The Lamont Icepod team is a blended mix of engineers and scientists learning from each other through the design and testing of this new instrument. With a range of talents and backgrounds, the project mixes seasoned field workers with those new to field work; experienced instrument developers with those newly learning this end of engineering; and scientists with countless hours spent pouring over Greenland ice sheet data with those exploring the ice sheet for the first time. It is the opportunity for mentoring and development that comes from this mix of early career with experienced personnel that has made the Icepod Instrument Development Project a good fit for its American Recovery and Reinvestment Act funding.
So who makes up the Icepod engineering and science team? As we work through data and examine the products collected in the first part of our field season there is an opportunity to introduce members of the team and the data and instruments they operate.
Chris Bertinato trained as an aerospace engineer before joining the Icepod team. In the air he is the team’s connection to the flight decisions made by the crew. Like the members of the flight crew he dons a headset as soon as aircraft begins its warm up. The headsets are connected into the plane electronics through lengthy cabling that trails behind each set. The cabling necessitates a threading and weaving between the crew as they move about the aircraft, testing and checking equipment and switches. Watching them work one can imagine a class devoted to practicing safe maneuvering about the plane while tethered to the electronics system – something like a Maypole dance!
Chris is a main operator of the equipment rack and has responsibility for the Laser Imaging Detection And Ranging (LIDAR) system part of the optical package in the pod taking constant measurements to find the surface elevation, and the inertial navigation system (INS) used to locate or ‘georeference’ the data. The INS is a critical navigation aid that employs several accelerometers (motion sensors) and gyroscopes (rotations sensors) to continuously calculate the position, orientation, direction and speed of the plane as it moves through space. INS were first developed for rockets, but have become essential instruments for collecting referenced data in an aircraft, since the pitch, roll and yaw of the plane (see drawing) as it moves through the air can make it difficult to correctly locate and orient the data for processing. For those of us used to flying on commercial airliners, movies and music can provide enough of a distraction that we don’t notice the regular rolling of the aircraft as it responds to buffeting by the air around it.
The cylindrical housing for the laser sits snuggly in one of the pod bays with the INS sitting atop in the small grey box. The laser focuses down through a clear panel, and scans back and forth in a swath that at 3000 ft. of altitude swings approximately 3000 ft. wide collecting elevation information. The data is then fed through a processor that turns it into elevation data.
The image above shows a swath of laser data over the airbase, and can be used to help explain the instrument. The color in the image shows the reflectance of different surfaces to the laser. You will see three of the LC130 aircraft lined up across the front of the airfield, cleaned from snow and clearly outlined in the data. There are two additional aircraft positioned in the middle of the image that are still surrounded by snow and therefore remain somewhat obscured. Trees, roads and other features in the adjacent area are clearly imaged.
In Greenland Lidar will be used to assist with locating features of interest in the icesheet. The image above of meltwater channels in Greenland will be important to track during the summer season as these channels can reactivate seasonally, becoming a blue stripe on the otherwise white landscape. These darkened blue sections will absorb more heat energy from the sun due to their altered reflectivity (albedo) encouraging additional surface melt. In an upcoming post we will discuss how the infrared camera carried in the pod will allow us to track the heat energy in the channel both in its current state, and as it begins to melt later in the season.
Lidar will also be used to detect openings in the ice sheet (crevasses). Many of the crevasses are deep yet not wide, making them difficult to detect without the assistance of instruments. Detecting crevasses is important as they pose danger for pilots attempting to land and deliver support to ground crews, can be deadly for overland traverses that are carry scientists and support staff across the ice, and can provide us with critical information on changes in the ice sheet. Lidar data collected in our Icepod flights can be used to help in all of these situations.
For more on the Icepod project: http://www.ldeo.columbia.edu/icepod
By Ana Camila Gonzalez
When we walked into the Sheraton in Springfield, Massachusetts we were greeted by none other than a wall full of cross sections from trees perfectly sanded to reveal the rings.
“No way” I say. “I forgot the camera!” says Neil.
We were just walking into the Northeast Natural History Conference, along with Dario and Jackie from the Tree Ring Lab. When I pictured my freshman year of college last summer, I pictured a lot of things. I did not picture getting to go to a conference to present a poster on my own research.
On the first day we listened to talks given by people who dealt with everything from conservation science to birds and berries and beetles. I’ve gone to multiple talks at Lamont, but those talks are mostly geared towards graduate students, so I’m always the slightest bit lost listening to them. This conference seemed to be geared towards a wider audience: I could actually understand the talks. I couldn’t believe it at first. After the first day I knew a little more about a wide range of topics: I can now tell you about the reproductive cycle of a lobster, what kind of fruits allow birds to fly farther during migration and even the life cycle of an Emerald Ash Borer in a tree.
I also learned more about the research process, since many people were presenting research projects that we weren’t already familiar with. I thought there was only a specific set of proxies for climate, but I found that people are continually finding more and more. I listened as someone described how they were using a mountainside as a proxy for climate change, and I realized that one of the great things about environmental science is that you can use the world as your lab, in many cases literally.
That afternoon during lunch we were told to make sure our GPS systems were safely hidden in our car. We were warned that we had to realize that we were now in a “big city.” We joked at our table—all being from New York—about how Springfield didn’t seem like a big city at all. I liked the thought, however, of a field of science where so many people are able to work in small rural towns that they do see Springfield as a big city. Want to know a secret? As much as I like school in the Big Apple, and I see myself living the city life for a while after school, I don’t see myself living anywhere with a population over five thousand after that.
Everyone in the lab was scheduled to present the next day. I was scheduled to give a poster, but Jackie, a Senior undergrad at Columbia, was scheduled to give a talk: we were both freaking out in the hotel room that night, but she probably had more justification. That night Jackie, Neil and Dario went through their talks while I made a big deal over how to cut my poster. Jackie ended up cutting it for me; my hands were too shaky. I must have asked a million questions to prepare that no one ever actually asked me, but by the end of that night I felt ready. “At least I’m not giving a talk!” That didn’t really calm Jackie’s nerves.
The next morning we had an awesome breakfast, I bought a piece of flan for no apparent reason, and we headed to the conference. I set up my poster and less than a half hour later sat to watch Jackie, Dario and Neil give their talks back to back. They were all wonderful, and some questions were asked that sparked some good conversation. Someone made a comment about baldcypress, and my ears turned up at the corners. She was mentioning how incredibly sensitive it was to drought, and I have to admit I got a little too excited. I talked to her afterwards: “That makes so much sense! I’ve been trying to cross-date this batch of baldcypress for so long, and it seems like every drought year thus far has produced either a narrow, missing or micro ring, and yeah, like you mentioned, isn’t it crazy that they’re so sensitive…” yeah, I was a little over-excited. It worked out well, because I had to go stand by my poster directly afterwards.
This is it. I’m standing by my poster. Someone comes up to me. THEY’RE GOING TO ASK ME SOMETHING I CAN’T ANSWER… THEY’RE GOING TO… “Hey, so can you tell me a bit about what you did?”
Wait. Really? I can do that!
The rest of the poster session went well. I was asked more than “can you tell me about your poster,” but it wasn’t half as bad as I had imagined. There were many questions I could answer, and there were many that I couldn’t. I ended up liking the questions I couldn’t answer more, however, because they told me what to do next. The same scientist who I had talked to previously about the baldcypress caught me off guard when she told me she’d look forward to reading about my findings in a paper. I hadn’t thought about it before, but I guess that’s my next step: take the unanswerables and answer them.
All in all, I learned more than I ever thought I could at the North East Natural History Conference, and walked away with much more than just natural history. I’m more excited than ever for what’s to come.
Ana Camila Gonzalez is finally out of the woods. She has, essentially, completed her first-year as a student in environmental science and creative writing at the Tree Ring Laboratory of Columbia University and Lamont-Doherty Earth Observatory. She has completed her blogging on the process of tree-ring analysis, from field work to scientific presentations…for now. We are happy to announce that she will be working with us for Summer 2013.
When we left Stratton Air Field almost two weeks ago, I recall smiling when a mechanical issue temporarily pulled us from the aircraft and the woman shepherding us back into the waiting area remarked, “Don’t worry, we keep doing it until we get it right!” Today we are faced with just that type of day. Testing a new system is all about running through the same set of operations “until you get it right.” For our team, this means flying the same patterns over the same locations looking for repeat targets to test and retest our instruments.
The aircrew arrives each morning ready to fly the patterns and routes we have selected. They are willing to redirect if the weather changes, or if our priorities shift, but we have stayed fairly consistent in our requests. Of course, being in Greenland, we talk about varying our plan and picking some of our science team’s favorite targets. It seems almost unfair to be here and not venture off to the fast changing Jakobshavn or Petermann glaciers. But we are a disciplined group with a specific mission…we need to do it “until we get it right.” The navigator programs the plans into his system and we are ready to fly.
We are lucky. No matter how many times we fly over the Sondrestrom Fjord, it always looks stunning: the water a deep blue, the ice pieces feathered along the edge where the floating tongue ends. Once we move over the deeper ice in the center of the glacier, we still marvel at the twisting, refrozen meltwater streams that wind across the ice face.
Over the rocky edges of the landmass it is still fascinating to see the twisting rolls of collapsing ice that pile and swirl along the brim of the flat-topped frozen lakes. The mountains themselves look like painted rocks with their smooth and shiny surfaces.
It is hard to believe one could ever tire of these flights. Each area we fly over is more stunning than the next. Today our flight is cut short. Engine trouble brings us back to the base, but we’re hoping that tomorrow we’ll be back up in the air trying one more time, “until we get it right.”
For more on this project: http://www.ldeo.columbia.edu
Holidays vary around the world with their dates and traditions, so it should have come as no surprise that we would find a holiday in our scheduled Greenland visit. Today, April 26, is “Store Bededag,” which translates as “Great Prayer Day,” brought by the Danish to Greenland when they ventured to this island from their homeland. Kangerlussuaq, and other populated areas of Greenland, are a mix of Danish and Greenlandic in people, language, food and tradition. The holiday does not stop our survey flights today, but a snow storm with low-visibility has brought us to the ground. In the end it is a good day to focus on data.
Prior to today we have completed several flights, each with a tightly designed purpose, and there is plenty of data to be gone through. With our newly designed system, each instrument must be tested individually for operational capability and range, and then assessed for the enhancement that comes from aligning the results with the data from the other instrumentation. Calibration runs are also required for some of the instruments. In the end, each flight ends with a stack of data disks which need to be reviewed in detail.
Each flight has a list of priorities designed around specific target locations and weather availability. Yesterday our target instruments were the visible and infrared cameras, the laser system and the deep ice radar system. For the two cameras we would fly down Sonderstrom Fjord building a set of matching images.
The Bobcat, our visible image camera, showed a wide swath of surface imagery, noting where fast moving ice had crumpled into bands of ridges, as well as where it had thinned, cracked, and showed evidence of refrozen melt water streams.
The Infrared Camera operates at a higher frame capture than the Bobcat, and collects temperature differences from the places where the ice has thinned or opened. The colder the surface, the blacker the infrared image; warmer surfaces show as white. The tongue of the fjord is an excellent testing area for this.
The Deep Ice Radar was being fine-tuned on this flight. Following the first Greenland test flight, the system was adjusted and the team was anxious to see the results. We headed up Russell Glacier to get to enough ice depth to receive the radar returns, but with the weather worsening and the winds kicking up, we didn’t go any further than needed.
The LIDAR (Laser Imaging Detection And Ranging) testing was our last test of the day. Designed to give us surface elevation, with repeat use it can show change in ice surface elevation over time. In order to show small change in ice elevation, a very tight accuracy is needed, on the order of 10 cms. The LIDAR calibration was designed as a gridded pattern of 4 by 4 lines flown at 170 knots of air speed. Calibration flights can be bumpy and twisty, as the plane will roll with the turns needed to create the pattern. The 20-knot headwinds cause some additional turbulence, but the full eight passes are completed before a return to the airfield.
For more on Icepod: http://www.ldeo.columbia.edu/icepod
Half of the people lining the walls of the Kangerlussuaq International Science Support (KISS) building are waiting to go north to the top of the ice sheet at Summit Camp, and the other half are waiting to go east to the top of the ice sheet at Raven Camp. The science and support teams have been ready and waiting for several days now, hoping for a break in the weather up on the ice sheet.
Ice sheets are large enough that they can create their own weather. Large mountains of ice several miles thick, they stretch into higher elevations and gather the clouds around them. The sunny but cold weather (-21 to -9 degrees C) is a tease to the group ready each morning and waiting for clearance, day after day.
For the Icepod team the waiting is just as difficult. A series of flight options have been drafted, but with the target of getting equipment and teams out to the camps, our flights are shifted for the moment to “piggybacks” with other flight missions. Piggybacks are actually an excellent opportunity for the project to show how the pod might work once the full system is tested and ready for science use. The project design is for the pod to be fully integrated into the guard’s NSF Operation Deep Freeze mission of supporting science in the polar-regions. In the future, as the LC130’s deliver cargo and personnel to the polar science camps, the pod can be switched on by the loadmaster to gather data as the aircraft transits.
Word comes mid-morning that the first flight of carpenters and materials will head to Raven Camp. There is not room for us but we are set for the second flight. The runway at Raven Camp is a groomed strip on the ice sheet, so the pod will make its first ice landing.
The first morning flight and ice landing go well for the pod, but one aircraft engine is causing some concern. The aircraft is looked over and the engine is cleared for us to take off late in the day with the second cargo delivery. We will fly out at high altitude before we stop at camp to install a temporary GPS for an Icepod GPS calibration. A forklift is used to load two large pallets of cargo onto the metal tracks that run the length of the aircraft and that assist the quick release of the supplies. The delivery at Raven Camp will be a “combat offload” with the cargo unstrapped and the plane moving forward on the ice so that the load slides out the back.The pod team is loaded and ready to head out.
Cargo Combat Offload
“Combat Offload at Camp Raven April 23, 2013 with the Icepod project. (credit Matt Patmore)”
With the cargo delivered, several of us exit the aircraft to install a GPS base station on the ice sheet so that the pod can complete its GPS calibration. A cloverleaf design will be flown with 20 to 30 degree turns closing the loops and straight lines between, while the GPS tracks the changes in direction and the movement in the air. In the pod design an array of GPS’s were mounted, one on the aircraft hatch and several on the pod itself, in order to determine the best location for “seeing” the satellites and yet be close to the instruments. The GPS is critical to all the data, used to tie back to a specific point on Earth. One station is set up back at Kangerlussuaq, and the second set up at Raven Camp will provide us a closure point so that we can tie together and adjust all the points in between.
The station is set to operate. The team returns to the aircraft from the ice sheet and the calibration is flown. A follow-up flight to Raven Camp over the next few days will retrieve the GPS station. Once completed, the team heads for home over the ice sheet for a 9 p.m. touchdown. Although the aircraft loses an engine in the return transit, the day is determined a success with the completed piggyback flights, ice ramp landings and the GPS instrument calibration.
For More on Icepod: http://www.ldeo.columbia.edu/icepod