Farrell involved in NASA’s ICESat-2 Ice Monitoring Mission

By Chrysandra Medley

On Saturday, September 15, NASA successfully launched the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2), a mission meant to measure the changing height of Earth’s ice over the next 3-7 years.

This comes at a critical time, as the Greenland and Antarctic ice sheets rapidly lose ice and contribute to sea level rise, requiring continuous monitoring.

ICESat-2 will carry the Advanced Topographic Laser Altimeter System (ATLAS), an instrument that will send 10,000 laser pulses a second to Earth’s surface and measure the height of ice sheets, glaciers, sea ice, and vegetation by calculating the time it takes the pulses to return to the spacecraft.

“The round-trip travel time of individual photons of green light from the spacecraft to the Earth’s surface and back is timed very precisely,” said ESSIC / CICS associate research scientist Sinead Farrell, “The spacecraft’s location is also precisely measured using GPS and star trackers. Using this information, we can obtain very precise measurements of terrain on the Earth’s surface.”

Farrell is a member of the NASA ICESat-2 science team, a group of about 20 scientists who guide NASA on mission development before launch and evaluate new data after launch.  She first became involved in this work in 2003 with NASA’s original ICESat mission.  Since then, she has also worked on the Operation IceBridge mission, an airborne mission designed to bridge the gap between the two ICESat missions as well as verify the accuracy of the space measurements.

The precise and complete coverage afforded by ICESat-2 will enable researchers to track changes in land and sea ice with unparalleled detail, providing better understanding of what drives these changes.

“Sea ice acts as a blanket, insulating the ocean from the atmosphere. It is so bright that it reflects sunlight back to space during the summer, helping to cool the planet,” says Farrell, “Changes in the sea ice cover impact both weather and climate, and can also alter the circulation of the ocean.”

Science team members will have access to data in just a few weeks post-launch to begin accessing the algorithms used to process raw data into meaningful measurements.  This data is expected to be made public in the Spring of 2019.

In addition to her work at ESSIC and CICS-MD, Sinead Farrell is a visiting scientist at the Laboratory for Satellite Altimetry, National Oceanic and Atmospheric Administration (NOAA) Center for Weather and Climate Prediction (NCWCP), and an affiliate of the Cryospheric Sciences Branch at the NASA Goddard Space Flight Center (GSFC).  She is also a principal investigator on the NASA/NOAA Ocean Surface Topography Science Team as well as the NASA ICESat-2 Science Definition Team.

To keep up with ICESat-2, follow updates posted on the mission homepage, and look for regular tweets by @sineadlfarrell.  To keep up with what is happening at ESSIC, be sure to follow our Twitter (@essicumd) and Facebook accounts.