Nitrous oxide in the earth's atmosphere contributes to catalytic stratospheric ozone destruction and is also a greenhouse gas component. A precise budgetary accounting of N(2)O sources has remained elusive, and there is an apparent lack of source identification. One source of N(2)O is as a by-product in the manufacture of nylon, specifically in the preparation of adipic acid. Characterization o...

The photolysis of chlorine peroxide (ClOOCl) is a key chemical step in the depletion of polar stratospheric ozone. As such, precise measurements of the absorption cross sections for ClOOCl are required. In this paper we provide two critical pieces of laboratory data with which to constrain the rate of ozone depletion. First, we provide an optically pure ClOOCl spectrum in the photolytically imp...

The atmosphere displays modes of variability whose structures exhibit a strong longitudinally symmetric (annular) component that extends from the surface to the stratosphere in middle and high latitudes of both hemispheres. In the past 30 years, these modes have exhibited trends that seem larger than their natural background variability, and may be related to human influences on stratospheric o...

The evolution of the tropopause in the past, present, and future climate is examined by analyzing a set of long-term integrations with stratosphere-resolving chemistry climate models (CCMs). These CCMs have high vertical resolution near the tropopause, a model top located in the mesosphere or above, and, most important, fully interactive stratospheric chemistry. Using such CCM integrations, it ...

An observed trend in the Southern Hemisphere annular mode (SAM) during recent decades has involved an intensification of the polar vortex. The source of this trend is a matter of scientific debate with stratospheric ozone losses, greenhouse gas increases, and natural variability all being possible contenders. Because it is difficult to separate the contribution of various external forcings to t...

Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within...

[1] The Antarctic ozone hole demonstrates large-scale, man-made affects on our atmosphere. Surface observations now show that human produced ozone-depleting substances (ODSs) are declining. The ozone hole should soon start to diminish because of this decline. We demonstrate a parametric model of ozone hole area that is based upon a new algorithm for estimating chlorine and bromine levels over A...

The authors report a hypothesis for the dynamical mechanisms responsible for the strengthening of the Southern Hemisphere circumpolar winds from the lower stratosphere to the surface due to the ozone hole. A general circulation model forced by stratospheric ozone depletion representative of the ozone hole period successfully reproduced these observed changes. Investigation of the dynamical char...

Mixing ratios of water (H2O) in the stratosphere appear to increase due to increased input of H2O and methane from the troposphere and due to intensified oxidation of CH4 in the stratosphere, but many of the underlying mechanisms are not yet understood. Here we identify and quantify three chemical mechanisms which must have led to more efficient oxidation of CH4 in the stratosphere over the pas...

Thirteen years of ozone soundings at the Antarctic Belgrano II station (78 S, 34.6 W) have been analysed to establish a climatology of stratospheric ozone and temperature over the area. The station is inside the polar vortex during the period of development of chemical ozone depletion. Weekly periodic profiles provide a suitable database for seasonal characterization of the evolution of stratos...