A Northern Laser Light Show
For Mike Obland, a postdoctoral fellow with the Science Directorate at NASA's Langley Research Center in Hampton, Va., the most interesting part of his job is the variety.
Obland is one of three scientists going to Barrow, Alaska, to work with the High Spectral Resolution Lidar (HSRL) instrument, which uses a sophisticated laser to measure properties of airborne particles, called aerosols, like smoke, dust or other pollutants.
Because the HSRL flight team is so small, the three researchers must be able to share and handle a number of different roles. "There will be days in the field that I act as a primary operator of the instrument, flying with it on the plane and gathering the data," Obland said. "Other days, another scientist will handle that role and I will analyze the data. The job requires flexibility and an ability to juggle a number of tasks under deadlines, but the reward is that I feel like I am working on something new everyday."
Flying out of Barrow on the NASA King Air B-200, Obland and the other HSRL scientists are responsible for operating the instrument and for analyzing, archiving and disseminating the resulting data on a daily basis. The HSRL, an instrument conceived and developed at Langley, has logged more than 120 flights and collected more than 450 hours of data.
The greatest virtue of the HSRL is that it can measure how aerosols scatter or absorb light. Those measurements go a long way in helping scientists figure out what kinds of particles they are.
HSRL can identify where the aerosols are located in the atmosphere and relay that information to other researchers in real-time. This helps scientists decide where they should collect samples for later study.
Scientists compare the HSRL data with measurements taken aboard satellites, such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO).
Together, measurements from the aircraft-based HSRL and the space-based MODIS and CALIPSO can “validate aerosol predictions from climate models and to try to solve a variety of other research questions involving the atmosphere," Obland said. The results are used to study changes in the Earth and its atmosphere, helping scientists understand climate change, how it occurs and what it affects.
Taking airborne measurements is not new for Obland. "I have a bit of experience from my graduate school days at Montana State University. One of those campaigns was in Barrow, so I am familiar with the area and its environment." That's important knowledge to have, given that current high temperatures in Barrow are averaging 7 degrees Fahrenheit below zero.
"The biggest challenge during this campaign is simply the environment; Point Barrow is the northernmost point of Alaska," Obland explained. "The freezing cold can cause severe problems for our instruments, which means we have to find ways to warm up the instruments correctly before we take data, and to keep them from getting too cold."
At the same time the HSRL is taking measurements aboard the B-200, other ARCTAS aircraft will be flying in coordination at lower altitudes, taking measurements of the same aerosols. These data provide different viewpoints of the same areas in the atmosphere. When combined, they provide knowledge that is crucial for understanding how natural and man-made emissions affect regional and global air quality.
"We're one of several Langley teams involved in ARCTAS," Obland said. "Fortunately, our team consists of a dedicated and talented group of scientists, engineers, pilots and maintenance crew who are very experienced achieving and surpassing campaign mission goals."
"As with every campaign, our team wants to take the highest quality data that we can, as often as we can, to contribute to the overall understanding of our dynamic atmosphere," Obland said.
ARCTAS is one of many missions included in the International Polar Year campaign, an effort to gather data to study the polar atmospheres, oceans, lands, ice and many other facets of Earth science in these regions.
Denise M. Stefula
NASA's Langley Research Center