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  1. Book: HALMA - Halogens in the Marine Atmosphere

    Friess, Udo

    Abstract: Reaktive Halogenverbindungen (Chlor- Brom- und Jodverbindungen) haben einen bedeutenden Einfluss auf die Chemie der Atmosphaere in Kuestengebieten der mittleren Breiten. Im Rahmen dieses bilateralen Forschungsprojektes fuehren NIWA und das IUP Heidelberg ...

    Institution Universitaet Heidelberg, Institut fuer Umweltphysik, Im Neuenheimer Feld 229, 69120, Heidelberg, DE
    Abstract Reaktive Halogenverbindungen (Chlor- Brom- und Jodverbindungen) haben einen bedeutenden Einfluss auf die Chemie der Atmosphaere in Kuestengebieten der mittleren Breiten. Im Rahmen dieses bilateralen Forschungsprojektes fuehren NIWA und das IUP Heidelberg im Fruehjahr 2013 eine gemeinsame Messkampagne in Kuestengebieten Neuseelands durch. Der Schwerpunkt liegt hierbei auf der Emission von reaktiven Halogenverbindungen (insbesondere BrO und IO) durch Seesalz und Algen sowie deren Einfluss auf die Photochemie der marinen Grenzschicht. Zur Bestimmung der raeumlichen Verteilung und zur Identifizierung der Quellen reaktiver Halogenverbindungen in Kuestengebieten Neuseelands kommen verschiedenste mobile DOAS- (Differentielle Optische Absorptionsspektroskopie) Messsysteme zum Einsatz. Durch die Kombination mehrerer Messtechniken kann sowohl die zeitliche Variation als auch die horizontale und vertikale Verteilung von reaktiven Halogenverbindungen im Detail untersucht werden, und deren Ort und Quellstaerke direkt bestimmt werden. Das Projekt wird in drei Phasen durchgefuehrt, bestehend aus einer explorativen Feldkampagne entlang der Kueste von Neuseeland, der eigentlichen Messkampagne sowie eines Workshops zur gemeinsamen Datenauswertung und Interpretation.
    Keywords Halogenverbindung ; Chlor ; Brom ; Jodverbindung ; Atmosphaerenchemie ; Kuestengebiet ; Fruehling ; Absorptionsspektralanalyse ; Emission ; Algen ; Photochemie ; Meer ; Grenzschicht ; Quelle ; Kueste ; Messgeraet ; Vertikalprofil ; Halogen ; Atmosphaere ; Neuseeland
    Language German
    Document type Book
    Remark Projektbeginn: 01.10.2012 Projektende: 30.09.2014 Foerdernummer: 01DR12100
    Database Environmental research database (UFORDAT) of the German Federal Environment Agency (UBA)

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  2. Book ; Online: Measurement Report

    Ryan, Robert G. / Marais, Eloise Ann / Gershenson-Smith, Eleanor / Ramsay, Robbie / Muller, Jan-Peter / Tirpitz, Jan-Lukas / Frieß, Udo

    eISSN:

    MAX-DOAS measurements characterise Central London ozone pollution episodes during 2022 heatwaves

    2023  

    Abstract: Heatwaves are a substantial health threat in the UK, exacerbated by co-occurrence of ozone pollution episodes. Here we report on the first use of retrieved vertical profiles of nitrogen dioxide ( NO 2 ) and formaldehyde ( HCHO ) over Central London from ... ...

    Abstract Heatwaves are a substantial health threat in the UK, exacerbated by co-occurrence of ozone pollution episodes. Here we report on the first use of retrieved vertical profiles of nitrogen dioxide ( NO 2 ) and formaldehyde ( HCHO ) over Central London from a newly installed multi-axis differential optical absorption spectroscopy (MAX-DOAS) instrument coincident with two of three heatwaves for the hottest summer on record. We evaluate space-based sensor observations routinely used to quantify temporal changes in air pollution and precursor emissions over London. Collocated daily mean tropospheric column densities from the high-spatial-resolution space-based TROPOspheric Monitoring Instrument (TROPOMI) and MAX-DOAS, after accounting for differences in vertical sensitivities, are temporally consistent for NO 2 and HCHO (both R = 0.71). TROPOMI NO 2 is 27 %–31 % less than MAX-DOAS NO 2 , as expected from horizontal dilution of NO 2 by TROPOMI pixels in polluted cities. TROPOMI HCHO is 20 % more than MAX-DOAS HCHO , greater than differences in past validation studies but within the range of systematic errors in the MAX-DOAS retrieval. The MAX-DOAS near-surface (0–110 m ) retrievals have similar day-to-day and hourly variability to the surface sites for comparison of NO 2 ( R ≥ 0.7) and for MAX-DOAS HCHO versus surface site isoprene ( R ≥ 0.7) that oxidises to HCHO in prompt and high yields. Daytime ozone production, diagnosed with MAX-DOAS HCHO -to- NO 2 tropospheric vertical column ratios, is mostly limited by availability of volatile organic compounds (VOCs), except on heatwave days. Temperature-dependent biogenic VOC emissions of isoprene increase exponentially, resulting in ozone concentrations that exceed the regulatory standard for ozone and cause non-compliance at urban background sites in Central London. Locations in Central London heavily influenced by traffic remain in compliance, but this is likely to change with stricter controls on vehicle emissions of NO x and higher likelihood of heatwave frequency, ...
    Subject code 511 ; 333
    Language English
    Publishing date 2023-06-28
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Book ; Online: Measurement report

    Ryan, Robert G. / Marais, Eloise A. / Gershenson-Smith, Eleanor / Ramsay, Robbie / Muller, Jan-Peter / Tirpitz, Jan-Lukas / Frieß, Udo

    eISSN: 1680-7324

    MAX-DOAS measurements characterise Central London ozone pollution episodes during 2022 heatwaves

    2023  

    Abstract: Heatwaves are a substantial health threat in the UK, exacerbated by co-occurrence of ozone pollution episodes. Here we report on the first use of retrieved vertical profiles of nitrogen dioxide ( NO 2 ) and formaldehyde ( HCHO ) over Central London from ... ...

    Abstract Heatwaves are a substantial health threat in the UK, exacerbated by co-occurrence of ozone pollution episodes. Here we report on the first use of retrieved vertical profiles of nitrogen dioxide ( NO 2 ) and formaldehyde ( HCHO ) over Central London from a newly installed multi-axis differential optical absorption spectroscopy (MAX-DOAS) instrument coincident with two of three heatwaves for the hottest summer on record. We evaluate space-based sensor observations routinely used to quantify temporal changes in air pollution and precursor emissions over London. Collocated daily mean tropospheric column densities from the high-spatial-resolution space-based TROPOspheric Monitoring Instrument (TROPOMI) and MAX-DOAS, after accounting for differences in vertical sensitivities, are temporally consistent for NO 2 and HCHO (both R = 0.71). TROPOMI NO 2 is 27 %–31 % less than MAX-DOAS NO 2 , as expected from horizontal dilution of NO 2 by TROPOMI pixels in polluted cities. TROPOMI HCHO is 20 % more than MAX-DOAS HCHO , greater than differences in past validation studies but within the range of systematic errors in the MAX-DOAS retrieval. The MAX-DOAS near-surface (0–110 m ) retrievals have similar day-to-day and hourly variability to the surface sites for comparison of NO 2 ( R ≥ 0.7) and for MAX-DOAS HCHO versus surface site isoprene ( R ≥ 0.7) that oxidises to HCHO in prompt and high yields. Daytime ozone production, diagnosed with MAX-DOAS HCHO -to- NO 2 tropospheric vertical column ratios, is mostly limited by availability of volatile organic compounds (VOCs), except on heatwave days. Temperature-dependent biogenic VOC emissions of isoprene increase exponentially, resulting in ozone concentrations that exceed the regulatory standard for ozone and cause non-compliance at urban background sites in Central London. Locations in Central London heavily influenced by traffic remain in compliance, but this is likely to change with stricter controls on vehicle emissions of NO x and higher likelihood of heatwave frequency, ...
    Subject code 511 ; 333
    Language English
    Publishing date 2023-06-28
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

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  4. Book ; Online ; Thesis: Spectroscopic measurements of atmospheric trace gases at Neumayer-Station, Antarctica

    Frieß, Udo

    2001  

    Title variant Spektroskopische Messungen atmosphärischer Spurenstoffe auf der Neumayer-Station, Antarktis
    Author's details presented by Udo Frieß
    Keywords Spurengas ; Stratosphäre ; DOAS ; Antarktis
    Language English
    Size Online-Ressource
    Edition [Elektronische Ressource]
    Document type Book ; Online ; Thesis
    Thesis / German Habilitation thesis Univ., Diss--Heidelberg, 2001
    Database Former special subject collection: coastal and deep sea fishing

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  5. Book ; Thesis: Spectroscopic measurements of atmospheric trace gases at Neumayer-Station, Antarctica

    Frieß, Udo

    2001  

    Title variant Spektroskopische Messungen atmosphärischer Spurenstoffe auf der Neumayer-Station, Antarktis
    Author's details Udo Frieß
    Language English
    Size IV, 234 S, Ill., graph. Darst
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Univ., Diss.--Heidelberg, 2001
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  6. Book ; Online: Detection of O4 absorption around 328 and 419 nm in measured atmospheric absorption spectra

    Lampel, Johannes / Zielcke, Johannes / Schmitt, Stefan / Pöhler, Denis / Frieß, Udo / Platt, Ulrich / Wagner, Thomas

    eISSN: 1680-7324

    2018  

    Abstract: Retrieving the column of an absorbing trace gas from spectral data requires that all absorbers in the corresponding wavelength range are sufficiently well known. This is especially important for the retrieval of weak absorbers, whose absorptions are ... ...

    Abstract Retrieving the column of an absorbing trace gas from spectral data requires that all absorbers in the corresponding wavelength range are sufficiently well known. This is especially important for the retrieval of weak absorbers, whose absorptions are often in the 10 −4 range. Previous publications on the absorptions of the oxygen dimer O 2 –O 2 (or short: O 4 ) list absorption peaks at 328 and 419 nm, for which no spectrally resolved literature cross sections are available. As these absorptions potentially influence the spectral retrieval of various trace gases, such as HCHO, BrO, OClO and IO, their shape and magnitude need to be quantified. We assume that the shape of the absorption peaks at 328 and 419 nm can be approximated by their respective neighbouring absorption peaks. Using this approach we obtain estimates for the wavelength of the absorption and its magnitude. Using long-path differential optical absorption spectroscopy (LP-DOAS) observations and multi-axis DOAS (MAX-DOAS) observations, we estimate the peak absorption cross sections of O 4 to be (1.96 ± 0.20) × 10 −47 cm 5 molec −2 and determine the wavelength of its maximum at 328.59 ± 0.15 nm. For the absorption at 419.13 ± 0.42 nm a peak O 4 cross-section value is determined to be (5.0 ± 3.5) × 10 −48 cm 5 molec −2 .
    Subject code 333
    Language English
    Publishing date 2018-02-06
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Observation of halogen species in the Amundsen Gulf, Arctic, by active long-path differential optical absorption spectroscopy.

    Pöhler, Denis / Vogel, Leif / Friess, Udo / Platt, Ulrich

    Proceedings of the National Academy of Sciences of the United States of America

    2010  Volume 107, Issue 15, Page(s) 6582–6587

    Abstract: In the polar tropospheric boundary layer, reactive halogen species (RHS) are responsible for ozone depletion as well as the oxidation of elemental mercury and dimethyl sulphide. After polar sunrise, air masses enriched in reactive bromine cover areas of ... ...

    Abstract In the polar tropospheric boundary layer, reactive halogen species (RHS) are responsible for ozone depletion as well as the oxidation of elemental mercury and dimethyl sulphide. After polar sunrise, air masses enriched in reactive bromine cover areas of several million square kilometers. Still, the source and release mechanisms of halogens are not completely understood. We report measurements of halogen oxides performed in the Amundsen Gulf, Arctic, during spring 2008. Active long-path differential optical absorption spectroscopy (LP-DOAS) measurements were set up offshore, several kilometers from the coast, directly on the sea ice, which was never done before. High bromine oxide concentrations were detected frequently during sunlight hours with a characteristic daily cycle showing morning and evening maxima and a minimum at noon. The, so far, highest observed average mixing ratio in the polar boundary layer of 41 pmol/mol (equal to pptv) was detected. Only short sea ice contact is required to release high amounts of bromine. An observed linear decrease of maximum bromine oxide levels with ambient temperature during sunlight, between -24 degrees C and -15 degrees C, provides indications on the conditions required for the emission of RHS. In addition, the data indicate the presence of reactive chlorine in the Arctic boundary layer. In contrast to Antarctica, iodine oxide was not detected above a detection limit of 0.3 pmol/mol.
    MeSH term(s) Arctic Regions ; Bromine/chemistry ; Chlorine/chemistry ; Environmental Monitoring/instrumentation ; Environmental Monitoring/methods ; Halogens/chemistry ; Models, Chemical ; Oceans and Seas ; Oxides/chemistry ; Ozone/chemistry ; Salts/chemistry ; Spectrum Analysis/methods ; Temperature ; Time Factors
    Chemical Substances Halogens ; Oxides ; Salts ; Chlorine (4R7X1O2820) ; Ozone (66H7ZZK23N) ; Bromine (SBV4XY874G)
    Language English
    Publishing date 2010-02-16
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.0912231107
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Book ; Online: Detection of O4 absorption around 328 nm and 419 nm in measured atmospheric absorption spectra

    Lampel, Johannes / Zielcke, Johannes / Schmitt, Stefan / Pöhler, Denis / Frieß, Udo / Platt, Ulrich / Wagner, Thomas

    eISSN: 1680-7324

    2017  

    Abstract: Retrieving the column of an absorbing trace gas from spectral data requires that all absorbers in the corresponding wavelength range are sufficiently well known. This is especially important for the retrieval of weak absorbers, whose absorptions are ... ...

    Abstract Retrieving the column of an absorbing trace gas from spectral data requires that all absorbers in the corresponding wavelength range are sufficiently well known. This is especially important for the retrieval of weak absorbers, whose absorptions are often in the 10 -4 range. Previous publications on the absorptions of the oxygen dimer O 2 -O 2 (or short: O 4 ) list absorption peaks at 328 nm and 419 nm, for which no spectrally resolved literature cross-sections are available. As these absorptions potentially influence the spectral retrieval of various trace gases, such as HCHO, BrO, OClO and IO, their shape and magnitude needs to be quantified. We assume that the shape of the absorption peaks at 328 nm and 419 nm can be approximated by their respective neighboring absorption peaks. Using this approach we obtain estimates for the wavelength of the absorption and its magnitude. Using Longpath Differential Optical Absorption Spectroscopy (LP-DOAS) observations and Multi-Axis (MAX)-DOAS observations, we estimate the peak absorption cross-sections of O 4 to be (1.7 ± 0.2) x 10 -47 cm 5 molec -2 and determine the wavelength of its maximum at 328.51 ± 0.15 nm. For the absorption at 419.0 ± 0.4 nm a peak O 4 cross-section value is determined as (3.7 ± 2.7) x 10 -48 cm 5 molec -2 .
    Subject code 333
    Language English
    Publishing date 2017-08-11
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Book ; Online ; Thesis: Spectroscopic measurements of atmospheric trace gases at Neumayer-Station, Antarctica

    Frieß, Udo [Verfasser]

    2001  

    Author's details presented by Udo Frieß
    Keywords Geowissenschaften ; Earth Sciences
    Subject code sg550
    Language English
    Document type Book ; Online ; Thesis
    Database Digital theses on the web

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  10. Book ; Online: Daytime HONO, NO2 and aerosol distributions from MAX-DOAS observations in Melbourne

    Ryan, Robert G. / Rhodes, Steve / Tully, Matthew / Wilson, Stephen / Jones, Nicholas / Frieß, Udo / Schofield, Robyn

    eISSN: 1680-7324

    2018  

    Abstract: Nitrogen oxides produced by high temperature combustion are prevalent in urban environments and toxic, contributing to a significant health burden. The chemistry of nitrogen oxides such as NO 2 and HONO in pollution are important for hydroxyl radical ... ...

    Abstract Nitrogen oxides produced by high temperature combustion are prevalent in urban environments and toxic, contributing to a significant health burden. The chemistry of nitrogen oxides such as NO 2 and HONO in pollution are important for hydroxyl radical production and overall oxidative capacity in urban environments, however current mechanisms cannot explain high daytime levels of HONO observed in many urban and rural locations around the world. Here we present HONO, NO 2 and aerosol extinction vertical distributions retrieved from MAX-DOAS measurements in suburban Melbourne, which are the first MAX-DOAS results from Australia. Using the optimal estimation algorithm HEIPRO we show that vertical profiles for NO 2 and HONO can be calculated with low dependence on the retrieval forward model and a priori parameters, despite a lack of independent co-located aerosol or trace gas measurements. Between December 2016 and April 2017 average peak NO 2 values of 8 ± 2 ppb indicated moderate traffic pollution levels, and high daytime peak values of HONO were frequently detected, averaging 220 ± 30 ppt in the middle of the day. HONO levels measured in Melbourne were typically lower than those recorded in the morning in other places around the world, indicating minimal overnight accumulation, but peaked in the middle of the day to be commensurate with midday concentrations in locations with much higher NO 2 pollution. Regular midday peaks in the diurnal cycle of HONO surface concentrations have only previously been reported in rural locations. The HONO measured represents an OH radical source in the middle of the day in Melbourne up to ten times stronger than from ozone photolysis. The dependence of the high HONO levels on time since rainfall, combined with the observed diurnal and vertical profiles, provide evidence for a strong photo-activated and ground-based daytime HONO source.
    Subject code 333
    Language English
    Publishing date 2018-05-18
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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