Observations from aircraft, an island station, and two research vessels are used to investigate the development of an elevated mixed layer or land plume over the Arabian sea during the Indian Ocean Experiment Intensive Field Phase 1999 (INDOEX) through air mass modification. Much of the transport of aerosols and gases occurs in this plume located above a well-mixed convective marine boundary la...

By comparing the ozone depletion potential-weighted anthropogenic emissions of N2O with those of other ozone-depleting substances, we show that N2O emission currently is the single most important ozone-depleting emission and is expected to remain the largest throughout the 21st century. N2O is unregulated by the Montreal Protocol. Limiting future N2O emissions would enhance the recovery of the ...

Tropical tropospheric ozone affects Earth’s radiative forcing and the oxidative capacity of the atmosphere. Considerable work has been devoted to the study of the processes controlling its budget. Yet, large discrepancies between simulated and observed tropical tropospheric ozone remain. Here, we characterize some of the mechanisms by which the photochemistry of isoprene impacts the budget of t...

Sudden depletions of tropospheric ozone during spring were reported from the Arctic and also from Antarctic coastal sites. Field studies showed that those depletion events are caused by reactive halogen species, especially bromine compounds. However the source and seasonal variation of reactive halogen species is still not completely un-5 derstood. There are several indications that the halogen...

Recent simulations predicted that the stratospheric ozone layer will likely return to pre-1980 levels in the middle of the 21st century, as a result of the decline of ozone depleting substances under the Montreal Protocol. Since the ozone layer is an important component in determining stratospheric and tropospheric-surface energy balance, the recovery of stratospheric ozone may have significant...

A continual trend of ozone depletion has drawn much attention to the biologically harmful UV-B radiation from the Sun reaching the Earth’s surface. Satellite remote sensing provides a sole means of monitoring the global distribution of surface UVB. At present, there are very few inversion algorithms with sufficient accuracy and robustness for operational application. A new algorithm is proposed...

Remote sensing of bromine monoxide (BrO) from the Ozone Monitoring Instrument (OMI) and other satellite instruments opens the possibility to extend our understanding of atmospheric halogen chemistry from local-scale studies to global scales. In the Arctic springtime boundary layer, these bromine monoxide radicals and bromine atoms are known to destroy ozone [1] and oxidize mercury [2], leading ...

Sudden depletions of tropospheric ozone during spring were reported from the Arctic and also from Antarctic coastal sites. Field studies showed that those depletion events are caused by reactive halogen species, especially bromine compounds. However the source and seasonal variation of reactive halogen species is still not completely understood. There are several indications that the halogen mo...

It is believed that ultraviolet (UV) radiation from the sun participated in events related to the chemical evolution and birth of life on the primitive Earth. Although UV radiation would be also a driving force for the biological evolution of life on Earth, life space of the primitive living organisms would be limited in the UV-shielded place such as in the water at an early stage of the evolut...