Geir O Braathen

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Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH 2 O) are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy) as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four(More)
Q10: Why has an " ozone hole " appeared over Antarctica when ozone-depleting substances are present throughout the stratosphere?. O zone is present only in small amounts in Earth's atmosphere. Nevertheless, it is vital to human well-being and ecosystem health. Most ozone resides in the upper part of the atmosphere. This region, called the stratosphere, is(More)
A total ozone depletion of 68±7 Dobson units between 380 and 525 K from 10 December 2002 to 10 March 2003 is derived from ozone sonde data by the vortex-average method, taking into account both diabatic descent of the air masses and transport of air into the vortex. When the vortex is divided into three equal-area regions, the results are 85±9 DU for the(More)
  • G Braathen, A Mälkki, Fmi J Staehelin, Eth Zürich, Chair J Sag, Igaco-O Tamminen +5 others
  • 2009
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The Match technique was used to determine chemically induced ozone loss inside the stratospheric vortex during the Arctic winter 2002/2003. From end of Novem-ber 2002, which is the earliest start of a Match campaign ever, until end of March 2003 approximately 800 ozoneson-des were launched from 34 stations in the Arctic and mid latitudes. Ozone loss rates(More)
As part of the EU project FORMAT (Formalde-hyde as a Tracer of Oxidation in the Troposphere), a field campaign was carried out in the vicinity of Milan during the summer of 2002. Results from a 3-D regional chemical transport model (NILU RCTM) were used to interpret the observations focusing primarily on HCHO and ozone. The performance of the model was(More)
As part of the EU project FORMAT (Formaldehyde as a Tracer of Oxidation in the Tro-posphere), a field campaign was carried out in the vicinity of Milan during the summer of 2002. Results from a 3-D regional chemical transport model (NILU RCTM) were used to interpret the observations focusing primarily on HCHO and ozone. The per-5 formance of the model was(More)
Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH 2 O) are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy) as part of the FORMAT-I field campaign. Eight instruments were employed by six independent 5 research groups using(More)
Ozone measurements from ozonesondes, AROTAL, DIAL, and POAM III instruments during the SOLVE-2/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 5 data are then used to intercompare(More)
The global atmosphere is at a critical stage, particularly in relation to climate change. There is considerable scientific evidence of the causes and solutions that could protect human health and ecosystems, and effective action has resulted in the achievement of some internationally agreed goals. The phase-out of ozone-depleting substances and lead in(More)