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  1. Article ; Online: High occurrence of new particle formation events at the Maïdo high-altitude observatory (2150 m), Réunion (Indian Ocean)

    B. Foucart / K. Sellegri / P. Tulet / C. Rose / J.-M. Metzger / D. Picard

    Atmospheric Chemistry and Physics, Vol 18, Pp 9243-

    2018  Volume 9261

    Abstract: This study aims to report and characterise the frequent new particle formation (NPF) events observed at the Maïdo observatory, Réunion, a Southern Hemisphere site located at 2150 m (a.s.l.) and surrounded by the Indian Ocean. From May 2014 to December ... ...

    Abstract This study aims to report and characterise the frequent new particle formation (NPF) events observed at the Maïdo observatory, Réunion, a Southern Hemisphere site located at 2150 m (a.s.l.) and surrounded by the Indian Ocean. From May 2014 to December 2015, continuous aerosol measurements were made using both a differential mobility particle sizer (DMPS) and an air ion spectrometer (AIS) to characterise the NPF events down to the lowest particle-size scale. Carbon monoxide (CO) and black carbon (BC) concentrations were monitored, as well as meteorological parameters, in order to identify the conditions that were favourable to the occurrence of nucleation in this specific environment. We point out that the annual NPF frequency average (65 %) is one of the highest reported so far. Monthly averages show a bimodal variation in the NPF frequency, with a maximum observed during transition periods (autumn and spring). A high yearly median particle growth rate (GR) of 15.16 nm h −1 is also measured showing a bimodal seasonal variation with maxima observed in July and November. Yearly medians of 2 and 12 nm particle formation rates ( J 2 and J 12 ) are 0.858 and 0.508 cm −3 s −1 , respectively, with a seasonal variation showing a maximum during winter, that correspond to low temperature and RH typical of the dry season, but also to high BC concentrations. We show that the condensation sink exceeds a threshold value (1.04×10 −3 s −1 ) with a similar seasonal variation than the one of the NPF event frequency, suggesting that the occurrence of the NPF process might be determined by the availability of condensable vapours, which are likely to be transported together with pre-existing particles from lower altitudes.
    Keywords Physics ; QC1-999 ; Chemistry ; QD1-999
    Subject code 333
    Language English
    Publishing date 2018-07-01T00:00:00Z
    Publisher Copernicus Publications
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: New particle formation in the volcanic eruption plume of the Piton de la Fournaise

    C. Rose / B. Foucart / D. Picard / A. Colomb / J.-M. Metzger / P. Tulet / K. Sellegri

    Atmospheric Chemistry and Physics, Vol 19, Pp 13243-

    specific features from a long-term dataset

    2019  Volume 13265

    Abstract: New particle formation (NPF) is a key atmospheric process which may be responsible for a major fraction of the total aerosol number burden at the global scale, including in particular cloud condensation nuclei (CCN). NPF has been observed in various ... ...

    Abstract New particle formation (NPF) is a key atmospheric process which may be responsible for a major fraction of the total aerosol number burden at the global scale, including in particular cloud condensation nuclei (CCN). NPF has been observed in various environments around the world, but some specific conditions, such as those encountered in volcanic plumes, remain poorly documented in the literature. Yet, understanding such natural processes is essential to better define pre-industrial conditions and their variability in climate model simulations. Here we report observations of NPF performed at the high-altitude observatory of Maïdo (2165 m a.s.l., La Réunion Island) between 1 January and 31 December 2015. During this time period, three effusive eruptions of the Piton de la Fournaise, located ∼39 km away from the station, were observed and documented, resulting in 29 d of measurement in volcanic plume conditions to be compared with 250 “non-plume days”. This dataset is, to our knowledge, the largest ever reported for the investigation of NPF in tropospheric volcanic plume conditions, and it allowed for the first time a statistical approach to characterize the process and also assessment of its relevance with respect to non-plume conditions. NPF was observed on 90 % of the plume days vs. 71 % of the non-plume days during the 4 months when the eruptions occurred. The events were on average detected earlier on plume days, most likely benefiting from larger amounts of precursors available at the site prior to nucleation hours. The overall effect of the plume conditions on the particle growth rate was limited. However, with the exception of September, particle formation rates were significantly higher on plume days. The signature of the volcanic plume on the aerosol spectra up to d p =600 nm was further investigated based on the analysis and fitting of the particle size distributions recorded under in-plume and off-plume conditions. The spectra recorded prior to nucleation hours, in the absence of freshly formed ...
    Keywords Physics ; QC1-999 ; Chemistry ; QD1-999
    Subject code 290
    Language English
    Publishing date 2019-10-01T00:00:00Z
    Publisher Copernicus Publications
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

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  3. Article ; Online: First results of the Piton de la Fournaise STRAP 2015 experiment

    P. Tulet / A. Di Muro / A. Colomb / C. Denjean / V. Duflot / S. Arellano / B. Foucart / J. Brioude / K. Sellegri / A. Peltier / A. Aiuppa / C. Barthe / C. Bhugwant / S. Bielli / P. Boissier / G. Boudoire / T. Bourrianne / C. Brunet / F. Burnet /
    J.-P. Cammas / F. Gabarrot / B. Galle / G. Giudice / C. Guadagno / F. Jeamblu / P. Kowalski / J. Leclair de Bellevue / N. Marquestaut / D. Mékies / J.-M. Metzger / J. Pianezze / T. Portafaix / J. Sciare / A. Tournigand / N. Villeneuve

    Atmospheric Chemistry and Physics, Vol 17, Iss 8, Pp 5355-

    multidisciplinary tracking of a volcanic gas and aerosol plume

    2017  Volume 5378

    Abstract: The STRAP (Synergie Transdisciplinaire pour Répondre aux Aléas liés aux Panaches volcaniques) campaign was conducted over the entire year of 2015 to investigate the volcanic plumes of Piton de La Fournaise (La Réunion, France). For the first time, ... ...

    Abstract The STRAP (Synergie Transdisciplinaire pour Répondre aux Aléas liés aux Panaches volcaniques) campaign was conducted over the entire year of 2015 to investigate the volcanic plumes of Piton de La Fournaise (La Réunion, France). For the first time, measurements at the local (near the vent) and at the regional scales were conducted around the island. The STRAP 2015 campaign has become possible thanks to strong cross-disciplinary collaboration between volcanologists and meteorologists. The main observations during four eruptive periods (85 days) are summarised. They include the estimates of SO 2 , CO 2 and H 2 O emissions, the altitude of the plume at the vent and over different areas of La Réunion Island, the evolution of the SO 2 concentration, the aerosol size distribution and the aerosol extinction profile. A climatology of the volcanic plume dispersion is also reported. Simulations and measurements show that the plumes formed by weak eruptions have a stronger interaction with the surface of the island. Strong SO 2 mixing ratio and particle concentrations above 1000 ppb and 50 000 cm −3 respectively are frequently measured over a distance of 20 km from Piton de la Fournaise. The measured aerosol size distribution shows the predominance of small particles in the volcanic plume. Several cases of strong nucleation of sulfuric acid have been observed within the plume and at the distal site of the Maïdo observatory. The STRAP 2015 campaign provides a unique set of multi-disciplinary data that can now be used by modellers to improve the numerical parameterisations of the physical and chemical evolution of the volcanic plumes.
    Keywords Physics ; QC1-999 ; Chemistry ; QD1-999
    Subject code 290
    Language English
    Publishing date 2017-04-01T00:00:00Z
    Publisher Copernicus Publications
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

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