scholarly journals Chemical characterization of atmospheric ions at the high altitude research station Jungfraujoch (Switzerland)

2017 ◽  
Vol 17 (4) ◽  
pp. 2613-2629 ◽  
Author(s):  
Carla Frege ◽  
Federico Bianchi ◽  
Ugo Molteni ◽  
Jasmin Tröstl ◽  
Heikki Junninen ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
High Altitude ◽  
Methanesulfonic Acid ◽  
Chemical Characterization ◽  
Solar Irradiation ◽  
Back Trajectory ◽  
High Signal ◽  
Research Station ◽  
Negative Spectrum ◽  
Air Masses

Abstract. The ion composition at high altitude (3454 m a.s.l.) was measured with an atmospheric pressure interface time-of-flight mass spectrometer (APi-TOF) during a period of 9 months, from August 2013 to April 2014. The negative mass spectra were dominated by the ions of sulfuric, nitric, malonic, and methanesulfonic acid (MSA) as well as SO5−. The most prominent positive ion peaks were from amines. The other cations were mainly organic compounds clustered with a nitrogen-containing ion, which could be either NH4+ or an aminium. Occasionally the positive spectra were characterized by groups of compounds each differing by a methylene group. In the negative spectrum, sulfuric acid was always observed during clear sky conditions following the diurnal cycle of solar irradiation. On many occasions we also saw a high signal of sulfuric acid during nighttime when clusters up to the tetramer were observed. A plausible reason for these events could be evaporation from particles at low relative humidity. A remarkably strong correlation between the signals of SO5− and CH3SO3− was observed for the full measurement period. The presence of these two ions during both the day and the night suggests a non-photochemical channel of formation which is possibly linked to halogen chemistry. Halogenated species, especially Br− and IO3−, were frequently observed in air masses that originated mainly from the Atlantic Ocean and occasionally from continental areas based on back trajectory analyses. We found I2O5 clustered with an ion, a species that was proposed from laboratory and modeling studies. All halogenated ions exhibited an unexpected diurnal behavior with low values during daytime. New particle formation (NPF) events were observed and characterized by (1) highly oxygenated molecules (HOMs) and low sulfuric acid or (2) ammonia–sulfuric acid clusters. We present characteristic spectra for each of these two event types based on 26 nucleation episodes. The mass spectrum of the ammonia–sulfuric acid nucleation event compares very well with laboratory measurements reported from the CLOUD chamber. A source receptor analysis indicates that NPF events at the Jungfraujoch take place within a restricted period of time of 24–48 h after air masses have had contact with the boundary layer. This time frame appears to be crucial to reach an optimal oxidation state and concentration of organic molecules necessary to facilitate nucleation.

scholarly journals Chemical characterization of atmospheric ions at the High Altitude Research Station Jungfraujoch (Switzerland)

2016 ◽  
Author(s):  
Carla Frege ◽  
Federico Bianchi ◽  
Ugo Molteni ◽  
Jasmin Tröstl ◽  
Heikki Junninen ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
High Altitude ◽  
Methanesulfonic Acid ◽  
Particle Formation ◽  
Back Trajectory ◽  
Research Station ◽  
New Particle Formation ◽  
Night Time ◽  
Negative Spectrum ◽  
Air Masses

Abstract. The ion composition at high-altitude (3450 m a.s.l.) was measured with an Atmospheric Pressure interface Time of Flight mass spectrometer (APi-TOF) during a period of nine months. The negative mass spectra were dominated by the ions of sulfuric, nitric, malonic and methanesulfonic acid (MSA) as well as SO5−. The most prominent positive ion peaks were from amines. The other cations were mainly organic compounds clustered with a nitrogen-containing ion, which could be either NH4+ or an aminium. Occasionally the positive spectra were characterized by groups of compounds each differing by a methylene group. In the negative spectrum, sulfuric acid was always observed during clear sky conditions following the diurnal cycle of sun irradiation. We also measured many events during night time where the signal of sulfuric acid was high and clusters up to the tetramer were observed. A plausible reason for these events could be evaporation from particles at low relative humidity. A remarkably strong correlation between the signals of SO5− and CH3SO3− was observed for the full measurement period. The presence of these two ions during both the day and the night suggests a non-photochemical channel of formation which is possibly linked to halogen chemistry. Halogenated species, especially Br− and IO3−, were frequently observed in air masses that originated mainly from the Atlantic Ocean and occasionally from continental areas based on back trajectory analyses. We measured I2O5 clustered with an ion, a species that was proposed from laboratory and modelling studies. All halogenated species exhibited an unexpected diurnal behaviour with low values during day time. New particle formation (NPF) events were observed and characterized by 1) highly oxygenated molecules (HOMs) and low sulfuric acid or 2) ammonia-sulfuric acid clusters. We present characteristic spectra for each of these two event types based on 26 nucleation episodes. The mass spectrum of the ammonia-sulfuric acid nucleation event compares very well with laboratory measurements reported from the CLOUD chamber. A source receptor analysis indicates that new particle formation events at the Jungfraujoch take place within a restricted period of time of 24–48 hours after air masses have had contact with boundary layer. This time frame appears to be crucial to reach an optimal oxidation state and concentration of organic molecules necessary to facilitate nucleation.

scholarly journals Characterization of the South Atlantic marine boundary layer aerosol using an aerodyne aerosol mass spectrometer

2008 ◽  
Vol 8 (16) ◽  
pp. 4711-4728 ◽  
Author(s):  
S. R. Zorn ◽  
F. Drewnick ◽  
M. Schott ◽  
T. Hoffmann ◽  
S. Borrmann
Keyword(s):  
Boundary Layer ◽  
Sulfuric Acid ◽  
High Resolution ◽  
Marine Boundary Layer ◽  
Methanesulfonic Acid ◽  
Field Measurements ◽  
Size Distributions ◽  
Air Masses ◽  
Unit Mass Resolution ◽  
Mass Concentrations

Abstract. Measurements of the submicron fraction of the atmospheric aerosol in the marine boundary layer were performed from January to March 2007 (Southern Hemisphere summer) onboard the French research vessel Marion Dufresne in the Southern Atlantic and Indian Ocean (20° S–60° S, 70° W–60° E). We used an Aerodyne High-Resolution-Time-of-Flight AMS to characterize the chemical composition and to measure species-resolved size distributions of non-refractory aerosol components in the submicron range. Within the "standard" AMS compounds (ammonium, chloride, nitrate, sulfate, organics) "sulfate" is the dominant species in the marine boundary layer with concentrations ranging between 50 ng m−3 and 3 μg m−3. Furthermore, what is seen as "sulfate" by the AMS is likely comprised mostly of sulfuric acid. Another sulfur containing species that is produced in marine environments is methanesulfonic acid (MSA). There have been previously measurements of MSA using an Aerodyne AMS. However, due to the use of an instrument equipped with a quadrupole detector with unit mass resolution it was not possible to physically separate MSA from other contributions to the same m/z. In order to identify MSA within the HR-ToF-AMS raw data and to extract mass concentrations for MSA from the field measurements the standard high-resolution MSA fragmentation patterns for the measurement conditions during the ship campaign (e.g. vaporizer temperature) needed to be determined. To identify characteristic air masses and their source regions backwards trajectories were used and averaged concentrations for AMS standard compounds were calculated for each air mass type. Sulfate mass size distributions were measured for these periods showing a distinct difference between oceanic air masses and those from African outflow. While the peak in the mass distribution was roughly at 250 nm (vacuum aerodynamic diameter) in marine air masses, it was shifted to 470 nm in African outflow air. Correlations between the mass concentrations of sulfate, organics and MSA show a narrow correlation for MSA with sulfate/sulfuric acid coming from the ocean, but not with continental sulfate.

scholarly journals Tracking isotopic signatures of CO<sub>2</sub> at the high altitude site Jungfraujoch with laser spectroscopy: analytical improvements and representative results

2013 ◽  
Vol 6 (7) ◽  
pp. 1659-1671 ◽  
Author(s):  
P. Sturm ◽  
B. Tuzson ◽  
S. Henne ◽  
L. Emmenegger
Keyword(s):  
High Altitude ◽  
Isotope Ratios ◽  
Particle Dispersion ◽  
High Temporal Resolution ◽  
Research Station ◽  
Close Link ◽  
Diurnal Variability ◽  
Air Masses ◽  
The Mean ◽  
Δ13c And Δ18o

Abstract. We present the continuous data record of atmospheric CO2 isotopes measured by laser absorption spectroscopy for an almost four year period at the High Altitude Research Station Jungfraujoch (3580 m a.s.l.), Switzerland. The mean annual cycles derived from data of December 2008 to September 2012 exhibit peak-to-peak amplitudes of 11.0 μmol mol−1 for CO2, 0.60‰ for δ13C and 0.81‰ for δ18O. The high temporal resolution of the measurements also allow us to capture variations on hourly and diurnal timescales. For CO2 the mean diurnal peak-to-peak amplitude is about 1 μmol mol−1 in spring, autumn and winter and about 2 μmol mol−1 in summer. The mean diurnal variability in the isotope ratios is largest during the summer months too, with an amplitude of about 0.1‰ both in the δ13C and δ18O, and a smaller or no discernible diurnal cycle during the other seasons. The day-to-day variability, however, is much larger and depends on the origin of the air masses arriving at Jungfraujoch. Backward Lagrangian particle dispersion model simulations revealed a close link between air composition and prevailing transport regimes and could be used to explain part of the observed variability in terms of transport history and influence region. A footprint clustering showed significantly different wintertime CO2, δ13C and δ18O values depending on the origin and surface residence times of the air masses. Several major updates on the instrument and the calibration procedures were performed in order to further improve the data quality. We describe the new measurement and calibration setup in detail and demonstrate the enhanced performance of the analyzer. A measurement precision of about 0.02‰ for both isotope ratios has been obtained for an averaging time of 10 min, while the accuracy was estimated to be 0.1‰, including the uncertainty of the calibration gases.

scholarly journals Chemical characterization of fog and rain water collected at the eastern Andes cordillera

2005 ◽  
Vol 2 (3) ◽  
pp. 863-885 ◽  
Author(s):  
E. Beiderwieden ◽  
T. Wrzesinsky ◽  
O. Klemm
Keyword(s):  
Electric Conductivity ◽  
Chemical Characterization ◽  
Rain Water ◽  
Back Trajectory ◽  
Mountain Forest ◽  
Hysplit Model ◽  
Fog Water ◽  
Air Masses ◽  
The Pacific ◽  
The Pacific Ocean

Abstract. During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl-, NO3-, PO43-, and SO42-, were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 µS cm-1 for the fog and 6 µS cm-1 for the rain. The concentrations of all analysed ions were relatively low compared to other mountainous sites (Weathers et al., 1988; Elias et al., 1995; Schemenauer et al., 1995; Wrzesinsky and Klemm, 2000; Zimmermann and Zimmermann, 2002). The continent samples exhibit higher concentrations of most ions as compared to the pacific samples.

scholarly journals Predicting abundance and variability of ice nucleating particles in precipitation at the high-altitude observatory Jungfraujoch

2016 ◽  
Vol 16 (13) ◽  
pp. 8341-8351 ◽  
Author(s):  
Emiliano Stopelli ◽  
Franz Conen ◽  
Cindy E. Morris ◽  
Erik Herrmann ◽  
Stephan Henne ◽  
...  
Keyword(s):  
Wind Speed ◽  
High Altitude ◽  
Source Region ◽  
Environmental Parameters ◽  
Residual Fraction ◽  
First Year ◽  
Research Station ◽  
Linear Regression Models ◽  
Air Masses ◽  
Precipitation Events

Abstract. Nucleation of ice affects the properties of clouds and the formation of precipitation. Quantitative data on how ice nucleating particles (INPs) determine the distribution, occurrence and intensity of precipitation are still scarce. INPs active at −8 °C (INPs−8) were observed for 2 years in precipitation samples at the High-Altitude Research Station Jungfraujoch (Switzerland) at 3580 m a.s.l. Several environmental parameters were scanned for their capability to predict the observed abundance and variability of INPs−8. Those singularly presenting the best correlations with observed number of INPs−8 (residual fraction of water vapour, wind speed, air temperature, number of particles with diameter larger than 0.5 µm, season, and source region of particles) were implemented as potential predictor variables in statistical multiple linear regression models. These models were calibrated with 84 precipitation samples collected during the first year of observations; their predictive power was successively validated on the set of 15 precipitation samples collected during the second year. The model performing best in calibration and validation explains more than 75 % of the whole variability of INPs−8 in precipitation and indicates that a high abundance of INPs−8 is to be expected whenever high wind speed coincides with air masses having experienced little or no precipitation prior to sampling. Such conditions occur during frontal passages, often accompanied by precipitation. Therefore, the circumstances when INPs−8 could be sufficiently abundant to initiate the ice phase in clouds may frequently coincide with meteorological conditions favourable to the onset of precipitation events.

scholarly journals Predicting abundance and variability of ice nucleating particles in precipitation at the high-altitude observatory Jungfraujoch

2016 ◽  
Author(s):  
Emiliano Stopelli ◽  
Franz Conen ◽  
Cindy E. Morris ◽  
Erik Herrmann ◽  
Stephan Henne ◽  
...  
Keyword(s):  
Wind Speed ◽  
High Altitude ◽  
Source Region ◽  
Environmental Parameters ◽  
Residual Fraction ◽  
First Year ◽  
Research Station ◽  
Linear Regression Models ◽  
Air Masses ◽  
Precipitation Events

Abstract. Nucleation of ice affects the properties of clouds and the formation of precipitation. Quantitative data on how ice nucleating particles (INPs) determine the distribution, occurrence and intensity of precipitation are still scarce. INPs active at −8 °C (INPs−8) were observed for two years in precipitation samples at the High-Altitude Research Station Jungfraujoch (Switzerland) at 3580 m a.s.l. Several environmental parameters were scanned for their capability to predict the observed abundance and variability of INPs−8. Those singularly presenting the best correlations with observed number of INPs−8 (residual fraction of water vapour, wind speed, air temperature, number of particles with diameter larger than 0.5 μm, season and source region of particles) were implemented as potential predictor variables in statistical multiple linear regression models. These models were calibrated with 84 precipitation samples collected during the first year of observations; their predictive power was successively validated on the set of 15 precipitation samples collected during the second year. The model performing best in calibration and validation explains more than 75 % of the whole variability of INPs−8 in precipitation and indicates that a high abundance of INPs−8 is to be expected whenever high wind speed coincides with air masses having experienced little or no precipitation prior to sampling. Such conditions occur during frontal passages, often accompanied by precipitation. Therefore, the circumstances when INPs−8 could be sufficiently abundant to initiate the ice phase in clouds may frequently coincide with meteorological conditions favourable to the onset of precipitation events.

scholarly journals Origin of Tropospheric Air Masses in the Tropical West Pacific and related transport processes inferred from balloon-borne Ozone and Water Vapour observations from Palau

2021 ◽  
Author(s):  
Katrin Müller ◽  
Ingo Wohltmann ◽  
Peter von der Gathen ◽  
Ralph Lehmann ◽  
Markus Rex
Keyword(s):  
Tropospheric Ozone ◽  
Large Scale ◽  
The Philippines ◽  
Transport Processes ◽  
Back Trajectory ◽  
Boreal Winter ◽  
Research Station ◽  
West Pacific ◽  
Air Masses ◽  
Tropical Asia

&lt;p&gt;Motivated by previous measurements of very low tropospheric ozone concentrations in the Tropical West Pacific (TWP) and the implied low oxidizing capacity of this key region for transport into the stratosphere in boreal winter (e.g. Rex et al. 2014), we set up an atmospheric research station in Palau (7&amp;#176;N 134&amp;#176;E) as part of the StratoClim campaign. Our analysis of regular balloon-borne tropospheric ozone observations at Palau from 01/2016-12/2019 gives unprecedented insights into transport processes and air mass origin in the TWP. We confirm the year-round dominance of a low ozone background in the mid-troposphere. Layers of enhanced ozone are often anti-correlated with water vapor and occur frequently. Moreover, the occurrence of respective layers shows a strong seasonality. Dry and ozone-rich air masses between 5 and 10 km altitude were observed in 71 % of the profiles from February until April compared to 25 % from August until October. By defining monthly atmospheric background profiles for ozone and relative humidity based on observed statistics, we found that the deviations from this background reveal a bimodal distribution of RH anomalies. A previously proposed universal bimodal structure of free tropospheric ozone in the TWP could not be verified (Pan et al. 2015).&lt;/p&gt;&lt;p&gt;Back trajectory calculations (ATLAS) confirm that throughout the year the mid-tropospheric background is controlled by local convective processes and the origin of air masses is thus close to or East of Palau in the Pacific Ocean. Dry and ozone-rich air originates in tropical Asia and reaches Palau in anticyclonic conditions over an area stretching from India to the Philippines. This supports the controversial hypothesis of several studies which attribute ozone enhancement against the ozone-poor background to remote pollution events on the ground such as biomass burning (e.g. Andersen et al. 2016). A potential vorticity analysis revealed no stratospheric influence and we thus propose large-scale descent within the tropical troposphere as responsible for dehydration of air masses on their way to Palau.&lt;/p&gt;

scholarly journals Observations of fluorescent aerosol–cloud interactions in the free troposphere at the High-Altitude Research Station Jungfraujoch

2016 ◽  
Vol 16 (4) ◽  
pp. 2273-2284 ◽  
Author(s):  
I. Crawford ◽  
G. Lloyd ◽  
E. Herrmann ◽  
C. R. Hoyle ◽  
K. N. Bower ◽  
...  
Keyword(s):  
High Altitude ◽  
Pseudomonas Syringae ◽  
Wide Band ◽  
Cloud Microphysics ◽  
Research Station ◽  
Air Masses ◽  
Hierarchical Agglomerative Cluster ◽  
Aerosol Fraction ◽  
Aerosol Cloud Interactions ◽  
A Minor

Abstract. The fluorescent nature of aerosol at a high-altitude Alpine site was studied using a wide-band integrated bioaerosol (WIBS-4) single particle multi-channel ultraviolet – light-induced fluorescence (UV-LIF) spectrometer. This was supported by comprehensive cloud microphysics and meteorological measurements with the aims of cataloguing concentrations of bio-fluorescent aerosols at this high-altitude site and also investigating possible influences of UV–fluorescent particle types on cloud–aerosol processes. Analysis of background free tropospheric air masses, using a total aerosol inlet, showed there to be a minor increase in the fluorescent aerosol fraction during in-cloud cases compared to out-of-cloud cases. The size dependence of the fluorescent aerosol fraction showed the larger aerosol to be more likely to be fluorescent with 80 % of 10 μm particles being fluorescent. Whilst the fluorescent particles were in the minority (NFl∕NAll  =  0.27 &amp;pm; 0.19), a new hierarchical agglomerative cluster analysis approach, Crawford et al. (2015) revealed the majority of the fluorescent aerosols were likely to be representative of fluorescent mineral dust. A minor episodic contribution from a cluster likely to be representative of primary biological aerosol particles (PBAP) was also observed with a wintertime baseline concentration of 0.1 &amp;pm; 0.4 L−1. Given the low concentration of this cluster and the typically low ice-active fraction of studied PBAP (e.g. pseudomonas syringae), we suggest that the contribution to the observed ice crystal concentration at this location is not significant during the wintertime.

scholarly journals Chemical characterization of fog and rain water collected at the eastern Andes cordillera

2005 ◽  
Vol 9 (3) ◽  
pp. 185-191 ◽  
Author(s):  
E. Beiderwieden ◽  
T. Wrzesinsky ◽  
O. Klemm
Keyword(s):  
Electric Conductivity ◽  
Chemical Characterization ◽  
Rain Water ◽  
Back Trajectory ◽  
Mountain Forest ◽  
Hysplit Model ◽  
Fog Water ◽  
Air Masses ◽  
The Pacific ◽  
The Pacific Ocean

Abstract. During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl−, NO3−, PO43−, and SO42− were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 μS cm−1 for the fog and 6 μS cm−1 for the rain. The continent samples exhibit higher concentrations of most ions as compared to the pacific samples, but these differences could not be detected statistically.

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