Ozone depletion in and below the Arctic vortex for 1997 (original) (raw)
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Ozone depletion in and below the Arctic vortex for 1997 (1998)
The winter 1996/97 was quite unusual with late vortex formation and polar stratospheric cloud (PSC) development and subsequent record low temperatures in March. Ozone depletion in the Arctic vortex is determined using ozonesondes. The diabatic cooling is calculated with PV-theta mapped ozone mixing ratios and the large ozone depletions, especially at the center of the vortex where most PSC existence was predicted, enhances the diabatic cooling by up to 80%. The average vortex chemical ozone depletion from January 6 to April 6 is 33, 46, 46, 43, 35. 33. 32 and 21% in air masses ending at 375,400, 425, 450, 475. 500, 525, and 550 K (about 14 -22 km). This depletion is corrected for transport of ozone across the vortex edge calculated with reverse domain-filling trajectories. 375 K is in fact below the vortex, but the calculation method is applicable at this level with small changes. The column integrated chemical ozone depletion amounts to about 92 DU (21%), which is comparable to the depletions observed during the previous four winters.
Vortex-averaged Arctic ozone depletion in the winter 2002/2003
Atmospheric Chemistry and Physics, 2005
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 collar region (closest to the edge), 52±5 DU for the vortex centre and 68±7 DU for the middle region in between centre and collar.
Atmospheric Chemistry and Physics Discussions Vortex-averaged Arctic ozone depletion in
2013
A total ozone depletion of 68 Dobson units from 10 December 2002 to 10 March 2003 is derived 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 DU for the collar region (closest to the edge), 52 DU for the vortex centre and 68 DU for the middle region in between centre and collar.
Temporal development of ozone within the Arctic vortex during the winter of 1991/92
Geophysical Research Letters, 1994
In this study we address the question of temporal ozone trends on isentropic surfaces within the Arctic polar vortex during EASOE. We have combined ozone sonde data from twelve campaign stations distributed throughout the European sector of the Arctic. The development of ozone at the 425,475, 550 and 700 K levels is presented, using analysed fields of isentropic potential vorticity and isentropic back-trajectories to separate inner vortex air from air staying outside the vortex.
ILAS observations of chemical ozone loss in the Arctic vortex during early spring 1997
Geophysical Research Letters, 2000
Chemical ozone loss rates were estimated for the Arctic stratospheric vortex by using ozone profile data (Version 3.10) obtained with the Improved Limb Atmospheric Spectrometer (ILAS) for the spring of 1997. The analysis method is similar to the Match technique, in which an air parcel that the ILAS sounded twice at different locations and at different times was searched from the ILAS data set, and an ozone change rate was calculated from the two profiles. A statistical analysis indicates that the maximum ozone loss rate was found on the 450 K potential temperature surface in February, amounting to 84 ppbv/day.
Geophysical Research Letters, 2001
Lower stratospheric in situ observations are used to quantify both the accumulated ozone loss and the ozone chemical loss rates in the Arctic polar vortex during the 1999-2000 winter. Multiple long-lived trace gas correlations are used to identify parcels in the inner Arctic vortex whose chemical loss rates are unaffected by extra-vortex intrusions. Ozone-tracer correlations are then used to calculate ozone chemical loss rates. During the late winter the ozone chemical loss rate is found to be-46 q-6 (1•) ppbv/day. By mid-March 2000, the accumulated ozone chemical loss is 58 q-4 % in the lower stratosphere near 450 K potential temperature (-19 km altitude).
Chemical Loss of Ozone in the Arctic Polar Vortex in the Winter of 1991-1992
Science, 1993
The H, O trend is estimated by calculating the difference between the average H20 with the H, O residual estimated in K. Kelly et a/. [Geophys. Res. Lett. 17, 465 (1989)], and scaling with the CH, trend. The H20 difference is a result of CH, oxidation in the stratosphere. 17. The HNO, trend is estimated by assuming that the NO, trend is the same as the N, O trend (0 2%) and using the scaling of NO, (10). 18. Projected injections of NO, and H, O are taken from scenario F in M. Prather et a/. [NASA Ref. Publ. 1272 (1992)l. In this report, NO is estimated to increase 4 ppbv and H, O will rncrease by about 1 ppmv, for an emission index of 15 and a Mach number 3.2. 19. T. Peter et a/. [Geophys. Res. Lett. 18, 1465 (1991)l calculated a doubling of the PSC probability for future fleets of stratospheric aircraft (a 1.7 K increase in the 50-hPa NAT saturation temperature using a two-dimensional chemistry model). 20. We thank all the partic~pants in the AASE II mission.
Geophysical Research Letters, 1999
Ozone depletion above Kiruna (67.9øN, 21.1øE), Sweden, was investigated using daily ozone and temperature measurements by ozonesondes between i February and 25 March 1997. Using UKMO Ertel's potential vorticity (EPV) and wind fields, three dynamically distinct regions were defined on a grid of isentropic surfaces viz.: the polar vortex boundary region characterized by steep EPV gradients, the area poleward of the boundary region (inside the polar vortex), and the area equatorward of the boundary region (outside the polar vortex). Due to dynamically induced displacements of the vortex, measurements were made in all three regions. By calculating the isentropic EPV at each measurement point and comparing it with the values defining the equatorward and poleward edges of the vortex boundary region, all ozone and temperature measurements could be binned according to their position relative to the vortex edge. Since the data outside the polar vortex were highly variable, mean ozone profiles and their standard deviations were calculated and compared only for the two other regions. To investigate whether differences between these mean profiles were indicative of ozone loss, the temporal evolution of ozone mixing ratios measured along several isentropic surfaces was examined, taking into account the diabatic descent of airmasses. Finally, ozone loss rates were calculated for six potential temperature surfaces and loss rates of up to 0.63ppm/month were found inside the Arctic vortex at surfaces descending from approximately 475 K (1 February) to 460 K (25 March). 1996 (•dited by R. D. Bojkov and G. Visconti), 971-974, 1998. Rex, M., et al., Prolonged stratospheric ozone loss in the 1995-96
Quarterly Journal of the Royal Meteorological Society, 2008
In this paper we investigate the evolution of the northern polar vortex during the winter 2002-2003 in the lower stratosphere by using assimilated fields of ozone (O 3) and nitrous oxide (N 2 O). Both O 3 and N 2 O used in this study are obtained from the Sub-Millimetre Radiometer (SMR) aboard the Odin satellite and are assimilated into the global three-dimensional chemistry transport model of Météo-France, MOCAGE. O 3 is assimilated into the 'full' model including both advection and chemistry whereas N 2 O is only assimilated with advection since it is characterized by good chemical stability in the lower stratosphere. We show the ability of the assimilated N 2 O field to localize the edge of the polar vortex. The results are compared to the use of the maximum gradient of modified potential vorticity as a vortex edge criterion. The O 3 assimilated field serves to evaluate the ozone evolution and to deduce the ozone depletion inside the vortex. The chemical ozone loss is estimated using the vortex-average technique. The N 2 O assimilated field is also used to substract out the effect of subsidence in order to extract the actual chemical ozone loss. Results show that the chemical ozone loss is 1.1 ± 0.3 ppmv on the 25 ppbv N 2 O level between mid-November and mid-January, and 0.9 ± 0.2 ppmv on the 50 ppbv N 2 O level between mid-November and the end of January. A linear fit over the same periods gives a chemical ozone loss rate of ∼18 ppbv day −1 and ∼9.3 ppbv day −1 on the 25 ppbv and 50 ppbv N 2 O levels, respectively. The vortex-averaged ozone loss profile from the O 3 assimilated field shows a maximum of 0.98 ppmv at 475 K. Comparisons to other results reported by different authors using different techniques and different observations give satisfactory results.