It is published for the first time the presence of Iodine Monoxide (IO) in the free troposphere (Atmos. Chem. Phys)

A new paper entitled “Iodine monoxide in the north subtropical free troposphere” has been published in Atmospheric Chemistry and Physics – Discussions. This paper has been leaded by researches of the Area de Investigación e Instrumentación Atmosférica from INTA (Instituto Nacional de Técnica Aeroespacial), with coauthorship of researches from  the Laboratory for Atmospheric and Climate Science (CSIC) and the Centro de Investigación Atmosfé erica de Izaña (AEMET).

In recent years, improvements in the Differential Optical Absorption Spectroscopy (DOAS) technique and advances in profile retrievals from Multi Axis-DOAS (MAXDOAS) observation modes have made possible the detection of trace gases of tropospheric interest at very low concentrations.

This paper is the first one reporting the presence of IO in the free troposphere Iodine monoxide (IO). IO was retrieved using a new multi-axis DOAS instrument deployed at the Izaña subtropical observatory as part of the Network for the Detection of Atmospheric Composition Change (NDACC) program. MAX-DOAS measurements show the presence of background levels of IO in the free troposphere, clearly above the inversion that delimits the Marine Boundary Layer (MBL). From May to August 2010 at different viewing angles, the spectral signature of IO was unequivocally detected on every day of measurement.

Another interesting result is the systematic enhancement of IO during Saharan dust intrusions, supporting the previously proposed explanation of the existence of a mechanism that introduces significant amounts of IO precursors during such events at the station level.

IO had been detected previously from ground-based measurements in the MBL, but never before in the free troposphere. The major sources of IO into the troposphere are thought to be form macroalgal sources releasing either IO molecules and/or organo-iodine compounds. IO plays an important role in the destruction of tropical ozone.

Full reference:

Puentedura, O., M. Gil, A. Saiz-Lopez, T. Hay, M. Navarro-Comas, A. Gómez-Pelaez, E. Cuevas, and J. Iglesias, Iodine monoxide in the north subtropical free troposphere, Atmos. Chem. Phys. Discuss., 11, 27833–27860, 2011 (doi:10.5194/acpd-11-27833-2011)

The pdf paper can be downloaded here.

To access the discussion, click here.