My adventure started over 9 months ago when I began graduate school at the University of Maine. Within the first couple weeks of the semester my advisor, Dr. Karl Kreutz, asked if I would be willing to join the scientific expedition to Denali National Park planned for April-June 2013. Without hesitation, I said of course!! The nine months to follow were full of course work, research and preparation for the trip.
One of the tasks I took on was becoming the weather station "expert." The goal was to install an automatic weather station near the drill site on Mount Hunter capable of recording the weather over the course of one year, and entirely powered by solar. I had to first determine which meteorological parameters we wanted to measure. After discussion with Karl we decided on the normal suite, including temperature, relative humidity, wind speed and direction, and barometric pressure. In addition to these, we specifically wanted to measure solar radiation and snow accumulation.
Once we had an idea of what we wanted to measure I began researching various companies who sell research-grade meteorological sensors- namely Campbell Scientific and Sutron. I requested price quotes based on the setup we had in mind, and after much deliberation we chose to go with Campbell Scientific. Previous weather stations have had Campbell sensors, and the company has a great reputation for reliable sensors. So we placed the order!
We had most of the hardware (20' tower, mounting poles/brackets, nuts and bolts) sent to Talkeetna Air Taxi, and the remainder of the order (sensors and data logger) sent to UMaine. It felt like Christmas when the order (several large boxes) finally arrived at the University!! Once I had all the packages open and the sensors and wires sorted, it was time to "play." It was a mixture of flipping through manuals, trial and error, and some incredibly valuable input from two Campbell engineers. The final product is one very unique weather station.
The program we wrote and uploaded to the data logger is the brain behind the entire system. It tells each sensor when to turn on and off, what to measure, and then records the measurement in its memory- remarkably for an entire year. The station is set to record hourly averages or samples of air temperature, wind speed and direction, atmospheric pressure, solar radiation, and snow depth/ accumulation. However, there are several aspects that make the station different from any other meteorological station.
First, we have two sensors to measure solar radiation, called pyranometers. One is orientated upward towards the sky to measure incoming solar energy. The other is downward facing to measure solar energy that is reflected off the glacier surface. And the ratio of the reflected energy to the incoming energy gives a value known as albedo. This value provides meaningful information about the balance of energy at the surface.
Another unique aspect of our station is its ability to precisely measure snow accumulation. This parameter is crucial for the interpretation of the ice core. Being of such importance, we wanted multiple ways of measuring snow accumulation and depth. The traditional method is with a sonic ranging sensor (depth sounder). This sensor measures the distance from the sensor to a target (snow surface) by sending out ultrasonic pulses and listening for the returning echos. Our back-up/secondary method for measuring snow accumulation is with a camera (specifically built for extreme conditions) pointed at a pole with markings every 10cm. The program has the camera take one picture every day at noon, and this will let us monitor snow accumulation up the marked pole. The combination of the depth sounder and camera allows us to closely examine the patterns of snowfall on the Mount Hunter plateau over the course of one year.
Finally and most exciting is the station's communication setup. The station is equipped with an Iridium modem and data logger interface that sends the recorded data, via satellites, to a network at Campbell Scientific Canada. The Canadian branch provides the service to initiate communications with the remote station, retrieve the recorded data (including one picture from the camera a week), and then upload everything to a webpage for access. This is such a powerful service because we will be receiving near real-time data from our station deployed at about 13,000' on the Mount Hunter plateau. Another benefit from this service is that we can ensure the sensors are operating correctly, and can make any changes to the program remotely.
Now after nine months of discussing this weather station, researching the companies, ordering all of the equipment, "playing" with the sensors, writing and testing the program, I am in the process of actually installing the station on Mount Hunter!! Today was day five of working on the station, and I'm proud to report it is near completion! Just a bit more wiring and testing to do.
I cannot help but look back at this remarkable journey (that is not even over yet)! Even though the weather station is a minor detail within the entire ice core recovery/analysis project, it has occupied much of my mind for the past 9 months. And I cannot help but feel pure ecstasy as I climb the 20 foot tower to mount and wire the sensors with views of Foraker, Hunter and much of the Alaska Range in any direction. I feel so fortunate to be part of such an incredible adventure, and am deeply honored to be part of this team. Even in the numbing cold, biting wind, and blowing snow, all of my dreams are coming true.
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