New article about H2S plume dispersal

New article about the distribution of H₂S from geothermal power plants near Reykjavik, and the conditions that lead to concentration above 50 µg/m³.

Throstur Thorsteinsson, Julia Hackenbruch, Einar Sveinbjörnsson, Thorsteinn Jóhannsson. 2013.
Statistical assessment and modeling of the effects of weather conditions on H₂S plume dispersal from Icelandic geothermal power plants.
Geothermics 45: 31 - 40. <

Paper on Geothermics web site

Abstract

Episodes of high atmospheric load of hydrogen sulfide (H₂S), where the concentration is over 50 μg m⁻³hourly average value, occur about 80 times a year in Reykjavik (data from 2007 to 2009). H₂S originates mainly from two geothermal power plants 25–30 km (south-)east of Reykjavik, at Hellisheidi and Nesjavellir. Certain weather-dependent dispersion conditions, such as wind, cloud cover and air temperature, allow the transport of emissions towards Reykjavik and the neighboring cities, causing local air pollution. High concentrations of H₂S occur within a narrow range of weather conditions, namely slow (mean value 2 ± 1 m s⁻¹) easterly (114° ± 23°) winds, together with cold air temperatures (median value −3 °C) and preferably no, or little, cloud cover. A classification of weather types shows the preferred occurrence of high H₂S concentrations in connection with low atmospheric exchange and autochthonous weather. Stable atmospheric stratification and inversions enable the transport of H₂S emissions to Reykjavik. The measured concentrations, the short lived peaks in concentration and different values at nearby measurement stations, indicate a very narrow plume, which fits well with a Gaussian plume distribution model.