Enter Zoom Meeting

HS1.2.1

EDI
The MacGyver session for innovative and/or self made tools to observe the geosphere

The MacGyver session focuses on novel sensors made, or data sources unlocked, by scientists. All geoscientists are invited to present:
- new sensor systems, using technologies in novel or unintended ways,
- new data storage or transmission solutions sending data from the field with LoRa, WIFI, GSM, or any other nifty approach,
- started initiatives (e.g., Open-Sensing.org) that facilitate the creation and sharing of novel sensors, data acquisition and transmission systems.

Connected a sensor to an Arduino or Raspberri Pi? Used the new Lidar in the new iPhone to measure something relevant for hydrology? 3D printed an automated water quality sampler? Or build a Cloud Storage system from Open Source Components? Show it!

New methods in hydrology, plant physiology, seismology, remote sensing, ecology, etc. are all welcome. Bring prototypes and demonstrations to make this the most exciting Poster Only (!) session of the General Assembly.

This session is co-sponsered by MOXXI, the working group on novel observational methods of the IAHS.

Co-organized by BG2/CL5.2
Convener: Rolf HutECSECS | Co-conveners: Theresa Blume, Andrew Wickert, Marvin ReichECSECS
Presentations
| Thu, 26 May, 13:20–14:50 (CEST)
 
Room 3.29/30

Thu, 26 May, 13:20–14:50

13:20–13:25
Introduction to the MacGyver Session

13:25–13:30
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EGU22-1657
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ECS
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Highlight
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On-site presentation
Aurélie Martin et al.

The eigenfrequencies of speleothems are fundamental parameters in the study of their response to earthquakes. To study these, the seismic ambient noise is measured by three-component seismic sensors adapted to the geometry of the speleothems. This method is currently being studied in the Han-sur-Lesse cave (Ardenne, Belgium).

A previous study (Martin et al. 2020) was carried out with a SmartSolo IGU-16HR 3C sensor on an imposing 4.5 m tall stalagmite.  This approach demonstrated the feasibility and interest of studying the eigenfrequencies of stalagmites from ambient noise. However, this sensor was too heavy for use on thin and slender stalagmites. The challenge was to find and adapt a lighter sensor able to record very weak movements while being easily adjustable to the various shapes of the stalagmite and securely attachable on these to reduce the impact of the sensor on frequencies measurements and the risks for the fragile structure.

A solution was found by using a Raspberry Shake 3D Personal Seismograph (RS) that initially integrates three orthogonal velocity sensors (Sunfull PS-4.5B), the digitizer, and the Raspberry Pi computer into a single plexiglass box​. The RS has the advantage of being less heavy while being composed of three weak motion geophones. After a comparison study, this sensor gives similar results for eigenfrequency and polarization analyses. However, the use of this new sensor on thin and slender stalagmites requires the creation of suitable support. The RS was split and distributed around the stalagmite. The geophone wiring was modified and extended to separate the geophones from the acquisition system. A 3D-printed support was created to guarantee the orthogonality of the horizontal sensors while reducing the stresses by distributing the weight of the sensor around the stalagmite.

This new configuration allowed determining the eigenfrequencies of 16 thin and slender stalagmites in the Han-sur-Lesse cave (Ardenne, Belgium) and the polarization of the motions associated with these frequencies. Moreover, a two-week recording period allows to measure the daily and weekly variation of ambient noise and transient events like earthquakes, quarry blasts or flooding events in the cave.

Reference: Martin, A.; Lecocq, T.; Hinzen, K.-G.; Camelbeeck, T.; Quinif, Y.; Fagel, N. Characterizing Stalagmites’ Eigenfrequencies by Combining In Situ Vibration Measurements and Finite Element Modeling Based on 3D Scans. Geosciences 2020, 10, 418. https://doi.org/10.3390/geosciences10100418

How to cite: Martin, A., Lecocq, T., Lannoy, A., Quinif, Y., Camelbeeck, T., and Fagel, N.: Measuring the eigenfrequencies of candlestick stalagmites with a custom 3D-printed sensor modified from a Raspberry Shake 3D , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1657, https://doi.org/10.5194/egusphere-egu22-1657, 2022.

13:30–13:35
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EGU22-940
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ECS
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Virtual presentation
Tom Müller et al.

With a rapid increase in the use of low-cost DIY Arduino solutions, many companies are providing low cost sensors for practically any environmental applications and new users can also benefit from a rich virtual community proposing diverse solutions and tutorials. Nowadays, these new hardware solutions, as well as more robust communication protocols, allow to design very simple almost plug-and-play automatic dataloggers.

In this talk we will discuss three simple datalogger solutions developed in the framework of a field campaign in a harsh proglacial environment in the Swiss Alps. The first solution consists of a simple autonomous datalogger (based on Seeeduino Stalker board) designed to record piezometric heads in wells, even during the winter cold season. The second station consists of two alternative main boards (SODAQ and CubeCell) that were used to develop a connected LoRaWAN automatic weather station to monitor air temperature and precipitation on the glacier. Connected to a base station LoRaWAN gateway (Dragino), this system successfully allowed for a remote monitoring of those parameters.

In a first step, we will quickly go through the main components of each system and detail the basic LoRaWAN architecture. We will then mostly focus on the practical deployment of these solutions in the field and discuss their potential and challenges. We will try to show a live demonstration of their functioning and will insist on the relative technical simplicity and low-cost of such solutions, which could be replicated for many other environmental applications. We will finally discuss the pros and cons of these solutions compared to professional senor companies.

How to cite: Müller, T., Schaefli, B., and Lane, S. N.: A simple low-cost Arduino based LoRaWAN automatic weather station , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-940, https://doi.org/10.5194/egusphere-egu22-940, 2022.

13:35–13:40
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EGU22-2722
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ECS
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On-site presentation
Mathis Björner et al.

Environmental monitoring programs carried out by expeditions or autonomous stations are expensive and only allow measurements for discrete times and locations. After data acquisition most of the data needs hand-operated validation and evaluation before being stored in databases.

For a higher local and temporal resolution on parameters of marine ecosystems, it is planned to extend monitoring programs by attaching a small-sized module, which combines a microcontroller with multiple sensors, to ships of opportunity or any other suitable platform. The modules design focuses on the usability, reliability and interoperability of the derived data by using metadata information and assessing in-situ which data is relevant to be measured and stored.

Using an ESP32, a popular microcontroller, to collect data from OEM sensors of different manufacturers enables a high flexibility in parameters and sensor types. The use of different OEM sensors also allows to experiment with unconventional hydrological sensors. The proposed open source module attempts to collect data as reliable as with conventional monitoring sensor systems.

This approach allows an event based data acquisition, e.g. by adjusting the sampling rate so that only as much data as necessary is measured. In order to provide precise spatio-temporal referencing, the system contains a real time clock and GPS positioning. Moreover, storing the raw data of the sensors alongside their calibration coefficients enables post-processing of the data. The ESP32 transmits the stored data to a server via WiFi or an external LTE module. From this point on, a machine-based validation, flagging of relevant data and basic visualization can assist the evaluation.

With such a module integrating multiple sensors and focusing on the interpretation and use of data starting at the measurement, reliable and pre-evaluated data from hard to access areas can be obtained and contribute to the assessment of dynamic and heterogeneous ecosystems.

How to cite: Björner, M., Naumann, M., Furkert, F., Stepputtis, D., Hermann, A., Gag, M., Eilek, S., and Wagner, R.: Using an open source approach to remotely collect reliable environmental data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2722, https://doi.org/10.5194/egusphere-egu22-2722, 2022.

13:40–13:45
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EGU22-1617
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ECS
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On-site presentation
Martin Dalvai Ragnoli

The role of freshwater ecosystems in the global carbon budget has yet to be accurately quantified. Substantial uncertainties remain in estimation of greenhouse gas (GHG) fluxes to the atmosphere due to heterogeneity, temporal variability and small scale of many systems. Additionally, methods to measure dissolved gases involve expensive equipment and/or are time consuming, making fine scale resolution challenging. We here present a self-made low-cost (~ 250 €) sensor unit which can measure carbon dioxide (CO2) and methane (CH4) in the water phase, allowing inexpensive continuous in-situ logging of GHG concentrations with little manpower.

The electronic hardware of the sensor unit is integrated into a polypropylene tubing with two parts: The sensor body is completely waterproof and houses electrical hardware and battery. The sensor head houses the gas sensors and is separated from the water phase by a semipermeable PTFE membrane that is hydrophobic but permeable to gases, thereby allowing the gaseous phase in the sensor head to equilibrate with the water phase.

For CO2, we use a miniature non-dispersive infrared sensor; data from the factory-calibrated sensor can be read via I2C serial communication. For CH4, we use a semiconductor gas quality sensor from the Figaro sensor family. Originally developed for explosion warning systems, these sensors were shown to detect CH4 near ambient concentration. Incorporated into a voltage divider, sensor output voltage can be measured and translated into CH4 concentration. Electrical resistance of this sensor varies in presence of combustible gases but also with temperature and humidity. Additional sensors provide pressure, temperature and relative humidity; and mathematical models fitted to calibration data allow to adjust for reference output voltage at background concentration levels, thereby allowing measurement of CH4 concentration. As a microprocessor, we use an Arduino mini board in combination with a real-time clock, a voltage regulator and a micro SD-card module. The microprocessor is programmed using Arduino´s integrated development environment. Data is stored on the internal SD card and powered by two Li-Ion 18650 batteries connected in series. The sensor is able to measure continuously for 24 hours.

Our low-cost, yet accurate-enough sensor can help to address the major bottlenecks in better quantification of GHG fluxes: continuous measurements to capture natural temporal variability, as well as spatially replicated measurements to map carbon sources and sinks across heterogeneous ecosystems with little investment costs. 

How to cite: Dalvai Ragnoli, M.: RiverRunner: a low-cost sensor prototype for continuous dissolved GHG measurements, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1617, https://doi.org/10.5194/egusphere-egu22-1617, 2022.

13:45–13:50
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EGU22-3517
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ECS
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On-site presentation
Reena Macagga et al.

Measurements of greenhouse gas (GHG) emissions such as carbon dioxide (CO­­2) play an important role in finding solutions to mitigate the global climate crises. In case of direct treatment comparisons, dynamic manual closed chamber systems are often used to measure the CO2 exchange and determine the treatment corresponding net ecosystem C balance (NECB). These measurements are commonly accompanied by records of non-destructive spectral vegetation indices such as RVI and NDVI, which can be used to validate obtained CO2 flux dynamics, to improve the accuracy and precision of determined CO2 exchange during gap-filling, and for up-scaling purposes. However, commercially available systems for both measurements of CO2 exchange and spectral vegetation indices are usually cost-intensive, which resulted in a long-term focus in GHG research on the northern hemisphere and the fact that studies on agroecosystems in sub-Saharan Africa as well as Southeast Asia are still being underrepresented.

We present two portable, inexpensive, open source devices to measure in situ 1) CO2 fluxes using the manual closed chamber method; and 2) vegetation spectral indices, such as NDVI and RVI. The CO2 flux measurement device consists of a combination of multiple low-cost sensors, such as a NDIR-based CO­2 sensor (K30FR; 0-10,000 ppm, ± 30 ppm accuracy), a DHT-22 (humidity and temperature) and a BMP280 (air pressure). Sensors are connected to a bluetooth enabled, battery powered, compact microcontroller based logger unit for data visualization and storage.  The handheld, NDVI measurement device consist of a combination of two faced up and two faced down visible (AS7262) and IR (AS7263) sensors, as well as a CCS811 and BME280 for parallel measurements of relevant environmental parameters (e.g., ambient temperature and relative humidity). Sensor control, data visualization and storage is implemented using again a bluetooth enabled, battery powered, compact microcontroller based logger unit. Here, we present the design, and first results of both low-cost devices. Results were validated against results of customized CO2 and NDVI measurement systems using regular scientific sensors (LI-COR 850 and SKR 1840(ND) and data logger components (CR1000). 

Keywords: CO2 exchange measurements, closed chamber, NDVI, low-cost open source DIY device

How to cite: Macagga, R., Antonijevic, D., Monzon, R., Bayot, R., Lueck, M., Asante, M., Sossa, L. G., Sanchez, P., Augustin, J., and Hoffmann, M.: Portable low cost devices for in situ measurements of CO2 exchange and vegetation spectral indices: Design and first results., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3517, https://doi.org/10.5194/egusphere-egu22-3517, 2022.

13:50–13:55
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EGU22-3719
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ECS
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On-site presentation
Paul Gäbel et al.

Analyses of the relationships between climate, air substances and health usually concentrate on urban environments due to increased urban temperatures, high levels of air pollution and the exposure of a large number of people compared to rural environments. Ongoing urbanization, demographic aging and climate change lead to an increased vulnerability with respect to climate-related extremes and air pollution. However, systematic analyses of the specific local-scale characteristics of health-relevant atmospheric conditions and compositions in urban environments are still scarce due to the lack of high-resolution monitoring networks. In recent years low-cost sensors became available, which potentially provide the opportunity to monitor atmospheric conditions with a high spatial resolution and which allow monitoring directly at exposed people.

We develop a measurement system for several air substances like ozone, nitrogen oxides, carbon monoxide and particulate matter as well as meteorological variables like temperature and relative humidity, based on low-cost sensors. This involves the assembly of compact, weatherproof boxes with 3D-printed parts. They contain a control unit based on Arduino hardware to gather the sensor data as well as self-designed printed circuit boards (PCBs). A Pycom microcontroller is used for low-power, high-temporal data transmissions by Long-Term Evolution Cat-M1 (LTE-M). These Atmospheric Exposure Low-cost Monitoring units (AELCM) include digital and analogue sensors for air substances and meteorological variables, LCD display, RTC module, uninterruptible power supply, active ventilation, a SD Module as a data black box in addition to an optional internally running FTP server and optional GPS module. A computational fluid dynamics (CFD) simulation is used to evaluate the air flow inside the AELCM units. Sensors are selected based on own analyses as well as according to evaluation and performance in other projects. The measurement equipment is extensively tested using the high-quality measurement unit for meteorology and air substances (Atmospheric Exposure Monitoring System, AEMS) of our research group, located at the Augsburg University Hospital.

How to cite: Gäbel, P., Koller, C., and Hertig, E.: Development of air quality boxes based on low-cost sensor technology, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3719, https://doi.org/10.5194/egusphere-egu22-3719, 2022.

13:55–14:00
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EGU22-5446
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ECS
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Highlight
Dirk Diederen
Water levels are a key ingredient for water resources management.
Surface water levels are monitored to manage open channels and rivers.
Groundwater levels are crucial to bridge times of drought and keep everything and everyone alive.
Worldwide, signals of changes in (ground)water levels are picked up by the GRACE satellite.
The development of groundwater use has led to depleted levels in many regions around the world [https://www.mdpi.com/2072-4292/10/6/829].
Coarse global data sets, provided by satellite gravity measurements, should be complemented with a global data set of accurate hand measurements.

Recently, we have launched our new public mobile app for (ground)water level measurements.
This means that now everyone can measure (ground)water levels, using their mobile phone.
Take a photo of a staffgauge, the surface water level will be returned!
Play a sound into a well/pvc pipe, the groundwater level will be returned!
Public measurements on this platform could hopefully lead to a consistent, global data set of high quality (ground)water level time series.

The app is currently available in the google play store as Mobile Water Manager.
Also, the app can be found at https://portal.mobilewatermanagement.com/ (chrome/safari - add to home screen for PWA).

 

How to cite: Diederen, D.: Global surface and groundwater levels - hand measurements with a mobile app., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5446, https://doi.org/10.5194/egusphere-egu22-5446, 2022.

14:00–14:05
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EGU22-3888
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ECS
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Highlight
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On-site presentation
Michael Stockinger et al.

Stable water isotopes (δ18O, δ2H) are used as tracers in hydrology to study the components of the terrestrial water cycle. The stable water isotopes of precipitation are affected by the passage of rainfall through tree canopy, resulting in a change of the tracer signal. Several processes within the canopy are thought to be responsible for this, including evaporation, liquid-vapor equilibration, redistribution, and legacy effects. However, it is currently not clear which processes dominate under which conditions, and predictions of these changes are not yet possible. This is partly due to a lack of high resolution throughfall data, as previous studies usually sampled throughfall in evaporation-reducing bulk containers placed under canopy. Here we propose to hang commonly available cotton products in tree canopy, let them soak up rainfall water, and subsequently measure the stable water isotopes directly from the wet cotton products using the direct liquid-vapor equilibration method in the laboratory. First, four products (two types of tampons, two types of cotton pads) were evaluated in terms of the minimum amount of water drops necessary for a reliable measurement, their price, and ease of handling. Cotton pads had the overall best rating and were therefor hung in a coniferous tree placed in a rainfall simulator. With a fixed rainfall intensity, we tested how long the cotton pads can be left hanging before significant isotopic changes due to evaporation occurred. While cotton pads that were on the outer edge of the canopy showed significant deviations after only half an hour, cotton pads inside the canopy as well as close to the stem could be left hanging for one hour. As a comparison, throughfall was also collected using a bulk sampler under the canopy, and this sample showed no significant changes even after four hours. It can thus be assumed that due to the comparatively low amount of water in the cotton pads (even if soaking wet), evaporative changes of isotope values had a stronger impact on the remaining water compared to the bulk throughfall sampler. This study presents first laboratory results and further tests, in the laboratory or in the field, are called for.

How to cite: Stockinger, M., Ziesel, G., and Stumpp, C.: Using cotton pads to sample the stable water isotopes of throughfall inside tree canopies, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3888, https://doi.org/10.5194/egusphere-egu22-3888, 2022.

14:05–14:10
5 minute buffer which we will need...

14:10–14:15
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EGU22-5620
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ECS
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Virtual presentation
Maria Marin et al.

Efficient water use is a must for sustainable agriculture, driving the need for affordable soil moisture sensors to guide irrigation timing. Sensors are limited by cost, maintenance and the need for wires for data capture and charging.  We are developing low-cost, long-life, wireless in-situ soil sensing networks, which can potentially enable a much higher sensor density for large farmland or intense research plot monitoring. This custom soil sensor is made from off-the-shelf electronics and consumes approximately 10x less energy per measurement, compared to commercially available sensors. Here we present our new sensor technology, while also investigating its repeatability and accuracy in controlled conditions and comparing it to that of commercially available soil moisture sensors. The final application of the custom soil moisture sensor is an underground in-situ sensing network, which will be enabled through wireless powering and telemetry systems implemented on autonomous vehicles, both ground and aerial.

How to cite: Marin, M., Elsakloul, F., Sanchez, J., Arteaga Saenz, J. M., Boyle, D., O’Keeffe, J. H., Goel, R., Hallett, P. D., Mitcheson, P. D., Norton, G. J., Yeatman, E., Young, D. J., Zesiger, C., and Roundy, S.: Low energy and cost soil moisture sensor technology, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5620, https://doi.org/10.5194/egusphere-egu22-5620, 2022.

14:15–14:20
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EGU22-7886
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On-site presentation
Michael R Prior-Jones et al.

Solar panels and batteries are commonly used to power autonomous instrumentation in remote locations. The use of solar power in the polar regions needs a special approach to the system design because of the need to store sufficient energy to cover the period of total darkness in the winter. In this presentation we review the key principles of solar power system design for the polar regions and provide a spreadsheet model to aid the design process. We demonstrate the importance of assessing the power consumption of ancillary electronics (such as solar regulators and low-voltage disconnect units), as this can often be greater or equal to that of the instrument itself. Consequently, the choice of solar regulator (and other ancillary devices) can have a major impact on the size of the battery required for successful operation. Controlled laboratory measurements  of power consumption for fourteen commonly-used models of solar regulator demonstrated that there can be disparity between the manufacturer’s specifications and measured power consumption, so we assess the most suitable  systems for low temperature, long-term deployment at polar latitudes.

How to cite: Prior-Jones, M. R., Bagshaw, E. A., Nylen, T. H., Pettit, J., and Carpenter, P.: Design of solar power systems for autonomous instruments deployed in the polar regions, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7886, https://doi.org/10.5194/egusphere-egu22-7886, 2022.

14:20–14:25
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EGU22-9749
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On-site presentation
Nick van de Giesen and Edward van Amelrooij

The ratio between slow or thermal (<2.2 km/s) and fast (>2.2 km/s) neutrons is known to be a good measure of the amount of water present in a radius of about 300m from the measurement. COSMOS detectors use this principle and measure neutrons by means of the helium isotope 3He. COSMOS has been in use for some time now and its large-scale observations are central to bridging the scaling gap between direct gravimetric observation of soil moisture (<<1m2) and the scale at which soil moisture is represented in hydrological models and satellite observations (>100m2). The main sources of 3He were nuclear warheads. The fortunate demise of nuclear weapons has had the less fortunate consequence that 3He has become expensive, leading to a search for more affordable alternatives.

Here, we present laboratory results of a boron-based neutron detector called BLOSM. About 20% of naturally occurring boron is 10B, which has a large cross-section for thermal neutrons. When 10B absorbs a neutron, it decays into lithium and alpha particles. Alpha particles can then be detected by ZnS(Ar), which sends out UV photons. Because real-estate is at a premium for most neutron detection applications, most boron detectors are based on relatively expensive enriched boron with >99% 10B. In hydrology, space is usually less of an issue, so one innovation here is that we use natural boron in a detector that is simply a bit larger than one based on enriched boron but much cheaper. A second innovation, put forward by Jeroen Plomp of the Delft Reactor Institute, are wavelength shifting fibers that capture UV photons by downshifting the wavelength to green. Green photons have a wider angle of total internal reflection and tend to stay in the fiber until they exit at the end. Here, a third innovation comes into play, inspired by Spencer Axani's $100 muon detector, namely the use of simple electronics and silicon photon multipliers (SiPMs).

Because we want to know the ratio between fast and slow neutrons, we need two detectors, one that just counts the thermal neutrons that continuously zap around and through us, and one covered by a moderator that slows down faster neutrons to thermal levels, so that they can be detected. Presently, we can build two detectors for about EU 1000. We expect that after the development of some custom electronics, this will come down to around EU 500. Ideally, we would like to build a network of these detectors in Africa in conjunction with the TAHMO network (www.tahmo.org).

How to cite: van de Giesen, N. and van Amelrooij, E.: DIY Neutron detection: Boron-based Large-scale Observation of Soil Moisture (BLOSM) , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9749, https://doi.org/10.5194/egusphere-egu22-9749, 2022.

14:25–14:30
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EGU22-9801
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On-site presentation
Danny Tholen et al.

Plant physiologists have used microscopy to study how leaf anatomy is related to photosynthetic performance and how this relation is affected by environmental conditions. However, leaf anatomy is not invariant over time: small pores on the leaf surface (stomata) open and close within minutes in response to the availability of water, CO2 and light. Within tens of minutes following a water deficit, cells in many leaves also shrink significantly in volume and the leaf undergoes structural changes as a result of wilting. Gas-exchange setups can monitor changes in photosynthesis and transpiration under such conditions, but classical microscopy techniques are not well-suited to capture the concomitant changes in leaf anatomy for two main reasons. First, available non-destructive microscopy techniques are limited in resolution and imaging depth, making it difficult to analyze changes in anatomy to the required detail. Second, using sectioned fixated samples is known to be associated with tissue shrinkage, swelling or deformation, making estimates of cellular volumes and surfaces prone to artifacts. Moreover, the destructive nature of these techniques makes it impossible to monitor changes in leaf anatomy during ongoing gas-exchange measurements. These limitations hinder advancing our understanding of the relation between leaf anatomy and photosynthesis or transpiration.

Here, we present a novel gas-exchange setup that combines synchrotron-based high-resolution computed tomography (microCT) with concurrent measurements of gas-exchange using an commercially available infra-red gas analyzer. We designed and constructed a novel gas-exchange cuvette with CO2 and H2O control that allows for non-invasive monitoring of leaf anatomy in a microCT setup. Custom-built sensors were used to measure light intensity and leaf temperature. At given time points during gas-exchange measurements, 300-500 X-ray projections (100 ms) were taken while the chamber rotated 180°. From this data, a leaf volume corresponding to 0.5 mm2 leaf surface was reconstructed at high resolution (0.325 µm per voxel edge).

The setup provides 3D images that can be used to measure the aperture of multiple stomata and the volumes, shapes and surface areas of cells and airspaces within the leaf. We found that the same leaf section can be scanned several times without measurable radiation damage, allowing for the combination of three spatial dimensions with time to create a 4D analysis of the leaf structure. Using poplar, willow and Arabidopsis leaves we studied how leaf anatomy rapidly adjusts after limiting water availability and show that such effects are not limited to the stomatal pore alone. We discuss the issues and pitfalls with the methodology and suggest avenues for future improvement.

How to cite: Tholen, D., Scheffknecht, S., Voggeneder, K., Weiss, E., and Théroux-Rancourt, G.: Leaf Structure and Function in Four Dimensions: Non-invasive MicroCT Imaging During Gas-exchange Measurements, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9801, https://doi.org/10.5194/egusphere-egu22-9801, 2022.

14:30–14:35
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EGU22-9972
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ECS
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On-site presentation
Sarah Elise Sapper et al.

An unknown source of methane (CH4) was recently discovered under the Kangerlussuaq sector of the Greenland Ice Sheet (GrIS). CH4 is transported dissolved in meltwater from the subglacial environment to the margin of the ice sheet, where it rapidly degasses to the atmosphere. Existing knowledge gaps concern the magnitude of emissions, seasonal patterns and spatial variations along the margin of the GrIS, which require long-term monitoring and large-scale measurement campaigns at multiple meltwater outlets. A limiting factor for such studies in remote areas is that CH4 analysers (laser spectroscopy) are power-hungry, maintenance-intensive, and expensive. To overcome these obstacles, we are developing a low-cost, low power sensor for measuring dissolved CH4 in subglacial meltwater systems in the MetICE project: the WaterWorm.

The WaterWorm is based on a metal oxide sensor (MOS) designed for CH4 detection (Figaro TGS2611-E00), which is highly sensitive to variations in relative humidity (RH) and temperature. In the WaterWorm, the MOS is encased in a hydrophobic but gas-permeable silicone tube, ensuring a stable and fully saturated headspace (100% RH) during submergence. We calibrated the analogue output (in mV) of the submerged WaterWorm against a reference CH4 analyser (μGGA, GLA-331, LGR Research) connected to a dissolved gas extraction system (DGES, LGR Research) in temperature-controlled laboratory experiments by stepwise enrichment of the water with CH4. These calibration tests showed that the sensor output (set at two readings per minute) is proportional to dissolved CH4 at constant humidity and temperature.

During fieldwork near Kangerlussuaq, Greenland, in summer 2021, a field baseline calibration was performed in a meltwater stream on the surface of the GrIS at ambient CH4 concentrations. WaterWorms were deployed for ten weeks in the meltwater of a small outlet of the Isunnguata Sermia glacier with known CH4 export and stable meltwater temperatures (0.0 - 0.1°C) to test the sensor under field conditions. Throughout this period, the WaterWorms measured elevated dissolved CH4 concentrations with diurnal variations that corresponded to similar diurnal variation in gaseous CH4 measurements performed with the reference CH4 analyser.

The WaterWorm is a promising and cost-efficient option for the seasonal monitoring of dissolved CH4 in glacial meltwater. With material costs of only 150€, the WaterWorm can be left unattended in the field and positioned directly at the ice edge. This makes the sensor suitable for a large-scale CH4 monitoring network along the margin of the GrIS. The next steps involve material tests to build WaterWorms for applications in other aquatic environments and at different water depths.

How to cite: Sapper, S. E., Christiansen, J. R., and Jørgensen, C. J.: The WaterWorm: a low-cost, low power sensor for the detection of dissolved CH4 in glacial meltwater , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9972, https://doi.org/10.5194/egusphere-egu22-9972, 2022.

14:35–14:40
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EGU22-10102
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ECS
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Virtual presentation
Barbara Vergara Niedermayr et al.
Barbara Vergara Niedermayr1,Danica Antonijevic,Oscar Monzón,and Matthias Hoffmann
Barbara Vergara Niedermayr et al. Barbara Vergara Niedermayr1, Danica Antonijevic, Oscar Monzón, and Matthias Hoffmann
  • 1Universität Potsdam, Potsdam, Germany (bvergaraniedermayr@gmail.com)
  • 2Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.
  • 1Universität Potsdam, Potsdam, Germany (bvergaraniedermayr@gmail.com)
  • 2Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.

Due to the large number of small and strongly anthropogenic influenced ponds (area <1 ha; IPCC 2019) and ditches there is a substantial emission of GHG, originating globally from open water (e.g., Peacock et al. 2017, Holgerson & Raymond 2016). Within those systems, high nutrient loadings from surrounding agriculture as well as low oxygen levels yield in N2O and especially CH4 emissions, sometimes exceeding those of small natural waterbodies many times over. The impact of land use and land use change on GHG emission regimes of these strongly anthropogenic influenced small systems is however still fairly unknown due to a lack of more broad data sets, exceeding single years and/or single case studies. The reason for this lies in the sheer variability of these systems (e.g., land use, underlying environmental conditions, hydrology, soil type, intensity of anthropogenic disturbances, etc.) as well as in the complexity to perform GHG emission measurements at a great number of locations with limited resources. The latter is even more of a problem, when considering the usually high cost-insensitivity of GHG emission measurements, as well as the persistence of an underrepresentation of data from developed or developing countries in e.g., Southeast Asia and or sub-Saharan Africa due to the long-term focus in GHG research on the northern hemisphere.

Here we present first results of an inexpensive, semi-automatic, do-it-yourself (DIY) floating chamber design, which can be used for in-situ measurements of CO2 and CH4 emissions from ponds and ditches. The floating chamber design consists of a star-shaped floating body (“rose dich”) with a cantered PVC chamber (A: 0,194 m²; V: 0,63m³. Low-cost NDIR-Sensors were attached to the chamber, for measuring CO2 (SCD30; 400-5,000 ppm, ± 50 ppm accuracy) and CH4 concentrations (Figaro Gas-Sensor TGS-2611; …). Environmental conditions during chamber deployment were recorded using a DHT-22 (humidity and temperature) and a BMP280 (air pressure) sensor device. All sensors were connected to a Bluetooth enabled, battery powered, compact microcontroller-based logger unit for data visualization and storage. Measured CO2 and CH4 emissions from ditches and ponds obtained on three locations spread over NE Germany were validated against in parallel performed GHG flux measurements using evacuated glass bottles for air sampling and subsequent GC-14A and GC-14B analyses (Shimadzu Scientifec Instruments, Japan).

 

First results indicate a generally good overall agreement of measured CO2 and CH4 emissions. Thus, the presented, semi-automatic floating chamber design might help to broaden the data basis/representativeness of GHG emission estimates of the globally relevant, small, strongly anthropogenic influenced ponds and ditches.

 

Keywords: Land use change, greenhouse gas emissions, low-cost floating chamber, semi-automatic measurements of CO2 and CH4, anthropogenic pond and ditches

How to cite: Vergara Niedermayr, B., Antonijevic, D., Monzón, O., and Hoffmann, M.: A novel, low-cost floating chamber design for semi-automatic measurements of CO2 and CH4 emissions from ponds and ditches, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10102, https://doi.org/10.5194/egusphere-egu22-10102, 2022.

14:40–14:45
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EGU22-10381
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ECS
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On-site presentation
Sara Maktabi et al.

Extended droughts are known to cause severe damage to crops. Short-term droughts of two to three weeks that occur in areas with high evapotranspiration demands and soils with low water-holding capacity can also significantly affect crop yields although their impact has not been well quantified. These short-term droughts are sometimes referred to as flash droughts. The timing of flash droughts likely has a major impact on whether or not they result in significant yield losses. An ongoing project funded by the U.S. National Oceanic and Atmospheric Administration (NOAA) is quantifying the effect of flash drought on rainfed agronomic crops and pasture grasses in the southeastern U.S. The project is also developing tools to forecast when flash drought periods result in significant yield losses. This paper reports on the development of a tool for estimating daily crop water use and soil water content for three commonly used pasture grasses of the southeastern U.S. – Bermudagrasses (Cynodon dactylon and C. dactylon´ C. nlemfuensis), Bahiagrass (Paspalum notatum), and Tall Fescue (Lolium arundinaceum). Five rainfed farmer-managed fields in which these grasses are grown for hay were instrumented with capacitance-type soil moisture sensors to continuously measure volumetric water content in 12 cm increments to a depth of 60 cm. These data are used to estimate daily crop water use / daily crop evapotranspiration (ETc) which in turn is used to estimate daily crop coefficient (Kc) values using Penman-Montieth evapotranspiration (ETo). ETo is calculated from the University of Georgia Weather Station Network weather stations located near the fields. The final product is a decision support tool that helps farmers quantify the duration of periods of low soil moisture content. The effect on the yield of these flash droughts is quantified by using the DSSAT CSM-CROPGRO-Perennial-Forage crop simulation model.

Keywords: remote sensing, evapotranspiration, crop coefficient, smart irrigation.

How to cite: Maktabi, S., Gallios, I., Knox, P., Kukal, S., and Vellidis, G.: Developing a soil moisture Decision Support Tool to quantify the occurrence of flash droughts and saturated soil conditions for pasture grasses in the southeast of the United States, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10381, https://doi.org/10.5194/egusphere-egu22-10381, 2022.

14:45–14:50
5 minute buffer and discussion