico has deep, warm water capable of fueling rapid intensification of hurricanes.

Oil spill update
Light offshore northwesterly winds are expected to blow over the northern Gulf of Mexico today through Saturday, resulting decreased threats of oil to the Louisiana shore, according to the latest trajectory forecasts from NOAA. These offshore winds may be able to transport oil southwards into the Loop Current Eddy that just formed; a streamer of oil moving southeastward into the Loop Current Eddy is visible in yesterday's NASA MODIS imagery (Figure 2). Winds will shift to onshore out of the south on Saturday night, then shift to southwesterly by Tuesday. The long-range forecast from the GFS model indicates continued southwesterly winds all of next week. If this forecast verifies, we will see our greatest chances yet of significant amounts of oil reaching the beaches of Mississippi, Alabama, and the Florida Panhandle.


Figure 2. Visible satellite image of the Gulf of Mexico taken at 2:55pm EDT Thursday May 27, 2010, by the MODIS instrument on NASA's Aqua satellite. Thin streaks of oil can be seen moving southeast and then southwest around the eastern side of the new Loop Current Eddy. Image credit: NASA.

Oil spill resources
My post, What a hurricane would do the Deepwater Horizon oil spill
My post Wednesday with answers to some of the common questions I get about the spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
NOAA trajectory forecasts
Deepwater Horizon Unified Command web site
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Surface current forecasts from NOAA's HYCOM model
Synthetic Aperture Radar (SAR) imagery from the University of Miami

Central American disturbance
The Atlantic is currently quiet, with none of our reliable global forecast models predicting tropical cyclone development over the next 6 days. There is an area of disturbed weather (90E) just off the Pacific coast of Mexico that will be a major concern for southern Mexico and much of Central America over the next 3 - 4 days. The disturbance will bring heavy rains to Central America during the weekend, potentially bringing serious flooding rains to portions of Mexico, Guatemala, El Salvador, Honduras, and Nicaragua. NHC is giving the disturbance a high (>60% chance) of the disturbance developing into a tropical depression by Sunday. Wunderbloggers Weather456 and StormW have more on the tropics.


Figure 3. Satellite image of the Central American disturbance 90E this morning.

Join the "Hurricane Haven" with Dr. Jeff Masters: a new Internet radio show
Beginning next week, I'll be experimenting with a live 1-hour Internet radio show called "Hurricane Haven." The show will be aired at 4pm EDT on Tuesdays, with the first show June 1. Listeners will be able to call in and ask questions. Some topics I'll cover on the first show:

1) What's going on in the tropics right now
2) Preview of the coming hurricane season
3) How a hurricane might affect the oil spill
4) How the oil spill might affect a hurricane
5) New advancements in hurricane science presented at this month's AMS Conference on Hurricanes and Tropical Meteorology
6) Haiti's vulnerability to a hurricane this season

I hope you can tune in to the broadcast, which will be at http://www.wunderground.com/wxradio/wubroadcast.h tml. If not, the show will be recorded and stored as a podcast.

I'll be back with at least one update over the coming 3-day Memorial Day weekend. Have a great holiday!

Jeff Masters

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Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting leo305:


No what I'm saying is an area of high pressure is forecasted to move towards the North west carribean, wouldn't that prevent 90E from moving towards the EAST towards the area of high pressure, since a high tends to push Lows around them or away from them. Which is why some models have 90E moving over the yucatan and not the carribean


You said an area of surface high pressure. Steering from a high pressure would have to be a high aloft.
Member Since: August 19, 2006 Posts: 0 Comments: 15948
Okay, looking at BOA Deep 2's feed, I'm not so worried. It clearly shows the top of the BOP, and the bent riser, and no other leaks from further down. Man, it sure looks like they've got the pressure jacked way up though on that mud!
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AOI

AOI

AOI

AOI

Humour in Comments
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Quoting kmanislander:


Don't underestimate what mountainous terrain can do to even the strongest of storms. Mitch was a Cat 5 sitting over Roatan island just offshore Honduras and once it went ashore it spun down fairly quickly and became a rainmaker that killed thousands.

I would expect the circulation to decouple over the Guatemala terrain that has mountains over 8000 feet
I can agree with that.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
702. IKE
T. Boone Pickens: Stop to the Gulf oil leak probably not happening soon

08:03 AM CDT on Wednesday, May 26, 2010

By CHERYL HALL / The Dallas Morning News
cherylhall@dallasnews.com

Accidents happen, T. Boone Pickens says. Some are just more monumental than others.

If the legendary oilman were President Barack Obama , he'd fly to the gulf, meet with the top executives of BP and offer his complete support.

"I'd get my boot off their throats and out of their way. I'd tell them we'd assess blame after the problem was fixed. I'd tell them it's OK to take risks to get this cleaned up – now."

But if we're expecting that fix anytime soon, we may be disappointed, he says.

"There are a lot of people working on this, and someone might find an answer. But I think this may take three months, and you're going to see it every night on the evening news," Pickens says.

Pickens, who makes it his business to know what's going on at top levels of the industry, says BP is doing everything in its power to find a solution and has tied up the entire inventory of amphibious equipment in the gulf that can operate in deep waters. "The thing I'd worry about is a traffic jam."

He's not ready to judge whether BP's contingency plan was inadequate. He hasn't seen it.

"But my God, this was a 100-year storm. I don't know how you prepare for that."
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Quoting MiamiHurricanes09:
Well I think it depends on how strong it is. If 90E can strengthen then it should be deep enough to move to the Caribbean. If steering currents persist 90E should go over Guatemala and then Belize and obviously into the Caribbean.

999-990 MSLP Steering Currents


Don't underestimate what mountainous terrain can do to even the strongest of storms. Mitch was a Cat 5 sitting over Roatan island just offshore Honduras and once it went ashore it spun down fairly quickly and became a rainmaker that killed thousands.

I would expect the circulation to decouple over the Guatemala terrain that has mountains over 8000 feet
Member Since: August 19, 2006 Posts: 0 Comments: 15948
Quoting kmanislander:


A surface high would curtail convection. You need low pressure at the surface and high pressure aloft to help a system spin up. Steering winds are not surface winds.


No what I'm saying is an area of high pressure is forecasted to move towards the North west carribean, wouldn't that prevent 90E from moving towards the EAST towards the area of high pressure, since a high tends to push Lows around them or away from them. Which is why some models have 90E moving over the yucatan and not the carribean
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Can somebody please explain this? The CSM reports:

"EPA girds for a fight with BP over dispersants in Gulf oil spill

The Obama administration's frustration with BP over the dispersant issue has been mounting since this weekend. By Sunday, it had become clear that BP would not heed an EPA directive to find an alternative to Corexit, the dispersant that the EPA rates as less effective and more toxic than as many as 12 other products. "


So I private corporation is telling our elected representatives to go to hell and they get away with it? I dont get it.
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From earlier
Quoting wunderkidcayman:
... WHAT IS THE P-3 HURRICANE HUNTER WAS DOING PARKED AT THE PARKING AREA RIGHT BY THE MET OFFICE


Telegraph.co.uk


The United States has strongly supported the operation, however, providing flak jackets for troops and police, and surveillance assistance in the shape of P-3 Orion aircraft.

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storms begining to move towards south and central west FL,both sea breezes colliding,hoping for somefun wx in my area!!
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Quoting photomunkey:
Why so much pressure from this well? Did they tap an unknown geothermal process which is now pressurizing the oil/natural gas resevoir? Those pressure are simply amazing to be blowing out that hard into 2500 PSI sea water!


Oil deposits generate natural gas over time. Ever shake up a soda?
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Quoting leo305:
A surface area of high pressure is expected to move into the NW carribean the next couple of days? Could that stop 90E from moving towards the carribean?


A surface high would curtail convection. You need low pressure at the surface and high pressure aloft to help a system spin up. Steering winds are not surface winds.
Member Since: August 19, 2006 Posts: 0 Comments: 15948
Why so much pressure from this well? Did they tap an unknown geothermal process which is now pressurizing the oil/natural gas resevoir? Those pressure are simply amazing to be blowing out that hard into 2500 PSI sea water!
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Quoting kmanislander:


Not at this time. Whether it or any part of it makes it into the NW Caribbean remains to be seen but a traverse over the mountains would seriosuly disrupt the circulation. It would have to regroup in the Gulf of Honduras
Well I think it depends on how strong it is. If 90E can strengthen then it should be deep enough to move to the Caribbean. If steering currents persist 90E should go over Guatemala and then Belize and obviously into the Caribbean.

999-990 MSLP Steering Currents
Member Since: September 2, 2009 Posts: 130 Comments: 21194
691. IKE
Quoting asgolfr999:


If that's as constructive as you can get with your comments, I for one would just as soon you took my old dad's advice. If you can't say something nice...shut up!

We, down here in the middle of this mess would like you all to know that you can have BP and everyone else you want to hang AFTER they have stopped this thing, til then, help or get out of the damn way.


I'm in the Florida panhandle. Oil hasn't reached the coast here yet. It's just a matter of time until it does. Weeks...maybe days and it will.

Best bet is the relief wells. Til then...I think it's just a shot in the dark. I hate to say that and be negative, but, that's how I feel.

I hope I'm proven wrong.
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A surface area of high pressure is expected to move into the NW carribean the next couple of days? Could that stop 90E from moving towards the carribean?
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They stuck an ROV arm with a tool on it over on the right side and did something, and now the lower leak from the right appears to be doing much better. The BP website feed has a better camera angle. Different camera on the same ROV I believe.
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Quoting Hurricanes101:
Can a system still get classified with an elongated center as long as it is completely closed?


One would have to suppose; classification is based on performance more than shape. The likelihood of a less than circular system maintaining the requirements without bcoming circular are pretty low though, I'd have to guess
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Quoting FIU2010:
kman, is 90e a caymen threater?


Not at this time. Whether it or any part of it makes it into the NW Caribbean remains to be seen but a traverse over the mountains would seriosuly disrupt the circulation. It would have to regroup in the Gulf of Honduras
Member Since: August 19, 2006 Posts: 0 Comments: 15948
I dont think next NHC report will declare 90E a TD but tomorrow yes.
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Me neither Ike.
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RE: 677

Thats depressing.
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682. IKE
Quoting lickitysplit:
Tony Hayward is saying that 'everything is going to plan'.

Interesting. At the same time he called this a 'natural disaster'.

Now...how stupid does he think we are?


I don't believe a word that guy says.
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Quoting leo305:


I guess they need to inject mud at a higher pressure then.. if that's true.. but if they do that, the pipe may burst.. so it looks like this isn't going to work


How do you know it will burst...your math workings please.
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From the Oil Drum:

"There is a new leak farther down on the BOP. They have blown a hose or a seal is leaking or one of the pipes associated with the LMRP has sprung a new leak. This is a new source IMO too steady new location just out of camera shot lower right. "
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Quoting DentalPainDMD:
CNN just hinted that BP delayed revealing ops stopped yesterday by 16 hrs b/c of concerns over stock price. I bet the call it quits now that the markets are about to close (and a nice long wkend)


If that's as constructive as you can get with your comments, I for one would just as soon you took my old dad's advice. If you can't say something nice...shut up!

We, down here in the middle of this mess would like you all to know that you can have BP and everyone else you want to hang AFTER they have stopped this thing, til then, help or get out of the damn way.
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Quoting lickitysplit:
NYT:

"...despite the injections at various pressure levels, engineers had been able to keep less than 10 percent of the injection fluids inside the stack of pipes above the well. "


I guess they need to inject mud at a higher pressure then.. if that's true.. but if they do that, the pipe may burst.. so it looks like this isn't going to work
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In any event 90E is fairly well organized at the surface. If the cloud pattern improves it could get classified later today IMO
Member Since: August 19, 2006 Posts: 0 Comments: 15948
NYT:

"...despite the injections at various pressure levels, engineers had been able to keep less than 10 percent of the injection fluids inside the stack of pipes above the well. "
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Can a system still get classified with an elongated center as long as it is completely closed?
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Tony Hayward is saying that 'everything is going to plan'.

Interesting. At the same time he called this a 'natural disaster'.

Now...how stupid does he think we are?
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Quoting Drakoen:


Looks like a closed low to me in that ASCAT pass. Completely circular
Me too.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Ambiguity


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Quoting nrtiwlnvragn:


Looks elongated NE to SW to me.







Link


I agree with that but satellite and IR imagery shows the system becomming much more circular.
Quoting kmanislander:


I thought that at first too but then saw that to the SSW from the dead center there appears to be a wind convergence line where you would expect to see only winds with a Westerly component. It may well be that the convergence line is early stage organization. It's as good as closed.


We can't forget that part of this system is connected to the ITCZ. This image shows it a little better with the convergence line along the equatorward band of the system but a circular core. You can also see converging winds on the northern side of the system. A good sign.

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Quoting nrtiwlnvragn:


Looks elongated NE to SW to me.







Link


That's what I meant
Member Since: August 19, 2006 Posts: 0 Comments: 15948
Quoting CycloneOz:


My webcam system design is "current"ly running directly DC to DC. It is a very safe and stable design, as I'm proving as we speak! :)


You're always better running delicate electronics off battery power; make sure you have spares and run your batteries all the way out occasionally,. Newer battery technology avoids "board error" under charges, but it always a good idea to drain the battery from time to time
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yea same here, looks elongated too
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Quoting Drakoen:


Looks like a closed low to me in that ASCAT pass. Completely circular


Looks elongated NE to SW to me.







Link
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Quoting Drakoen:


Looks like a closed low to me in that ASCAT pass. Completely circular


I thought that at first too but then saw that to the SSW from the dead center there appears to be a wind convergence line where you would expect to see only winds with a Westerly component. It may well be that the convergence line is early stage organization. It's as good as closed.
Member Since: August 19, 2006 Posts: 0 Comments: 15948
Quoting IKE:


From the article that was linked...

"“I won’t say progress was zero, but I don’t know if we can round up enough mud to make it work,” the technician said. “Everyone is disappointed at this time.”"......


That doesn't sound very encouraging. Just my personal opinion...it isn't working. Maybe that will change.


Yeah, not having enough mud would be a pretty serious issue...
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660. IKE
Quoting Floodman:


The guy that "leaked" the current shut down said they had maintained about 10% of the drilling mud in column...

My understanding was that this wasn't going to be a continuous process and that they were going to stop the process every now and again to recheck pressures and reassess the condition of the pipes and BOP


From the article that was linked...

"“I won’t say progress was zero, but I don’t know if we can round up enough mud to make it work,” the technician said. “Everyone is disappointed at this time.”"......


That doesn't sound very encouraging. Just my personal opinion...it isn't working. Maybe that will change.
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Quoting kmanislander:


Look at the South side of the center. Not truly closed off


Looks like a closed low to me in that ASCAT pass. Completely circular
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658. JLPR
Quoting wunderkidcayman:
sorry forgot the link
Link


use the eastern east pacific one, its closer XD
Link
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Quoting IKE:


Translated into plain English.....the truth...it isn't working.


The guy that "leaked" the current shut down said they had maintained about 10% of the drilling mud in column...

My understanding was that this wasn't going to be a continuous process and that they were going to stop the process every now and again to recheck pressures and reassess the condition of the pipes and BOP
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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