Polar stratospheric cloud processed air and potential voracity in the northern hemisphere lower stratosphere at mid‐latitudes during winter

Small-scale (<1000 km) features in ER-2 measurements of ClO, O3, H2O, N2O, and NOy, outside the lower stratospheric Arctic vortex of 1988–1989 are compared with features on potential vorticity maps from the European Centre for Medium-range Weather Forecasts (ECMWF). The potential vorticity maps are obtained from Tl06 analyses and forecasts. Some of the plots have been truncated to lower resolution (T63 or T42) which smooths out the finer-scale structure. Comparison of these lower resolution plots shows how much detail is lost by excessive smoothing. It is also evident that the forecast plots lose fine-scale structure due to dissipation in the model resulting mainly from horizontal diffusion. We conclude that blobs of air on the maps at latitudes between the vortex edge and 25°N having potential vorticities characteristic of the vortex, did indeed originate from the vortex, but that the real atmosphere is more sharply differentiated (inhomogeneous) than the meteorological analyses, implying that the potential vorticity maps underestimate the amount of peeled-off material. Areal budgets of the ex-vortex air are considered for ER-2 flight days, and are performed for 24-hour forecasts at T63, and analyses at T42, T63, and T106 resolution at θ = 475 K. Finally, it is concluded that the lower stratospheric Arctic vortex of 1988–1989 spread considerable amounts of air to mid-latitudes which had been processed by polar stratospheric clouds, and that this mechanism is a realistic explanation for the wintertime loss of ozone observed over northern mid-latitudes during the last decade.

[1]  D. Murphy.  Ozone loss rates calculated along ER-2 flight tracks , 1991 .

[2]  D. Toohey,et al.  In situ measurements of midlatitude ClO in winter , 1991 .

[3]  K. Kelly,et al.  Ozone loss in the Arctic polar vortex inferred from high-altitude aircraft measurements , 1990, Nature.

[4]  E. Danielsen.  In defense of Ertel's potential vorticity and its general applicability as a meteorological tracer , 1990 .

[5]  K.,et al.  The Meteorological Measurement System on the NASA ER-2 Aircraft , 1990 .

[6]  M. McIntyre,et al.  On the Conservation and Impermeability Theorems for Potential Vorticity , 1990 .

[7]  D. Fahey,et al.  Observations of denitrification and dehydration in the winter polar stratospheres , 1990, Nature.

[8]  K. Kelly,et al.  Stratospheric constituent trends from ER-2 profile data , 1990 .

[9]  M. McCormick,et al.  SAGE II observations of polar stratospheric clouds near 50°N January 31–February 2, 1989 , 1990 .

[10]  S. Wofsy,et al.  Loss of ozone in the Arctic vortex for the winter of 1989 , 1990 .

[11]  S. Kinne,et al.  Radiative effects of polar stratospheric clouds , 1990 .

[12]  D. McKenna,et al.  On the influence of polar stratospheric cloud formation on chemical composition during the 1988/89 Arctic winter , 1990 .

[13]  Roderic L. Jones,et al.  Calculations of ozone destruction during the 1988/89 Arctic winter , 1990 .

[14]  D. Fahey,et al.  Redistribution of reactive odd nitrogen in the lower arctic stratosphere , 1990 .

[15]  A. Tuck,et al.  Airborne lidar observations in the wintertime Arctic stratosphere: Ozone , 1990 .

[16]  D. Fahey,et al.  Measurements of total reactive nitrogen during the Airborne Arctic Stratospheric Expedition , 1990 .

[17]  D. Toohey,et al.  In situ observations of ClO in the Arctic stratosphere: ER‐2 aircraft results from 59°N TO 80°N latitude , 1990 .

[18]  L. Heidt,et al.  A comparison of ER-2 measurements of stratospheric water vapor between the 1987 Antarctic and 1989 Arctic Airborne missions , 1990 .

[19]  I. Isaksen,et al.  Studies of Arctic stratospheric ozone in a 2‐D model including some effects of zonal asymmetries , 1990 .

[20]  S. W. Bowen,et al.  Temperature and wind measurements and model atmospheres of the 1989 Airborne Arctic Stratospheric Expedition , 1990 .

[21]  S. Strahan,et al.  ATLAS instrument characterization - Accuracy of the AASE and AAOE nitrous oxide data sets , 1990 .

[22]  Roderic L. Jones,et al.  The polar stratospheric cloud event of January 24, 1989, part 1. Microphysics , 1990 .

[23]  W. Brune,et al.  In situ observations of BrO over Antarctica: ER‐2 aircraft results From 54°S to 72°S latitude , 1989 .

[24]  Adrian F. Tuck,et al.  In situ ozone measurements within the 1987 Antarctic ozone hole from a high-altitude ER-2 aircraft , 1989 .

[25]  D. Murphy.  Time offsets and power spectra of the ER-2 data set from the 1987 Airborne Antarctic Ozone Experiment , 1989 .

[26]  R. Nagatani,et al.  Meteorological atlas of the Northern Hemisphere lower stratosphere for January and February 1989 during the Airborne Arctic Stratospheric Expedition , 1989 .

[27]  Roderic L. Jones,et al.  Diagnostic studies of the Antartctic vortex during the 1987 Airborne Antarctic Ozone Experiment: Ozone miniholes , 1989 .

[28]  S. Strahan,et al.  Nitrous oxide as a dynamic tracer in the 1987 airborne Antarctic ozone experiment , 1988, Annual Meeting Optical Society of America.

[29]  W. D. Hypes,et al.  Dehydration in the lower Antarctic stratosphere during late winter and early spring, 1987 , 1989 .

[30]  Adrian F. Tuck,et al.  Synoptic and chemical evolution of the Antarctic vortex in late winter and early spring, 1987 , 1989 .

[31]  D. Fahey,et al.  In situ measurements of total reactive nitrogen, total water, and aerosol in a polar stratospheric cloud in the Antarctic , 1989 .

[32]  A. Tuck,et al.  The planning and execution of ER‐2 and DC‐8 aircraft flights over Antarctica, August and September 1987 , 1989 .

[33]  K. Kelly,et al.  Indicators of transport and vertical motion from correlations between in situ measurements in the Airborne Antarctic Ozone Experiment , 1989 .

[34]  David R. Hanson,et al.  Laboratory studies of the nitric acid trihydrate: Implications for the south polar stratosphere , 1988 .

[35]  W. Baker,et al.  Meteorological atlas of the Southern Hemisphere lower stratosphere for August and September 1987 , 1988 .

[36]  M. Juckes,et al.  A high-resolution one-layer model of breaking planetary waves in the stratosphere , 1987, Nature.

[37]  Ellis E. Remsberg,et al.  The Area of the Stratospheric Polar Vortex as a Diagnostic for Tracer Transport on an Isentropic Surface , 1986 .

[38]  A. Tuck,et al.  Aircraft Measurements Near Jet Streams , 1985 .

[39]  Lennart Bengtsson,et al.  Medium-Range Forecasting at the ECMWF , 1985 .

[40]  Tim Palmer,et al.  The «surf zone» in the stratosphere , 1984 .

[41]  J. Anderson.  The absolute concentration of O(³P) in the Earth's stratosphere , 1975 .