More Ice Crystals and Halos in the Air
Temperature: minus 27 Celsius, minus 17 F Windchill: minus 42 Celsius, minus 43 F Wind: up to 19 knots Weather: blowing snow: a white out
The day started a 4:30 am with posting journals, and photos. As I looked out of the window, I could not see far: the winds had picked up and we had a "white out", meaning that so much snow was stirred up that it looked like a snow storm. I knew we could not fly a balloon today. All day only one plane out of 6 actually made it to the South Pole and back to McMurdo.
During the morning I organizing the broadcast for tomorrow with Mike and Henry from the IT department and making plans for future communications. Bryan and I also discussed what to do when he is not here since he will be leaving back home tomorrow.
We also went to ARO to check out some surface ozone data and compared it to an ozone sonde reading he prepared. The halo over the observatory was magnificent.
Halo over ARO
The halo formation was just right under these wind conditions.*
Snow sculptures everywhere
On the way to ARO the wind has carved interesting sculptures.*
The crystals in the air made it possible for an occasional "halo with sundogs". We were able to observe a halo for most of the afternoon after the "white out" lifted a little bit.
Answer to yesterday's question of "What is a halo and sundog"?
A halo is the shining full circle around the sun. The conditions must be cold temperatures wind and a certain amount of snow crystals in the air. The sun light is refracted by the ice crystals producing a circle around the sun. This is similar to the phenomena in warmer areas when light is refracted by rain droplets producing a rainbow. Sundogs are the brighter dots on the horizontal line of 180 degrees of the circle opposite each other. They are not always visible on an image.
It is time to go to bed to be rested for the 5:30 am "Life from IPY" webinar.