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Unexpectedly high concentrations of ultrafine particles were observed over a wide range of latitudes in the upper troposphere and lower stratosphere. Particle number concentrations and size distributions simulated by a numerical model of ion-induced nucleation, constrained by measured thermodynamic data and observed atmospheric key species, were consistent(More)
Simultaneous in situ measurements of hydrochloric acid (HCl) and chlorine monoxide (ClO) in the Arctic winter vortex showed large HCl losses, of up to 1 part per billion by volume (ppbv), which were correlated with high ClO levels of up to 1.4 ppbv. Air parcel trajectory analysis identified that this conversion of inorganic chlorine occurred at air(More)
In situ measurements of chlorine monoxide, bromine monoxide, and ozone are extrapolated globally, with the use of meteorological tracers, to infer the loss rates for ozone in the Arctic lower stratosphere during the Airborne Arctic Stratospheric Expedition II (AASE II) in the winter of 1991-1992. The analysis indicates removal of 15 to 20 percent of ambient(More)
In situ measurements of chlorine monoxide (ClO) at mid- and high northern latitudes are reported for the period October 1991 to February 1992. As early as mid-December and throughout the winter, significant enhancements of this ozone-destroying radical were observed within the polar vortex shortly after temperatures dropped below 195 k. Decreases in ClO(More)
[1] Large (>2 mm diameter) HNO3-containing polar stratospheric cloud (PSC) particles were measured in situ by the NOAA NOy instrument on board the NASA ER-2 aircraft during seven flights in the 1999/2000 Arctic winter vortex. Here we discuss the detection of these large PSC particles, their spatial distribution, the ambient conditions under which they were(More)
Probability distribution functions (PDFs) can be used to assist in the validation of trace gas retrievals made by satellites. A major advantage of this approach is that large statistical samples are used that do not require correlative measurements to be co-located in space and time. Examples are shown from the launch of UARS through to the present. This(More)
[1] We have analyzed thirteen years (1993 to 2005) of HALOE and over two years of EOS MLS observations (September 2004 to December 2006) for QBO and annual cycle trace variations in tropical H2O, HCl, ozone, N2O, CO, HF, and CH4. We use these results to develop the theory explaining both Brewer-Dobson circulation (BDC) and QBO driven fluctuations in(More)
On 19 January 1992, heterogeneous loss of HNO(3), ClNO(3), and HCl was observed in part of the Mount Pinatubo volcanic cloud that had cooled as a result of forced ascent. Portions of the volcanic cloud froze near 191 kelvin. The reaction probability of ClNO(3) and the solubility of HNO(3) were close to laboratory measurements on liquid sulfuric acid. The(More)
Stratospheric meteorological conditions during the Airborne Arctic Stratospheric Expedition II (AASE II) presented excellent observational opportunities from Bangor, Maine, because the polar vortex was located over southeastern Canada for significant periods during the 1991-1992 winter. Temperature analyses showed that nitric acid trihydrates (NAT(More)
Ozone measurements from ozonesondes, AROTAL, DIAL, and POAM III instruments during the SOLVE2/VINTERSOL period are composited in a time-varying, flow-following quasi-conservative (PV-θ ) coordinate space; the resulting composites from each instrument are mapped onto the other instruments’ locations and times. The mapped data are then used to intercompare(More)