The beginning of the week of Dec. 5th brought some more unpleasant weather. By Thursday, December 8th we were finally able to go on a helicopter ride to both Linda AWS and Lorne AWS. For this trip, only Lee and myself would be going on the flight because we needed to call Dave back in the office on the Iridium phone to check for a transmission. Linda AWS had been transmitting its data in real-time via the radio network due to its close proximity to McMurdo. Unfortunately, the AWS was dropping transmission often during the winter or other random times. In order to fix this, we decided to change the transmission style of Linda AWS to Iridium. The Iridium network is much more reliable then the radio network.
Once we arrived at Linda AWS, Lee worked to switch out the freewave modem for the iridium modem in the enclosure. Then I worked to switch out the freewave antenna for the iridium antenna on the tower. We got everything plugged in and the new cable coiled. Then it was time to turn the station back on and test to see if Dave could see the Iridium transmissions coming through. Lee gave Dave a call and it looked like the transmission hadn’t been received yet. Within seconds of hanging up, Dave saw the transmission was received. Unfortunately, there was no way for Dave to call Lee to notify him of this, so Dave just had to wait for Lee to call him back. We waited in the helicopter, since it was blowing nearly 20 kts, for the next transmission to send in 10 minutes. Lee called Dave back and explained that it had worked correctly! Eureka!
Then we flew to Lorne AWS. The problem at Lorne AWS started after November 23rd when the new pressure sensor was installed. Once the pressure was working correctly then the wind and relative humidity values were incorrect. We went back to Lorne AWS that afternoon to check if it was an issue with the wiring or the sensors. After about an hour and a half of troubleshooting, we couldn’t conclude anything and we decided to leave.
We asked to be on the helicopter schedule again the next day to go back to Lorne AWS in order to bring a new wind sensor to make sure that the sensors hadn’t suddenly failed. We got to take the New Zealand helicopter which was a little bit different and fun! This time Dave was able to come and troubleshoot as well. After a few tests with the new and old aerovane, it was decided that the sensors weren’t the problem. Then it must be something with the datalogger or the program that the datalogger is running. We doubled checked the program and the code was incorrect for the type of wind and RH sensor at the site. Once the values were changed, all the sensors were reporting correctly again! Eureka again!
Once Linda AWS and Lorne AWS were all done, we only needed to take a Twin Otter plane to Gill AWS in the middle of the Ross Ice Shelf. Due to weather, scheduling, and priority issues, this site wasn’t able to be visited this season. Luckily, this site is running fine. It’s just that we haven’t been to it in nearly 6 years. We can hopefully get there in 2017!
With that, we’ll all be leaving McMurdo on Thursday, December 15th if all goes to plan. Thanks for following the adventure this season and Happy Holidays!