Having made successful UAV test flights at home in the Peak District, we have relocated to Svalbard for a week to test the equipment in the most challenging possible conditions. We are flying in temperatures as low as -10 C, in gusty wind and after pulling the UAV to the field site in its flight case on a sled behind a snow scooter. It is taking off and landing on platforms of compacted snow.
Nevertheless, so far it has performed magnificently. There has been no damage even to the delicate props during transport, suggesting the flight case is sufficient, and the autopilot seems to be deftly dealing with the gusty wind. It interfaces quickly with the laptop and it is easy to load a preprogrammed flight, even in these very cold conditions. It was quite difficult to take of and land in ‘stabilize’ mode with the wind though.
A few modifications I’d still like to make include a new landing gear design. The three legs are OK for flat, hard ground, but for ice and snow I think it would be much better to have something with skids, or possibly a circular base, as this would protect it from landing with a leg in a cryoconite hole and prevent the camera touching the snow if the legs sink. Also, at the moment any problem with a single leg compromises the UAV’s ability to land, whereas a unit that joins to the UAV in more than one place would give more redundancy.
The battery life is also significantly reduced in these temperatures. That’s to be expected, but I’m wondering if there are more mods we can make to extend the flight time for surveying big areas in Greenland.
This performance gives me hope for a successful mapping mission in Greenland, where the UAV will be used to map the ice surface in much less demanding conditions than we are experiencing here, but will be worked on more ambitious missions (higher, further, more frequent). We are continuing to test the UAV protocol in the field for a few more days, but will now focus on our methodology for pairing UAV flights with ground sampling rather than flight tech and UAV control.
As a bonus, we were treated to a spectacular aurora on the way in…
The past few weeks have been spent working down in the robotics department at the University of Sheffield building a UAV (unmanned aerial vehicle, a.k.a drone). Ultimately, it will be used to make measurements of spectral reflectance of the ice surface in Greenland. It’s been great fun working in robotics – entering the lab is like walking onto the set of Robot Wars! UAV expert Owen McAree has been a huge help in developing the hardware and software for the drone – affectionately known as ‘albedrone’ in recognition of the albedo work it will enable – and we have now made successful test flights.
It began as an off-the-peg Steadidrone Mavrik quadcopter. However, we have made several modifications. We added a new brushless gimbal powered from the autopilot, machined a new mount that allowed us to better balance the camera and minimize the power being drawn by the gimbal, and added a GPS that can be used to trigger the image capture. We have also invested significant time into tuning the flight parameters and making it as stable and easy to fly as possible.
Flying can still be quite challenging, so I also invested in flight simulator software that interfaces with the real UAV controller, meaning I have been able to get the hang of flying safely without endangering the UAV. Significant time and effort has also gone in to writing a flight manual and logbooks for the batteries, build modifications and flight records.
We have been flight-testing the UAV at the University of Sheffield’s High Bradfield site and have now successfully made a pre-programmed flight and captured overlapping images in five spectral bands. Some examples are shown below. These are interesting as they were captured over an area with a thick cover of green vegetation, perfect for NDVI analysis. Next jobs are to a) keep modifying the UAV to extend the flight time and perhaps add some additional sensors, and b) test the software that will stitch the images and analyse the spectral information…
We are now well into planning 2017 field work so I revisited some archive footage from previous trips. The short clip below provides a good summary of the great diversity of microbial habitats that exist, even within a very small area of ice. These include cryoconite holes, a cryo-pond (the big cryoconite and water filled pool), algal blooms on the ice surface, dispersed cryoconite, streams, cryoconite ‘alluvium’ stranded on the stream banks, weathered ice and the snowpack. The clip also shows how hummocky and non-uniform the ice surface is near the margin of the ice sheet.
To get a better idea of how these habitats are arranged spatially we also flew a small UAV (unmanned aerial vehicle) with a downwards-looking HD camera. The clip below shows some of the footage. The winds were pretty strong and you can actually see the landing gear bow into shot every so often. We’ll have a more sophisticated UAV system in Greenland in 2017 that will collect images at specific wavelengths of light.
Finally, here is a short clip of the 2016 team at the S6 camp enjoying a beautiful full moon over the ice sheet. This site is well into the ‘dark zone’ where impurity loading is very high. We’ll be back there this summer to measure the effect of this on the reflectivity and therefore melt rate of the ice sheet.
I was lucky enough to spend November working at NASA’s Jet Propulsion Laboratory. The purpose was to develop ongoing collaborations with expert glaciologists Johan Nilsson (who joined me in Greenland in the summer) and Alex Gardner, meet new potential collaborators and present my recent work on “bioalbedo”.
It was an extremely productive trip – being face-to-face with these top experts helped to confirm, refine and advance my current work and plans for 2017. I was lucky enough to meet researchers from the Airborne Snow Observatory and Europa Mission and got a tour around some of the labs and talk about potential collaborations.
Speaking at JPL was a huge honour and total boyhood dream-come-true as this is one of the world’s leading centres for cutting edge earth science. I spoke to the Earth Sciences division on the topic of “Bio-albedo” (the effect of microbial life on the colour of ice). The feedback and follow-up conversations were really valuable and will help stimulate some exciting science in 2017!
It also happened to be my 30th birthday while I was out there so to celebrate, Johan, fellow researcher Aumery and I hiked up Mount Baldy before going to the cinema for some appropriately space-themed sci-fi in the evening!
So #thanksNASA for hosting me and showing me the incredible Earth and space science being done at JPL.
Here is a brief field report from our 2016 field season which i also posted on the Arctic Club website (here).
2016 Greenland Field Work Report
Our field work aimed to deepen our understanding of the processes darkening the Greenland Ice Sheet. This is important because the colour of the ice sheet is one of the main drivers of its melt rate because it controls how much sunlight the ice sheet reflects or absorbs. The more sunlight absorbed, the more energy is available for melting ice.
In 2016 a team of researchers from Bristol, Sheffield, Leeds, Potsdam, Aberystwyth and NASA JPL camped on the ice sheet throughout the summer melt season in order to measure and monitor the changing colour of the ice and determine the causes of the darkening. The camp was inhabited in two month-long shifts. The first team comprised Joseph Cook (University of Sheffield), Chris Williamson (University of Bristol), Johan Nilsson (NASA JPL), Ewa Sypianska (Cardiff University), Tom Gribbin (Bristol University), Tris Irvine Fynn (Aberystwyth University) and Jim McQuaid (University of Leeds). Three weeks in, we were joined by Liane Benning, Steffi Lutz and Jenine McCutcheon (all University of Leeds). The team and all the camping and scientific kit was delivered in two flights on an Air Greenland Sikorsky S-61 helicopter.
The camp was built around two large Mountain Hardware “Space Station” tents, one of which was used as a mess tent (with a dining table and chairs, gas hob and food storage) and the other was a laboratory (kitted out with microscopes, spectrometers, filtration units, gas analysers, and all the usual lab consumables). The lab tent was also our power station, with the batteries, inverters and tracking system for our solar array. The long daylight hours and low temperatures helped the solar arrays to perform extremely well and we were able to charge all our scientific equipment, as well as laptops and satellite phones any time without issue. We were even able to run extension cables from the solar array to the mess tent to provide power across the camp! Around these two large tents were our own sleeping tents. Each person had a 3-man tent to provide room for bags and belongings.
A big problem is that the tents can melt the underlying ice, so we pitched on top of layers of white ‘polfelt’ and plyboard that both insulated the floor and provided a flat(ish) surface to walk on. However, this insulation also meant that after a few days the tents rested upon large ice pinnacles so needed to be repitched regularly!
For most of the season the weather was very friendly, with clear skies and very little precipitation – typical of summer on the SW Greenland ice Sheet. However, there was a significant rainfall event early on that washed away the crunchy, weathered ice layer and left a slick, slippery surface that was impossible to walk on without sharp crampons. It is also hard to dry out wet clothes and equipment in cold, overcast conditions. The rain also caused lots of glacier surface sediment (called ‘cryoconite’) to be washed onto the ice surface, instead of being held at the bottom of ‘cryoconite holes’. The combination of washed cryoconite and the loss of the crunchy, white ice made the surface noticeably darker.
We were particularly interested in the role of algae on the colour of the ice, and therefore our microbiology team was hard at work characterising the biology of the ice surface, including identifying the species present, their productivity, abundance and colouration. It seems that algae can bloom very densely and have a severe darkening effect on the ice surface. Coupled with this were detailed measurements of the reflectivity of the surface and the deposition of dark particulates from the atmosphere.
After the first month, the ‘in’ team decamped and was replaced by the project’s head-honcho Martyn Tranter, Alex Anesio, Alex Holland and Andrew Tedstone. Jenine also stayed out there with the second team. By the end of the season, the temperature had dropped significantly – large streams were freezing up completely every evening and remaining frozen until the middle of the day. What were almost 24 hour days at the start of the season became shorter and shorter and the team was treated to spectacular sunrises and sunsets over the ice sheet. In the far distance was a plume of water that, upon close inspection in the helicopter, turned out to be spray from a huge meltwater river crashing round a tight bend. Cryoconite holes grew, coalesced, divided and migrated around the camp.
The field season was successful in terms of the science and the team also reported feeling both awestruck at the scale of the ice sheet and simultaneously surprised by its sensitivity. The growth of microscopic algae and deposition of nanoscale particles of dust and soot influence the rate at which the vast ice sheet melts, and may therefore amplify climate changes and accelerate sea level rise. The challenge now is to quantify these processes and integrate them into future melt predictions.
In April this year I had the pleasure or working with a group from Manchester Met and Derby Universities in Iceland. There was opportunity for some useful skills-swapping: I provided some insights into albedo measurements on the ice surface and the MMU team gave me a tour of the mysterious basal ice.
The trip was focussed upon the team’s regular field sites – standard practice for them but refreshing new territory for me – especially since the focus was on ice that had been pushed up from the base of the glaciers (‘basal ice’).
There were several very rewarding outcomes of the trip: first, I got to see a new research group at work and observe their approach to glacier microbiological studies. Second, I had the opportunity to chat to the team at length about their experimental design – hopefully I was able to make some positive contributions as well as learning about their science. Third, I got to visit some wonderful new sites and learn about subglacial processes, including the microbiology of several basal ice ‘facies’. Finally, I got to talk to the team about some of the processes operating on the ice surface and introduce them to spectral reflectance measurements – great training for me prior to deploying these methods in Greenland later in summer.
The team’s research is fascinating and I’m really looking forward to seeing the data and working with them more as the project develops. Mario, the team’s PhD student has been hard at work generating big datasets that should shed some light onto the dark underside of these Icelandic glaciers.
I recently wrote a chapter on the application of biogeochemical measurement techniques to glacier surfaces which will hopefully be of interest to students and fellow early career researchers, especially now during MSc project proposal time!