Archive

Archive for May, 2010

New Altimetry & SST

May 31st, 2010 No comments

Figure 1.  Was happy to see today’s update of the altimetry from Colorado.  As usual, the large scale circulation patterns are well represented, with the partially separated Loop Current Eddy. Most of the Loop Current entering the Gulf then quickly turning east and out, with a smaller amount of that water making the full loop around the eddy.  At first I was interested in the northwest corner of this eddy, since the altimetry has a large bulge in this direction.  And the bulge and other circulation features (indicated with red arrows) in this region do appear to line up well with the NOAA forecast location of the oil spill shown as the thin black line.  Especially that strong jet to the southeast.  Also note the clockwise circulation feature observed in the altimetry between 89.5 W and 90 W.  Thats where the Navy gliders are operating (see figures below).

Figure 2.  But when I copy those red arrows drawn from the altimetry over Matt’s 3 day composite SST, it looks like the pure altimetry product is not correct in the region with the strong southeast jet.  The SST product has the loop current eddy further south. There also is a Horizon Marine drifter exactly in the path of the strong southeastward jet in the altimetry, and the drifter is barely moving.  Clearly a track by track assimilation into a model is going to give a better result than a pure statistical interpolation of altimeter tracks, and this is one example where it appears to make a difference.  It also highlights the need for additional assimilation data in this region, since altimetry carries a very strong weight in many assimilation schemes. In other highlights, it looks like RU21 is pulling out of the warmest water of the Loop Current Eddy and, looking downstream, pulling off to the left, while the Horizon Marine drifter is staying with the eddy and pulling off to the right. We hope the separation between these two continues to grow as we loop RU21 back onto the shelf.  The USF Glider Sam is finding 15 cm/sec currents to the southeast on the midshelf inshore of the warm filament.  Seaglider remains surveying the region near the Deepwater Horizon site.  More gliders are scheduled for tomorrow.

Figure 3. Here is one navy glider.

Figure 4. And the second Navy glider.

Tags:

Afternoon Update on RU21.

May 31st, 2010 No comments

Update on the RU21 surfacing.  I’ll save Oscar the trouble of posting it.

Here is a google earth and a snapshot of the tail message. CURRENTS are reduced to 40 cm/sec and turned a bit more to the east, now at 206 degrees. GLIDE speed is now 28 cm/sec, and heading is 106 degrees This is again good. The path is curving more towards the shelf, and currents are getting smaller and turning back east. Hope is that the currents continue to swing counterclockwise towards the east, and we can start marching the waypoint north.

The slight disparity in the heading continues, with google earth giving me 223 km at 99 degrees, the tail reporting 223 km at 103 degrees, and the speed calculations giving us 106 degrees.While I wish I could search down these differences, its actually a confidence builder in the Webb glider dynamics model used to estimate the depth averaged currents. A spread of just a few degrees on 3 independent calculations of direction is pretty good. This is a very cool undergraduate research topic for the summer. What causes the speed variations, minor direction differences, etc.

Very cool.  Its great being in the water.


Tags:

RU-21 Finds Filament again???

May 31st, 2010 No comments

This is a good sign that RU-21 is leaving the Loop Current. Looks like a sign of the fresh filament we saw earlier…

Tags:

Update and RU21 thoughts from Scott

May 31st, 2010 No comments

Reading through the back emails, the evolving plan for RU21 looks perfect. The current waypoint for RU21 is perfectly aligned to pull us out of the strong current and back onto the shelf. In google earth, clicking on the glider tail, the CURRENT is running 46 cm/sec towards 214 degrees. The glider is moving at a GLIDE speed of 33 cm/sec towards 117 degrees. The angle between the two is 97 degrees. This is the perfect situation – all the glider speed is being used to get us out of the strong jet to the south.

One question we seem to be uncertain about is how deep we are into this current. If we look at the HyCOM results, it may look like we are getting pulled in, but also note that the HYCOM forecast available to us in google earth has not updated since May 27.   And while the eddy is not going away in the model, the edges do change over time, and our questions concerns the edge. So lets check out some more up to date datasets.  The most up to date altimetry is from May 29. It says we are leaving the eddy already (clearly not the case) and will be entering a quiet zone, and then heading into an onshore current.  The features may be correct, but in the wrong locations.

Best bet for the most up to date locations are the sst. Attached is the most recent sst daily composite (May 30) from Matt. It has us right at the edge of the warm (orange) water front that is likely the outer edge of the loop current. If we keep flying perpendicular to this current, we will soon start to bend trajectory into the yellow region on the outer shelf.  is this region flowing onshore like in the altimetry?  or is it extending out in arcs from that meander impinging on the shelf farther south, we don’t know.
But the currents are likely much smaller than the Loop current, we have good glider speed,
and we will investigate another area of uncertainty on the way in. Maybe Matt has an enhanced version for this region?

I think we have a good waypoint. We can watch the currents evolve over the day, and move the waypoint as the currents turn. One interesting point to note, that the bearing to the waypoint looks to be reported at 105 degrees in the surface dialog, if you measure it in google earth, you get 100 degrees, and if you base it on how the glider is flying, you get 117 degrees. At least they are all in the same general direction, but a good thing to investigate further when things quiet down. That’s my 2 cents.  I think we are looking good this morning.

Thanks
Scott

Tags:

Memorial day morning glider update: May 31st

May 31st, 2010 3 comments

Five gliders are doing well this morning. The various regions show similar data patterns as yesterday. The 2 NAVO gliders and the iRobot Seaglider patrols in the northern Gulf, while USF SAM and Rutgers Ru21 patrol to the south offshore Florida.  Current plans has the U Delaware glider being deployed in southern Florida early this week.

The 2 NAVO gliders show patterns similar as yesterday.  There is enhanced CDOM with depth in their operations over Mississippi canyon.  The CDOM at depth does not appear to be extremely high. There does appear to be in the upper two hundred meters two distinct layers with a subsurface CDOM maximum at ~100 m.  My guess is that this is associated with chlorophyll maximum which is leading to local production.  We will contact our NAVO partners to see if we can have access to the temperature/salinity/chlorophyll data to confirm this.

Seaglider continues its survey and has encountered another deep CDOM signal.  This is of interest, and ship confirmation will be important.  This is especially true as the BP Chairman was skeptical about deep ocean oil plumes in the news yesterday. However the deep CDOM signal is of interest and was associated with some enhanced chlorophyll flourescene.  At that depth there should be no viable algae,  unless it is asscoiated big layer of sinking marine snow, which is unlikely.  So key goals in the early week will be to dig up some fluorescence excitation/emission matrices of hydrocarbons to assess if the enhanced chlorophyll fluorescence could actually be associated with hydrocarbons.

SAM appears to be making the turn, as the large eddy offshore Florida is providing a challenging region in which to fly.   The strong currents easily out-match glider flying speeds.  SAM is now heading onshore and it shows the similar enhanced particles  as RU21 saw on the shelf.  For SAM however there are two distinct layers.  One at depth and one at the chlorophyll maximum.  CDOM is higher at depth and it shows enhanced values at the chlorophyll maximum which resides just above the pycnocline.

For RU21, there has been much discussion, and effort, to break out of the eddy currents which are carrying it to the south and increasingly to the west.  Given the potentially long journey, we have decided to start limiting the optical data we collect to extend battery time and that these waters we have already sampled extensively and are not impacted by the spill.  The current scenarios for ru21, break out of the current and head back across the shelf.  This is the current plan.  If we do not, we need to get as close to the edge as possible, and we are to the south sneak into the loop currents to carry us east and then jump into Florida shelf waters.  The other scenario, not our desire, is we ride the eddy for a full revolution.  Next day should see how well we are are at getting out of the eddy currents.  As for the Ru21 data, it shows similar features as yesterday.  We see a highly stratified system, with a deepening pycnocline.  Associated with the pycnocline is enhanced chlorophyll and particles.  CDOM is highest at depth.

Tags:

History Repeats Itself

May 31st, 2010 No comments

History_Repeats_Itself_Oil_Spill_Version_Prose_Before_Hos

Tags:

BP CEO disputes claims of underwater oil plumes

May 30th, 2010 No comments

MATTHEW BROWN, Associated Press Writer

VENICE, La. – BP PLC CEO Tony Hayward on Sunday disputed claims by scientists that large undersea plumes have been set adrift by the Gulf oil spill and said the cleanup fight has narrowed to surface slicks rolling into Louisiana’s coastal marshes.

BP CEO Tony Hayward takes a first hand look at the recovery operations aboard the Discover Enterprise drill ship in the Gulf of Mexico 55 miles south of Venice, Louisiana on May 28. BP engineers scrambled Sunday to implement another high-risk plan to stem the devastating Gulf oil spill now being described as likely the worst environmental disaster in US history.… (AFP/Pool/File/Sean Gardner)

During a tour of a company staging area for cleanup workers, Hayward said BP’s sampling showed “no evidence” that oil was suspended in large masses beneath the surface. He didn’t elaborate on how the testing was done.

“The oil is on the surface,” Hayward said. “Oil has a specific gravity that’s about half that of water. It wants to get to the surface because of the difference in specific gravity.”

Scientists from several universities have reported plumes of what appears to be oil suspended in clouds stretching for miles and reaching hundreds of feet beneath the Gulf’s surface.

Those findings — from the University of South Florida, the University of Georgia, Southern Mississippi University and other institutions — were based on initial observations of water samples taken in the Gulf over the last several weeks. They continue to be analyzed.

One researcher said Sunday that their findings are bolstered by the fact that scientists from different institutions have come to similar conclusions after doing separate testing.

“There’s been enough evidence from enough different sources,” said Marine scientist James Cowan of Louisiana State University, who reported finding a plume last week of oil about 50 miles from the spill site that reached to depths of at least 400 feet.

Hayward said BP’s efforts are concentrated on fighting surface slicks.

At the company’s bustling Venice staging center, the embattled CEO tromped through the mud to inspect stacks of orange-colored booms being deployed to protect Louisiana’s fragile brackish marshes.

He said the company is pouring cleanup resources into Louisiana for a fight that could last months, and that the effort would continue until “every drop” of oil is cleaned up.

Hundreds of workers already are set up in “floating hotels” at the mouth of the Mississippi River, from where they can quickly respond to slicks of crude once they are spotted in the marshes, Hayward said.

An estimated 18 to 40 million gallons of oil have been unleashed since BP’s Deepwater Horizon platform exploded and sank last month, killing 11.

Tags:

Glider status on morning of May 30

May 30th, 2010 No comments

The morning finds the glider fleet moving well.  Overall all five gliders are surveying their respective zones effectively.  Discussion will ramp up after the Memorial day weekend on not only piloting the gliders in the water but also plans of where to deploy the new gliders in the coming week.  We expect that Scripps, Rutgers, and U Delaware gliders to join the effort next week, and deciding where to deploy will be a big focus.  Depending on repairs perhaps Waldo and BASS will return, depending on the ongoing efforts to reconcile the issues encountered last week.

The NAVO gliders (blue dot indicates their area of operations in the map above) continue their survey over Mississippi canyon.  Not many changes from the analysis from yesterday, with enhanced CDOM at depth.  The values slightly higher then the Florida gliders, however they are collecting data deeper, so it is difficult to assess whether these values are anomalous.

Looking at Seaglider we see good progress.No more deep water CDOM anomalies and confirmation will be interesting.  The enhanced CDOM at depth was also associated with enhanced chlorophyll fluorescence. Regardless the Seaglider shows the greatest depth-depend variability of the other four glider systems, which given its proximity to the spill will be a big area of focus in the coming week.  The ship data will be invaluable.

SAM is flying well.  The general features show a stratified system with a chlorophyll maximum at the thermocline and CDOM values enhanced in the bottom waters.

RU21 is definetely entrained in the eddy, encountering strong southerly flows.  The glider has ~18 days of battery left using all instruments.  Also given that data within the eddy will nt be useful for this mission, the glider has been given a waypoint east.  The glider should fight its way out the eddy, and we will conduct shelf line.  The data snapshots this morning are not much different then as we saw yesterday.  Particle load, shows a maximum associated with the pycnocline  but values are lower than was encountered  on the shelf.  CDOM values lower in bottom waters below the pycnocline. We track the progress of ru21 over the next day to see the progress getting out of the eddy edge.

Tags:

Morning Spatial Analysis – May 30, 2010

May 30th, 2010 No comments

Figure 1. The most up to date spatial data I have this morning are the Sea Surface Temperature maps, so we’ll stick with these for now.  This figure is the 3-day composite showing the extent of the warm Loop Current Eddy.  This large eddy extends well onto the Florida Shelf between 25 N and 27 N.  To the North of this, a warm filament extends out to the northwest along the inshore side of the shelfbreak. To the South, the cooler Florida Shelf water is being pulled off the shelf and around the southern side of the eddy.  In the shallow coastal waters around Louisiana, we see a lot of warming.

Figure 2: Here we zoom into the seaglider track, along with one of the Horizon Marine drifters.  Seaglider 515 is just west of the incident site, conducting a spatial survey.  The Horizon Marine drifter if heading east in the region of this survey.

Figure 3. The Horizon Marine drifters tell a major part of the story here. The drifter near the Seaglider 515 and the Deepwater Horizon site is moving east, the two drifters to the west are heading west, one along the white line indicating the shelf break, another further inshore that appears to be following the temperature break between the warmest inner shelf waters in red and the yellow/orange colors of the rest of the shelf.  North of the Deepwater Horizon site, one Horizon Marine drifter is heading in to the northwest in a series of loops.  Just outside the NOAA forecast oil spill location to the east, another drifter is now heading south, away from the Florida panhandle coast.

Figure 4.  We now slide the image south to the portion of the Florida shelf near the Loop Current Eddy intrusion.  To the north is USF Glider Sam. It surveying the base of the warm filament that extends northwest along the shelf break.  It is just on the warm side, experiencing strong currents to the southeast.  It is heading across the front into the cooler shelf water.  It will give us a good look at this side of the filament.  Further south, glider RU21 is now in the Loop Current eddy and is rapidly moving south in a >70 cm/sec current.  We are in the process of turning RU21 perpendicular to this current to move this glider back into the cooler and slower waters of the Florida shelf.  As we cross back in and head onshore, RU21 will survey the base of the cold filament that is being pulled around the southern side of the Loop Current Eddy.

The gliders are in good positions.  USF & RU21 surveying the base of  the two major interactions of the Loop Current with the shelf, Seaglider 515 in the immediate vicinity of the incident site, and the NAVO gliders reported in the previous posts further to the southwest of the site.

Tags:

How-to stop oil leak – from DeepWater Horizon Oil Spill visitor

May 29th, 2010 13 comments

Look over my design on how to crush the casing to stop the leak. See drawing attached. This will crush the casing to stop the flow of oil. The leak we are being showed is very small to the one at the end of the casing. They don’t wont us to see that one. It’s much larger. The C-Clamp smasher is very easy to build and install with ROV help. Please forward to who ever could help me get this in the Wright hand to see how important this matter really is. I work for a major wellhead company in Corpus Christi and this is the kind of problem’s I deal with. Coming up with the answer to fix major issues or customer are having with their well. This will work.

Randy McMullin

Randymac37@yahoo.com

361-945-3408

Please forward to anyone who could help get this going. Our water and beaches need to be saved. And soon

Tags: