Measurements of Methane Emissions from a Biofertilizer Storage Tank Using Ground-Based Hyperspectral Imaging and Flux Chambers.

Open storages of organic material represent potentially large sources of the greenhouse gas methane (CH), an emissions source that will likely become more common as a part of societal efforts toward sustainability. Hence, monitoring and minimizing CH emissions from such facilities are key, but effective assessment of emissions without disturbing the flux is challenging. We demonstrate the capacity of using a novel high-resolution hyperspectral camera to perform sensitive CH flux assessments at such facilities, using as a test case a biofertilizer storage tank for residual material from a biogas plant.

Higher Apparent Gas Transfer Velocities for CO Compared to CH in Small Lakes.

Large greenhouse gas emissions occur via the release of carbon dioxide (CO) and methane (CH) from the surface layer of lakes. Such emissions are modeled from the air-water gas concentration gradient and the gas transfer velocity (). The links between and the physical properties of the gas and water have led to the development of methods to convert between gases through Schmidt number normalization.

Sensitive Drone Mapping of Methane Emissions without the Need for Supplementary Ground-Based Measurements.

Methane (CH) is one of the main greenhouse gas for which sources and sinks are poorly constrained and better capacity of mapping landscape emissions are broadly requested. A key challenge has been comprehensive, accurate, and sensitive emission measurements covering large areas at a resolution that allows separation of different types of local sources. We present a sensitive drone-based system for mapping CH hotspots, finding leaks from gas systems, and calculating total CH fluxes from anthropogenic environments such as wastewater treatment plants, landfills, energy production, biogas plants, and agriculture.

Ground-based remote sensing of CH and NO fluxes from a wastewater treatment plant and nearby biogas production with discoveries of unexpected sources.

This study is an attempt to assess CH and NO emissions from all the treatment steps of a wastewater treatment plant (WWTP) in Sweden, serving 145 000 persons, and an adjacent biogas production facility. We have used novel mid-IR ground-based remote sensing with a hyperspectral camera to visualize and quantify the emissions on 21 days during a year, with resulting yearly fluxes of 90.4 ± 4.

Turbulence in a small boreal lake: Consequences for air-water gas exchange.

The hydrodynamics within small boreal lakes have rarely been studied, yet knowing whether turbulence at the air-water interface and in the water column scales with metrics developed elsewhere is essential for computing metabolism and fluxes of climate-forcing trace gases. We instrumented a humic, 4.7 ha, boreal lake with two meteorological stations, three thermistor arrays, an infrared (IR) camera to quantify surface divergence, obtained turbulence as dissipation rate of turbulent kinetic energy () using an acoustic Doppler velocimeter and a temperature-gradient microstructure profiler, and conducted chamber measurements for short periods to obtain fluxes and gas transfer velocities ().

Remote sensing of methane and nitrous oxide fluxes from waste incineration.

Incomplete combustion processes lead to the formation of many gaseous byproducts that can be challenging to monitor in flue gas released via chimneys. This study presents ground-based remote sensing approaches to make greenhouse gas (GHG) flux measurements of methane (CH) and nitrous oxide (NO) from a waste incineration chimney at distances of 150-200 m. The study found emission of NO (corresponding to 30-40 t yr), which is a consequence of adding the reduction agent urea to decrease NO emissions due to NO regulation; a procedure that instead increases NO emissions (which is approximately 300 times more potent as a GHG than CO on a 100-year time scale).