February 23, 2004

Is it ever cloudy in Eureka?

When Richard B. returned to the Weather Station for breakfast, after a night of lidar measurements, he reported that there was a quite a lot of cloud cover. As we set out for AStrO, it appeared that it might not be the best day for solar measurements. But much can change over the course of a day.

The DOAS spectrometer started taking measurements today (at 96 degrees) after being installed in its new plywood and plexiglas "dome". Annemarie's quick look at her data proved promising. The temperature in the dome is being lowered to prevent frost on the window and make the CCD detector more stable.

After moving the PARIS instrument closer to the suntracker, to provide better access to the suntracker controls, some alignment check measurements were performed this morning. By a quarter after 12, the bank of cloud in the path of the Sun had mostly cleared and the tracker could be operated through the remaining thin cirrus cloud. About one hour of alternating measurements (due to the shared solar input beam) were made by Richard M. and Keeyoon with the DA8 and PARIS instruments.

Today was the day for calibrating the SPS and MAESTRO instruments. Hongjiang and Clive spent an extra long day at the Observatory getting this completed. This will help them do on site analysis of the data from these instruments. Also, Hongjiang spent some time testing the optimum operating temperature for the SPS and found that it would be better if the temperature was lower.

The ACE occultation points are steadily approaching Eureka. The average latitude of the occultations within 1000 km of us at AStrO was 77.8N. Tomorrow we will begin two weeks of daily ozonesonde launches. These have been planned to span the intensive phase of the validation campaign and coincide with the time of closest approach to Eureka. We hope to get higher in altitude than yesterday but this will depend in part on the weather conditions present at launch.

After a lot of work yesterday to install the DOAS instrument in the "dome", Tobias, Keith and Annemarie took a bit of a break today and went tobogganing. The wind was a little high (even some of the road edge markers were vibrating in the wind) so they lasted only about 30 minutes outside.

We had a second opportunity to observe some of the local wildlife this evening. There were two arctic hare near the Weather Station when we came down from AStrO for dinner. Tobias and I were able to get within about 2 m of them. (Of course, there will be pictures on the website.) Also we had a visit from the three arctic wolves that come by the Station from time to time. In this case, it was recommended that we observe from inside (with binoculars) rather than going out to see them.

Best regards,
Kaley.