Radiation and weather at Summit Station, Greenland via BSRN, NOAA and the 50-meter Swiss Tower.
Weather conditions: Temperature High 24 F Low -15 F Wind-chill 0 to – 30 F
Today was a day of information gathering for me as well as the scientific equipment. We started the day by going back out to the AWS to repair a “fussy” sonic sensor that measures snow fall. The AWS transmits data on the hour via satellite to the University of Colorado at Boulder, where CIRES is located. Nico has access to the data almost as soon as the AWS transmits it to CO. Every AWS has two of everything, meaning if one instrument fails, the other will hopefully continue to transmit a signal. Nico and I loaded up a sled and snow machine and made our way to the AWS. With Nico precariously balanced on the ladder, he one-handedly disassembled the instrument and replaced the faulty sensor. Once again, we had to wait to verify the sensor was functioning. After two consecutive hours of successful transmitting, the sensor was back to perfect working order and we were happy with the outcome.
After lunch, I made my way to the Baseline Surface Radiation Network instruments. The Swiss technicians had just finished installing a short extension tube in preparation for the winters snow. I was able to get an up-close look at the radiation recording instruments.
Solar radiation is the major energy source that drives our climate and supports life on earth. The measurements are part of an international effort to record radiation called the Baseline Surface Radiation Network project. The data collected will be used to further study the Greenland Ice Sheet and it’s processes such as melting and gas exchange with the atmosphere.
Studying heat balance is an important concept in climatology because light surfaces, like snow, reflect more radiation back into space while dark surfaces, like water, absorb more radiation. When you have snow cover, about 90% of the solar energy that goes through the atmosphere is reflected back into space. But increasing the amount of water on the Ice Sheet causes less radiation to reflect and more heat to be absorbed. This increases the temperature and causes more ice to melt.
My next stop was at the NOAA research facility. Here I got to see some of the most specialized equipment to record atmospheric properties at Summit Station.
Next stop was the 50-meter Swiss Tower. The tower has sensors located every 10 meters. The sensors are used to record minute changes in the atmosphere in very small increments up to 50 meters.
I was fortunate enough to have one of the Swiss technicians, Hansjoerg Frei, take may camera up to the top of the tower and get some pictures of Summit. My wife, Mimi, would be very relieved to know that I was not the one going up the tower!
The day ended with clear skies, which means no trapping of the sun’s radiation. When the skies are clear at night, the solar radiation escapes into space, thus creating cooler evenings. In fact the temperatures dropped so fast that frost grew on just about every surface, including my tent. It was going to be a cold night of camping on the ice sheet!
Until next time, this is Jim Pottinger signing off from Summit Station, Greenland