Kate Ramseyer: I can’t find the right words to describe summer sea ice from the air – which is unfortunate, as I am writing this post about NASA’s ICESat-2 summer airborne campaign on sea ice.
It’s like miles and miles of shattered glass, these little bits and pieces of ice falling apart and piling together again. It resembles a honeycomb pattern, except for a mixture of geometric shapes, without elegant hexagons. A 10,000-piece puzzle of white floating ice, teal melting ponds, and dark open oceans? Let’s go with that.
We’re flying over the Arctic Ocean in NASA’s Gulfstream V, a repurposed corporate executive jet (the former owner’s trademark still graces the ladder). On board are two laser instruments that accurately measure the height of ice, snow, thaws and the open ocean below. Hundreds of miles above us, earlier that morning, the ICESat-2 satellite flew the exact same trajectory, measuring the same ice. Scientists will compare data sets to improve how satellite measurements are used, and to better understand how and when sea ice melts in the hot summer months.
Aligning device measurements and satellite measurements is not easy. Days earlier, scientists gathered in a common room in our hotel at Thule Air Force Base in northwest Greenland, and compared ICESat-2’s orbital trajectories with weather forecasts for clouds. Clouds are the scourge of airborne summer campaigns in the Arctic – large storm systems can cover almost the entire ocean, and weather forecasting models are not reliable at this high latitude.
But on this first expedition of the expedition, the clouds were clear for extended periods, sending scientists, instrument operators, and you really into the windows to marvel at the stunning ice below.
“Now that’s the good stuff,” said Rachel Tilling, a sea glaciologist at NASA’s Goddard Space Flight Center, as abstract colored glass mosaics (and better?) of sea ice appear under a sunny sky.
It’s magical, watching all the ice pass by, seeing the cracks between streams and hills where bits of ice bumped into each other and refrozen. This expedition is particularly concerned with measuring thaw puddles, bright bits of teal as ice covering sea ice melts and collects, causing the ice to thin from the surface.
As we kneel in front of the port windows, looking outside, the lasers are right next to us, looking down. On this flight, Goddard’s Land, Plant, and Ice Sensor (LVIS, pronounced as The King) fires its laser at the time it takes for the light to travel from the plane to the ice, pond or water and back; ICESat-2 does the same from orbit.
However, not everything is smooth. To calibrate the LVIS, the aircraft must perform a series of tones and coils. Up in the air. over the polar ocean. With me on the plane.
I am not a big fan of flying. It’s been a decade or so until I can fly without imagining a fiery death every time we feel some turbulence. (I know, “physics,” but still.) I tolerate it, though, because I love going places.
But now we’re in a small plane, and we deliberately do a series of flaps (up fast, then down quickly) and roll (one wing down, then the other wing). intentionally. three times. The first time is the worst, says Nathan Kurtz, ICESat-2 deputy project scientist and campaign leader. Maybe for some. not mine. The first time was kind of fun, I’ll give you, and there’s a video evidence somewhere where I’m laughing nervously.
The second time: “Isn’t LVIS calibrated well enough?” The main idea was on my mind, which is why I’m not a machine scientist.
The third time, I regretted the snacks I brought during the flight. I said to myself, look at the horizon – just as the plane began to make its moves. Soon the horizon disappeared, then the plane rolled in the other direction, everything was icy, and then it rolled in the other direction….
I closed my eyes, took a deep breath, and imagined the wonderful sight, a mixture of ice and water, that would be there as soon as the plane stopped spinning.