3 bright moving lights over Lake Elsinore, Jan 6

Driving West this evening, about 7:30 pm, I saw three lights over the basin of Lake Elsinsore do a little dance in the sky. I wasn't alone observing this. The initial impression was of the meteor scene from the movie Dinosaur. There were three objects with trails and more than once one of the three would merge with another. I thought perhaps military helicoptors with lights, but I'm more inclined to believe it was a night parachuting activity, as the movement of the lights, and their proximity is consistent with parachutes.

I observed the lights on Scott Road, and lost them as Scott Road nears the large hill with the transmission towers. however, I thought one of the lights that I could still see while the other two were cut off by the silhouette of the hill appeared to wink out on it's own, though a pilot turned off his light or flare.

I'm eager to learn if others observed this.

jg

cold weather atmospheric optics

Astronomy is a 24-hour hobby, as I'm always seeing something worth capturing. Below is a Christmas sundog and an exceptional shadow from a contrail.

Sundog photographed on Christmas day

Contrail casting a long shadow

jg

Vostok icecore and Earth's orbit graphs

Almost two weeks ago, I had the honor of guest posting at Skeptical Science, sharing my latest illustration project, the Vostok Viewer, an interactive graphing tool that displays data from the Vostok icecore alongside calculations of Earth's orbit (data sources: Vostok; orbit; modern CO2).

My guest post: Skeptical Science: Ice data made cooler 

I received a lot of constructive feedback and have started adding the suggested features. I've exposed my version 2 and qualified it as beta (in progress), as I have a couple known programming bugs:

A cautious user (someone not trying to evoke a failure) will have the benefit of displaying graphs, adjusting their scale, and showing and hiding labels for an informative yet uncluttered display.

My known bugs are:
1. Displaying the modern CO2 graph while viewing a pre-modern time era will create a later failure where orbit graphs fail to update when changing time periods.
2. The graph labels may fail to align with their graphs when time periods are changed.
jg

Tangential Arc

On Dec 1, I saw for my first time, a tangential arc, an optical effect caused by the refraction of sunlight through ice crystals. Also visible, though barely perceptible, was a circumzenithal arc. The top right photo was manipulated to bring out the color of the circumzenithal arc.

I highly recommend the website Atmospheric Optics to learn more about this an other related phenomena.

jg

Palaeoclimate graphs from Vostok Ice Core and Orbit Calculations

I have envied the climate charts I've seen in Wikipedia and in science journals showing temperatures, CO2, insolation, and orbit parameters over the past million years, so I decided to create my own viewer: Vostok Viewer

I've taken the data from these sources:

• Petit, J.R., et al., 2001,  Vostok Ice Core Data for 420,000 Years, IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series #2001-076. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.
• Astronomical Solutions for Earth Paleoclimates. A&A 428, 261-285 (2004), DOI: 10.1051/0004-6361:20041335; Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A.C.M., Levrard, B. : 2004, A long term numerical solution for the insolation quantities of the Earth.

and created this:
 

...which is a Flash-based viewer that allows you to see graphs of data from these sources and to zoom in on specific periods, such as the Eemian:

My program is crude at this time. I plan to add more features for controlling the appearance of the graphs as well as flexible views of the timeline (so a user can focus on any period rather than those I've configured). And of course, I'll add other data sets, but for now I hope to iron out the features using the data I have.

I started this project when I wanted to see if observations I was making about the Eemian held up for other interglacials. I saw a strong correlation between summer insolation at 65 degrees N and the onset of interglacial temperatures. This correlation was consistent with what I've read from science journals. However, from my Vostok Viewer, I'm observing that the correlation isn't as visually striking for the interglacials at 240 kya and 325 kya:

The green line in the above graphs is June insolation at 65 degrees N. For the onset of the Holocene and Eemian, you can see that the green curve corresponds to rises in temperature (yellow) and CO2 (lavender), but in the earlier interglacials, the solar forcing peaks before the peak in temperature and CO2.

This discrepancy invites more study from me. Are there see-saw effects that delayed warming in Antarctica or are there margins of error in the dating of the CO2 and temperature values? Is it time for me to open the book on more sophisticated data analysis? I'm sure the climatologists know. Here, I'm trying to do my homework before asking.

jg

Dark sky Wildomar, a standard for preservation

I'm using the Milky Way as a metric for local light pollution. I don't expect to restore the skies of ten years ago, rather, I hope only to keep the Milky Way visible from typical backyards. Below is a photo of the Milky Way on August 12, 2010 from my backyard. Though the contrast is poor, our galaxy is still visible to the naked eye and to the camera.

Photo: Region near Sagitarius and Scutum.

jg

Comet Hartely 2

I just started following comet Hartley 2. It's faint, but detectable from moderately light polluted skies. Below is a wide-field view taken with a 28mm camera lens and an inset taken with a 3-inch telescope at a focal ratio of f5. (Click to enlarge the photo.)



jg