2012-11-23

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.

2012-11-01

Sand / ash storm and very high values of PM10 at Raufarfell

Very high levels of PM10 are now recorded at Raufarfell.

image

Location of Raufarfell.

20121101_Raufarfell_PM10

The concentration of PM10 reached over 900 µg/m3 today, 1 November 2012 (data from VISTA).

Wind-speed has been very high, at Kvísker for instance (see vedur.is for location of station SE-Iceland).

20121101_Kvisker_Vindur_IMO

And satellite image from 13:40 today shows that sand and ash is blowing up and out to the ocean from all of the south part of Iceland (MODIS NASA/Rapidfire).

20121101_modis_1340_crop

Dust/ash storm

Strong northerly winds blew dust and ash from all the usual “suspects”, common source areas in the south of Iceland today, 31 October 2012.
imageData from IMO station at Kvísker, showing the wind speed and gusts there.
20121031_modis_truecol_A20123051300 Satellite image (MODIS/NASA Rapidfire, retrieved from the IMO) taken at 13 today.