[show abstract][hide abstract] ABSTRACT: The Match technique was used to determine chemically induced ozone loss inside the stratospheric vortex during the Arctic winter 2002/2003. From end of November
2002, which is the earliest start of a Match campaign ever, until end of March 2003 approximately 800 ozonesondes were launched from 34 stations in the Arctic and mid
latitudes. Ozone loss rates were quantified from the beginning of December until mid-March in the vertical region of 400–550K potential temperature. In accordance with the
occurrence of a large area of conditions favourable for the formation of polar stratospheric clouds in December ozone destruction rates varied between 10–15 ppbv/day depending
on height. Maximum loss rates around 35 ppbv/day were reached during late January. Afterwards ozone loss rates decreased until mid-March when the final warming of the vortex began. In the period from 2 December 2002 to 16 March 2003 the accumulated ozone loss reduced the partial ozone column of 400–500K potential temperature by 56±4 DU. This value is in good agreement with that inferred from the empirical relation of ozone loss against the volume of potential polar stratospheric clouds within the northern hemisphere. The sensitivity of the results on recent improvements of the approach has been tested.
Atmospheric Chemistry and Physics 07/2006; · 4.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: Changes in the UTLS region over Central Europe are presented in connection with global changes during the last 20-30 years The research is based mainly on the series of ozonesoundings and radiosoundings from Poland since 1979 Special attention was paid to two characteristic surfaces within the UTLS region -- the thermal tropopause important for energy balance and the chemopause ozonopause relevant to the transport and mixing of mass and chemical species between the stratosphere and troposphere The ozonopause is defined as the bottom layer of ozone rich stratospheric air In most cases the ozonopause can be found easily by visual inspection but in some cases the wavy structure of ozone profile or weak ozone gradient in the UTLS region make some difficulties Profiles of temperature and relative humidity can give additional information A large change of the structure of the UTLS region has occurred in recent years During the years 1989-2005 the ozonopause on the average was located about 200m below the tropopause whereas the previous estimate for 1979-2000 situated the ozonopause about 600 m below the tropopause It is also noted that the percentage of multiple tropopause has increased since 1979 The ozonopause is next used to separate the cases of tropical advection ozonopause above the tropopause from the cases of middle and higher latitude advection Long term changes of temperature at the tropopause and at the ozonopause are examined in dependence of their mutual location When the ozonopause was located above the thermal tropopause the
[show abstract][hide abstract] ABSTRACT: The budget of ozone water vapour and other substances in the UTLS region is influenced by the transport and mixing across the tropopause The research is based mainly on regular ozonesoundings performed in Legionowo Poland 52 40 N 20 97 E since 1979 Until May 1993 the OSE ozone sensor of Brewer Mast type has been used and since June 1993 the ozonesoundings are continued with the ECC sensors Special attention was paid to the ozonopause defined as the bottom layer of ozone rich stratospheric air In most cases the ozonopause can be found easily by visual inspection but in some cases the wavy structure of ozone profile or weak ozone gradient in the UTLS region make some difficulties Profiles of temperature and relative humidity can give additional information The analysis of mutual location of tropopause and ozonopause show cases of tropical advection high tropopause and cases of ozone intrusions into the troposphere low ozonopause For some episodes dispersed throughout the year the ozonopause descended down to the altitude of 4-6 km For studying the origin of the air masses coming over Poland the 3-D backward and forward trajectories are used A unique episode of deep stratospheric intrusion into the troposphere occurred on the 11 th October 2005 The ozone sonde launched at Legionowo on that day revealed record ozone amount in the troposphere 78 D and record ozone mixing ratio near 4km 160 ppbv During earlier episode on the 4 th August 1993 very high ozone values of 100-110 ppbv were observed at Legionowo in the layer
[show abstract][hide abstract] ABSTRACT: The ENVISAT was launched in 2002 Three of its instruments offer the
scientific community unique opportunities for atmospheric research The
radiosoundings as part of the daily worldwide routine measurements are
reliable source of data for the validation of atmospheric profiles
Radiosonde data from three Polish upper-air stations Legionowo Wroclaw
Leba are used for validation of temperature pressure and water vapour
profiles twice daily routine and from one station Legionowo for
validation of ozone profiles weekly routine To improve the effectiveness
of validation additional ozone soundings are performed in close
collocation with relevant satellite observations Nine validation ozone
soundings were performed in 2003 eighteen in 2004 and forty in 2005 The
radiosoundings selected for the validation must have good time and space
coincidence with satellite measurements closer than 3 hours and 200 km
The first validation was performed for MIPAS for the year 2003 78 PTU
and 9 ozone profiles The radiosounding profiles are available up to
altitude of about 35 km while the MIPAS profiles from the altitude
approximately 12 km at 8 levels to the height of 35 km with resolution
about 3 km so only stratospheric profiles can be evaluated The
investigation was executed for original and smoothed radiosounding
profiles with 3 km span Preliminary results of MIPAS validation indicate
that satellite pressure and ozone concentration profiles are well
correlated with radiosounding profiles while temperature profiles do not
correlate well The
[show abstract][hide abstract] ABSTRACT: Abstract. The Match technique was used to determine chemically induced ozone loss inside the stratospheric vortex during the Arctic winter 2002/2003. From end of November 2002, which is the earliest start of a Match campaign ever, until end of March 2003 approximately 800 ozonesondes were launched from 30 stations in the Arctic and mid latitudes. Ozone loss rates were quantified from the beginning of December until mid of March in the vertical region of 400–550 K potential temperature. In December ozone destruction rates varied between 10–15 ppbv/day depending on height. Maximum loss rates around 35 ppbv/day were reached during late January. Afterwards ozone loss rates decreased until mid-March when the final warming of the vortex began and measurements for the campaign were no longer possible. In the period of 2 December 2002 to 16 March 2003 the accumulated ozone loss reduced the partial ozone column of 400–500 K potential temperature by 56±4 DU. The sensitivity of the results on recent improvements of the approach has been tested.
Atmospheric Chemistry and Physics Discussions. 07/2005;
[show abstract][hide abstract] ABSTRACT: Abstract. A total ozone depletion of 68±7 Dobson units between 380 and 525K 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±9DU for the collar region (closest to the edge), 52±5DU for the vortex centre and 68±7DU for the middle region in between centre and collar.
Our results compare well with other studies: We find good agreement with ozone loss deduced from SAOZ data, with results inferred from POAM III observations and with results from tracer-tracer correlations using HF as the long-lived tracer. We find a higher ozone loss than that deduced by tracer-tracer correlations using CH4.
We have made a careful comparison with Match results: The results were recalculated using a common time period, vortex edge definition and height interval. The two methods generally compare very well, except at the 475K level which exhibits an unexplained discrepancy.
Atmospheric Chemistry and Physics 01/2005; · 4.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: 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-?) coordinate space; the resulting composites from each instrument are mapped onto the other instruments' locations and times. The mapped data are then used to intercompare data from the different instruments. Overall, the four ozone data sets are found to be in good agreement. AROTAL shows somewhat lower values below 16 km, and DIAL has a positive bias at the upper limits of its altitude range. These intercomparisons are consistent with those obtained from more conventional near-coincident profiles, where available. Although the PV-? mapping technique entails larger uncertainties of individual profile differences compared to direct near-coincident comparisons, the ability to include much larger numbers of comparisons can make this technique advantageous.
Atmospheric Chemistry and Physics 11/2004; · 4.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: 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.
Atmospheric Chemistry and Physics Discussions. 10/2004;
[show abstract][hide abstract] ABSTRACT: A UV Index forecast method for polish territory has been elaborated in
2000. The forecast has been implemented operationally and is published
daily on IMWM home page http://www.imgw.pl during summer months
(May-September). Heidke method has been used to validate the total ozone
column forecasts. For comparison of the forecasted UV Indices,
measurements performed with SL501 Biometers at Leba, Legionowo and
Zakopane have been used. UV Index clear sky forecasts of IMWM, DWD and
GOME have been compared, with GOME total ozone as a reference. It
appears that IMWM forecast elaborated for local conditions (neural
network was trained on data from Legionowo and Belsk) can give better
results for polish sites than forecasts worked out for larger areas. DWD
forecasts underestimate the UV Indices while comparison of IMWM and KNMI
forecasts show a difference of 0.2-0.5 UV Index, what can be accounted
for different radiative transfer models used in calculations.
[show abstract][hide abstract] ABSTRACT: During Arctic winters with a cold, stable stratospheric circulation, reactions on the surface of polar stratospheric clouds (PSCs) lead to elevated abundances of chlorine monoxide (ClO) that, in the presence of sunlight, destroy ozone. Here we show that PSCs were more widespread during the 1999/2000 Arctic winter than for any other Arctic winter in the past two decades. We have used three fundamentally different approaches to derive the degree of chemical ozone loss from ozonesonde, balloon, aircraft, and satellite instruments. We show that the ozone losses derived from these different instruments and approaches agree very well, resulting in a high level of confidence in the results. Chemical processes led to a 70% reduction of ozone for a region ∼1 km thick of the lower stratosphere, the largest degree of local loss ever reported for the Arctic. The Match analysis of ozonesonde data shows that the accumulated chemical loss of ozone inside the Arctic vortex totaled 117 ± 14 Dobson units (DU) by the end of winter. This loss, combined with dynamical redistribution of air parcels, resulted in a 88 ± 13 DU reduction in total column ozone compared to the amount that would have been present in the absence of any chemical loss. The chemical loss of ozone throughout the winter was nearly balanced by dynamical resupply of ozone to the vortex, resulting in a relatively constant value of total ozone of 340 ± 50 DU between early January and late March. This observation of nearly constant total ozone in the Arctic vortex is in contrast to the increase of total column ozone between January and March that is observed during most years.
Journal of Geophysical Research 10/2002; · 3.17 Impact Factor
[show abstract][hide abstract] ABSTRACT: The UTLS region can be characterised by two boundary surfaces, the tropopause for energy exchange and the ozonopause for the ozone exchange between the troposphere and stratosphere. A study of the changes of the tropopause temperature and height, as well as mutual relation between the tropopause and the ozonopause heights was performed. The statistical analysis was done on the base of the radiosoundings (since 1963) and ozone soundings data (since 1979) from Legionowo upper-air station. Moreover, the relation between total ozone and tropopause height was analysed, using the Belsk ozone data (since 1963). For trend calculations of the temperature in the UTLS region and the height of the tropopause, a linear regression model was applied. Relevant macro circulation indexes were also included into the model. Significant cooling in the UTLS region in winter, spring and summer and the growth of the tropopause height in winter were found. The negative correlation between monthly means of total ozone and tropopause height is observed for the whole year. However, the annual total ozone maximum in spring is delayed about one month in relation to the lowest tropopause height that occurs at the end of winter. For the years 1980-1992, and especially for the period 1993-2000, in comparison to earlier years 1971-1979, for all months an ozone decrease was observed, the largest in spring. There is a linear relation between the tropopause and ozonopause, with increasing dispersion towards lower tropopause heights. The patterns of annual courses of monthly average tropopause and ozonopause heights are very similar throughout the year. On average, the ozonopause lies about 600m below the tropopause, however, a large dispersion of +/-850m was observed. The ozone changes in the UTLS region and episodes of stratospheric ozone intrusions into the troposphere were analysed on the base on a shorter period, 1993- 2000, and the results will be presented.
[show abstract][hide abstract] ABSTRACT: 1] Ozone observations made by the Airborne Raman Ozone, Temperature, and Aerosol Lidar (AROTEL) and Differential Absorption Lidar (DIAL) on board the NASA DC-8 aircraft, the NOAA in situ instrument on board the NASA ER-2 aircraft, and Third European Stratospheric Experiment on Ozone 2000 (THESEO 2000) ozonesondes are analyzed by applying a quasi-conservative coordinate mapping technique. Measurements from the late winter/early spring SAGE III Ozone Loss and Validation Experiment (SOLVE) period (January through March 2000) are incorporated into a time-varying composite field in a potential vorticity-potential temperature coordinate space; ozone loss rates are calculated both with and without diabatic effects. The average loss rate from mid-January to mid-March near the 450 K isentropic surface in the polar vortex is found to be approximately 0.03 ppmv/d.
Journal of Geophysical Research 01/2002; 107(8274). · 3.17 Impact Factor
[show abstract][hide abstract] ABSTRACT: Chemical ozone loss rates inside the Arctic polar vortex were determined in early 1998 and early 1999 by using the Match technique based on coordinated ozonesonde measurements. These two winters provide the only opportunities in recent years to investigate chemical ozone loss in a warm Arctic vortex under threshold conditions, i.e., where the preconditions for chlorine activation, and hence ozone destruction, only occurred occasionally. In 1998, results were obtained in January and February between 410 and 520 K. The overall ozone loss was observed to be largely insignificant, with the exception of late February, when those air parcels exposed to temperatures below 195 K were affected by chemical ozone loss. In 1999, results are confined to the 475 K isentropic level, where no significant ozone loss was observed. Average temperatures were some 8°–10° higher than those in 1995, 1996, and 1997, when substantial chemical ozone loss occurred. The results underline the strong dependence of the chemical ozone loss on the stratospheric temperatures. This study shows that enhanced chlorine alone does not provide a sufficient condition for ozone loss. The evolution of stratospheric temperatures over the next decade will be the determining factor for the amount of wintertime chemical ozone loss in the Arctic stratosphere.
Journal of Geophysical Research 04/2001; · 3.17 Impact Factor
[show abstract][hide abstract] ABSTRACT: This paper discusses the influence of ozone and temperature profiles on surface UV radiation, and on total ozone column derived from global irradiance measurements. Measured ozone and temperature profiles from Legionowo, Poland, are used together with typical surface and cloudless atmosphere conditions. The effects of assuming a U.S. standard profile with scaled ozone column instead of actual profiles are analyzed. Variable temperature/ozone vertical distributions and different sets of ozone absorption cross section data may change erythemally weighted radiation by as much as 14% with respect to reference conditions. The mean and standard deviations of errors were generally below 2% but increased another 2-3% for large solar zenith angles. Uncertainties of up to 10% may be caused by using an inappropriate profile in total ozone column retrieval. We analyzed the underlying processes causing the uncertainties by selecting three ozone and temperature profile pairs characterized by the same unscaled total ozone amount but with different vertical distributions. Results obtained for cases with ozone redistribution from the stratosphere to the troposphere are consistent with earlier work. However, if the temperature profiles differ significantly in the stratosphere, an ozone redistribution may lead to a strong decrease in UV doses for high solar zenith angles. It is also shown that differences in ozone maximum height as well as in ozone concentration in the upper troposphere have a significant influence on surface UV radiation.
Journal of Geophysical Research 01/2000; 105:5001-5008. · 3.17 Impact Factor
[show abstract][hide abstract] ABSTRACT: With the Match technique, which is based on the coordinated release of ozonesondes, chemical ozone loss rates in the Arctic stratospheric vortex in early 1997 have been quantified in a vertical region between 400 K and 550 K. Ozone destruction was observed from mid February to mid March in most of these levels, with maximum loss rates between 25 and 45ppbv/day. The vortex averaged loss rates and the accumulated vertically integrated ozone loss have been smaller than in the previous two winters, indicating that the record low ozone columns observed in spring 1997 were partly caused by dynamical effects. The observed ozone loss is inhomogeneous through the vortex with the highest loss rates located in the vortex centre, coinciding with the lowest temperatures. Here the loss rates per sunlit hour reached 6 ppbv/h, while the corresponding vortex averaged rates did not exceed 3.9 ppbv/h.
Geophysical Research Letters 01/2000; · 3.98 Impact Factor
[show abstract][hide abstract] ABSTRACT: The chemically induced ozone loss inside the Arctic vortex during the winter 1994/95 has been quantified by coordinated launches of over 1000 ozonesondes from 35 stations within the Match 94/95 campaign. Trajectory calculations, which allow diabatic heating or cooling, were used to trigger the balloon launches so that the ozone concentrations in a large number of air parcels are each measured twice a few days apart. The difference in ozone concentration is calculated for each pair and is interpreted as a change caused by chemistry. The data analysis has been carried out for January to March between 370 K and 600 K potential temperature. Ozone loss along these trajectories occurred exclusively during sunlit periods, and the periods of ozone loss coincided with, but slightly lagged, periods where stratospheric temperatures were low enough for polar stratospheric clouds to exist. Two clearly separated periods of ozone loss show up. Ozone loss rates first peaked in late January with a maximum value of 53 ppbv per day (1.6 % per day) at 475 K and faster losses higher up. Then, in mid-March ozone loss rates at 475 K reached 34 ppbv per day (1.3 % per day), faster losses were observed lower down and no ozone loss was found above 480 K during that period. The ozone loss in hypothetical air parcels with average diabetic descent rates has been integrated to give an accumulated loss through the winter. The most severe depletion of 2.0 ppmv (60 %) took place in air that was at 515 K on 1 January and at 450 K on 20 March. Vertical integration over the levels from 370 K to 600 K gives a column loss rate, which reached a maximum value of 2.7 Dobson Units per day in mid-March. The accumulated column loss between 1 January and 31 March was found to be 127 DU (36 %).
Journal of Atmospheric Chemistry 01/1999; 32(1):35-59. · 1.33 Impact Factor
[show abstract][hide abstract] ABSTRACT: Eighteen radiative transfer models in use for calculation of UV index are compared with respect to their results for more that 100 cloud-free atmospheres, which describe present, possible future and extreme conditions. The comparison includes six multiple-scattering spectral models, eight fast spectral models and four empirical models. Averages of the results of the six participating multiple-scattering spectral models are taken as a basis for assessment. The agreement among the multiple-scattering models is within +/- 0.5 UV index values for more than 80% of chosen atmospheric parameters. The fast spectral models have very different agreement, between +/- 1 and up to 12 UV index values. The results of the empirical models agree reasonably well with the reference models but only for the atmospheres for which they have been developed. The data to describe the atmospheric conditions, which are used for the comparison, together with the individual results of all participating models and model descriptions are available on the Internet: http://www.meteo.physik.uni-muenchen.de/++ +strahlung/cost/.
Photochemistry and Photobiology 07/1998; 67(6):657-62. · 2.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: In this paper, we show that the rate of ozone loss in both polar and mid-latitudes, derived from ozonesonde and satellite data, has almost the same vertical distribution (although opposite sense) to that of ozone laminae abundance. Ozone laminae appear in the lower stratosphere soon after the polar vortex is established in autumn, increase in number throughout the winter and reach a maximum abundance in late winter or spring. We indicate a possible coupling between mid-winter, sudden stratospheric warmings (when the vortex is weakened or disrupted) and the abundance of ozone laminae using a 23-year record of ozonesonde data from the World Ozone Data Center in Canada combined with monthly-mean January polar temperatures at 30 hPa.Results are presented from an experiment conducted during the winter of 1994/95, in phase II of the Second European Stratospheric And Mid-latitude Experiment (SESAME), in which 93 ozone-enhanced laminae of polar origin observed by ozonesondes at different time and locations are linked by diabatic trajectories, enabling them to be probed twice or more. It is shown that, in general, ozone concentrations inside laminae fall progressively with time, mixing irreversibly with mid-latitude air on time-scales of a few weeks. A particular set of laminae which advected across Europe during mid February 1995 are examined in detail. These laminae were observed almost simultaneously at seven ozonesonde stations, providing information on their spatial scales. The development of these laminae has been modelled using the Contour Advection algorithm of Norton (1994), adding support to the concept that many laminae are extrusions of vortex air. Finally, a photochemical trajectory model is used to show that, if the air in the laminae is chemically activated, it will impact on mid-latitude ozone concentrations. An estimate is made of the potential number of ozone molecules lost each winter via this mechanism.
Journal of Atmospheric Chemistry 04/1998; 30(1):187-207. · 1.33 Impact Factor
[show abstract][hide abstract] ABSTRACT: It is well established that extensive depletion of ozone, initiated by heterogenous reactions on polar stratospheric clouds (PSCs) can occur in both the Arctic and Antarctic lower stratosphere. Moreover, it has been shown that ozone loss rates in the Arctic region in recent years reached values comparable to those over the Antarctic. But until now the accumulated ozone losses over the Arctic have been the smaller, mainly because the period of Arctic ozone loss has not—unlike over the Antarctic—persisted well into springtime. Here we report the occurrence—during the unusually cold 1995–96 Arctic winter—of the highest recorded chemical ozone loss over the Arctic region. Two new kinds of behaviour were observed. First, ozone loss at some altitudes was observed long after the last exposure to PSCs. This continued loss appears to be due to a removal of the nitrogen species that slow down chemical ozone depletion. Second, in another altitude range ozone loss rates decreased while PSCs were still present, apparently because of an early transformation of the ozone-destroying chlorine species into less active chlorinenitrate. The balance between these two counteracting mechanisms is probably a fine one, determined by small differences in wintertime stratospheric temperatures. If the apparent cooling trend in the Arctic stratosphere is real, more dramatic ozone losses may occur in the future.
[show abstract][hide abstract] ABSTRACT: Long-term variations in the vertical temperature structure of the atmosphere play an important role in the detection of climate change. Over Poland, these changes can be studied with the available data from upper air stations at Legionowo, Leba, and Wroclaw. For trend calculations, a multiple linear regression model, including the dependence on macro circulation patterns, was applied to monthly mean temperatures of the series 1961-2002 from the surface up to 200 hPa, and for the period 1979-2002 up to 50 hPa. Estimations of the temperature trends indicate accelerated warming of the boundary layer and free troposphere since 1979, exceeding 2K/decade for winter months. In the upper troposphere, the temperature trends reverse. At the tropopause negative trends for 1961-2002 can be observed throughout the year. Significant cooling at the heights 1-2 km around the tropopause has been stated. The maximum negative trend, exceeding -2K/decade for January, is related to the increase in the tropopause height. An enhanced subtropical advection over Poland in late autumn and early winter manifested itself by the increased occurrence of the multiple tropopause. At higher levels in the stratosphere, increasing cooling, reaching -2K/decade in cold season was observed. The acceleration of the cooling of the stratosphere has been stated since 1979. It can be attributed to large negative ozone trends observed on Legionowo soundings. The frequency of episodic intrusions of ozone depleted air masses from the cold Arctic polar vortex has increased over Poland since the early 1990s.