Haze and smoke from western Canada

Haze and smoke visible in on the visible satellite image for this afternoon might give the less humid weather the next few days in Chicago a tinge of non-clarity.

http://www.osdpd.noaa.gov/ml/land/hms.html

Jupiter's SEB has gone pale

Jupiter's South Equatorial Belt, normally a brown-red, has gone as pale as the cream white zones surrounding it. Check out the report with images at the Planetary Society Blog: http://networkedblogs.com/3Jnoh. This is one of those things that happens every 5-10 years or so.

Eyjafjallajökull eruption: planes vs. volcano

An interesting data point about the Eyjafjallajökull eruption: the disruption of the European aviation market reduces the CO2 output by an order of magnitude more than the CO2 released by the volcano itself,

Source: http://www.informationisbeautiful.net/2010/planes-or-volcano/

Video of the day: rocket destroys a sun dog

Sun Dogs are bright refractions of the Sun coming from horizontal ice crystals in the atmosphere. The ice crystals are usually oriented horizontally because that it their stable falling pattern. Watch as the rocket carrying the Solar Dynamic Observatory pierces through a cirrus cloud and the sound waves from the rocket completely obliterate the preferred ice crystal orientation.

http://www.spaceweather.com/swpod2010/11feb10/anna-herbst1.mov?PHPSESSID=ndlp741nbtasb6f51eloa6dp81

SO2 plume from Galapagos volcanic eruption

You can see the sulfur dioxide (SO2) plume from the Galapagos volcanic eruption via the OMI on the Aura satellite (which I'm using to watch for hopefully great sunsets here):


NOAA/NESDIS/NASA-Goddard -- Click to enlarge to global view

Redoubt volcano ash plume and sunsets

You may recall some fantastic sunsets in Chicago this summer from some eruption in the Aleutians. Now, since Redoubt has erupted, I was curious if the plumes were heading this way. In July I was unable to find readable (i.e. a common image format) data from the ozone monitor on the Aura satellite (which can track SO2 emissions as well). But now I've found this stuff, and it looks like at least one plume is over the contiguous 48 states, and Chicago in particular:



So if it's clear for you, and there is a plume somewhere within a few hundred miles of you, hope for a great sunset or sunrise!

It appears based on the weather there will be no clear sunsets for a while in Chicago though.

Crescent Venus movie

I took this Wednesday evening. Venus is close to the Earth, big in angular size, close to the Sun and getting lower every day. Turbulence, turbulence, turbulence. And an orange filter.

Inbound bolide: 2008 TC3

Astronomers have discovered a small inbound object a few meters across that appears to be on an impact course with the Earth. The object may enter the Earth's atmosphere somewhere over Europe or North Africa just after 2:30AM UT Tuesday (9:30PM CDT tonight). The orbit is uncertain enough to have a number of possible interactions with the Earth, including missing entirely. It is small enough, based on its brightness, to cause no concern, but should be a nice bright fireball and might drop some meteorites. The self-assigned ID is 8TA9D69, and it was discovered on Mt. Lemmon near Tucson, Arizona by the Mt. Lemmon Sky Survey.
http://tech.groups.yahoo.com/group/mpml/message/21070

Update: It's now designated 2008 TC3
http://cfa-www.harvard.edu/mpec/K08/K08T50.html

Volcanic sunsets part 2

Jennifer points out the local Chicago view from 8/31. Last night the colors were all there without any crepscular rays. Another image at WGN Weather. Spaceweather says the cloud is moving off from North America, but I still thought last night's was great.

volcanic sunset

Me, earlier this week walking to the supermarket: "Boy, it's funny. The western sky has odd colors. They vaguely remind me of the Mount Pinatubo colors from so many years ago. But there hasn't been any eruption lately."

Me, just now, reading Space Weather: Facepalm. Aleutian volcanic eruption a couple of weeks ago.


Also see WGN weather blog for a number of identical "Boy, what a sunset" posts.

EDIT: And thinking about it made me remember catching some news on Highly Allochthonous about how three of the Aleutian volcanoes were erupting and whether the volcanism was related.

Aurora activity

Despite still being in the dregs of the solar cycle the aurora occasionally really activates, and it's doing so right now. While it's daytime here in North America, the aurora is detectable by the way it distorts radio signals, producing a warbling effect on ionospherically bounced waves. The enhanced ionization also provides the ability to bounce much higher frequency radio signals than is usual, although everything is still subject to that pesky warbling.

Current observed aurora here via a NOAA satellite--it takes some time to refresh in orbit.

Spaceweather.com will have updates at some point soon; they are usually on the ball with sightings of neat events.
See the aurora forecast at UAF; which is useful, although long-term forecasts are always tough.

This alert was brought to my attention by the DXrobot, which monitors radio amateur's contacts for notes about unusual VHF radio conditions. Click here for the arcane info.

P.S. It would seem unlikely for this to be an "event" for Chicago city folk--the moon is out, light pollution is as bad as ever, clouds are coming in, and sometimes these events are short-lived.

Flying over Colorado in the near infrared

Click to enlarge

Simply putting a double layer of fully-exposed color negative over a Canon A540 revealed it does have some decent near-IR leakage. Exposures were deliberately underexposed at 1/3 second to prevent image shake. I used some auto-leveling in Photoshop and faded it back a little.

You can see a number of interesting details in the image.

The first is the darkness of the sky above the horizon. Anyone from the old photography days with a red filter and black and white film is familiar with this effect. The blue sky is caused from Rayleigh scattering of photons by the molecules of air, and it's dependent on the inverse fourth power of the wavelength of light. So, blue photons of 450nm scatter 16 times more intensely than near-infrared light of 900nm. Right at the horizon the only scattering is visible in the red channel, which from previous posts we know is the nearest of the near-IR (i.e., just past 750nm). In the green there is no scattering---just a solid ball of earth with no haze. Like a planet with no atmosphere.

Expanding further on the RGB channels: the red is clearly a tail effect of the red filter--so we know the output is or around 700-750nm. It may have an additional output somewhere higher up if the coloring fades away in the IR. The blue should have a passband around 900nm, given that most bandpass filters will also pass double their wavelength (450nm being blue). Green would, if the doubling held, pass 1000nm, i.e. 1 micron, but at that point most CCDs made of silicon begin to really drop out and to get decent response you'd need an optically thick chip (as light absorption varies in depth in silicon in proportion to photon energy. See the Foveon chips for a practical use of this). And this seems to match the intensity of each channel: Red and Blue dominate, making a raw image very purple out of the camera. Green is always the weakest channel. It may either be passing generic IR from a weak filter or from the color negative filter.

I assume the clouds and the snow-covered peaks (right-center) reflect all wavelengths equally. Assuming that, the ground appears to reflect the lower-wavelength (i.e. deeper into the IR) IR better than the near-IR wavelengths.

The ground itself has some real variations in IR reflectivity, although it's difficult to see clearly: far-right center shows a redder response on a slope. I'd love to correlate some near-IR curves to some common mineral types. I do need to calibrate the wavelength response of the cameras. This isn't the image to do it with and I have some better ones with simultaneous visible light images.

P.S. The curvature of the horizon is just from the camera lens, not the real curvature of the earth.

The Japan nuclear plant earthquake leak

Robert Merkel does the calculations on the leaks from the nuclear power plant in Japan and makes the point most media missed: the leak of water into the ocean wasn't anything. The media missed the much larger release into the atmosphere--nearly 300 million becquerels, or about 3000x times the amount of radioactive material. (A becquerel is one atom disintegrating per second). But looking only at the total amount of radioactivity doesn't tell the whole story. A release of the noble gas krypton-85, for instance, does not really accumulate in organisms in any way; while a release of iodine-131 would concentrate and damage your thyroid. Half-lifes and the particular radiation emitted is also important in consideration: the weak beta electrons (~18keV) from tritium decay is considered not as hazardous as a multi-MeV alpha particle from polonium-210.

The reprocessing of nuclear fuel rods in France releases huge amounts of krypton-85 into the air: 1.8 × 10^17 Bq in 1994 alone.

The 90,000 becquerels of whatever went into the ocean (I am guessing it was tritium) is actually not that much: your own body has about 4000Bq of potassium-40 and 3000Bq of carbon-14 in it; in addition, at least here, tritium is allowed to be diluted by large amounts of river water in Illinois.

The end result is the release wasn't a lot; it sounded like a lot from the numbers, but that's due to the definition of a Becquerel more than anything else. The reality is most people don't have much of an education on radioactivity, and this affects how they irrationally perceive a risk.

All of this is really just a minor detail though, when the real issue is any delay or hiding of release information, which according to the press is endemic in the Japanese nuclear industry.

UPDATE: I've found descriptions of the leaks here. The spent fuel pool water sloshed onto the floor and leaked out via cabling. The second leak, to the atmosphere, was iodine and radioactive dust from a main exhaust line.

Harvey fire smoke plume on radar

A large fire in south suburban Harvey (Chicago) is producing enough particulates to produce a visible return on the clear-air NEXRAD radar system extending out over the lake.


Images from NWS/NOAA via http://weathorr.com

Mercury, the Moon, and Venus

As I mentioned in my last post, more images from the evening of May 17th.

You can see the Moon--but look closely at the support wires on the left side of the crane--see Mercury?


Through the telescope, the autofocus picks up the high contrast of the crane--and makes Mercury a round blur.


Forcing the focus to Mercury.


Venus, much higher up in the sky, but still subject to atmospheric dispersion.


You can see the turbulence by viewing this video of Venus here (753kB, 0:17 WMV).

The wide view.

Biodiesel vs. petroleum: greenhouse gas emissions and N2O

A press release recently reported research that claims biodiesel will cause more greenhouse gas effect than using petroleum oil. The gist is that agriculture with industrial fertilizers release some N₂O unintentionally as part of nitrogen fertilization, and that nitrous oxide has a much stronger effect on global warming because it has a long lifetime in the atmosphere. The UN defines a "Global Warming Potential" for each greenhouse gas. Lifetime in the atmosphere is the primary factor (perhaps the only factor?), so nonreactive gases like CFCs, which live nearly forever, have incredible numbers (50000) for their "effect". CO₂, though, is just defined as 1, even though it has a variable lifetime in the atmosphere of 5-200 years (page 38). I don't know if the spectral absorption of each gas was taken into effect for these--I see no information that it is. N₂O lives for about 120 years in the atmosphere, a fairly nonreactive gas, and it is this multiplication factor, (296x), that drives the conclusion about how biodiesel via rapeseed is worse than petroleum in greenhouse gas emissions.

I would have liked to read the actual paper via my institutional subscription, but it's not available yet online or in paper.

The linked press release is actually from a tropical conservation group, and interestingly they happened to add a graph with yields of biodiesel per acre, showing rapeseed as middle of the pack in terms of yield. What would happen to the analysis with other crops? What if we didn't use so much nitrogen fertilizer or didn't exclusively produce rapeseed? (You can nitrogenate with legumes to avoid using some fertilizer). Was the absorption of CO₂ from the atmosphere into the plant matter taken into consideration during the analysis? Questions I have, answers I can't find.

You might know rapeseed by another name: a special variety breed called canola (CANadian Oil Low Acid), which has much lower amounts of a naturally occurring toxic acid in it.

Terrestrial oxygen

Terrestrial oxygen as seen in the sun's spectrum, originally taken March 17, 2003.



It's terrestrial only in the sense of being non-astronomical; to all but astronomers it would be called "atmospheric".

Radioactive Krypton in the atmosphere

The radioactivity of atmospheric krypton in 1949–1950
Anthony Turkevich, Lester Winsberg, Howard Flotow, and Richard M. Adams
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=33711

Highlights:

"The work reported here was carried out in the old ruling engine room for grating production in the basement of the Ryerson Physics Laboratory of the University of Chicago."

"As mentioned earlier, atmospheric krypton in the 1990s has a radioactivity of tens of thousands of disintegrations per minute per liter. It is now about a hundred times more radioactive than the samples reported on here."

"The largest current producer of radioactive krypton is the French reprocessing plant at Cap-de-la-Hague, which released 1.8 × 10¹⁷ Bq of krypton radioactivity in 1994. If diluted by the whole world's atmosphere, this would produce a radioactivity of krypton of 2,400 dpm per liter (STP). Cap-de-la-Hague's output may represent about half of the present input into the atmosphere of this radioactive nuclide."