Jess and I (Zig) ran the lidar systems from February 18th to February 26th, an almost 6 and a half day lidar run resulting in approximately 122 hours of data. Runs of this length are rare, since they require extended periods of clear, cloudless skies. Such long runs provide rare opportunities to research the upper atmosphere over an extended period of time, however they always come with challenges.

Extended lidar runs are invaluable in researching atmospheric events such as gravity waves. Gravity waves can have periods of hours or even days, so a 122 hour lidar run can capture long-period gravity waves that would otherwise be difficult to research. In addition, a multi day lidar run contains many short term atmospheric events. The Chu research group can find and isolate smaller portions of the run that contain data they want to research. An extra long lidar run gives them a large range of data to choose from, giving them a better chance to find data that satisfies the conditions they need.

However, an extended lidar run presents challenges when operating. The weather wasn’t perfectly clear for the entire 6.5 days, so there were multiple times where we had to partially or fully shut down for some hours. Such a long lidar run is also tough on both the lidar systems and the operators. Jess and I traded off 12 hour shifts of operating the systems each day. During these shifts we’re confined to a fairly small laboratory and lounge area where we have to watch the systems closely to make sure that the lasers have enough power, there are no leaks in the cooling systems, and the signal is clear. We frequently encounter problems with the systems that we need to resolve (the 374 nm Fe system was particularly troublesome during this run).

By the end of the 6.5 days we were both very tired but despite the challenges that come with such a long lidar run, we are proud to have gotten so much data! We’re sure the data will be used for valuable research.

During this run we were lucky enough to see the first sunset of the season, which occurred on February 20th around 1 am.

Above: First sunset of the season seen from the Arrival Heights laboratory while the lidar systems ran. The sun just barely touched the horizon and then rose back into the sky. Below is a picture of the laboratory with the sunset behind. The lidar systems are running in the photo below.