Crepuscular Ray
-
Posts
3,824 -
Joined
-
Days Won
1
Content Type
Forums
Blogs
Gallery
Events
Learn About Weather and Meteorology
Community guides
Posts posted by Crepuscular Ray
-
-
They've done the casual look on Countryfile since the summer, as if their taking their jackets off makes a forecast more relevant to 'countryfolk' (or perhaps the media types in television centre think it does). At least it's not as bad as Breakfast: did anyone else spot Matt Taylor in waders up to his chest in a pond full of floating cranberries at Kew Gardens earlier in the autumn. What a waste of licence fee
-
SpaceWeather.com are now getting rather excited about this particular region's imminent emergence over the Sun's limb. Given that the new sunspot cycle seems to be sluggish and rather reluctant to get into gear, any activity seems welcome. Although the British Isles are badly placed for seeing aurorae because the geomagnetic north pole is somewhere in Canada(and getting farther southwest each year) rather than in the same place as the geographic north pole, anything that promises really big X-class solar flares, especially if the Sun's magnetic field is oriented to the south (again see SpaceWeather.com for updates) might be promising at this time of year. But don't count on it.
-
Superb CME profile caught by SOHO from a sunspot just over the limb featured on today's Spaceweather. You can also hear it too!
Hopefully the region responsible will remain as active once it gets round to this side of the Sun.
-
Am I the only sad person around who finds that Klyuchevskoy picture absolutely stunning? :blink:
thanks for posting the link, Viking!
-PBS-
Not sad at all: it's beautiful - on a par with Mt Fuji, I think.
-
Congrats on your pass Viking, now you'll be able to go a Viking in safety!!!
Wasn't the last Major eruption of Vesuvius (of the scale being mooted to occur soon'ish ) the one witnessed by Pliny the younger as his Father ?(the elder) choked to death in an attempted rescue on the beach at Herculinium? Isn't Naples built on top of the pyroclastic flow from that eruption? Doesn't look good does it?
Plinies - think they were uncle and nephew....
-
It will probably be this one CR:
Yes, that's the one Blitzen. Thanks.
-
In my rented flat in nw London we only lost power for about 10 hours and the wall at the bottom of the garden (which took Brent Council 6 months to replace, naturally), but my parents in East Sussex were without power for about 3 days (even though they had underground power cables) and lost loads of trees, especially evergreens. What was truly depressing was when my boss had to call someone we were working with at Kew, and he just cried down the phone for about quarter of an hour because they'd lost so much.
What I remember better, because it happened during daytime, was the late January 1990 (?) storm in the southeast. Oxford Street was an amazing sight, with hoardings and bits of shop signs sailing along about 30 feet in the air and just smacking through plate glass windows. Not a good day to go shoe-shopping!
-
Congratulations on getting your coastguard qualifications, Viking. Well deserved.
A friend visited Monserrat a few weeks ago as part of a conservation project - even though Souffriere Hills is not now classified as dangerous, he and his colleagues were still very impressed by the near daily 'minor' eruptions and ash-falls, which still get pretty near to the inhabitable parts of the island when the wind is in the right (or perhaps wrong) direction.
-
Oct. 19, 2006
Erica Hupp/Dwayne Brown
Headquarters, Washington
202-358-1237/1726
Anatta
NOAA, Earth System Research Laboratory, Boulder, Colo.
303-497-6288
RELEASE: 06-338
NASA AND NOAA ANNOUNCE ANTARCTIC OZONE HOLE IS A RECORD BREAKER
NASA and National Oceanic and Atmospheric Administration (NOAA)
scientists report this year's ozone hole in the polar region of the
Southern Hemisphere has broken records for area and depth.
The ozone layer acts to protect life on Earth by blocking harmful
ultraviolet rays from the sun. The "ozone hole" is a severe depletion
of the ozone layer high above Antarctica. It is primarily caused by
human-produced compounds that release chlorine and bromine gases in
the stratosphere.
"From September 21 to 30, the average area of the ozone hole was the
largest ever observed, at 10.6 million square miles," said Paul
Newman, atmospheric scientist at NASA's Goddard Space Flight Center,
Greenbelt, Md. If the stratospheric weather conditions had been
normal, the ozone hole would be expected to reach a size of about 8.9
to 9.3 million square miles, about the surface area of North America.
The Ozone Monitoring Instrument on NASA's Aura satellite measures the
total amount of ozone from the ground to the upper atmosphere over
the entire Antarctic continent. This instrument observed a low value
of 85 Dobson Units (DU) on Oct. 8, in a region over the East
Antarctic ice sheet. Dobson Units are a measure of ozone amounts
above a fixed point in the atmosphere. The Ozone Monitoring
Instrument was developed by the Netherlands' Agency for Aerospace
Programs, Delft, The Netherlands, and the Finnish Meteorological
Institute, Helsinki, Finland.
Scientists from NOAA's Earth System Research Laboratory in Boulder,
Colo., use balloon-borne instruments to measure ozone directly over
the South Pole. By Oct. 9, the total column ozone had plunged to 93
DU from approximately 300 DU in mid-July. More importantly, nearly
all of the ozone in the layer between eight and 13 miles above the
Earth's surface had been destroyed. In this critical layer, the
instrument measured a record low of only 1.2 DU., having rapidly
plunged from an average non-hole reading of 125 DU in July and
August.
"These numbers mean the ozone is virtually gone in this layer of the
atmosphere," said David Hofmann, director of the Global Monitoring
Division at the NOAA Earth System Research Laboratory. "The depleted
layer has an unusual vertical extent this year, so it appears that
the 2006 ozone hole will go down as a record-setter."
Observations by Aura's Microwave Limb Sounder show extremely high
levels of ozone destroying chlorine chemicals in the lower
stratosphere (approximately 12.4 miles high). These high chlorine
values covered the entire Antarctic region in mid to late September.
The high chlorine levels were accompanied by extremely low values of
ozone.
The temperature of the Antarctic stratosphere causes the severity of
the ozone hole to vary from year to year. Colder than average
temperatures result in larger and deeper ozone holes, while warmer
temperatures lead to smaller ones. The NOAA National Centers for
Environmental Prediction (NCEP) provided analyses of satellite and
balloon stratospheric temperature observations. The temperature
readings from NOAA satellites and balloons during late-September 2006
showed the lower stratosphere at the rim of Antarctica was
approximately nine degrees Fahrenheit colder than average, increasing
the size of this year's ozone hole by 1.2 to 1.5 million square
miles.
The Antarctic stratosphere warms by the return of sunlight at the end
of the polar winter and by large-scale weather systems
(planetary-scale waves) that form in the troposphere and move upward
into the stratosphere. During the 2006 Antarctic winter and spring,
these planetary-scale wave systems were relatively weak, causing the
stratosphere to be colder than average.
As a result of the Montreal Protocol and its amendments, the
concentrations of ozone-depleting substances in the lower atmosphere
(troposphere) peaked around 1995 and are decreasing in both the
troposphere and stratosphere. It is estimated these gases reached
peak levels in the Antarctica stratosphere in 2001. However, these
ozone-depleting substances typically have very long lifetimes in the
atmosphere (more than 40 years).
As a result of this slow decline, the ozone hole is estimated to
annually very slowly decrease in area by about 0.1 to 0.2 percent for
the next five to 10 years. This slow decrease is masked by large
year-to-year variations caused by Antarctic stratosphere weather
fluctuations.
The recently completed 2006 World Meteorological Organization/United
Nations Environment Programme Scientific Assessment of Ozone
Depletion concluded the ozone hole recovery would be masked by annual
variability for the near future and the ozone hole would fully
recover in approximately 2065.
"We now have the largest ozone hole on record," said Craig Long of
NCEP. As the sun rises higher in the sky during October and November,
this unusually large and persistent area may allow much more
ultraviolet light than usual to reach Earth's surface in the southern
latitudes.
-
Yes, it was very interesting. In the immediate sense, it would be fascinating to compare the different amounts of dust this year and last, given the vast differences in tropical storm numbers.
Vikings Volcanic Activity Thread
in Space, Science & nature
Posted
Cheers Viking. Nice to see it at a different, more informative, angle than from the volcano webcam from Johnston Ridge.
What happened to the massive slab that was projecting at one side of the new mound at a near vertical angle earlier in the year? I forgot to look for a few weeks and it disappeared from mention on the web.
CR