OIB ATM sitrep Nov 3, 2016 pm

Some days are more difficult than others, and this morning (preparing for the 13th science mission of the deployment), we had our share of pre-mission difficulties. The ATM T6 laser required some pre-mission adjustment, which unintentionally created some impact on both the ATM real time display (requiring about a 30 minute delay in takeoff as we worked out a solution) and also impacted the in-flight ATM data processing, causing a false impression the ATM data might be corrupt (requiring some in-flight modification of data processing parameters). We worked thru the issues, and both ATM T5 narrow scan and T6 wide scan lidars acquired good data throughout the mission. The DMS, Gravity, and CReSIS radars, and Mission science data systems all acquired good data today.
Today’s science target site was Thwaites Glacier, which we first mapped in 2002 flying on a Chilean Navy P3 aircraft and many times since that initial mission. The 14-year timespan of ATM lidar elevations, CReSIS radar bedrock soundings and other OIB measurements over this massive and important glacier have documented recent ice loss, as the glacier surface is subjected to warmer air temperatures, and warm seawater intrudes into and under the glacier ice. The bedrock under this glacier is depressed well below sea level (a retrograde glacier), so seawater intrusion can rapidly progress “upstream” under the glacier and accelerate melting.

Today’s flight lines formed a grid over the lower portion of Thwaites. Mount Takahe was at the west end of the grid pattern providing an interesting contrast to the Thwaites glacier scenery, some images attached below.

The weather forecast continues good for the next few days, so we hope to attempt another mission tomorrow.


Approaching the edge of the Thwaites Ice Shelf, with Thwaites extending into the distance.
High winds keep sea ice from forming on the water, and also results in snow blowing from the shelf edge on the right side of the image.
Blowing snow at the Thwaites Ice Shelf edge
The north side of Thwaites glacier as the ice begins breaking up and calving into the ocean.
High winds causing lenticular clouds on the downwind side of Mt Takahe, early in the mission with partially overcast skies

Later in the mission, the skies had cleared and clouds mostly dissipated over Mt Takahe 
As we passed by Mt Takahe late in the science portion of the mission, everyone was on the right side of the DC8 making the most of the photo op.
Mt Takahe on the fly-by.
Below are two ATM T6 wide scan elevation plots of Thwaites crevasses.The first plot shows crevasses in the center of Thwaites Glacier, The second plot shows crevasses on the shoulder of Mt Takahe.


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