Quasi-stationary planetary wave long-term changes in total ozone over Antarctica and

Arctic

A.Grytsai, O.Evtushevsky, O. Agapitov, A.Klekociuk, V.Lozitsky, G. Milinevsky

gennadim@gmail.com, Andrew.Klekociuk@aad.gov.au

National Taras Shevchenko University of Kyiv, UkraineAustralian Government Antarctic Division, Hobart, Australia

Research in the framework of SCAR ICESTAR Program

Task:

Analysis of interannual and decadal changes of the quasi-stationary wave amplitude and structure of zonal extremes are analyzed using the TOMS satellite data. Comparison to Northern Hemisphere

Time interval: 1979-2005.

Season: the spring months September-November.

Analysis method: zonal wave parameters determination using longitudinal distribution of the total ozone at individual latitude circles within 50S-80S.

Dataset:TOMS measurements of total ozone content

Regular satellite measurements of total ozone content (TOC) have been carried out using TOMS (Total Ozone Mapping Spectrometer) since 1978 (with a gap in 1993-95). Spatial resolution is equal 1° on latitude and 1.25° on longitude.

Akademik Vernadsky

Total ozone distribution on 1.10.1979 and 1.10.2004

http://toms.gsfc.nasa.gov

Traveling wave from ground-based observations.

Planetary waves in total ozone

Total ozone distribution to the south of 30S, 25.09.2001. Dashed

line marks the latitude circle 65S.

Time-longitude distribution of total ozone in the Southern Hemisphere spring

Zonal wave in total ozone is presented by quasi-stationary maximum corresponded to mid-latitude air and minimum, which is caused by ozone hole displacement and elongation.

Traveling planetary waves are seen as inclined strips.

September-November 1996, 55°S-75°S

50°S

55°S

60°S

70°S

65°S

Structure of ozone zonal asymmetry

October mean total ozone over the southern latitudes 40S-90S by the TOMS data. The dashed circle marks the Vernadsky Station latitude 65S.

Two ozone anomalies in Southern Hemisphere:

low ozone (200 DU) in ozone hole and

high ozone (400 DU) in mid-latitude band.

Monthly mean longitudinal distributions of the total ozone by the TOMS data for

(a) the 9 months of the southern summer, autumn and winter 2005 at 60S;

(b) the spring months September, October and November 2005 at 60S.

Increasing of ozone asymmetry in spring

Interannual variations of quasi-stationary wave in total ozone during 1979-2005 on different latitudes 50°S-80°S

The 3-month mean longitudinal distributions of total ozone at the seven latitude circles within 50°S-80°S

Trends in the quasi-stationary wave maximum and minimum

Different trends in the regions of zonal maximum and minimum cause long-term increase of wave amplitude.

Lower trend values at the wave maximum is due to mid-latitude origin of stratospheric air, whereas the higher trends at wave minimum is result of polar air penetration to this region.

-23 DU/decade

-38 DU/decade

-12 DU/decade

-15 DU/decade

55°S

65° S

Amplitude of quasi-stationary temperature wave

Interannual variations of the August-mean amplitude of quasi-stationary wave in the

100-hPa temperature, NCEP-NCAR reanalysis data 1979-2005.

Large amplitude of stationary wave in the lower stratosphere temperature in August 2002 preceded the large stratospheric warming in September 2002.

The event 1988 shows also anomalously high amplitude but at middle latitude only.

5 0 5 5 6 0 6 5 7 0 7 5

Am

plitu

de, K

S o u th e rn la titu d e

Geographical position of zonal extremes in total ozone

The average positions of the quasi-stationary extremes in September-November 1979-2005 (left) and the 5-year means for 1979-1983 and 2001-2005 (right).

Minima are located along Antarctic Peninsula in average data of 1973-1983 and shift eastward during last decades.

Shift distance is about 45, or 2000 km at 65 S.

Long-term change in temperature fields

The 5-year mean eddy tropopause temperature (left) and

eddy temperature at the 100-hPa pressure level (right)

for 1979-1983 (top) and 2001-2005 (bottom)

by NCEP-NCAR reanalysis data.

Eastward shift of about 30 is observed in the region of zonal minimum and the position of zonal maximum is almost unchanged.

(a) Spring mean distribution of total ozone (September-November) and (b) its deviation from zonal mean averaged over 1979-2005. TOMS data were used.

(a) (b)

Total ozone and tropopause pressure for spring 1979-2005

(c)

(c) Zonal asymmetry in tropopause pressure during spring 2005, NCEP-NCAR reanalysis data.

SON 2005

SON 1979-2005 SON 1979-2005

The highest asymmetry along meridians 45W-135E exists, that corresponds in general to the longitudes of ozone extremes. These data confirm reverse relation between total ozone and tropopause height.

Tropopause height decreases monotonically between 15.5 km and 9.5 km (i.e. by about 4 km) over Antarctica in October 2005.

Tropopause zonal asymmetry

Meridian profiles of tropopause pressure over Southern Hemisphere in October 2005, NCEP-NCAR reanalysis data.

Over the Arctic region ozone distribution is dislike to Southern Hemisphere’s one. During spring ozone maximum is observed in the middle and high Northern latitudes. The lowest values are registered in the autumn months, but they are significantly larger, than into southern ozone hole. Wave structure is complicated without wave 1 domination.

Northern Hemisphere

Northern Hemisphere

Ozone values at 60N are higher comparatively with the ones in the edge region of southern ozone hole in the corresponding time period (early spring). But from the 1990s low total ozone levels have been observed in the Greenwich longitudinal sector approximately. Wave 1 with the quasi-stationary maximum and minimum exists during considered months.

1. During the last 27 years amplitude of quasi-stationary wave in total ozone in Antarctic spring increased with maximal amplitude value and its trend at the latitude 65°S.

2.The long-term eastward displacement of quasi-stationary minimum is observed over the sector 60°W-0°E, whereas the maximum takes enough stable position in the quadrant 90°E-180°E.

3. Spatial distribution of tropopause height exhibits zonal asymmetry structure and long-term tendency which are similar to total ozone ones.

4. Ozone values in the Northern hemisphere high latitudes are larger than in the Southern hemisphere, but their negative trend exists as well.

Conclusion - 1

Conclusion - 25. Pre-ozone hole condition have been observed over North Pole in the last 10-15 years.

6. Quasi-stationary wave 1 prevails in the southern ozone hole edge region during spring. In the Northern hemisphere high latitudes wave 1 affects ozone distribution.

7. Northern minimum is observed during autumn and southern low values appear in the second part of winter. Wave activity in the Northern hemisphere corresponds to large ozone levels.

Intercomparison of ozone dynamics in Northern and Southern Hemispheres will allow to study the similarities and differences in ozone structure, connections, and separate the impact to ozone dynamics of the underlying Earth (sea) surface and planetary wave activity.

This research was partly made in the framework of SCAR ICESTAR Program, was supported by National Taras Shevchenko University of Kyiv, project 06BF051-12, by Grant of Ministry Education and Science of Ukraine: Greece-Ukraine M/86-2006, and Australian Antarctic Science project 737.