SO<sub>2</sub> emissions from Popocatépetl volcano: emission rates and plume imaging using optical remote sensing techniques

Abstract

Abstract. Sulfur dioxide emissions from the Popocatépetl volcano in central Mexico were measured during the MI-LAGRO field campaign in March 2006. A stationary scanning DOAS (Differential Optical Absorption Spectrometer) was used to monitor the SO 2 emissions from the volcano and the results were compared with traverses done with a COSPEC from the ground and a DOAS instrument on board an ultra-light aircraft. Daytime evolutions as well as day-today variation of the SO 2 emissions are reported. A value of 2.45±1.39 Gg/day of SO 2 is reported from all the daily averages obtained during the month of March 2006, with large variation in maximum and minimum daily averages of 5.97 and 0.56 Gg/day, respectively. The large short-term fluctuations in the SO 2 emissions obtained could be confirmed through 2-D visualizations of the SO 2 plume measured with a scanning imaging infrared spectrometer. This instrument, based on the passive detection of thermal radiation from the volcanic gas and analysis with FTIR spectrometry, is used for the first time for plume visualization of a specific volcanic gas. A 48-h forward trajectory analysis indicates that the volcanic plume was predominantly directed towards the Puebla/Tlaxcala region (63%), followed by the Mexico City and Cuernavaca/Cuautla regions with 19 and 18% occurrences, respectively. 25% of the modeled trajectories going towards the Puebla region reached altitudes lower than 4000 m a.s.l. but all trajectories remained over this altitude for the other two regions.

Volcanic SO<sub>2</sub> and SiF<sub>4</sub> visualization using 2-D thermal emission spectroscopy – Part 2: Wind propagation and emission rates

“…SO 2 emission of Popocatépetl has been estimated for different times and periods. An average emission rate of 2000-3000 t day −1 is reported by Delgado-Granados et al (2001) for the preeruptive phase, and an average with standard deviation of (2450 ± 1390) t of daily SO 2 emission was found by Grutter et al (2008a) during an intensive measurement campaign in March of 2006. The average of the daily SO 2 emission during a two-year period (2005)(2006)(2007) was calculated by the NOVAC project and found to be 1503 t day −1 with a standard deviation of 1154 t day −1 (Rivera, 2009).…”

“…This can be done, for example, by walking (McGonigle et al, 2002), from an ultra-light aircraft (Grutter et al, 2008a) or by using a fixed instrument to scan the plume from below, as was done by the NOVAC project in a network of multi-axis instruments (MAX-DOAS) set up in various volcanoes around the world (Galle et al, 2010).…”

“…Johansson et al, 2009b) and volcanoes (e.g. Grutter et al, 2008a) have allowed for the determination of the total emission rates. The same principle applies if a scanning device measures a closed traverse of almost horizontal slant columns around a point source.…”

Physical and chemical properties of the regional mixed layer of Mexico's Megapolis Part II: evaluation of measured and modeled trace gases and particle size distributions

“…The Popocatepetl volcano, with strong, intermittent emissions of sulfur dioxide (SO 2 ), has an impact on atmospheric chemistry and secondary aerosols production (Grutter et al, 2008). Due to this intermittency, the volcano emissions are highly variable and this feature is addressed in the model by adding to the emissions inventory an emission rate that varies day to day according to observations.…”

“…Phys., 12, 10161-10179, 2012 www.atmos-chem-phys.net/12/10161/2012/ the natural variability. The SO 2 emissions from Popocatepetl parameterized in the model vary from day to day corresponding to measurements made by Grutter et al (2008) and were greatest on 18 and 19 March when the air masses were from the SW. This is the source of the modeled SO 2, seen in Fig.…”