Impact of Iodine Oxides on Troposphere

Ozone plays a crucial role in atmosphere by absorbing harmful ultraviolet rays coming from the sun and maintaining the heat budget.Iodine after escaping from the surface of the ocean in to atmosphere has an important impact on atmosphere by reacting with ozone in troposphere.Recent studies shows that photolysis of iodine containing molecular species such as CH3I, CH2I2, CH2ClI, I2 and HOI may convert into IO by reacting with ozone in troposphere, which has been observed in MBL, polar regions and free troposphere and lower stratosphere.Atmospheric chemistry of iodine is significant for a number of reasons.The first way is that iodine species contribute to ozone depletion through catalytic cycles by changing the concentration of hydroxyl radicals (OH) in the atmosphere, which may affect the oxidizing chemistry of the atmosphere.The change in oxidizing capacity of atmosphere may results into environment pollution and climate change.Second, it is hypothesized that polar iodine species may promote the oxidation of elemental mercury to reactive gaseous mercury compounds.This might be deposited in snowpack, while some part of the gaseous mercury reduced and goes back to the atmosphere, but the remaining part run off in melted water and may enter in to the food chain.Entry of mercury in food chain may cause serious effects on human health and other living organisms.Third, the production of new particles in atmosphere is also an important aspect of the iodine species.These newly formed particles may convert into cloud condensation nuclei (CCN), which can alter the atmosphere's radiative balance and, consequently, the climate.Iodine monoxide produced iodine dioxide (OIO) after self combination in MBL.Higher order iodine oxides (IxOy) are created by recombining iodine oxide (IO) and iodine dioxide (OIO), and in a dry atmosphere, they finally produce an aerosol with an I2O5 composition.These iodine oxide particles (IOPs) may act as ice nucleation particles (INPs) and by involving in new particle formation (NPF), which then may affect the cloud formation processes and radiation budget.