Development of a Laser-Induced Fluorescence Ground-Based Instrument for Measurements of Atmospheric Iodine Monoxide

Harvard University, Cambridge MA

Investigators

Abstract

The trace atmospheric free radical species, iodine monoxide (IO), is thought to be a key photochemical constituent in the marine boundary layer where it participates in ozone depletion reactions. It is also implicated in mercury removal processes occurring in the polar spring, and may take part in the formation of marine aerosols. Its potential reactivity with other radical families(NOx and HOx cycles), further underline its elusive reactivity in global photochemical processes in both the troposphere and stratosphere. However, its concentration and distribution over time and space are notably under-observed. Instrumentation emplying laser-induced fluorescence spectroscopy, intended for either ground based or airborne use, will be constructed and implemented to have an estimated detection limit of 0.1 ppt per second or better. As well as presenting a challenging detection threshold, this fast response sensor is needed to resolve the expected highly inhomogeneous distribution of IO in marine boundary layers and other parts of the atmosphere.