550 Geowissenschaften
Refine
Year of publication
- 2008 (48) (remove)
Document Type
- Article (35)
- Doctoral Thesis (8)
- Working Paper (3)
- Part of a Book (1)
- Part of Periodical (1)
Has Fulltext
- yes (48)
Is part of the Bibliography
- no (48)
Keywords
- Klimawandel (2)
- Aerosolpartikel (1)
- Alkylphenole (1)
- Archäopedologie (1)
- Atmosphäre (1)
- BTEX (1)
- BTX-Aromaten (1)
- Biodegradation (1)
- Biologischer Abbau (1)
- Boden (1)
Institute
- Geowissenschaften (44)
- Geographie (2)
- Extern (1)
- Geschichtswissenschaften (1)
- Gesellschaftswissenschaften (1)
Wasser weltweit : wie groß sind die globalen Süßwasserressourcen, und wie nutzt sie der Mensch?
(2008)
Ohne Wasser kein Leben – die ersten organischen Moleküle entwickelten sich im Wasser, aus Wasser plus Kohlenstoff und Stickstoff, und auch heute brauchen Pflanzen, Tiere und Menschen viel Wasser, um zu überleben. Die Erde ist der einzige Planet mit flüssigem Wasser und der einzige Planet, auf dem es Leben gibt, zumindest in unserem Sonnensystem. Zwei Umstände bewirken gemeinsam, dass nur die Erde die richtige Temperatur für flüssiges Wasser an ihrer Oberfl äche hat: ihr Abstand zur Sonne und ihre Masse. Aufgrund ihrer ausreichend großen Masse kann sie eine Atmosphäre halten, die die mittlere Oberflächentemperatur von –18 °C auf +15 °C erhöht. Nur daher konnte sich im Frühstadium der Erdentstehung das Wasser, das in großen Mengen aus dem Erdinnern ausgaste, an der Oberfläche als flüssiges Wasser in den Ozeanen sammeln.
Wolken haben einen maßgeblichen Einfluss auf den Wasserhaushalt der Erde, das Wettergeschehen und das Klima. Sie wissenschaftlich zu beschreiben, ist schwierig – und das erschwert die Niederschlagsvorhersage ebenso wie die Klimamodellierung. Wichtig für die Entstehung von Regen in unseren Breiten sind Eispartikel. Sie machen einen großen Teil der Wolken aus. Doch wie bilden sie sich, und warum sind sie für viele physikalische Prozesse in den Wolken unentbehrlich? Und schließlich: Wirkt sich menschliches Handeln auf die Wolken aus?
Staubwolken sind im Universum die Geburtsstätten neuer Sterne. Dort wiederholen sich Prozesse, die vor 4,56 Milliarden Jahren auch zur Entstehung unseres Sonnensystems geführt haben. Noch heute gibt es Zeugen aus dieser Zeit: Kometenstaub, Sternenstaub und interstellarer Staub. Die »Stardust-Mission« hat sie eingefangen, und Frankfurter Geowissenschaftler haben darin – dank modernster Labor-Analytik – erstaunliche Funde gemacht.
The Match method for the quantification of polar chemical ozone loss is investigated mainly with respect to the impact of the transport of air masses across the vortex edge. For the winter 2002/03, we show that significant transport across the vortex edge occurred and was simulated by the Chemical Lagrangian Model of the Stratosphere. In-situ observations of inert tracers and ozone from HAGAR on the Geophysica aircraft and balloon-borne sondes, and remote observations from MIPAS on the ENVISAT satellite were reproduced well by CLaMS. The model even reproduced a small vortex remnant that remained a distinct feature until June 2003 and was also observed in-situ by a balloon-borne whole air sampler. We use this CLaMS simulation to quantify the impact of transport across the vortex edge on ozone loss estimates from the Match method. We show that a time integration of the determined vortex average ozone loss rates, as performed in Match, results in a larger ozone loss than the polar vortex average ozone loss in CLaMS. The determination of the Match ozone loss rates is also influenced by the transport of air across the vortex edge. We use the model to investigate how the sampling of the ozone sondes on which Match is based represents the vortex average ozone loss rate. Both the time integration of ozone loss and the determination of ozone loss rates for Match are evaluated using the winter 2002/2003 CLaMS simulation. These impacts can explain the majority of the differences between CLaMS and Match column ozone loss. While the investigated effects somewhat reduce the apparent discrepancy in January ozone loss rates reported earlier, a distinct discrepancy between simulations and Match remains. However, its contribution to the accumulated ozone loss over the winter is not large.
The total stratospheric organic chlorine and bromine burden was derived from balloon-borne measurements in the tropics (Teresina, Brazil, 5°04´ S, 42°52´ W) in 2005. Whole air samples were collected cryogenically at altitudes between 15 and 34 km. For the first time, we report measurements of a set of 28 chlorinated and brominated substances in the tropical upper troposphere and stratosphere including ten substances with an atmospheric lifetime of less than half a year. The substances were quantified using pre-concentration techniques followed by Gas Chromatography with Mass Spectrometric detection. In the tropical tropopause layer at altitudes between 15 and 17 km we found 1.1–1.4% of the chlorine and 6–8% of the bromine to be present in the form of very short-lived organic compounds. By combining the data with tropospheric reference data and age of air observations the abundances of inorganic chlorine and bromine (Cly and Bry) were derived. At an altitude of 34 km we calculated 3062 ppt of Cly and 17.5 ppt of Bry from the decomposition of both long- and short-lived organic source gases. Furthermore we present indications for the presence of additional organic brominated substances in the tropical upper troposphere and stratosphere.
Vorwort: Klima ist vor allem deswegen nicht nur von wissenschaftlichem, sondern auch von öffentlichem Interesse, weil es veränderlich ist und weil solche Änderungen gravierende ökologische sowie sozioökonomische Folgen haben können. Im Detail weisen Klimaänderungen allerdings komplizierte zeitliche und räumliche Strukturen auf, deren Erfassung und Interpretation alles andere als einfach ist. Bei den zeitlichen Strukturen stehen mit Recht vor allem relativ langfristige Trends sowie Extremereignisse im Blickpunkt, erstere, weil sie den systematischen Klimawandel zum Ausdruck bringen und letztere wegen ihrer besonders brisanten Auswirkungen. Mit beiden Aspekten hat sich unsere Arbeitsgruppe immer wieder eingehend befasst. Hinsichtlich der Extremereignisse bzw. Extremwertstatistik sei beispielsweise auf die Institutsberichte Nr. 1, 2 und 5 sowie die dort angegebene Literatur hingewiesen. Hier geht es wieder einmal um Klimatrends und dabei ganz besonders um die räumlichen Trendstrukturen. Der relativ langfristige und somit systematische Klimawandel läuft nämlich regional sehr unterschiedlich ab, was am besten in Trendkarten zum Ausdruck kommt. Solche regionalen, zum Teil sehr kleinräumigen Besonderheiten sind insbesondere beim Niederschlag sehr ausgeprägt. Zudem sind die räumlichen Trendstrukturen auch jahreszeitlich/monatlich sehr unterschiedlich. In unserer Arbeitsgruppe hat sich Herr Dr. Jörg Rapp im Rahmen seiner Diplom- und insbesondere Doktorarbeit intensiv mit diesem Problem beschäftigt, was zur Publikation des „Atlas der Niederschlags- und Temperaturtrends in Deutschland 1891-1990“ (Rapp und Schönwiese, 2. Aufl. 1996) sowie des „Climate Trend Atlas of Europe – Based on Observations 1891-1990“ (Schönwiese und Rapp, 1997) geführt hat. Die große Beachtung dieser Arbeiten ließ es schon lange als notwendig erscheinen, eine Aktualisierung vorzunehmen. Dies ist zunächst für den Klima-Trendatlas Deutschland geschehen, der nun für das Zeitintervall 1901-2000 vorliegt (Institutsbericht Nr. 4, 2005). Hier wird nun auch eine entsprechende Aktualisierung für Europa vorgelegt, und zwar auf der Grundlage der Berechnungen, die Reinhard Janoschitz in seiner Diplomarbeit durchgeführt hat. Dabei besteht eine enge Querverbindung zum Projekt VASClimO (Variability Analysis of Surface Climate Observations), das dankenswerterweise vom Bundesministerium für Bildung und Forschung (BMBF) im Rahmen von DEKLIM (Deutsches Klimaforschungsprogramm) gefördert worden ist (siehe Institutsbericht Nr. 6, in den vorab schon einige wenige Europa-Klima-Trendkarten einbezogen worden sind). Mit der Publikation des hier vorliegenden „Klima-Trendatlas Europa 1901-2000“ werden in insgesamt 261 Karten (davon 17 Karten in Farbdarstellung in den Text integriert) wieder umfangreiche Informationen zum Klimawandel in Europa vorgelegt. Sie beruhen vorwiegend auf linearen Trendanalysen hinsichtlich der bodennahen Lufttemperatur und des Niederschlags für die Zeit 1901-2000 sowie für die Subintervalle 1951-2000, 1961-1990 und 1971-2000, jeweils aufgrund der jährlichen, jahreszeitlichen und monatlichen Beobachtungsdaten. Die Signifikanz der Trends ist im (schwarz/weiß wiedergegebenen) Kartenteil durch Rasterung markiert. Da sich die Analyse eng an die oben zitierte Arbeit von Schönwiese und Rapp (1997) anlehnt, wo ausführliche textliche Erläuterungen zu finden sind (ebenso in Rapp, 2000) wurde hier der Textteil sehr knapp gehalten.
This thesis deals with the analysis of “presolar” silicates and oxides by high resolution mass spectrometry and electron microscopy techniques. This “stardust” was identified by its extreme oxygen isotopic anomalies, which point to nucleosynthetic reactions in stellar interiors, in the carbonaceous chondrite Acfer 094. Isotopic, chemical and mineralogical studies on these stardust grains therefore allow the testing of astrophysical questions on Earth, which are otherwise only accessible by spectroscopy and theoretical models. The class of presolar silicates has been identified only six years ago in 2002, although it was known already from spectroscopic observations that silicates represent the most abundant type of dust in the galaxy. The development of the “NanoSIMS” was a crucial step in this respect, because this ion probe with its superior spatial resolution of only 50 nm allowed the detection of the typically 300 nm sized presolar silicates. A total of 142 presolar silicates and 20 presolar oxides were identified within Acfer 094, whose matrix therefore contains 163 ± 14 ppm presolar silicates and 26 ± 6 ppm presolar oxides. This is among the highest amounts reported so far for any primitive solar system material. The majority of detected stardust grains derive from asymptotic giant branch stars of 1 – 2.5 Msun and close-to-solar or slightly lower-than-solar metallicity. However, by measuring the Si isotopic compositions of some enigmatic grains, it could be shown that there is a sub-class of presolar silicates characterized by an extreme enrichment of 17O and a moderate enhancement of 30Si relative to solar, whose origins might be explained by formation in binary stellar systems. About 10% of all grains exhibit an enrichment in 18O and some of them also of 28Si relative to solar, which most likely point to an origin in type II supernova explosions. The Si isotopic measurements also allowed to quantify the effect of the s-process on the Si isotopes in low-mass asymptotic giant branch stars. The results agree well with theoretical predictions. The grains were furthermore characterized by SEM and the chemistries of about half of the grains were determined by Auger electron spectroscopy. The majority of grain morphologies are consistent with what is expected from condensation experiments. However, a lot of grains are altered by Fe-rich minerals, which are either of primary condensation or of secondary ISM or solar nebula origin. Furthermore, complex presolar grains consisting of refractory Al-rich grains attached to silicate material could be identified, which have been predicted by condensation theory and observational evidence. Nine presolar silicates were analyzed by combined NanoSIMS/TEM studies. The majority of grains are Mg-rich and amorphous, which is in contrast to astrophysical evidence, which mainly postulate crystalline Mg-rich and amorphous Fe-rich circumstellar condensates. However, the grains might have been rendered amorphous by secondary processes in the ISM or could have condensed under non-equilibrium, low-temperature conditions in the circumstellar outflow. The grains are more likely characterized by a variable, pyroxene-like chemistry, which could be a result of sputtering in the ISM, which preferentially removes Mg. The detected crystalline presolar silicates in this study and in other work are all olivines, whereas grains with a pyroxene stoichiometry are all amorphous except one. This supports astrophysical models which point to different formation pathways for these two types of grains and therefore different crystallinity. However, the relatively high Fe content of three detected presolar olivines in this study and in other work is in contrast to astrophysical evidence and theoretical considerations, which predict essentially Fe-free crystalline grains. It is therefore possible that the infrared spectra might also be compatible with less Mg-rich olivines. The only crystalline presolar silicate with a pyroxene-like stoichiometry is the unusual grain 1_07: although it is chemically enstatite, the electron diffraction pattern could only be indexed to silicate perovskite, which is stable above ~23 GPa. The discovery of a high-pressure phase of presolar origin shows that dust grains encountering interstellar shocks might not necessarily be completely destroyed. In astrophysical models it is in principle also possible that a fraction of larger grains might survive such a shock wave encounter as a high-pressure modification, which is supported by this discovery.
The present study was elaborated within the scope of the INTAFERE (Integrated Analysis of Mobile Organic Foreign Substances in Rivers) project which investigates the occurrence of xenobiotics in small freshwater streams with particular consideration of social impact factors. The aim of this study is to investigate the seasonal and spatial variance of organic micropollutants in small fresh water streams and to identify possible sources and sinks. Therefore four small freshwater river systems in Hesse, Germany, have been investigated with respect to common organic pollutants such as: the organophosphates tri-n-butyl phosphate (TBP), tris(2-butoxyethyl)phosphate (TBEP), tris(2-chloroethyl)phosphate (TCEP), tris(1-chloro-2-propyl)phosphate (TCPP), and tris(1,3-dichloro-2-propyl)phosphate (TDCPP), the synthetic musk fragrances 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methylcyclopenta-[g]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), the endocrine disruptors bisphenol A (BPA), 4-tert-octylphenol (OP) and the technical isomer mixture of 4-nonylphenol (NP), the herbicide terbutryn [2-(t-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine] as well as the insect repellent N,N-diethyl-m-toluamide (DEET). Water samples were collected in the time span from September 2003 to September 2006 at 26 sampling locations. The samples were extracted with solid phase extraction (SPE) and analyzed by coupled gas chromatography-mass spectrometry (GC-MS). For quantification the internal standard method was used. The results of the study showed an ubiquitous occurrence of organic pollutants in the fresh water streams of the study area. The organophosphates have been detected in 90 % of the water samples with mean concentrations of 502 ng/l (TCPP), 276 ng/l (TBP), 183 ng/l (TBEP), 118 ng/l (TCEP) and 117 ng/l (TDCPP). Sewage treatment plant (STP) effluents were identified as the dominating source for the chlorinated organophosphates as well as for the synthetic musk fragrances and the insect repellent DEET in the river systems. Consequently the highest concentrations were observed in the Schwarzbach system characterized by the highest proportion of waste water compared to the other river systems. Mean concentration levels of the synthetic musk fragrances HHCB and ATHN were 141 ng/l and 46 ng/l, respectively and 124 ng/l in case of DEET. The synthetic musk fragrances showed a clear seasonal trend with significantly lower concentrations in summer times compared to winter times, which is ascribed to stronger photodegradation and volatization during summer times. In contrast, mean DEET concentrations and loads were significantly higher in summer than in autumn, winter and spring, in parallel with the main insect season. The concentrations of the endocrine disruptors BPA, NP and OP in the river water samples ranged from <20 ng/l to 1927 ng/l, <10 ng/l to 770 ng/l, and <10 ng/l to 420 ng/l, respectively. Whereas OP was present in about 2/3 of the samples, NP and BPA could only be detected in 56% and 13% of the water samples, respectively. BPA levels exceeded in two samples the predicted no-effect concentration (PNEC) for water organisms. In case of NP, highest concentrations and loads were found in September 2003 and decreased significantly since then. In contrast, concentrations and loads of OP which serves in a similar application field remained nearly constant during the sampling period. The decrease of NP can be attributed to the implementation of the European Directive 2003/53/EG, which restricts the use of nonylphenols and nonylphenol ethoxylates since January 2005. However, at the end of the sampling period in September 2006, NP could still be detected at mean concentrations of 18 ng/l in the river waters of the sampling area. Furthermore, absence of NP in several samples from associated STP effluents indicate that the STPs cannot be the only sources for NP found in the river water. The herbicide terbutryn was present in the rivers during the whole sampling period from September 2003 to September 2006 despite a ban on its use as a herbicide from January 2004 on. Terbutryn levels ranged from < 4 ng/l to 5600 ng/l, showing a clear spatial pattern with high terbutryn concentrations in the Weschnitz and Modau river systems and significantly lower terbutryn levels in Schwarzbach and Winkelbach. Results from the analysis of two STP effluents discharging into the Weschnitz and the Modau, respectively, indicate that terbutryn enters the rivers from this source. Furthermore, terbutryn concentrations and loads showed a clear seasonal trend with significantly higher levels in summer and autumn. Obviously, the ban on agricultural use of terbutryn at the end of 2003 had no discernable influence on terbutryn concentration in the rivers because there was no trend of decreasing.
The purpose of this study was to reconstruct the depositional environment, the genesis and the composition of Miocene coals in the Kutai Basin, East Kalimantan, Indonesia and to improve our understanding of the factors controlling the organic and inorganic composition, variation of biomarkers, and the peat forming vegetation of the coals. To achieve the aim methods belonging to three different disciplines were applied: 1. Coal petrology (chapter 3) 2. Inorganic geochemistry: sulfur, pyrite and mineral matter distributions (chapter 4) 3. Organic geochemistry of saturated, aromatic hydrocarbon fractions and stable carbon isotopic composition (chapter 5 and 6) Coal petrology Coal developes from peat deposited in mires, mainly in swamps and raised bogs. It is therefore necessary to consider how peat was formed in the past. Coal contains a variety of plant tissues in different degrees of preservation. Tissues of distinct origin are microscopically identifiable and can frequently be related to certain parts of the plant, such as cuticles, woody structures, spores, algal, resin, etc. Together with the particles of less certain origin they are termed macerals which are the petrographic components of coal. During and after deposition of plant remains in sedimentary basins, the organic matter will undergo a sequence of physical, biochemical and chemical changes, which finally results in the formation of coals of increasing rank depending mainly on the temperature influence. The process of coalification begins with practically unaltered plant material and peat, and continues with increasing rank through brown coal, bituminous coal, and finally to anthracite as well as graphite. Coal petrography provides valuable of data of maceral and mineral percentages with reflectance values, which can be used to reconstruct the depositional environment and the coalification processes. In lower rank coals, the material is represented by a group of macerals called huminite, and in bituminous and anthracite coals by a group of macerals called vitrinite. Coal petrography analyses have been carried out on samples from some Miocene coal seams from Kutai Basin. The study has shown that huminite reflectance values of coal samples from ...
Chemical ozone loss in winter 1991–1992 is recalculated based on observations of the HALOE satellite instrument, Version 19, ER-2 aircraft measurements and balloon data. HALOE satellite observations are shown to be reliable in the lower stratosphere below 400 K, at altitudes where the measurements are most likely disturbed by the enhanced sulfate aerosol loading, as a result of the Mt.~Pinatubo eruption in June 1991. Significant chemical ozone loss (13–17 DU) is observed below 380 K from Kiruna balloon observations and HALOE satellite data between December 1991 and March 1992. For the two winters after the Mt. Pinatubo eruption, HALOE satellite observations show a stronger extent of chemical ozone loss towards lower altitudes compared to other Arctic winters between 1991 and 2003. In spite of already occurring deactivation of chlorine in March 1992, MIPAS-B and LPMA balloon observations indicate that chlorine was still activated at lower altitudes, consistent with observed chemical ozone loss occurring between February and March and April. Large chemical ozone loss of more than 70 DU in the Arctic winter 1991–1992 as calculated in earlier studies is corroborated here.
During the APE-THESEO mission in the Indian Ocean the Myasishchev Design Bureau stratospheric research aircraft M55 Geophysica performed a flight over and within the inner core region of tropical cyclone Davina. Measurements of total water, water vapour, temperature, aerosol backscattering, ozone and tracers were made and are discussed here in comparison with the averages of those quantities acquired during the campaign time frame. Temperature anomalies in the tropical tropopause layer (TTL), warmer than average in the lower part and colder than average in the upper TTL were observed. Ozone was strongly reduced compared to its average value, and thick cirrus decks were present up to the cold point, sometimes topped by a layer of very dry air. Evidence for meridional transport of trace gases in the stratosphere above the cyclone was observed and perturbed water distribution in the TTL was documented. The paper discuss possible processes of dehydration induced by the cirrus forming above the cyclone, and change in the chemical tracer and water distribution in the lower stratosphere 400–430 K due to meridional transport from the mid-latitudes and link with Davina. Moreover it compares the data prior and after the cyclone passage to discuss its actual impact on the atmospheric chemistry and thermodynamics.
Appropriate precautions in the case of flood occurrence often require long lead times (several days) in hydrological forecasting. This in turn implies large uncertainties that are mainly inherited from the meteorological precipitation forecast. Here we present a case study of the extreme flood event of August 2005 in the Swiss part of the Rhine catchment (total area 34 550 km2). This event caused tremendous damage and was associated with precipitation amounts and flood peaks with return periods beyond 10 to 100 years. To deal with the underlying intrinsic predictability limitations, a probabilistic forecasting system is tested, which is based on a hydrological-meteorological ensemble prediction system. The meteorological component of the system is the operational limited-area COSMO-LEPS that downscales the ECMWF ensemble prediction system to a horizontal resolution of 10 km, while the hydrological component is based on the semi-distributed hydrological model PREVAH with a spatial resolution of 500 m. We document the setup of the coupled system and assess its performance for the flood event under consideration. We show that the probabilistic meteorological-hydrological ensemble prediction chain is quite effective and provides additional guidance for extreme event forecasting, in comparison to a purely deterministic forecasting system. For the case studied, it is also shown that most of the benefits of the probabilistic approach may be realized with a comparatively small ensemble size of 10 members.
The main objective of the study presented in this paper was to develop an evaluation scheme which is suitable for spatially explicit groundwater vulnerability assessment according to the Water Framework Directive (WFD). Study area was the Hase river catchment, an area of about 3 000 km2 in north-west Germany which is dominated by livestock farming, in particular pig and poultry production. For the Hase river catchment, the first inventory of the WFD led to the conclusion that 98% of the catchment area is "unclear/unlikely" to reach a good groundwater status due to diffuse nitrogen emissions from agriculture. The groundwater vulnerability assessment was embedded in the PartizipA project ("Participative modelling, Actor and Ecosystem Analysis in Regions with Intensive Agriculture", www.partizipa.net), within which a so-called actors´ platform was established in the study area. The objective of the participatory process was to investigate the effects of the WFD on agriculture as well as to discuss groundwater protection measures which are suitable for an integration in the programme of measures. The study was conducted according to the vulnerability assessment concept of the Intergovernmental Panel on Climate Change, considering sensitivity, exposure and adaptive capacity. Sensitivity was computed using the DRASTIC index of natural groundwater pollution potential. Exposure (for a reference scenario) was computed using the STOFFBILANZ nutrient model. Several regional studies were analysed to evaluate the adaptive capacity. From these studies it was concluded that the adaptive capacity in the Hase river catchment is very low due to the economic importance of the agricultural sector which will be significantly affected by groundwater protection measures. As a consequence, the adaptive capacity was not considered any more in the vulnerability assessment. A groundwater vulnerability evaluation scheme is presented which enjoys the advantage that both exposure and sensitivity can be operationalized in a spatially resolved manner (500×500 m grid) by the two models mentioned above. The evaluation scheme was applied in the Hase river catchment. 21% of the catchment was classified as highly vulnerable, another 73% as medium vulnerable. Only 6% of the Hase river catchment has low vulnerability. Grid cells of the high vulnerability class are considered as priority areas for groundwater protection measures in the programme of measures of the WFD. Measures will be particularly effective in the north-eastern part of the catchment where groundwater vulnerability is mainly due to high nitrogen emissions.
Strong perturbations of the Arctic stratosphere during the winter 2002/2003 by planetary waves led to enhanced stretching and folding of the vortex. On two occasions the vortex in the lower stratosphere split into two secondary vortices that re-merged after some days. As a result of these strong disturbances the role of transport in and out of the vortex was stronger than usual. An advection and mixing simulation with the Chemical Lagrangian Model of the Stratosphere (CLaMS) utilising a suite of inert tracers tagging the original position of the air masses has been carried out. The results show a variety of synoptic and small scale features in the vicinity of the vortex boundary, especially long filaments peeling off the vortex edge and being slowly mixed into the mid latitude environment. The vortex folding events, followed by re-merging of different parts of the vortex led to strong filamentation of the vortex interior. During January, February, and March 2003 flights of the Russian high-altitude aircraft Geophysica were performed in order to probe the vortex, filaments and in one case the merging zone between the secondary vortices. Comparisons between CLaMS results and observations obtained from the Geophysica flights show in general good agreement. Several areas affected by both transport and strong mixing could be identified, allowing explanation of many of the structures observed during the flights. Furthermore, the CLaMS simulations allow for a quantification of the air mass exchange between mid latitudes and the vortex interior. The simulation suggests that after the formation of the vortex was completed, its interior remaind relatively undisturbed. Only during the two re-merging events were substantial amounts of extra-vortex air transported into the polar vortex. When in March the vortex starts weakening additional influence from lower latitudes becomes apparent in the model results. In the lower stratosphere export of vortex air leads only to a fraction of about 5% polar air in mid latitudes by the end of March. An upper limit for the contribution of ozone depleted vortex air on mid-latitude ozone loss is derived, indicating that the maximum final impact of dilution is on the order of 50%.
From July 2002 to March 2004 the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aboard the European Space Agency´s Environmental Satellite (Envisat) measured nearly continuously mid infrared limb radiance spectra. These measurements are utilised to retrieve the global distribution of the chlorofluorocarbon CFC-11 by applying a new fast forward model for Envisat MIPAS and an accompanying optimal estimation retrieval processor. A detailed analysis shows that the total retrieval errors of the individual CFC-11 volume mixing ratios are typically below 10% in the altitude range 10 to 25 km and that the systematic components dominate. Contribution of a priori information to the retrieval results are less than 5 to 10% and the vertical resolution of the observations is about 3 to 4 km in the same vertical range. The data are successfully validated by comparison with several other space experiments, an air-borne in-situ instrument, measurements from ground-based networks, and independent Envisat MIPAS analyses. The retrieval results from 425 000 Envisat MIPAS limb scans are compiled to provide a new climatological data set of CFC-11. The climatology shows significantly lower CFC-11 abundances in the lower stratosphere compared with the Reference Atmospheres for MIPAS (RAMstan V3.1) climatology. Depending on the atmospheric conditions the differences between the climatologies are up to 30 to 110 ppt (45 to 150%) at 19 to 27 km altitude. Additionally, time series of CFC-11 mean abundance and variability for five latitudinal bands are presented. The observed CFC-11 distributions can be explained by the residual mean circulation and large-scale eddy-transports in the upper troposphere and lower stratosphere. The new CFC-11 data set is well suited for further scientific studies.