xsolvation, or exsolution, the dissolved gases from aqueous samples (e.g., CO2 aqueous, and CH4) followed by measurements employing integrated field analyzers. Mobile EC stations may also be placed near or within water features to obtain GHG fluxes as described previously to augment exsolvation sample data.
Hartmann, Jan F., Amanda Schiller, Torben Gentz, Markus Greule, Hans-Peter Grossart, Danny Ionescu, Frank Keppler, Karla Martinez-Cruz, Armando Sepulveda-Jauregui, and Margot Isenbeck-Schröter. “Real Time Measurement of Concentration and δ 13 C-CH 4 in Water.” Procedia Earth and Planetary Science 17 (2017): 460-463.
Sorribas, Mino Viana, David Motta Marques, Nilza Maria dos Reis Castro, and Fernando Mainardi Fan. “Fluvial carbon export and CO2 efflux in representative nested headwater catchments of the eastern La Plata River Basin.” Hydrological Processes 31, no. 5 (2017): 995-1006.
Gonzalez-Valencia, Rodrigo, Felipe Magana-Rodriguez, Oscar Gerardo-Nieto, Armando Sepulveda-Jauregui, Karla Martinez-Cruz, Katey Walter Anthony, Doug Baer, and Frederic Thalasso. “In situ measurement of dissolved methane and carbon dioxide in freshwater ecosystems by off-axis integrated cavity output spectroscopy.” Environmental science & technology 48, no. 19 (2014): 11421-11428.
Soil gas probes are hollow metal tubes (e.g., 1/4″ diameter) with perforations to allow gas transfer from the soil atmosphere, at desired depths, to the tube available for sampling above ground. The main purpose of the soil gas probe is to directly sample the soil atmosphere to determine and verify the CO2 and other gas concentrations and isotopic signatures of the soil gas at a given depth or feature of the project landscape. Soil gas probes are fixed in place at various depths across the project landscape and sampled at scheduled intervals by allowing gas to flow into field analyzers or capturing the gas in a sample flask for subsequent analysis.
Chen, Fu, Wangyuan Zhang, Jing Ma, Yongjun Yang, Shaoliang Zhang, and Run Chen. “Experimental study on the effects of underground CO 2 leakage on soil microbial consortia.” International Journal of Greenhouse Gas Control 63 (2017): 241-248.
Laemmel, T., M. Maier, H. Schack‐Kirchner, and F. Lang. “An in situ method for real‐time measurement of gas transport in soil.” European Journal of Soil Science 68, no. 2 (2017): 156-166.
Watkins, Cody S. “Hydrocarbon and CO 2 emissions from oil and gas production well pad soils comparative to background soil emissions in eastern Utah.” PhD diss., Utah State University, 2017.
Biose, E., G. U. Nnaji, C. F. Amaechi, N. O. Erhunmwunse, and A. F. Eghomwanre. “Effects of Below Ground Controlled Injections of CO2 on Microbial Respiration of Soil Planted With Wheat (Triticum aestivum L.).” African Scientist 17, no. 2 (2016).
Soils act as source and sink for CO2, CH4, and N2O and require precise quantification to obtain reliable project budgets. Soils typically contain 2 to 3 times the amount of carbon compared to the overlying biomass and is typically heterogeneous across the landscape posing challenges to determine average values for a given landscape or project area. In the context of Pα projects, soil accumulation chambers would be deployed at fixed locations and across selected sites for a mobile system. The efflux of CO2 isotopologues could also be measured and directly linked to below ground carbon as described previously. Eddy covariance can also be employed to determine soil CO2 efflux . Soil accumulation chambers can be operated manually or by automated systems.
Delle Vedove, Gemini, Giorgio Alberti, Michel Zuliani, and Alessandro Peressotti. “Automated monitoring of soil respiration: an improved automatic chamber system.” Italian Journal of Agronomy 2, no. 4 (2007): 377-382.
Dinsmore, Kerry J., Julia Drewer, Peter E. Levy, Charles George, Annalea Lohila, Mika Aurela, and Ute M. Skiba. “Growing season CH 4 and N 2 O fluxes from a subarctic landscape in northern Finland; from chamber to landscape scale.” Biogeosciences 14, no. 4 (2017): 799.
Jassal, Rachhpal S., T. Andrew Black, Zo