Gone with the Wind: Providing Forecasts to the Polar Windsled Expeditions

Assembling the Windsled into the blizzard (photo: Windsled team)

About the Authors:

Sergi González is a weather forecaster and research scientist at the Spanish State Meteorological Agency AEMET. He earned his PhD in Physics from the University of Barcelona in 2019. Sergi has been a weather forecaster at the Spanish Research Station Juan Carlos I and participated in the MICROAIRPLAR scientific campaign in Antarctica. He co-leads the YOPP-endorsed M-AWS project with his colleagues from the Autonomous University of Madrid. His research interests cover precipitation, remote sensing and in-situ measurements, mesoscale dynamics and multidisciplinary science in both mountain and polar regions.

Hilo Moreno is a polar explorer and member of the International Polar Guides Association. He has been a mountain guide and field assistant at the Spanish Antarctic Campaign for twelve years. Since 2016, Hilo has been a member of the Windsled team participating in expeditions in both the Arctic and Antarctic. Besides his activity in logistic support for scientific activities, he has explored the polar regions for more than twenty years and disseminates his experiences through literary texts and pictures.

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Plateau Station, Eastern Antarctica, January 7^th, 2019
I am in the middle of the Antarctic Plateau. It is 4 a.m. and my pocket thermometer indicates 53 degrees below zero. I am walking through the corridors of an abandoned scientific station almost buried by the snow. My headlamp illuminates a calendar. The last day crossed out is January 29th 1969 – 50 years ago. Since then, only a couple of expeditions have been here but none of them has employed a zero-emissions vehicle. Unlike the heavy convoys, we have reached this point powered only by the winds, carrying out different scientific experiments along the way. The final destination is more than one thousand kilometres away. Have carefully planned this expedition based on knowledge of Antarctic meteorology, we trust that the winds that brought us here also lead us home.

A Vehicle to Accomplish an Ancient Quest

The Windsled project was born in the year 2000 with the aim of resolving an ancient quest dating from the Heroic Age of Polar Exploration: to take advantage of the winds to navigate over the polar caps. Since then, many prototypes have been developed and several expeditions took place to design a light vehicle capable of moving over the ice using a set of kites.  In 2016, this private initiative took a new direction by devoting this vehicle, originally designed by the Spanish polar explorer Ramon Larramendi, to science as a zero-emissions mobile laboratory for polar areas.

After two years of operating the scientific vehicle in Greenland, the Windsled team headed to the least-known area of Antarctica, the Eastern Plateau, where the research stations are hundreds of kilometres apart. This campaign named Antarctica Unexplored Dome Fuji was funded by Prince Albert II of the Monaco Foundation and the European Space Agency in addition to some contributions via crowdfunding. In Antarctica, the Windsled verhicle headed to Dome F loaded with more than 2,000 kg. On a route that covered more than 2,500 km, powered only by the winds, the team carried out work for ten international scientific projects.

In this kind of expedition that combines adventure and science in a harsh environment, weather is a key factor. Physical and mental strength is necessary to withstand extreme weather. Sometimes it involves handling instruments at temperatures below minus 40 ºC. Aspects such as clothing, the daily schedule, the route, and materials used also depend on weather conditions.

When it comes to the expedition planning, the route must be chosen such that favourable winds tend to blow from behind. For the Eastern Plateau, it is known that katabatic winds, flowing perpendicular to the height level, increasing with slope angle and turning anticlockwise due to the Coriolis force. prevail. Based on this knowledge, we designed an optimal route. However, it was not possible to avoid a difficult ascent to the dome against the winds. This struggle required skilful navigation, especially during the first part of the expedition during which we were forced to use the faintest whisper of a favourable breeze.

Forecasts for the Windsled Expedition

The necessity to ensure safety and security of scientists and expeditions in Antarctica led to the inclusion of weather forecasters as staff members of at least some Antarctic stations. Forecasts provide important information for Antarctic logistics and operations in general. However, since the windsled, like a sailboat, depends on the winds to move, accurate weather predictions are of particular importance for a successful expedition. During the first non-scientific expeditions of the windsled, expeditioners did not have specific meteorological information available. The logistics and conditions of the expedition changed when five forecasters of the AEMET Antarctic Group volunteered to provide forecasts for the Windsled route.

Before the AEMET forecasters started to make predictions for the expedition, the expeditioners were constantly on alert, waiting for the proper conditions for navigation. Not knowing whether the winds would be favourable during the next few hours or even days, readiness to take advantage of appropriate conditions needed to be maintained. The expeditioners were thus forced to work in unusually long and exhausting shifts with sleep deprivation. In contrast, weather bulletins enabled the expeditioners to manage their time much more efficiently, dedicating times favourable winds to navigation and other times to conducting science or resting. Using weather predictions provided by AEMET forecasters therefore optimized the available time and reduced the expedition tiredness.

Another key improvement was noted in the navigation. Expeditioners had observed that winds near the ground can be very different from the winds a few meters above the surface where the kites are located. In previous expeditions, when only near-surface wind information was available, expeditioners often tried to navigate in unsuitable conditions. Since the weather forecasters have started to provide wind predictions for both low levels and 100 m elevation, the windsled has been able to navigate more efficiently, setting a course that would have seemed impossible when considering only surface conditions.

Providing weather information to the expeditions was not easy. The latest Antarctic expedition was equipped with a Garmin Inreach device that allowed to communicate via 160-characters messages. To convey meteorological information with only 160 characters, the team had selected the most important variables, namely the winds, the temperature range, and blizzard warnings. Using this selection, the meteorologists had developed a code based on the aeronautical TAF (terminal aerodrome forecast, a format for reporting airport weather information). Since the expedition was going to cover considerable distances, the weather forecasters needed to find a way to provide forecasts for a moving target.

Mobile-Automatic Weather Stations around the Ice Sheets

On-board the windsled, the MICROAIRPOLAR project and AEMET installed a mobile Automatic Weather Station called M-AWS. M-AWS has been designed to endure the harsh conditions of ice sheets. The M-AWS project has been initiated in 2017 when the members of the project installed an experimental station with some sensors on-board the windsled to complement the biological samples taken during the Ice River Expedition Greenland. During that test expedition, everything that could have gone wrong went wrong. The station had to be prepared quickly, and we did not anticipate numerous failures that happened. However, these failures were a valuable learning experience to prepare us for the following campaign.

After the return from Greenland, we started to design a proper weather station capable of operating at temperatures below minus 40°C and withstanding the shocks that the windsled would be exposed to when hitting wind-built sastrugi ridges in Antarctica. All elements that did not require being outside were mounted inside a paddle box container connected to the station. The container was heated with an electrical resistance powered by two 10 W solar cells. The cables were shock-resistant and suitable for low temperatures. A custom-made battery manufactured for the icy conditions of the Antarctic continent was deployed. Overall, we developed a powerful automatic weather station, able to withstand the extreme conditions of the expedition.

At the moment, the M-AWS is providing in-situ data mainly to validate models. However, future plans are to employ a fleet of windsleds with on-board M-AWS systems that are able to transmit their data in real-time to the WMO Global Telecommunication System to feed weather forecasts. In addition, the M-AWS could drop soundings from those locations where they provide the highest added-value contribution to forecast models. With the windsled vehicle and the M-AWS design, it will be possible to take weather observations in remote locations based on inexpensive and environmentally sustainable methods.

The data from the expedition is published on the PANGAEA Database https://doi.pangaea.de/10.1594/PANGAEA.906189

An article on the windsled expedition that employed the YOPP-endorsed M-AWS has also been published in BAMS:
Gonzalez, S., Bañon, M., Albero, J.V., Larramendi, R., Moreno, H., Vasallo, F., Sanz, P., Quesada, A., and Justel, A., 2019: Weather Observations of Remote Polar Areas Using an AWS Onboard a Unique Zero-Emissions Polar Vehicle. Bulletin of the American Meteorological Society (BAMS). doi: :10.1175/BAMS-D-19-0110.1.