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On the ice with climate boffins, April 29 2008: Chris PetrichWhat should have been a routine trip to take another snapshot of snow and ice conditions promised to turn into a rather frustrating couple of days in Barrow. Everything took me longer than expected, whiteout conditions made snow dunes invisible, and recent snow fall covered the ice with a blanked of fluffy snow only waiting to be blown away once the wind picked up. Oddly enough, it all fell into place on the last day of this trip: the wind blew away much of the fluffy snow, the clouds were thinner and I could see the ground, and I had a very energetic group of ambassadors of Ben and Jerry's Climate Change College helping me on the ice. Everything worked out very nicely after all. There is coverage of the last day of this trip in the online edition of the British tabloid newspaper, The Sun. SIZONet Campaign, April 2008: Daniel PringleThe International Polar Year (IPY) is now in full swing. Led by Hajo, our group is heavily involved in SIZONet ( Seasonal Ice Zone Observing Network) to make and coordinate sea ice measurements in the seasonal ice zone. The seasonal ice zone is the area where ice is not present year round, but grows in the winer and melts in the summer. This is a usual cycle for much of the western and northern Alaska coast. Hajo, Matt, Jonas, Malcolm Ingham and myself were all up there sometimes between April 4 - April 16.
Left: Malcolm working with the new, autoamted geolelectrics system. Right: Malcolm, Stefan, Blake and Mike. Bottom: leads in the near-shore ice en route from Prudhoe Bay to Barrow. I like the cool "vapor trail" caused by the condensation of water evaporating form the long linear lead.
More than just our group, this was a coordinated effort in Barrow with many visiting groups converging to make measurements on both the landfast ice attached to shore, and to use helicopters to access off-shore ice. A central interest was ice thickness measurements. On an Arctic scale, satellites can image the area of sea ice, but not the depth, so extra measurements are needed to monitor sea ice thinning and its change in total volume. Regionally, thickness measurements are useful to determine whether or not ice ridges are grounded on the sea floor, providing additional stability to the ice. Barrow is a good meeting point for these two interests, and we had a mix of experienced operators of established devices and researchers new to sea ice with developmental devices. Stefan Hendricks from (AWI )( the Alfred Wegener Institute, for German Polar and Oceanography Research) was back in Barrow again. Stefan was operating his `EM bird`, a torpedo-like device slung from helicopters to measure ice thickness using a process called electromagnetic (EM) induction. The bird generates an oscillating magnetic field (4 kHz), which induces currents in the ice and water below, which in turn generate secondary magnetic fields. The bird measures the total response, from which Stefan can determine the position of the bottom of the ice. This is because the salty sea water is much more conductive that ice, so the secondary fields are dominated the bird basically measures A laser altimeter measures the height above snow, and the difference is the total thickness of snow + ice. Stefan has operated all over the Arctic and Antarctica - but hopes to finish his PhD soon! Malcolm and I again made DC electrical resistivity measurements using surface arrays and 4 strings frozen into the ice back in January. Armed with a new, automated system, we were much faster, warmer and happier than previous trips of laborious manual measurements - which nevertheless did lay the groundwork for the current measurements. Brent Nowak and his student Austin Derric were up from San Antonio Texas to field-test an ROV (Remotely Operated Vehicle) for under ice photography and videography. It seemed like a very valuable trip for them - a lot of things can (and did) go wrong at -20 C that you wouldn’t anticipate in Texas. They were never flustered, and it would be nice to see them back in Barrow later on. Under ice images are really cool and it would be need to inspect the grounded ridges in Barrow that anchor the landfast ice in place. Mike Lewis and Blake Weissling were also up from Texas for field testing. Their instrument is a multi-frequency EM device and they were calibrating and field testing. Blake has the dubious distinction of being on two research boats on which fires have broken out. Matt Druckenmiller continued his work mapping local whaling trails. Each spring these snow machine trails are cut through rubble fields of ice to the preferred position at the ice edge of each whaling captain. Matt collected more than 40 km of thickness measurements by walking these trails with a surface-based version of the EM bird (Geonics EM-31). A real highlight of the trip for me was joining Matt and Lewis Brower to cut trail one night, then heading back to his Dad’s house for hot tea. Lewis is the Logistics Coordinator at BASC and the youngest son of esteemed whaling captain Arnold Brower Snr, who is lithe, extremely knowledgeable and very sharp at 84 years old and still hunts by himself 100 miles from town. He was preparing whaling equipment when we visited at 11pm and over tea and cookies shared stories and insights. back to top Curious bears, March 2008: Daniel PringleIt seems that we are not the only ones interested in our mass balance site. A curious bear appears to have inspected our site in mid March. Scott Oyagak from BASC went out to change over the batteries and found prints all around and some damage to our masts. Reports this year are of higher bear activity out on the ice in this general area (site map). This may be related to the whalebone dump being closer this year. This is where previous seasons whalebones are left so that the congregating bears are safely out of town.
Left to right: site as installed; bear damaged but still standing; data logger box still standing and operating, note metal conduit to protect cables from foxes.
Thankfully none of the cables were cut, and transmission resumed as usual once the batteries were replaced. The snow pinger was dangling about though so it was fortunate also that Chris Petrich was heading up this week for other work and was able to repair things. Last year it was a fox eating through Malcolm Inghams electrode strings. Joe Trodahl once had a thermistor string in McMurdo Sound catastrophically bent by either a seal or big Arctic cod. What next? back to top Installing Mass Balance Site; February 7, 2008: Chris PetrichHajo, Jeremy, Jonas and myself went to the ice in Barrow to deploy the mass balance probe, and to do snow and ice measurements. Bear guard Michael used his snowmachine to scare away four polar bears (a mom with two cups, and a young bear) that were roaming the area when we arrived. Watch Jeremy and Jonas sampling snow:
back to top First impressions; January 9, 2008: Chris PetrichI went to Barrow for a first reconnaissance of sea ice conditions. Also, I measured the snow thickness profile along a 300 m transect with Matthew Sturm's Magnaprobe. This established a base line for snow thickness this season. There were hardly any snow dunes that would have made this survey exciting at the time. Had a white fox carefully watch me cut a sea ice core for salinity measurement. Bear guard Nok Acker frightened-off an approaching polar bear with the noise of an idling snowmachine. back to top Melt season, June 2007: Daniel PringleBy early June, the sea ice has melted back a lot. Conditions are warmer for field work, but can be windy still - and we now need to contend with melt water. At this time of year, the sun is getting stronger and the snow on top of the ice is melting more and more each day. We were a large group this trip - Christina Williams who has been working on the radar imagery made her first trip to Barrow, joining myself, Hajo and Chris from UAF. The super-enthusiastic Ken Golden (aka frogman) was up from the University of Utah. Ken has long been interested in the fluid permeability of sea ice, so melt season is his time of year. As it is for Don Perovich, from CRREL New Hampshire. Don works on the spectral albedo. He is an expert on what effect the ponding water has on how much incident sunlight is reflected back.
back to top A new Fieldwork Season, January 2007: Daniel PringleWe arrived in Barrow at about the same time as the sun. This season, we had wanted to install the ice mass balance equipment back in November, but first ice conditions and then the winter night held us back until now. The 2006 summer was a bit different from recent times in that there was a lot of old winter ice drifting by and within sight of land. However this did not translate directly into an early freeze-up of the land fast ice. It was plenty cold enough, but it seems that prevailing north-easterlies blew the newly-forming ice away from shore at the time when ice building needed westerlies to bring pack ice and in and secure the new ice against land. Our group included Matt Druckenmiller, Chris Petrich, Guy Dubuis, Yoshiki Kawano, and myself. It was the first trip to Barrow for all the others except Matt, and overall it was very successful. Chris and Yoshiki recovered multiple cores for measuring the variability of salinity profiles. I think the key discovery here gaining familiarity with the field and laboratory equipment, and operating conditions in Barrow. Guy and I installed this season's wireless mass balance site.
Left ro right: sunrise from the sea ice; and installing the sea ice mass balance site, with Nok Acker in the foreground; Group outside Browers Restaurant; installing hydraprobes to measure sea ice dielectric properties. back to top Barrow in June, 2006: Daniel Pringle
The last trip to Barrow was timed perfectly. Last measurements were made and our equipment extracted just before the onset of a lot of surface snow melt that would have complicated snow machine travel and access to our site as well as interfering with the measurements.
The landfast ice has been very consolidated and stayed in a long time this year. Usually wind and ocean currents would have broken this ice into smaller pieces by now, allowing it to more away from shore and opening up leads (open water in the ice pack) so important for whaling. It was a terrible spring whaling season - only 3 whales from a quota of 22 strikes and 20 landings. It was the talk of the town. They'll wait now for fall whaling - hunting from boats in more open water - and pray for enough whales to see them through the winter. We took a reccie out to the ice rubble zone, where stresses crumble the ice up and older ice is sometimes caught up in the first-year ice just grown in the last winter. I love this picture of Hajo and Matt Druckenmiller up on a huge block. The water is a melt pond - the sun has melted snow on the ice surface but the water can't drain through the ice. As the ice warms up closer to its bulk melting point (-1.8 C) the ice actually does become porous enough to allow drainage - and this change in 'permeability' of the ice is what my work looks at. One evening we also went 'birding' aka bird spotting. Hajo got super excited when he thought he'd seen some puffins, but it turns out they were more likely spectacles eiders (as in the ducks that give their name to eider-down). We did see tundra - and trumpeter- swans, phalaropes, loons, snipes, different types of jaegers, and the local favourite, Steller's eider. Too bad we didn't see any snowy owls though. We had a warm spell too - so now I've experienced -56 F and + 54 F up here (-49 C to +12 C). The on-ice equipment worked well this year, and preliminary results from the measurements with Malcolm Ingham from VUW look promising too. So all up, a good field year. I'll probably be back up in November. back to top Barrow April 23, 2006: Daniel PringleI'm now back up in Barrow for fieldwork, this time with Hajo Eicken (my boss), and Malcolm Ingham from Victoria University of Wellington. Malcolm is a physics professor at VUW who uses electro-magnetic methods to study the earth's subsurface. In Barrow, we're testing a new method to measure the connectivity of the brine inclusions in sea ice. If successful, this will enable us to make fully-automated measurements of the state of the ice in places like the McMurdo Sound runway in Antarctica. back to top Barrow Excursion April 18-20, 2006: Patrick CotterThis follow-up trip to re-install the repaired radar was rather uneventful. It was much sunnier and warmer than the previous trips, although it still managed to hit -27F one morning. My first task was to wax the radar's antenna with the hope that any ice or snow buildup would slough off before causing damage to the motor. It felt odd to be breaking out car wax in Barrow. With the help of Keith Williams of BASC, I was able to get the radar hooked up later that afternoon and recording data once again. The most difficult part of the re-installation turned out to be feeding the power cable through the hole in the building. The second day of the trip was spent testing de-icing techniques, primarily using this heat tape sort of stuff. Testing the interference with the radar proved difficult, and the lack of additional holes in the building prevented me from setting up anything permanent. Luckily its late enough in the winter that there probably isn't much need for additional de-icing. In true Alaska Air style, my flight out on the evening on the 19th was cancelled, so I spent an extra night at the NARL hotel and caught next morning's flight back to Fairbanks. Thanks to clear skies I finally got a decent view of the Brooks Range, although I was stuck sitting above the wing. back to top Barrow Excursion Feb 28-March 1, 2006: Patrick CotterThis quick trip to Barrow was for maintenance and troubleshooting of our Barrow Observatory equipment. My first task upon arrival was to figure out why our mass balance site had stopped transmitting data back to our computer in the Theatre. Initially this sounded like a major problem with the site, but turned out to only require a re-setting of the software used for data transfer. A quick trip out to the site revealed that everything had withstood 70mph winds during a storm early in February. The next task was to take down and ship out the radar. The antenna had stopped spinning in late December and had been subsequently turned off. Apparently heavy icing of the antenna had occurred which, in turn, ground the gears in the motor to dust. Luckily I had Scott Oyagak to assist me in the removal process. We moved as quickly as possible since the ambient air temperature was near -40 with a stiff breeze making it feel even colder. Back in the warmth of the BASC theatre, I cleaned up and boxed the unit to be shipped to the manufacturer for repairs. back to top
Barrow Fieldwork, January 29-Feb 03, 2006: Daniel PringleAs part of the developmental phase of the Alaska Ocean Observing System (AOOS) we were installing a collection of instruments called a 'mass balance site'. Instruments included thermistor strings to measure the temperature profile through the sea ice as well as the water below and snow and air above, and 'hydraprobes' for measuring the salinity (salt content) of the ice.
As an improvement on previous mass balance sites, this site is equipped with a radio system to transmit the data back to a computer at BASC, which will then be transmitted to our computers back at Fairbanks, and posted on the web in near-real time. You can see the antenna in the picture above.
back to top Barrow Excursion October 18-19, 2005: Patrick CotterOctober 18, 2005 Andy and I arrived in Barrow on the morning flight to overcast skies and some freezing rain. We made our way to BASC where we organized our equipment for installing the webcam and firing up the radar. It was actually quite nice not worrying about getting snowmobiles, sleds and gear for going out onto the ice.
October 19, 2005 Since the radar wasn't cooperating and we couldn't address any problems until we heard from ASTAC, we went ahead and mounted the webcam. We were able to get the camera up and running, but had to take it offline for the time being until a new hole for the wires was drilled into the building. Image quality and the view from the ASRC building are great and should provide excellent data to complement the radar data. back to top Barrow excursion March 27-31, 2005: Patrick CotterMarch 27, 2005 As we came in for a landing the plane banked over the coast, revealing a major fracture in the ice running parallel to the shore for several kilometers in either direction. The afternoon was spent unpacking and organizing gear for the next day.
March 28, 2005 A brisk day, but not uncomfortable. Our first task was to assist Heike with the installation of some 4x8 sheets of UHMW plastic under the ice using Lew’s monster chain saw. With Jeremy running the saw, it was actually quite easy to slide the plastic sheets into the ice. The day also saw us taking some cores for temperature and salinity measurements, as well as scouting out a location for the extraction of a block for Jeremy’s research. We also attempted to remove the tide gauge via Andy's PVC tube. Unfortunately the tube had filled with sea water and subsequently froze, making it impossible to open the tube. There were some issues with the generator as well, but we managed to devise a method for keeping the engine warm while we transported it between the garage and the ice.
March 29, 2005 Another crisp day, but nice. We managed to extract a full depth block using the 7’ chainsaw and the block and tackle, and also cut a nice vertical slab off the block which would accompany us back to Fairbanks for further analysis. The ice shanty had to be assembled and everything was organized for the following day’s job of processing the huge block.
March 30, 2005 All day was spent processing the block. After a while, Jeremy and I became quite automated in our approach to routing off a layer, setting up the lights and taking pictures. It was actually quite comfortable inside the shanty, thanks to its wind-blocking ability. March 31, 2005 We finished off the block early in the day and were able to take a couple temperature and salinity cores, as well as deploy several of Andy’s ‘tasselometers’. Everything was brought back to the garage, cleaned thoroughly, and put in storage for our next visit. The flight back was quite nice, with houses in Anaktuvuk Pass glowing in the darkness of early evening. back to top Barrow excursion Feb 6-10 2005: Andy MahoneyBarrow Cabled Seafloor Observatory. Feb 6 –Feb 8 Arrived in Barrow on Sunday evening to attend a workshop on a proposed Barrow Cabled Seafloor Observatory. Approximately 25 people from many disciplines of ocean science and the local community attended. There are many scientific applications for such an installation, but the biggest hurdle appears to be protecting the cable from ice keels until it is in sufficiently deep water. Tuesday, Feb 8 Picked Heike up from the airport in a strong blizzard on Tuesday evening. At times it was difficult to see further than the hood of the truck and the drifts across the beach road made it difficult to know where the road was, but we made it safely back to NARL and began pulling gear out and loading sleds. One sled was taken up by four 8-inch PVC pipes and four 4-foot by 8-foot sheets of white plastic. These were to to be frozen into the ice to study how sea ice micro structure and biota develop in the absence of bottom currents (see Heike’s research). Another sled was required to haul all the augers, drills, chainsaws, hand saws, shovels, ice chippers, tape measures, power cords, generators, ice tongs and plumb lines that were needed to do the job. After that retired to the NARL hotel hoping that the weather would improve. Lesson of the day: Don’t tie down the sled until everything is on
Wednesday, Feb 9 The windows of the hotel had stopped rattling and so I hoped that the wind had calmed down. The 5 second walk outside from the hotel to the dining hall proved me wrong. A quick check on the internet informed me that 21 knot wind was blowing out of the east, giving the ambient temperature of –6 C a wind chill of –45 C. That’ll wake you up. The weather improved a little by noon and we headed out onto the landfast ice in the bight of the spit of Point Barrow, where the ice is usually less prone to deforming. Installation of the PVC tubes went smoothly, using the 10-inch auger to make holes in the 80 cm ice. The plastic sheets required a series of four, 4-foot long slots cut into the the ice with the chainsaw, making a square and cutting loose a block of ice. This proved much harder and turned into a constant battle to keep the cuts from refreezing after they were cut while the chainsaw froze-up or ran out of fuel. After a trip back to the warehouse to swap the blade onto a different motor, we retired for dinner cold and tired and with the plastics sheets back on the sled. Lessson of the day: When cutting out a block of ice, don’t stand on the block as you make your final cut. Thursday, Feb 10
No respite in the weather, but Heike and I headed back out to deploy a PAR (photosynthetically active radiation) sensor for Christopher Krembs and a pressure guage to measure changing water depth beneath the landfast ice. Deployment of both of these went easily, requiring just some holes in the ice with the auger. A final attempt to freeze-in the plastic sheets was foiled once again by the chainsaw freezing-up and so they completed their second round-trip to the sea ice. Lesson of the day: A 3m long 6-inch diamater air-filled pipe is surprisingly buoyant. back to top |
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