How oil might affect a hurricane
There's no major changes to the forecast for the Gulf of Mexico oil spill. As I discussed in yesterday's post, on Sunday, the winds will begin increasing and shifting to the southeast. The latest run of the GFS model shows that this will be a week-long period of southeast winds, with wind speeds at times reaching 20 - 25 knots. These winds will threaten to bring oil to a large portion of the Louisiana coast, including regions of the central Louisiana coast west of the mouth of the Mississippi River. The Mississippi and Alabama coasts will also be at risk next week, but the risk to the Florida Panhandle is lower. Yesterday's post also has the long-range outlook for oil to get into the Loop Current and spread to the Florida Keys and beyond.
What will oil in the Gulf of Mexico do to a hurricane?
With hurricane season fast approaching and the oil spill in the Gulf of Mexico likely to still be around once hurricane season starts in June, we need to ask, how will oil affect any hurricanes that might traverse over the spill? And how might a hurricane's wind and storm surge affect the spill? Let's consider the first of those questions today.
From the time of the ancient Greeks to the days of the wooden ships and iron men, mariners dumped barrels of oil onto raging seas to calm them during critical moments of violent storms (Wyckoff, 1886.) Oil does indeed calm wind-driven waves, thanks to the reduction in surface tension of the water that oil causes. Ripples with a wavelength shorter than 17 mm are affected by surface tension, and these ripples then cause a feedback that reduces the height of larger waves with longer wavelengths (Scott, 1986.) The reduction of surface tension also impacts the flow of air above the water, and reduces the amount of sea spray thrown into the air, both of which could affect the wind speed. Oil also damps waves by forming a thick, viscous film at the top of the water that resists water motion (Scott, 1999.) Oil also helps calm raging seas by switching off of the wind energy input needed by the wave to break. This occurs because the surface film of oil prevents the generation of ripples on the exposed crests of the waves, and this smoother surface makes the wind less able to grab onto the wave and force it to break.
So, what would happen to a hurricane that encounters a large region of oily waters? A 2005 paper by Barenblatt et al. theorize that spray droplets hurled into the air by a hurricane's violent winds form a layer intermediate between air and sea made up of a cloud of droplets that can be viewed as a "third fluid". The large droplets in the air suppress turbulence in this "third fluid", decrease the frictional drag over the ocean surface, and accelerate the winds. According to this theory of turbulence, oil dumped on the surface of the ocean would reduce the formation of wind-whipped spray droplets, potentially calming the winds. The authors propose spraying oil on the surface of the ocean to reduce the winds of a hurricane. However, the turbulence theory championed by Barenblatt et al. has been challenged by other scientists. In a 2005 interview with Newscientist magazine, turbulence expect Julian Hunt at University College London, UK, remarks, "I am very doubtful about this approach." Hunt studies turbulence both theoretically and in the laboratory, and believes that the high wind speeds in a hurricane are not caused by sea spray. In an article he wrote for the Journal of Fluid Dynamics, Hunt suggests that variations in the turbulence between different regions of the hurricane cause sharp jumps in wind speed, which are responsible for the hurricane's strongest winds.
Oil reduces evaporation
Hurricanes are sustained by the heat liberated when water vapor that has evaporated from warm ocean waters condenses into rain. If one can reduce the amount of water evaporating from the ocean, a decrease in the hurricane's strength will result. Oil on the surface of the ocean will act to limit evaporation, and could potentially decrease the strength of a hurricane. However, if the oil is mixed away from the surface by the strong winds of a hurricane, the oil will have a very limited ability to reduce evaporation. According to a 2005 article in Popular Science magazine, Dr. Kerry Emanuel of MIT performed some tests in 2002 to see if oil on the surface of water could significantly reduce evaporation into a hurricane. He found that the slick quickly dissipated under high wind conditions that generated rough seas.
Figure 1. A comparison of the size of 2008's Hurricane Gustav with the size of the Gulf oil spill. The spill is only about 60 miles in diameter, while a hurricane like Gustav is typically 400+ miles in diameter.
Conclusion
A tropical cyclone in its formative stage--as either a tropical depression or a tropical storm with 40 mph winds--might be adversely affected if it encountered the Gulf of Mexico oil slick, due to the reduction of evaporation into the storm. However, a full-fledged hurricane would mix the oil into the ocean to such a degree that the storm would probably not see any significant reduction in evaporation. It remains unknown how the reduction of sea spray by oil might affect a hurricane. If the oil slick expands to a much larger size, there might be a significant reduction in strength of the hurricane, if theory of how a reduction of sea spray will decrease a hurricane's winds is correct. However, the oil slick is currently Delaware-sized, while a hurricane tends to be Texas-sized, and I doubt that the oil slick at its current size is large enough to have a significant impact on a hurricane's intensity. The slick is about 60 miles across, and it would take a hurricane about four hours to traverse the spill at a typical hurricane forward speed of 15 mph. Furthermore, the slick is within 50 miles land, and interactions with land will dominate the behavior of a hurricane that gets that close to the coast. Unfortunately, there is a decent chance that we'll get a real-world opportunity to see what will happen. June tropical storms tend to form in the Gulf of Mexico, and we've been averaging one June storm every two years since 1995. This year, the odds of a June Gulf of Mexico storm are probably a little lower than usual, shear from our lingering El Niño may bring wind shear levels a bit above average. I expect there is a 20% chance that we'll see a June tropical storm in the Gulf of Mexico that would interact with the oil spill.
References
Barenblatt, G.I, A.J. Chorin, and V.M. Prostokishin, 2005, A note concerning the Lighthill sandwich model of tropical cyclones, PNAS August 9, 2005 vol. 102 no. 32 11148-11150 doi: 10.1073/pnas.0505209102.
Hunt, J.C.R, and I. Eames, 2006, Mechanics of inhomogeneous turbulence and interfacial layers,, Journal of Fluid Dynamics, vol. 554, pp. 499519 doi:10.1017/S002211200600944X.
Scott, J.C., 1986, "The Effect of Organic Films on Water Surface Motions," in Oceanic Whitecaps, edited by E. C. Monohan and G. Mac Niocaill, D. Reidel Publishing Company.
Scott, J.C., 1999, Ocean Surface Slicks - "Pollution, Productivity, Climate and Life-saving", IEEE Proceedings of the International Geoscience and Remote Sensing Symp. IGARSS99, Hamburg, Germany, 28 June-2 July 1999, vol. 3, pp 1463-1468, 1999.
Wyckoff, A.B., 1886, The Use of Oil in Storms at Sea, American Philosophical Society, April 2, 1886.
http://www.archive.org/stream/proceedingsofamep23 amer/proceedingsofamep23amer_djvu.txt
First tropical wave of the season leaves the coast of Africa
Yesterday, the National Hurricane Center noted the first tropical wave of the year coming off the coast of Africa in their Tropical Weather Discussion. The first half of May is the typical time when the first tropical wave comes off the coast of Africa. The wave is currently positioned in the far eastern Atlantic near 5N 45W, and I don't expect it to develop, since it is too close to the Equator to leverage the Earth's spin to gain the rotation needed. The wave has quickly been joined by two new ones today, located at 15W and 36W off the African coast. Tropical waves serve as the seed that form most Atlantic and Eastern Pacific hurricanes.
Portlight delivers major aid shipment to Haiti
Portlight continues to focus its energy and funds on the situation in Haiti, where the rainy season is fast approaching the needs for shelter, medical supplies, food and water remain urgent. Their latest effort was a shipment of several thousand pounds of Durable Medical Equipment and 30,000 pounds of rice that arrived this week via the schooner Halie and Mathew.
Portlight.org is also preparing to respond the the Gulf Coast oil spill by deploying one of more mobile kitchens to feed the hundreds of volunteers likely to flood the coast when the oil finally comes ashore. Please visit the Portlight.org web site or the Portlight blog to learn more and to donate to Portlight's efforts in Haiti and the Gulf Coast.
Figure 2. Relief supplies from the schooner Halie and Mathew sitting at the Portlight Haiti warehouse, ready for distribution.
Next Post
I'm on my way to Tucson today for the American Meteorological Society's 29th Conference on Hurricanes and Tropical Meteorology, which will be held in Tucson next week. My next post will probably be on Monday night, when I plan to discuss the record SSTs observed last month in the tropical Atlantic. I'm excited to be catching up on and blogging about all the latest advancements in hurricane research!
Jeff Masters
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 — Blog Index
I'll chase the piddly stuff then. Someone's got to take up the slack! ;)
L-A N-I-N-A. Most certainly looks alot like a La Nina!
How can the atmosphere "respond"? The atmosphere is what is causing the SSTs to cool....it's an atmospherically-driven El Nino. There is no lag. The ocean is what is responding to the atmosphere.
If this was an ocean-driven El Nino then we could be talking about atmospheric lag.
the atmosphere seems to have triggered this el nino. serves to reason that, atleast in most respects, the atmosphere will be ahead and it will be the oceans that are lagging. You can go back and look at SSTs vs SOI to see the chicken vs the egg here.
So hang tight, 2010 sure to have a Big room.
The atmosphere is already screaming La Nina....that's why the SOI is so insanely high relative to what it was 30 days ago.
Special weather statement
Issued by Environment Canada Ontario region.
Friday 7 May 2010.
Special weather statement issued for..
City of Toronto
Windsor - Essex - Chatham-Kent
Sarnia - Lambton
Elgin
London - Middlesex
Simcoe - Delhi - Norfolk
Dunnville - Caledonia - Haldimand
Oxford - Brant
Niagara
City of Hamilton
Halton - Peel
York - Durham
Huron - Perth
Waterloo - Wellington
Dufferin - Innisfil
Grey - Bruce
Barrie - Orillia - Midland
Belleville - Quinte - Northumberland
Kingston - Prince Edward.
..Possible severe thunderstorms Southwestern Ontario today..
..Very strong winds expected Saturday..
An intensifying spring storm currently found over southern lower
Michigan is moving towards Southern Ontario as expected. The low
pressure system will move across Lake Huron and Southern Ontario
Into Eastern Ontario Saturday afternoon.
Showers and thunderstorms are associated with this weather system
and they will soak the district today into Saturday. There is a risk
that thunderstorms over Southwestern Ontario may become severe
Later this evening and a severe thunderstorm watch is in effect.
In the wake of this storm centre strong westerly winds on Saturday
will be a significant issue. The strong winds will usher in
unseasonably cold air with sustained wind speeds of 50 km/h with
gusts of 80 km/h quite likely throughout most of southwestern
Ontario and the Golden Horseshoe. Exposed areas along the north
Shore of lakes Erie and Ontario could see winds as high as 70 km/h
with gusts to 100. Wind warnings have been issued.
The winds will slowly begin to diminish Saturday evening in the
southwest and overnight for areas near Lake Ontario.
In addition some areas to the east of Lake Huron..Particularly the
Dundalk Highlands..may receive enough flurries in the colder
Air Saturday afternoon for local accumulations of a centimetre or
Two on grassy surfaces.
Listen for further statements. Additional information
may also be found by consulting the latest public forecast.
The next public forecast will be issued by 5.00 AM Saturday
END/OSPC
--------------------------------------------------------------------------------
Box to contain oil spill in Gulf has been placed over leak, BP reports
By The Associated Press
May 07, 2010, 5:08PM
A spokesman for BP PLC says a 100-ton concrete-and-steel box has been placed over a massive oil leak at the bottom of the Gulf of Mexico and is settling down into the mud.
BP spokesman Bill Salvin said Friday it may take as many as 12 hours for the containment box to settle in place but everything appears to be going as planned.
If the box settles properly, crews will then turn their attention to hooking up a pipe to pump the oil out. Salvin cautions though that there are still many challenges ahead as BP makes this first-of-its-kind attempt.
Officials have said it may take two days for crews to hook the device up to a tanker on the surface and begin to siphon off the spewing oil.
Link
Not sure which of us you're talking to but we're right you know...
Neutral or El Nino it doesn't matter....the atmosphere can't "respond" if it is what is causing the switch in the first place. It is the ocean responding to the atmosphere, not the other way around. That's why the SOI, an atmospheric indicator, spiked and THEN the water cooled.
It appears to be working at my end, though a bit choppy, but that could be me, I suppose.
Link
a few salient quotes:
HOUSTON, May 7 (Reuters) - BP has given up on efforts by underwater robots to close valves on a failed blowout preventer at the site of a massive oil leak in the U.S. Gulf of Mexico, an executive said on Friday.
"We've essentially used up all those options," Doug Suttles, chief operating officer for BP (BP.L) (BP.N) said regarding the robots' unsuccessful efforts to close the valves, called rams, and plug the leak at the well.
...
BP is continuing to study two other options, which he said could be risky, in addition to the containment chamber and relief well.
One involves what Suttles called a "junk shot" that would entail injecting heavy fluids and other materials "to basically clog up the blowout preventer" and plug the leak. Other BP executives have referred to that option as a "top kill."
...
The second option involves replacing a piece of equipment atop the failed blowout preventer with a new blowout preventer with valves that will close as designed and plug the leak.
A second, smaller leak is coming from the bent pipes that stem from that piece of equipment on top of the failed blowout preventer. Experts are studying whether removing that equipment could risk a worse leak.
"We don't want to do anything that would make the situation worse," Suttles said.
The choppyness varies but it's watchable. Now would you please pass that gray car.
thanks, im not in the best area for internet, i would say my speed are around 200k, I will be in the Austin area in about 45 min. That will be high speed.
The wave by 8N42W TO 2N46W is impressing the NHC the most.
Link
iam not disagreeing with ya kid but if ya like it here one should not be so quick with the lip
( snort, giggle, snicker )
;)
Thank goodness....it sure needs it. They say the tests resulted in less intensity bias, which has been a big problem.
Good explanation Storm.
Yea, certainly welcome update
TEST RESULTS FROM THE COMBINATION OF THESE UPGRADES SHOWED IMPROVED
TRACK AND INTENSITY FORECAST SKILL AND REDUCED INTENSITY BIAS FOR BOTH ATLANTIC AND EASTERN NORTH PACIFIC BASINS.
Ill be watching this in particular, if it starts under doing storms, we'll know they over adjusted for the HWRF
Check the High bridging... if that type of setup persists (- NAO) throughout this HURR season the Northern Caribbean, Central America, and the Gulf region will be in big trouble.
The proper way would be to stream oil-drenched rags.
The thin film of oil forming to windward is reducing the shape and impact of the waves.
Remember, the ship is slowly slipping to leeward when hove-to.
There usually has not been enough oil in the hold to “dump barrels” for any length of time, with only short-time effect.
The 2010 ATL Hurricane season is gonna be a doosey.
Lovely "E" is putting on a light show on her rear flank, molten magma lighting up a portion of the summit. Link below:
Link
Here it comes!
Link
Actually, there's an El Nino with a La Nina forming to the south of it.
Doesnt really make a difference anymore.
20100407,20100506,9.7
Central Florida's chilly and soggy winter is about to melt from our collective memory amid a hot, stormy summer %u2014 one that may bring an increased hurricane threat, National Weather Service forecasters say.
Some computer models already predict that La Nia conditions, which do nothing to impede tropical-storm formation, will replace the current El Nio conditions by September, one of the most active months of the hurricane season.
"La Nia suppresses wind shear over the tropical Atlantic," said Matt Bragaw, a forecaster with the National Weather Service in Melbourne. "It removes one hurricane suppressor."
That means there could be a greater likelihood of more tropical storms making landfall up and down the peninsula, Bragaw and other Weather Service experts said.
El Nio, a general warming of the water temperatures in the eastern Pacific, is largely credited with making the 2009 storm season mild.
La Nia, its opposite, calms the atmosphere, allowing storms to develop uninhibited.
"There is a correlation between La Nias in the Pacific and hurricane frequency in the Atlantic," Bragaw said.
Experts already predict the upcoming hurricane season will be busy because El Nio is dissipating and sea-surface temperatures in the tropical Atlantic Ocean already are at record-high levels.
In late March and early April, experts in Orlando for the National Hurricane Conference called for an above-average season.
And in December, the Tropical Meteorology Project at Colorado State University predicted 11 to 16 named storms and six to eight hurricanes, which include three to five major hurricanes of Category3 or greater.
However, the influence of the changing conditions is still uncertain, and El Nio seasons are not without their own threats. El Nio conditions in the winter months have been linked to devastating tornadoes in Central Florida due to influences on the jet stream.
"Pick your poison," said Bragaw, who added that the ideal climate conditions for Florida would be El Nios during the summer and fall and La Nias during winter and spring.
Dennis Feltgen, a spokesman for the National Hurricane Center, said a formal forecast of the upcoming season from NOAA's Climate Prediction Center is not expected until May20.
By then, he said, there may be a better idea of how much influence the emerging La Nia will have on Florida's hurricane forecast.
"That will all be addressed," Feltgen said. "You'll find out when I find out."
Sources- Orlando Sun Sentinal
Viewing: 251 - 301
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 — Blog Index