Atmospheric Physical Parameters and Pollution Probing with Paragliders

What is AP5?

Thibaut Roger and I initiated the AP5 project, as co-PIs.

AP5 is a citizen science project done in collaboration with two research institutes: the LPC2E in Orléans (France) and the IAC in Zürich (Switzerland). Our team is currently composed of 10 members:

With AP5, we aim to contribute to ​atmosphere and climate sciences with an additional focus on ​pollution issues​. In particular, it will help refine our understanding of small-scale dynamics structures such as thermals, and their role in the transport mechanisms of aerosols​.

AP5 will map pollution, aerosols and atmospheric parameters over the Jura/Alps regions​. A network of citizen paraglider pilots ​will be equipped with affordable ​atmospheric sensors built during the project from off-the-shelf components. Paragliders fly in a currently poorly measured altitude range of the atmosphere and are a unique platform to get measurements directly correlated to the dynamics of the atmosphere. Citizens’ involvement is a must for AP5 in order to achieve a ​high spatial and time coverage​.

As a first step, we plan on ​equipping 200 units​, 100 in Switzerland and 100 in France. Longer-term goal is to add 100/year/partner country and to expand all over Europe and even around the world. Pilots will be recruited via various channels: private networks, building on the community already involved, and public advertisement. We will also target partnering with the Swiss/French paragliding federations, paragliding schools, clubs and equipment shops.

Results will be of interest for ​public research institutes such as IAC (Zürich) or LPC2E (Orléans), but also to ​public services and private institutes dealing with ​health, weather forecast, traffic regulation, environment​, etc.

Why paragliders and nothing else?

The atmosphere is structured in multiple layers of changing properties. In particular, the boundary layer, extending from the ground to one or two kilometers of altitude, impacts human lives and activities and is directly influenced by them. Existing solutions to probe the atmosphere all have limitations: it can be the platform’s cost (e.g.: satellites), the functionality (e.g.: ​Lidars cannot obtain measurements below ~750m), etc. Other remote sensing techniques (e.g.: spectroscopy, ​radar​, ​photometers​) each present advantages but always rely on retrieval or inversion algorithms, and thus have a lower precision in comparison to in-situ measurements despite using various platforms. In-situ measurements are collected in ​ground stations​ or with various mobile platforms:

  • Balloons​: ​can have heavy payloads,​ but move only straight up in the low atmosphere, and pose a few problems: ​incertain instrument recovery​, reduction of flyable areas, etc.
  • Commercial drones​: payload limited, serious ​flight limitations in Switzerland without special authorisation/licences (150m altitude, no-fly zones, etc.).
  • Planes​: commercial flights only above ~10km altitude, and dedicated flights very costly.
  • Cable-cars​: give access to mountain regions but only on limited defined trajectories.

In addition to those platform limitations, it is rare to have spatially distributed measurements campaigns that are regular and available on a long-term, both for remote sensing and in-situ measurements. We thus propose this new solution: ​paragliders​. They usually fly up to 2000m and sometimes 5000m. As such, paragliders have the capacity of probing a unique altitude range, inaccessible to any other platform. In addition, paragliders usually fly near mountains, regions otherwise difficult to access. Of course, they also have some obvious constraints: only relatively low-mass payload (still way higher than commercial drones), limited weather conditions, limitation to day-time measurements (except with special authorisation) and restriction to hilly/mountainous topography (flying to the winch in plain remains rare). But paragliders have also five other main benefits:

  • they don’t need an energy source to fly and so are the most ecological vehicles available, while keeping flight durations/distance up to a few hours/hundreds of kms depending on the pilot/weather conditions.
  • they usually cross the boundary layer/troposphere interface and probe various layers of the Earth’ atmosphere.
  • for this project they can provide a unique temporal coverage while maintaining an extended geographical one.
  • they are useful to easily test components and sensors in real atmospheric conditions before balloon, plane, etc. flights which can be costly and/or might not guarantee the recovery of the instruments.
  • finally, other platforms follow man-made or straight trajectories. While paragliders are piloted, pilots follow thermals to reach higher altitude. As such, part of the data taken with paragliders would be directly correlated to the atmosphere small-scale dynamics. This characteristic would be ​absolutely unique to the paragliders​.

At which step is the project?

We have currently built an alpha prototype which delivered promised results, in accordance with the expected precision. It is based on « Arduino » components and we are planning on the following atmospheric properties to be measured:

  • Atmospheric parameters​: pressure, temperature, humidity, dew point.
  • Pollution and aerosols​: ​PM 2.5, PM 10​.
  • Trace gases/chemicals​: exact ones still to be determined. Potentially ​NOx, CO2, O3 and/or SO2​, to be able to calculate the Air Quality Index (AQI).
  • GPS​ position, orientation and barometric altitude.
  • 3-axis acceleration​ (to link with airflow) in particular the vertical wind speed.

Other quantities might be implemented, such as ​pollen​, ​PM 1.0​, UV index, wind speed, thermal imaging or air ​conductivity​. One goal is to develop an alternative instrument more expensive to measure additional elements and to equip only the most active pilots or, pilots only in specific regions, e.g.: ​sulphur over active volcanic regions​.

Render of the prototype

We applied for public institutional grant to fund the first step of the project of 200 instruments. This will cover the cost for us to test other electronic components building additional prototypes, and then to produce 200 instruments and pilot kits, as well as to do outreach. We are also currently in discussion with private companies for additional sponsoring. You are a company and want to sponsor us? Please contact us!

Render of the kit each pilot will receive

What science will it contribute to?

With those measurement we will be able to study the following scientific questions:

  • Variability of the low-atmosphere over the Jura/Alps region ​variability, seasonality and evolution of the boundary layer/troposphere interface altitude. which is assumed to be constant, by lack of data. Vertical profile of the atmospheric composition and chemistry: gases and particles.
  • Role of thermals regarding boundary layer injection: how can aerosols and pollution reach higher layers? How do aerosols, gas and chemical concentration evolve inside thermals? Is the temperature increase linked to the vertical speed?
  • Impact of topography on the atmosphere dynamics and transport mechanism.
  • Effect of events on the low atmosphere properties (e.g.: aerosols before/after rain or forest fire).
  • Study the influence of the surrounding natural environment and aerology on a city/town pollution evolution.
  • Study the arrival and concentration evolution of aerosols from very distant sources (e.g: ​volcano in Iceland​, Sahara desert storms, etc.).
  • Special measurements campaigns dedicated to specific objectives(e.g.: sulphur traces detection for pilots flying over Etna or volcanoes with visible activity when no erupting.

I’m not a pilot, can I still contribute?

YES! A very big Yes! First of all, as this is a citizen science project conducted during our free-time, we take all the help available! Secondly, in order to reduce our ecological footprint, we aim to produce the insert for the pilot kits out of the recycled paper, and the protection case of the instruments out of recycled plastic. For the latter, we plan to use HDPE, what bottle caps are usually made of. As such, we will run campaign of bottle cap collection, and you can help by collecting and sending us some! (Contact me for more info about that!).

If you would like to participate financially, we currently don’t accept donations from private persons but we will in the future. Furthermore, we plan to implement three switchable operation modes on the instruments:

  • Flight mode by default.
  • Hike and bike: focusing on ground-level pollution. Data taken during this mode would also be available to scientists.
  • Home monitoring: this will enable the pilots to monitor the air quality in their house using tools available on the project’s website. Data will be personal and inaccessible to the scientists.

So another way for you to contribute would be to built your own instrument to use when you hike or bike. Indeed, once the prototype completed, it will be open-source and the informatics program running it too so you can build yours. Count between 100 and 150 CHF/euros to make one. Also the hike and bike mode is for now only a side feature, we plan in the long term future to dedicate a project to it after we will have launched AP5 at a European scale.

Finally, and very importantly, the data collected will have the potential to be used as a leverage on political decisions. We thus aim at involving not only pilots, but also anyone wanting to act for our planet. This leverage could be at all levels of the political sphere, from the ​European Union Green Deal​, to small villages at the initiative of pilots/bikers using for example the results they will gather with the bike and hike mode to identify hotspots for pollution concentration and working with territorial development entities to solve those problems.