Tag Archives: Kurtz

Operation IceBridge Featured in EOS

Posted on by .

By George Hale, IceBridge Science Outreach Coordinator, NASA Goddard Space Flight Center

The new quick look sea ice data product released by NASA’s Operation IceBridge was the subject of a cover story in the Jan. 22 issue of the American Geophysical Union publication EOS. The article discusses the sea ice data product created by IceBridge scientists during the 2012 Arctic campaign last April and how these datasets provide new ways for researchers to measure Arctic sea ice.

Maps of survey of Arctic sea ice

Map showing quick look sea ice data from Arctic 2012 campaign


EOS article:

http://onlinelibrary.wiley.com/doi/10.1002/2013EO040001/abstract

For more about IceBridge’s quick-look sea ice product and its use in seasonal forecasts, visit:

https://www.nasa.gov/mission_pages/icebridge/news/spr12/arctic-seaice.html

https://www.nasa.gov/topics/earth/features/seaice-forecasting.html

New perspectives on the IceBridge sea ice campaign

Posted on by .

By Nathan Kurtz, IceBridge scientist, NASA Goddard Space Flight Center/Morgan State Univ.

As the IceBridge Arctic sea ice campaign continues another successful year, I’ve been given this wonderful opportunity to discuss my experiences on the mission, and more importantly, how they relate to the critical science questions that need to be answered. I realize that there are many details I find intriguing as a scientist that are inherently uninteresting to non-scientists, so I won’t wax philosophical about how impressed I was to see things like the self-similar structure of deformation patterns in sea ice (if you actually came here for that, I apologize). My aim is to communicate the importance of what we are learning to the broader public who funds and ultimately benefits from this work. I hope you learn something about why we are devoting so many resources to this scientific study, as this is perhaps the most effective type of ‘bridge’ the IceBridge mission can make: to raise awareness of the state of the climate and present the scientific facts as we have gathered them through a long and arduous field campaign.

IceBridge science team member Nathan Kurtz checking out the sea ice conditions

IceBridge science team member Nathan Kurtz checking out the sea ice conditions. Credit: James Yungel/NASA.

This was my first trip to the ice-covered regions of the Arctic and I fully admit to reverting back to an excited childlike state of wonder as my initial flight to Thule, Greenland, touched down. It was quite striking to take in the sight of the vast snow-covered mountains and frozen sea, feel the bitter cold draining the heat and life from my body and realize that actual ‘monsters’ with an instinctive mindset to view humans as prey were all around. But I was shocked to see a hardened community of people standing resolute against these elements. Even more shocking, was to imagine why humans came here thousands of years ago without modern technology. What led them here? For me, the Arctic has always symbolized the unknown, but with hidden treasures awaiting anyone brave enough to explore it. But I realize my subjective symbolic interpretation is also remarkably universal in that native settlers, polar explorers and scientists must also have come to the Arctic with a desire to explore an unknown wilderness and gain some new knowledge from their experience. 

On the scientific end of this knowledge spectrum, recent studies have increasingly shown the importance of the Arctic to the climate. The once seemingly insignificant and remote Arctic region is now understood to be intimately connected to the rest of the planet. Sea ice variability affecting the severity of snow storms in Europe, melting sea ice increasing the absorption of sunlight by the Earth and melting ice sheets causing sea level rise are but a few of many such connections. We are learning that what happens in the Arctic will profoundly affect the whole of humanity all over the Earth. Viewed in this way, it is no longer a coincidence that humans have taken such a keen interest in the Arctic, and that this wild frontier is indeed a source of valuable knowledge waiting to be unearthed.

Looking out across the sea ice near Thule, Greenland

Looking out across the sea ice near Thule, Greenland. Credit: Nathan Kurtz/NASA

As a scientist, the purpose of my trip here is to learn more about the Arctic sea ice cover. My job is to use a combination of lasers, radars, cameras and infrared sensors to determine how the thickness of sea ice is changing, and whether any observed changes can be linked to the larger climate system. Flying over the sea ice with all the IceBridge instruments operating simultaneously has given me a whole new perspective on the mission. It has taken me from my normal desk job of looking at numbers on a computer screen, to the reality of what those numbers represent, and back again full-circle to connecting these concepts in a meaningful way. It has given me the opportunity to physically see that an increased laser surface elevation is actually a large sea ice pressure ridge, a widely spaced radar return is actually a snow drift. That, ultimately, all of the IceBridge results are indeed real and meaningful. It is this connection between numbers on a computer screen to the reality of the ground which will provide me and other scientists with the ability to come up with a rigorous scientific explanation of precisely what role sea ice thickness changes will have on the climate. 

In the course of my own analysis of the IceBridge data I have been constantly questioning my methods to ensure that my excursions into the abstract realm of mathematical and scientific theory do not lose sight of this connection to the things I’ve seen on the ground. Questions such as what do I do when I try to invert a matrix of IceBridge data and it explodes? How can I utilize statistics to determine just how accurate these measurements are? Are my solutions to these problems in tune with the physical environment I have witnessed? This ultimately translates into maintaining high standards and objectivity, which is critical to any scientific research area.

Sunrise over sea ice near the North Pole

Sunrise over sea ice near the North Pole. Credit: James Yungel/NASA

But this is, admittedly, my own subjective understanding of my role in this project. More important, is how my understanding and use of these concepts relates to the scientific results being obtained, and how these results can then be translated into a general statement for the public such as ‘the sea ice thickness decreased by x centimeters’ Towards this end, I and a large team of people have worked for the past two years on developing methods to turn the instrument data from IceBridge into clear and understandable scientific data products. We recently reached a major milestone in the project by demonstrating our ability to produce easy to understand products such as snow depth and sea ice thickness from past missions. In the interest of promoting honest and open exchange of scientific knowledge, we have given public access to these data sets (http://nsidc.org/data/idcsi2.html) in such a way that anyone can look at the latest results of the project. In doing so, we went from the realm of raw instrument data, to something that anyone can understand and interpret.

To further improve the utility of the IceBridge sea ice campaigns, we are attempting an unprecedented feat: to produce a quick version of the scientific products to support operational forecasting of sea ice. This is shaping up to be a monumental undertaking, and we are working hard to understand how to work with days-old field data. It remains to be seen what role IceBridge can play in sea ice forecasting and how we can interpret the data to come up with statements about the state of Arctic sea ice for the general public. But, so far the results from the first few flights look fantastic! We have also provided our preliminary results to support an ESA sponsored campaign conducting field missions in the area. Everything is proceeding in a positive direction, so stay tuned for more updates as the IceBridge mission continues!

Second Weddell Sea Ice Mission and CryoSat Underflight

Posted on by .

From: Nathan Kurtz, NASA’s Goddard Space Flight Center/University of Maryland, Baltimore County

Our flight today, Oct. 28, was a partial repeat of a mission conducted last year. The flight was to take place at 1,500 feet along the western edge of the Weddell Sea following the Antarctic Peninsula, turning south and east along the Ronne Ice Shelf, then heading north into the central Weddell Sea. The primary instruments used on this flight were a specially designed suite of laser and radar altimeters for measuring the thickness of the snow and ice underneath.

I began my journey in the cockpit of the NASA DC-8, my first time seeing what all is involved in bringing a large aircraft from the runway into the sky. We took off on schedule flying briefly around the countryside surrounding Punta Arenas, heading back over the airport ramp to calibrate some of the instruments. We then started our push towards the Weddell Sea. Along the way there were spectacular views of the normally cloud enshrouded mountains and glaciers of Tierra del Fuego. Even at an altitude of 18,000 ft the 8,000 ft peaks looked a bit too close for comfort, but the calmness and confidence of the pilots helped rid my mind of any thoughts of catastrophe.

After a couple hours transiting through serene blue skies we spotted the Antarctic Peninsula and began our descent to low altitude. My first ever science flight to the polar regions from two days ago was still fresh in my mind, but the view of the pristine landscape still captivated me. As we passed over the peninsula, there were breathtaking views of jagged brown mountains, bright white snow, sky blue glacier ice, and murky black water all mixed together in a chaotic jumble. I was struck by how truly remote and harsh the world down below was. A place only for well prepared humans and the hardiest of animals. Despite the uninviting look of the land below, I couldn’t help imagining what it might be like to ride a sled or go skiing down some of the mountains.

As we left the peninsula, we passed southward over still waters filled with icebergs, finally entering into the sea ice region to begin our science mission. We first entered into a region of small sea ice floes which had been broken up by wind and waves. The aircraft instruments showed the surface and air temperatures were near the freezing point, probably the reason for the absence of any newly growing ice in the open water areas. As we continued our flight southward we entered the consolidated ice cover of the western Weddell Sea. The region we were flying over today is some of the thickest and most compact ice in the Southern Ocean. The vastness of the sea ice cover became readily apparent as this leg of the journey consisted of miles of ice extending into the horizon in all directions. The area was a mixture of open water, freshly grown ice, smooth areas, rubble fields, ridges, and many other ice types each with intricate geometries reflecting the physical processes which shaped their formation. Towards the end of the peninsula region we turned east following the outline of the Ronne Ice Shelf. Though we couldn’t see it in the distance, evidence of its presence was all around us as numerous icebergs could be seen. The huge size of the icebergs dwarfed the surrounding sea ice, but the icebergs were held steady inside like giants chained into a prison of sea ice.

The sea ice itself looked benign and serene, like a vast unmoving and unchanging landscape. But looks can be deceptive as the aircraft instruments showed temperatures of -10 C and 60+ mph winds outside. Telltale signs of the force of wind and water acting on the ice could be seen in the piled up and crushed ice of the ridges. The wind had also blown the snow into patterns called sastrugi, some of them looked like flowers dotting the landscape. The plane marched on relentlessly throughout the day as miles of sea ice passed below us. The last leg of the science portion of the flight took us underneath the orbit of CryoSat-2, a radar altimeter launched earlier this year by ESA.


Data from the Airborne Topographic Mapper (ATM) show a swath of sea ice at the time of the CryoSat-2 overpass on Oct. 28, 2010. Data in this image are preliminary. Credit: NASA/ATM Group

One goal of this mission was to collect coincident data between IceBridge and CryoSat-2 for doing intercomparisons between the various altimeter data sets used in cryospheric research. We were a bit ahead of schedule however, so we looped back over portions of our flight line to ensure that we were still collecting data when the satellite crossed over. Finally, as the sun hung began to sink low on the horizon, hundreds of miles above us CryoSat-2 passed silently overhead covering hours of our flight track in a matter of minutes. We continued flying northward a little while longer towards the edge of the ice pack where the ice became less consolidated and more broken up. Our mission finished, we climbed high into the sky and sped back to our temporary home in Punta Arenas.

Image is courtesy of NASA/Jim Yungel

It’s difficult for me to tell much about the ice cover properties from the limited perspective of my human eyes, but memories of the journey will remain with me for a long time to come. An enduring and detailed record has also been written into the hard drives of the IceBridge instrument archives. I and other scientists are eagerly anticipating doing a thorough analysis of the data collected. Hopefully it will tell us more about what we saw today and how this record can be used to enhance our understanding of the climate system.