An overview of the SOLVE/THESEO 2000 campaign

Abstract

Between November 1999 and April 2000, two major field experiments, the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) and the Third European Stratospheric Experiment on Ozone (THESEO 2000), collaborated to form the largest field campaign yet mounted to study Arctic ozone loss. This international campaign involved more than 500 scientists from over 20 countries. These scientists made measurements across the high and middle latitudes of the Northern Hemisphere. The main scientific aims of SOLVE/THESEO 2000 were to study (1) the processes leading to ozone loss in the Arctic vortex and (2) the effect on ozone amounts over northern midlatitudes. The campaign included satellites, research balloons, six aircraft, ground stations, and scores of ozonesondes. Campaign activities were principally conducted in three intensive measurement phases centered on early December 1999, late January 2000, and early March 2000. Observations made during the campaign showed that temperatures were below normal in the polar lower stratosphere over the course of the 1999–2000 winter. Because of these low temperatures, extensive polar stratospheric clouds (PSC) formed across the Arctic. Large particles containing nitric acid trihydrate were observed for the first time, showing that denitrification can occur without the formation of ice particles. Heterogeneous chemical reactions on the surfaces of the PSC particles produced high levels of reactive chlorine within the polar vortex by early January. This reactive chlorine catalytically destroyed about 60% of the ozone in a layer near 20 km between late January and mid‐March 2000, with good agreement being found between a number of empirical and modeling studies. The measurements made during SOLVE/THESEO 2000 have improved our understanding of key photochemical parameters and the evolution of ozone‐destroying forms of chlorine.

From molecules to meteorology via turbulent scale invariance

“…The ER-2 also carried a suite of chemical instruments on the polar ozone missions; see for example Tuck et al (1997) and Newman et al (2002). While the ozone instrument produced data of sufficient quality for generalized scale invariance on all missions, a subset of the other instruments did so only on the later missions (Tuck et al, 2002).…”

“…The data were obtained during the two most recent polar ozone ER-2 missions, POLARIS during the Arctic summer of 1997 and SOLVE during the Arctic late winter and early spring of 2000 (Newman et al, 1999(Newman et al, , 2002. The value of J [O 3 ], the ozone photodissociation rate, varies over a range of a factor of four against a range of a factor of three in the intermittency of temperature, C 1 (T); see Figure 13.…”

The Lagrangian chemistry and transport model ATLAS: validation of advective transport and mixing

“…The model results for the methane tracer are compared to measurements of the ACATS-IV (Romashkin et al, 2001), ALIAS (Webster et al, 1994) and Argus (Loewenstein et al, 2002) instruments on 11 flights of the ER-2 aircraft between 20 January and 12 March (Newman et al, 2002). The Halon-1211 model results are compared to ACATS measurements on the same flights.…”

Testing our understanding of Arctic denitrification using MIPAS-E satellite measurements in winter 2002/2003

“…However, it was not possible to deduce the onset of denitrification from observations in these winters. In the 1999/2000 Arctic winter, denitrification occurred between the deployment phases of the SOLVE/THESEO 2000 campaign (Newman et al, 2002) and was essentially complete by the time of the first ER-2 flight (Davies et al, 2005). In 1996/97, the Improved Limb Atmospheric Spectrometer (ILAS) satellite-borne instrument observed HNO 3 and N 2 O during the onset of the low temperatures required for PSC formation and for potential denitrification (Kondo et al, 2000).…”