Mountains like the Swiss Alps are highly sensitive to events taking place in other areas, despite often being perceived as distant and separate from their surroundings.

Image Credit: OTT HydroMet
The Alpine Research Station Furka (ALPFOR) – situated 2440 meters above sea level in the Furka mountain pass located in the central Swiss Alps – is home to teams of scientists working to understand the impact of human beings on the alpine environment.
The scientists’ work is varied, with flexibility and accuracy at its core. To ensure the most reliable and actionable results, the Station primarily uses instruments from OTT HydroMet in its work. An OTT Pluvio² L was recently installed to support this project.
Nitrogen oxide (NOx) emissions have been widely reduced thanks to catalyzers being installed in industrial facilities and in every car.
Despite these advances, the agricultural sector still emits high levels of ammonia nitrogen (NH3) into the air via fertilizers and industrial-scale livestock farming.
These emissions eventually return to the Earth’s surface, entering vegetation and local environments such as woods, moors or grasslands as nitrogen deposits.
Using the OTT Pluvio² to Better Understand the Nitrogen Cycle
In mountainous environments, these soluble nitrogen compounds are typically deposited via rain and snow.
These compounds function as a unilateral fertilizer, causing harm to delicate ecosystems and biodiversity by boosting the growth of simple plants like blackberries and nettles and causing these to supplant frugal, rarer and slow-growing alpine plants.
There is an estimated tenfold increase in nitrogen deposition compared to preindustrial times, even in remote areas of the higher Alps. Scientists at the Station are, therefore, keen to better understand this ecological problem and are leveraging the power of OTT Pluvio² to do this.

Landscape at the Furka mountain pass. Image Credit: OTT HydroMet

The OTT Pluvio2 helps the scientists of the ALPFOR research station to investigate the amount atmospheric nitrogen deposited into the alpine vegetation. Image Credit: OTT HydroMet

Two radiometers Kipp & Zonen CMP11 and one ultrasonic anemometer Lufft Ventus are part of the OTT HydroMet portfolio, too. Image Credit: OTT HydroMet

Two radiometers Kipp & Zonen CMP11 and one ultrasonic anemometer Lufft Ventus are part of the OTT HydroMet portfolio, too. Image Credit: OTT HydroMet

Landscape at the Furka mountain pass. Image Credit: OTT HydroMet

The ALPFOR research station has access to power supply. Image Credit: OTT HydroMet
In order to thoroughly assess levels of pollution in alpine ecosystems, it is necessary to determine the precise amounts of soluble nitrogen deposition and to be able to characterize alpine plants’ reaction to this.
Accurate precipitation monitoring is central to this task, prompting the team at ALPFOR to run an automated weather station.
This is a challenging operation, however, because a significant part of a year’s precipitation falls as snow in this region, and this is often accompanied by strong winds.
Ordinary tipping-bucket rain gauges are unreliable in this setting, and their small orifices cannot reliably measure precipitation, even when these are heated. A weighing-rain gauge with a heated ring is, therefore, the instrument of choice.
Working in a Unique Research Location
The local nitrogen concentration of precipitation in the Furka mountain pass is determined from water and air samples collected close to the pluviometer.
The Pluvio² also provides the team with the respective amount of precipitation, allowing the scientists to assess both parameters and calculate the annual atmospheric nitrogen deposition.
This particular research project is led by Dr. Erika Hiltbrunner.
The institute’s location in the Furka mountain pass is typical of many areas in the higher Alps. The Station is housed in a former Swiss military camp, meaning it has access to the power supply and mobile radio communication required for the Pluvio’s heated orifice ring and data access.
While these features are in place, the location is virtually inaccessible during winter due to a high risk of avalanches - the mountain pass road is closed from mid-October to May.
It is therefore essential that any instrumentation used is suitable for remote operation. When the Pluvio’s bucket does need to be emptied, it is necessary to access the Station using touring skis.
The Pluvio’s smart software is able to adapt to the challenges of this process, identifying and signaling the need for the emptying process to be completed and helping to avoid gaps in the data.
It is also important to note that the amounts of local precipitation in mountain regions can vary significantly across small distances due to wind direction and speed.
In the example presented here, the Pluvio² is located at a point with average precipitation, located within 2 kilometers of an area where a previously conducted study had assessed this with 12 measuring points.
The OTT Pluvio² confidently complements the scientists’ other equipment, including a range of OTT HydroMet sensors designed for other applications.
For example, the team measures solar radiation and reflection using two Kipp & Zonen CMP11 radiometers, and thanks to a Lufft Ventus, they are always aware of the exact wind speed and direction.
Acknowledgments
Produced from materials originally authored by Professor Christian Körner and Dr. Erika Hiltbrunner.

This information has been sourced, reviewed and adapted from materials provided by OTT HydroMet - Meteorology.
For more information on this source, please visit OTT HydroMet - Meteorology.