Arctic winter 2005: Implications for stratospheric ozone loss and climate change (original) (raw)
Related papers
Ozone depletion in and below the Arctic vortex for 1997
Geophysical Research Letters, 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.
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.
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.
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.
Severe ozone depletion in the cold Arctic winter 2004-05
Geophysical Research Letters, 2006
1] During a flight of the M55 Geophysica into the Arctic polar vortex on 7 March 2005, ozone, halogen species, tracers and water vapor were measured. Up to 90% chlorine activation and up to 60% ozone loss were found above 14 km, reflecting the low temperatures and extensive PSC formation prevalent in the Arctic stratosphere over the 2004/05 winter. Observations are generally well reproduced by CLaMS model simulations. The observed levels of active chlorine can only be reproduced by assuming significant denitrification of about 70%. Moderate dehydration up to 0.5 ppm is observed in some locations. We deduce a partial column ozone loss of 62 (+8/À17) DU below 19 km on 7 March.
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
Ozone depletion in the late winter lower Arctic stratosphere: Observations and model results
Journal of Geophysical Research, 1997
Ozone loss rates in the lowermost part of the Arctic stratosphere (at potential temperature levels <-375 K) in the period January and February 1993 are calculated using a chemistry-trajectory model and 30-day back trajectories. The results were compared with observations carried out during the first Stratosphere Troposphere Experiment by Aircraft Measurements (STREAM) in February 1993 in the Arctic lower stratosphere. Relatively low N20 and low 03 concentrations were measured during STREAM, and 03 loss rates of 8.0 (_+3.6) ppbv d -• were calculated from O3-N20 STREAM data in the vortex area. The average 03 loss rate calculated by the model is 8.6 ppbv d -• (1.3% d-•), in agreement with observations. However, the calculated 03 loss rate decreases to the lower value of the observed loss rates when taking into account N20-Cly interrelations from different studies.
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).
Atmospheric Chemistry and Physics, 2010
Most of the ozone loss (60-75%) at this level results from nitrogen catalytic cycles rather than halogen cycles. At both 475 and 675 K levels the simulated ozone and ozone loss evolution inside the vortex is in reasonably good agreement with the MLS observations. The ozone partial column loss in 350-850 K deduced from the model calculations at the MLS sampling locations inside the polar vortex ranges between 43 DU in 2005/2006 and 109 DU in 2004/2005, while those derived from the MLS observations range between 26 DU and 115 DU for the same winters. The partial column ozone depletion derived in that vertical range is larger than that estimated in 350-550 K by 19±7 DU on average, mainly due to NO x chemistry. The column ozone loss estimates from both Mimosa-Chim and MLS in 350-850 K are generally in good agreement with those derived from ground-based ultravioletvisible spectrometer total ozone observations for the respective winters, except in 2010.