Forecasting the volcanic ash plume of Iceland's volcano
The eruption of Iceland's volcano with the unpronounceable name, Eyjafjallajökull, has virtually ceased over the past few hours, with ash only reaching up to 6,000 feet (1800 meters), according to the latest advisory from the UK Met Office. Lightning images from UK Met Office show no new lightning strikes from the volcano's plume since midnight local time today. The relatively small amount of ash present at low altitudes will probably not be able to make it all the way to mainland Europe before falling to the surface and dissipating, since 6,000 feet is below the altitude that the strong winds of jet stream blow. Wednesday through Sunday, the volcano emitted a towering cloud of volcanic ash 6 - 11 km (20,000 - 36,000') high in the air from its 1666 meter (5500') high peak. The jet stream blows strongly at that altitude range, which allowed for efficient transport of the ash cloud to mainland Europe.
Figure 1. Lightning lights up the night sky in this photo of Eyjafjallajökull's eruption taken on April 16, 2010. Ash particles colliding together separate electric charge, much as ice particles in a thunderstorm do, leading to spectacular lightning displays. Image credit: Marco, Fulle, Stromboli Online.
Forecasts of the movement of the ash cloud are made using trajectory models, which have a number of uncertainties to consider. Firstly, the amount of ash ejected by the volcano is highly uncertain, since our measurements of this quantity are limited. Secondly, the models must compute how high the ash cloud will rise (plume rise), based on the best available measurements of atmospheric stability. Since upper air-observations are taken just twice daily by a very coarse network of balloon soundings, our knowledge of the stability is rather crude. Finally, the trajectory models use forecast winds from a global model such as the GFS model to predict where the plume may go. The forecast winds from this model do not capture much of the complicated structure of the wind field over Europe, leading to a rather fuzzy approximation of where the ash will go. Nevertheless, these models have in general done a respectable job forecasting where the ash from Eyjafjallajökull will go over the past few days.
Figure 2. Cross section of the atmosphere over time over Paliseau, France, on April 16, 2010, as observed using ground-based lidar. Image taken using a 532nm cross polarization NFOV telescope. Note how the ash layer sinks closer to the ground as time progresses, as gravity makes the ash sink to the ground. There may also be some atmospheric subsidence occurring (downward moving air due to large-scale atmospheric processes.) Image credit: Ray Hoff, World Meteorological Organization's Global Atmosphere Watch's Aerosol Lidar Network (GALION).
For the next few days, these models continue to indicate that northwest winds at the jet stream level will continue to affect Iceland. As a result, Spain, Portugal, and Greece will offer the best locations to fly from. The northwesterly winds are expected to continue for the remainder of the week, thanks to an upper-level trough of low pressure over northern Europe. On Saturday April 24, the ECMWF model predicts that the trough will slide eastwards, and a ridge of high pressure will build over Europe. This will bring upper-level winds out of the southwest to Iceland, directing any volcanic ash northwards over the North Pole. Thus for the remainder of this week, expect continued ash clouds over much of Europe if the volcano resumes significant eruptions. But by next Sunday, the ash over Europe should decline considerably. For the latest one-day forecasts of where the ash cloud is expected to go, consult the UKMET Office. The Rhenish Institute for Environmental Research at the University of Cologne also has some excellent simulations from an atmospheric dispersion model of Eyjafjallajökull's eruption plume. The Norwegian Institute for Air Research runs a computer trajectory model called FLEXPART that has 1-day forecasts showing a cross section of the atmosphere. NOAA's Air Resources Laboratory (ARL) lets you perform your own model run using their HYSPLIT model, going out up to 48 hours, using the GFS model as input.
Figure 3. NASA's Aqua satellite captured this image of the eruption at 1:20 UTC on April 17, 2010. Image credit: NASA Earth Observatory.
Links
An excellent source of links of information on the eruption is available at http://islande2010.mbnet.fr/2010/04/eyjafjallajok ul-links-liens-a-propos-de-leyjafjallajokul/. My post on Thursday discusses the likely non-impact of this eruption on Earth's climate. Finally, we need to be keeping an eye on earthquake activity at the dangerous Katla volcano next to Eyjafjallajökull. If that volcano blows, it could mean dwarf the headaches caused by Eyjafjallajökull.
Jeff Masters
Reader Comments
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no...
Link
Out of curiosity, does that mean that you are disagreeing with the NHC track, or was is preliminarily rated Cat 5 by NHC and later downgraded at that point during post storm analysis, or am I just missing it entirely?
Whole bunch of links on my blog. But this is probably the on you want. Link
Links
An excellent source of links of information on the eruption is available at http://islande2010.mbnet.fr/2010/04/eyjafjallajokul-links-liens-a-propos-de-leyjafjallajokul/. My post on Thursday discusses the likely non-impact of this eruption on Earth's climate. Finally, we need to be keeping an eye on earthquake activity at the dangerous Katla volcano next to Eyjafjallajökull. If that volcano blows, it could mean dwarf the headaches caused by Eyjafjallajökull.
Jeff Masters
That's just me disagreeing with the NHC. It's probably just because they had no recon vortex messages near that time.....but just take one long look at that picture. A Cat 5 can pretty much be defined as a "perfect" hurricane, because it literally has to be perfect.
i figured if you guys can talk about how smart Palin is, i could talk about what i'm baking!
i can finally see the volcano.
From what I've read, it would be like having a space-based Doppler radar that would really improve tropical storm monitoring.
I haven't seen anything in the news about it launching or being in use. Does anyone know about the schedule or delay?
And on the subject of weather, I notice there is no data about damages to the Bahamas from the 1947 hurricane. I'm sure there is something available at the National Archives or in the dead files of either of the two Nassau dailies. Maybe I'll make a vacation project out of digging into that....
there at least one on this page, and prolly several more on the last page.. I'm addicted too
Gotcha. I have always thought that Ivan was a rather unimpressive Cat 5 during that time as well, but I've never thought it through as much as that. Thanks for clarifying!
Link below to the UK Met Office:
Link
Easy to disagree when you've never experienced the Weather of a Hurricane,or thunderstorms..per say.
Its way more than any number can quantify,..ask anyone from Masters to others about their collective experiences in The Eyewall and you will get a lot of input on Hurricanes.
AT the end of the day..its how it interacts in our Lives,and thats a thing one cant put a number on in retrospect.
LoL
Speaking of wx, did u guys get any more rain today?
Oh my, a "Tempest in a Teapot"!!
if it continues for the next four months or more
next winter in the northern hemisphere is gonna be a wee bit colder and snowier than normal
if you stop getting upset at everyone i'll give you bite!
We should be either in a "neutral" or a moderate La Nina for winter 2010-11.
Need to wait and see, this volcano, while wreaking havoc over Europe and parts of Asia, has not really emitted enough ash/sulfur dioxide yet to cool that atmosphere.
But, if Katla erupts, that may change.
When I tried to go to http://www.mulakot.net/myndavelar.html I got
mulakot.net skilar villum. Tæknimönnum 1984 ehf hefur verið gert viðvart! Referred by http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1463
translation:
mulakot.net returns errors. Technicians 1984 Ltd. has been notified! Referred by http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1463
1463 is the number of Dr. Masters last blog. If you look in your address bar, you can see this blog is 1464.
Aha!!! But I wonder why they got that now?
edit: Are you sure I thought that was the comment number, which I notice is now gone from the last blog.
ARE YOU JFV????
Anybody notice anything.... odd.... about this Wiki entry?
As it moved west-northwestward on the 27th and 28th, it rapidly intensified to a 150 mph (240 km/h) major hurricane. It weakened slightly to a 140 mph (225 km/h) hurricane, but restrengthened by the time David ravaged the tiny Leeward Island of Dominica on the 29th.[1]
David continued west-northwest through the Bahamas where it caused heavy damage, and became a Category 5 hurricane in the northeast Caribbean Sea, reaching peak intensity with maximum sustained winds of 175 mph (280 km/h) and minimum central pressure of 924 mbar (hPa) on August 30. An upper-level trough pulled David northward into Hispaniola as a Category 5 hurricane on the 31st. The eye passed almost directly over Santo Domingo, capital of the Dominican Republic with over a million people. The storm crossed over the island and emerged as a weak hurricane after drenching the islands.[1]
OK I WAS THIS MAKEING SURE
Katla is still quiet.
for now but not for long
How did it go through the Bahamas then back to the DR? It never looped.
not true, the web recorder shows an increase since the one who can't be named decreased.
MAP 5.2 2010/04/20 00:17:08 -30.530 121.653 10.0 WESTERN AUSTRALIA
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