scholarly journals Using freezing spectra characteristics to identify ice-nucleating particle populations during the winter in the Alps

2019 ◽  
Vol 19 (12) ◽  
pp. 8123-8140 ◽  
Author(s):  
Jessie M. Creamean ◽  
Claudia Mignani ◽  
Nicolas Bukowiecki ◽  
Franz Conen
Keyword(s):  
Spectral Characteristics ◽  
Research Station ◽  
Air Mass ◽  
Airborne Measurements ◽  
The Alps ◽  
Cloud Environments ◽  
Biological Sources ◽  
Freezing Temperatures ◽  
Cloud Ice ◽  
Precipitation Formation

Abstract. One of the least understood cloud processes is modulation of their microphysics by aerosols, specifically of cloud ice by ice-nucleating particles (INPs). To investigate INP impacts on cloud ice and subsequent precipitation formation, measurements in cloud environments are necessary but difficult given the logistical challenges associated with airborne measurements and separating interstitial aerosol from cloud residues. Additionally, determining the sources of INPs is important given the dependency of glaciation temperatures on the mineral or biological components and diversity of such INP populations. Here, we present results from a comparison of INP spectral characteristics in air, cloud rime, and fresh fallen snow at the High Altitude Research Station, Jungfraujoch. The goal of the study was twofold: (1) to assess variability in wintertime INP populations found in cloud based on wind and air mass direction during snowfall and (2) to evaluate possible INP sources between different sample types using a combination of cumulative INP (K(T)) and differential INP (k(T)) spectra. INP freezing temperatures and concentrations were consistently higher on average from the southeast as compared to the northwest for rime, snow, and especially aerosol samples, which is likely a result of air mass influence from predominantly boundary layer terrestrial and marine sources in southern Europe, the Mediterranean, and North Africa. For all three sample types combined, average onset freezing temperatures were −8.0 and −11.3 ∘C for southeasterly and northwesterly days, respectively, while K(T) were 3 to 20 times higher when winds arrived from the southeast. Southeasterly aerosol samples typically had a clear mode in the warm-temperature regime (i.e., ≥-15 ∘C) in the k(T) spectra – indicating a putative influence from biological sources – while the presence of a warm mode in the rime and snow varied. Evaluating K(T) concert with k(T) spectra exhibited variable modality and shape – depending on the types of INPs present – and may serve as a useful method for comparing different sampled substances and assessing the possible relative contributions of mixed mineral and biological versus only biological INP sample populations.

scholarly journals Using spectra characteristics to identify ice nucleating particle populations during winter storms in the Alps

2018 ◽  
Author(s):  
Jessie M. Creamean ◽  
Claudia Mignani ◽  
Nicolas Bukowiecki ◽  
Franz Conen
Keyword(s):  
Spectral Characteristics ◽  
Research Station ◽  
Winter Storms ◽  
Air Mass ◽  
Airborne Measurements ◽  
The Alps ◽  
Cloud Environments ◽  
Freezing Temperatures ◽  
Cloud Ice ◽  
Viable Method

Abstract. One of the least understood cloud processes is modulation of their microphysics by aerosols, specifically of cloud ice by ice nucleating particles (INPs). To investigate INP impacts on cloud ice and subsequent precipitation formation, measurements in cloud environments are necessary but difficult given the logistical challenges associated with airborne measurements and separating interstitial aerosol from cloud residues. Additionally, determining the sources of INPs is important given the dependency of glaciation temperatures on the mineral or biological components and diversity of such INP populations. Here, we present results from a comparison of INP spectral characteristics in air, cloud rime, and fresh fallen snow for storm days at the High-Altitude Research Station, Jungfraujoch. The goal of the study was two-fold: (1) to assess variability in wintertime INP populations found in-cloud based on air mass direction during snowfall and (2) to evaluate INPs between different sample types using normalized differential INP spectra. INP freezing temperatures and concentrations were consistently higher on average from the southeast as compared to the northwest for rime, snow and especially aerosol samples which is likely a result of air mass influence from boundary layer terrestrial and marine sources in Southern Europe, the Mediterranean, and North Africa. For all three sample types combined, average onset freezing temperatures were −7.7 and −12 °C for southeasterly and northwesterly days, respectively, while INP concentrations were 3 to 20 times higher when winds arrived from the southeast. Southeasterly aerosol samples typically had bimodal freezing spectra – indicating a putative influence from biological sources – while bimodality of the rime and snow varied depending on meteorological context. Evaluating normalized differential INP spectra exhibited variable modality and shape – depending on the types of INPs present – and may serve as a viable method for comparing different sampling substances and assessing the possible mixed mineral and biological versus only biological contributions to INP sample populations.

scholarly journals Airborne Measurements of Air Mass from O2A-Band Absorption Spectra

1998 ◽  
Vol 15 (6) ◽  
pp. 1272-1286 ◽  
Author(s):  
D. M. O’Brien ◽  
R. M. Mitchell ◽  
S. A. English ◽  
G. A. Da Costa
Keyword(s):  
Absorption Spectra ◽  
Air Mass ◽  
Airborne Measurements ◽  
Band Absorption

scholarly journals Concentrations of higher dicarboxylic acids C<sub>5</sub>–C<sub>13</sub> in fresh snow samples collected at the High Alpine Research Station Jungfraujoch during CLACE 5 and 6

2009 ◽  
Vol 9 (6) ◽  
pp. 2097-2112 ◽  
Author(s):  
R. Winterhalter ◽  
M. Kippenberger ◽  
J. Williams ◽  
E. Fries ◽  
K. Sieg ◽  
...  
Keyword(s):  
Organic Acids ◽  
Phthalic Acid ◽  
Dicarboxylic Acids ◽  
Back Trajectory ◽  
Research Station ◽  
Air Mass ◽  
Median Concentration ◽  
Fresh Snow ◽  
Alpine Research ◽  
Snow Samples

Abstract. Samples of freshly fallen snow were collected at the high alpine research station Jungfraujoch (Switzerland) in February and March 2006 and 2007, during the Cloud and Aerosol Characterization Experiments (CLACE) 5 and 6. In this study a new technique has been developed and demonstrated for the measurement of organic acids in fresh snow. The melted snow samples were subjected to solid phase extraction and resulting solutions analysed for organic acids by HPLC-MS-TOF using negative electrospray ionization. A series of linear dicarboxylic acids from C5 to C13 and phthalic acid, were identified and quantified. In several samples the biogenic acid pinonic acid was also observed. In fresh snow the median concentration of the most abundant acid, adipic acid, was 0.69 μg L−1 in 2006 and 0.70 μg L−1 in 2007. Glutaric acid was the second most abundant dicarboxylic acid found with median values of 0.46 μg L−1 in 2006 and 0.61 μg L−1 in 2007, while the aromatic acid phthalic acid showed a median concentration of 0.34 μg L−1 in 2006 and 0.45 μg L−1 in 2007. The concentrations in the samples from various snowfall events varied significantly, and were found to be dependent on the back trajectory of the air mass arriving at Jungfraujoch. Air masses of marine origin showed the lowest concentrations of acids whereas the highest concentrations were measured when the air mass was strongly influenced by boundary layer air.

scholarly journals Airborne observations and modeling of springtime stratosphere-to-troposphere transport over California

2013 ◽  
Vol 13 (4) ◽  
pp. 10157-10192 ◽  
Author(s):  
E. L. Yates ◽  
L. T. Iraci ◽  
M. C. Roby ◽  
R. B. Pierce ◽  
M. S. Johnson ◽  
...  
Keyword(s):  
Air Quality ◽  
Free Troposphere ◽  
Air Mass ◽  
Air Masses ◽  
Airborne Measurements ◽  
Mixing Ratios ◽  
Stratospheric Intrusion ◽  
Tropospheric O3 ◽  
Carbon Dioxide Co2 ◽  
The Impact

Abstract. Stratosphere-to-troposphere transport (STT) results in air masses of stratospheric origin intruding into the free troposphere. Once in the free troposphere, O3-rich stratospheric air can be transported and mixed with tropospheric air masses, contributing to the tropospheric O3 budget. Evidence of STT can be identified based on the differences in the trace gas composition of the two regions. Because ozone (O3) is present in such large quantities in the stratosphere compared to the troposphere, it is frequently used as a tracer for STT events. This work reports on airborne in situ measurements of O3 and other trace gases during two STT events observed over California, USA. The first, on 14 May 2012, was associated with a cut-off low, and the second, on 5 June 2012, occurred during a post-trough, building ridge event. In each STT event, airborne measurements identified high O3 within a stratospheric intrusion which was observed as low as 3 km above sea level. During both events the stratospheric air mass was characterized by elevated O3 mixing ratios and reduced carbon dioxide (CO2) and water vapor. The reproducible observation of reduced CO2 within the stratospheric air mass supports the use of non-conventional tracers as an additional method for detecting STT. A detailed meteorological analysis of each STT event is presented and observations are interpreted with the Realtime Air Quality Modeling System (RAQMS). The implications of the two STT events are discussed in terms of the impact on the total tropospheric O3 budget and the impact on air quality and policy-making.

scholarly journals The Total Carbon Column Observing Network Site Description for Lauder, New Zealand

2017 ◽  
Author(s):  
David F. Pollard ◽  
Vanessa Sherlock ◽  
John Robinson ◽  
Nicholas M. Deutscher ◽  
Brian Connor ◽  
...  
Keyword(s):  
New Zealand ◽  
Near Infrared ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Research Station ◽  
Solar Absorption ◽  
Airborne Measurements ◽  
Clear Sky ◽  
Prevailing Wind Direction ◽  
Populated Region

Abstract. In this paper we describe the retrievals of atmospheric trace gases from near infrared, high resolution solar absorption spectroscopy measurements at the Lauder atmospheric research station in New Zealand and submitted to the Total Carbon Column Observing Network (TCCON) archive. The Lauder site (45.034°S, 169.68°E, 370 masl) is located within a sparsely populated region of the South Island of New Zealand, and is sheltered from the prevailing wind direction by the Southern Alps, which gives the site a high number of clear-sky days and an airmass that is largely unmodified by regional anthropogenic sources. The Lauder TCCON archive consists of data from two instruments; a Bruker IFS 120HR from June 2004 to February 2010 and a Bruker IFS 125HR from February 2010 to present. The bias between the two instrument is assessed to be 0.068% for CO2. Since measurements using the IFS 125HR began, the standard deviation about the hourly mean has been better than 0.1% for 96.81% of CO2 column retrievals. The retrievals have been calibrated against in situ airborne measurements to correct for biases and provide traceability to the World Meteorological Organisation (WMO) scales with an accuracy of 0.1% for CO2. The Lauder TCCON time series of retrieved dry-air mole fractions of CO2, CH4, N2O, HF, H2O, HDO and CO are available from the TCCON data archive. The DOIs are: doi:10.14291/tccon.ggg2014.lauder01.R0/1149293 for the IFS 120HR data doi:10.14291/tccon.ggg2014.lauder02.R0/1149298 for the IFS 125HR data.

scholarly journals Variability of aerosol, gaseous pollutants and meteorological characteristics associated with continental, urban and marine air masses at the SW Atlantic coast of Iberia

2011 ◽  
Vol 11 (12) ◽  
pp. 31585-31642 ◽  
Author(s):  
J.-M. Diesch ◽  
F. Drewnick ◽  
S. R. Zorn ◽  
S.-L. von der Weiden-Reinmüller ◽  
M. Martinez ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Gas Phase ◽  
Meteorological Parameters ◽  
Atlantic Coast ◽  
Dimethyl Sulfate ◽  
Organic Aerosol ◽  
Research Station ◽  
Air Mass ◽  
Air Masses ◽  
Marine Air

Abstract. Measurements of the ambient aerosol were performed at the Southern coast of Spain, within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from 20 November until 9 December 2008 at the atmospheric research station "El Arenosillo" (37°5'47.76" N, 6&amp;deg44'6.94" W). As the monitoring station is located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean a variety of physical and chemical parameters of aerosols and gas phase could be characterized in dependency on the origin of air masses. Backwards trajectories were examined and compared with local meteorology to classify characteristic air mass types for several source regions. Aerosol number and mass as well as polycyclic aromatic hydrocarbons and black carbon concentrations were measured in PM1 and size distributions were registered covering a size range from 7 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS). Gas phase analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) and a weather station provided meteorological parameters. Lowest average submicron particle mass and number concentrations were found in air masses arriving from the Atlantic Ocean with values around 2 μg m−3 and 1000 cm−3. These mass concentrations were about two to four times lower than the values recorded in air masses of continental and urban origins. For some species PM1-fractions in marine air were significantly larger than in air masses originating from Huelva, a closely located city with extensive industrial activities. The largest fraction of sulfate (54%) was detected in marine air masses and was to a high degree not neutralized. In addition small concentrations of methanesulfonic acid (MSA), a product of biogenic dimethyl sulfate (DMS) emissions could be identified in the particle phase. In all air masses passing the continent the organic aerosol fraction dominated the total NR-PM1. For this reason, using Positive Matrix Factorization (PMF) four organic aerosol (OA) classes that can be associated with various aerosol sources and components were identified: a highly-oxygenated OA is the major component contributing an average of 43% of the particulate organic mass while the semi-volatile OA accounts for 23%. A hydrocarbon-like OA mainly resulting from industries, traffic and shipping emissions as well as particles from wood burning emissions also contribute to total OA dependent on the air mass origin. The variability of ozone is not only affected by different types of air masses but also significantly by the diurnal variation as a consequence of the solar radiation as well as local meteorological parameters.

scholarly journals Migrating bats cross top of Europe

2016 ◽  
Author(s):  
Peter E Zingg ◽  
Fabio Bontadina
Keyword(s):  
High Altitude ◽  
Climatic Conditions ◽  
Swiss Alps ◽  
Research Station ◽  
Long Distance ◽  
Tadarida Brasiliensis ◽  
The Alps ◽  
Shed Light ◽  
The Way

Bats have evolved migration to escape unfavourable climatic conditions. However, their migratory flyways and the way how they surmount geographical barriers are still unknown. The Jungfraujoch in the Swiss Alps is a mountain covered in permafrost (3460m ASL), known colloquially as the “Top of Europe”. Using broadband ultrasound recorders, we tested the occurrence of bats at the high altitude research station. In 36 nights, we recorded 268 bat call sequences of 8 species, including all European long-distance migrant bats. Since no feeding buzzes were recorded, we assume the bats were on transit. This is the first evidence to show that migrating bats can fly at unprecedented altitudes to cross the Alps. This feat outperforms the spectacular behaviour of the high altitude foraging bat Tadarida brasiliensis. Our findings shed light on the bats’ migratory flyways and demonstrate that the field of aeroecology can still uncover unexpected perspectives on the behaviour of bats.

scholarly journals Top-down and Bottom-up aerosol-cloud-closure: towards understanding sources of uncertainty in deriving cloud radiative flux

2017 ◽  
Author(s):  
Kevin J. Sanchez ◽  
Greg C. Roberts ◽  
Radiance Calmer ◽  
Keri Nicoll ◽  
Eyal Hashimshoni ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Radiative Flux ◽  
Research Station ◽  
Top Down ◽  
Bottom Up ◽  
Airborne Measurements ◽  
Aerosol Cloud ◽  
Microphysical Properties ◽  
Holistic Understanding

Abstract. Top-down and bottom-up aerosol-cloud-radiative flux closures were conducted at the Mace Head atmospheric research station in Galway, Ireland in August 2015. This study is part of the BACCHUS (Impact of Biogenic versus Anthropogenic emissions on Clouds and Climate: towards a Holistic UnderStanding) European collaborative project, with the goal of understanding key processes affecting aerosol-cloud-radiative flux closures to improve future climate predictions and develop sustainable policies for Europe. Instrument platforms include ground-based, unmanned aerial vehicles (UAV), and satellite measurements of aerosols, clouds and meteorological variables. The ground-based and airborne measurements of aerosol size distributions and cloud condensation nuclei (CCN) concentration were used to initiate a 1D microphysical aerosol-cloud parcel model (ACPM). UAVs were equipped for a specific science mission, with an optical particle counter for aerosol distribution profiles, a cloud sensor to measure cloud extinction, or a 5-hole probe for 3D wind vectors. UAV cloud measurements are rare and have only become possible in recent years through the miniaturization of instrumentation. These are the first UAV measurements at Mace Head. ACPM simulations are compared to in-situ cloud extinction measurements from UAVs to quantify closure in terms of cloud radiative flux. Two out of seven cases exhibit sub-adiabatic vertical temperature profiles within the cloud, which suggests that entrainment processes affect cloud microphysical properties and lead to an overestimate of simulated cloud radiative flux. Including an entrainment parameterization and explicitly calculating the entrainment fraction in the ACPM simulations both improved cloud-top radiative closure. Entrainment reduced the difference between simulated and observation-derived cloud-top radiative flux (δRF) by between 30 W m−2 and 40 W m−2. After accounting for entrainment, satellite-derived cloud droplet number concentrations (CDNC) were within 30 % of simulated CDNC. In cases with a well-mixed boundary layer, δRF is less than 25 W m−2 after accounting for cloud-top entrainment, compared to less than 50 W m−2 when entrainment is not taken into account. In cases with a decoupled boundary layer, cloud microphysical properties are inconsistent with ground-based aerosol measurements, as expected, and δRF is as high as 88 W m−2, even after accounting for cloud-top entrainment. This work demonstrates the need to take in-situ measurements of aerosol properties for cases where the boundary layer is decoupled as well as consider cloud-top entrainment to accurately model stratocumulus cloud radiative flux.

scholarly journals Spatial and temporal variability in the ice-nucleating ability of alpine snowmelt and extension to frozen cloud fraction

2020 ◽  
Vol 20 (1) ◽  
pp. 163-180 ◽  
Author(s):  
Killian P. Brennan ◽  
Robert O. David ◽  
Nadine Borduas-Dedekind
Keyword(s):  
Cloud Fraction ◽  
Swiss Alps ◽  
Spatial And Temporal Variability ◽  
Research Station ◽  
Large Variability ◽  
Cloud Water Content ◽  
Central Switzerland ◽  
Freezing Temperatures ◽  
Ground Based Lidar ◽  
The Impact

Abstract. Ice-nucleating particles (INPs) produce ice from supercooled water droplets through heterogeneous freezing in the atmosphere. INPs have often been collected at the Jungfraujoch research station (at 3500 m a.s.l.) in central Switzerland; yet spatially diverse data on INP occurrence in the Swiss Alps are scarce and remain uncharacterized. We address this scarcity through our Swiss alpine snow sample study which took place during the winter of 2018. We collected a total of 88 fallen snow samples across the Alps at 17 different locations and investigated the impact of altitude, terrain, time since last snowfall and depth upon freezing temperatures. The INP concentrations were measured using the home-built DRoplet Ice Nuclei Counter Zurich (DRINCZ) and were then compared to spatial, temporal and physicochemical parameters. Boxplots of the freezing temperatures showed large variability in INP occurrence, even for samples collected 10 m apart on a plain and 1 m apart in depth. Furthermore, undiluted samples had cumulative INP concentrations ranging between 1 and 200 INP mL−1 of snowmelt over a temperature range of −5 to −19 ∘C. From this field-collected dataset, we parameterized the cumulative INP concentrations per cubic meter of air as a function of temperature with the following equation cair*(T)=e-0.7T-7.05, comparing well with previously reported precipitation data presented in Petters and Wright (2015). When assuming (1) a snow precipitation origin of the INPs, (2) a cloud water content of 0.4 g m−3 and (3) a critical INP concentration for glaciation of 10 m−3, the majority of the snow precipitated from clouds with glaciation temperatures between −5 and −20 ∘C. Based on the observed variability in INP concentrations, we conclude that studies conducted at the high-altitude research station Jungfraujoch are representative for INP measurements in the Swiss Alps. Furthermore, the INP concentration estimates in precipitation allow us to extrapolate the concentrations to a frozen cloud fraction. Indeed, this approach for estimating the liquid water-to-ice ratio in mixed-phase clouds compares well with aircraft measurements, ground-based lidar and satellite retrievals of frozen cloud fractions. In all, the generated parameterization for INP concentrations in snowmelt could help estimate cloud glaciation temperatures.

Communicating Climate Change to broad public through Educations - Project KlimaAlps

2021 ◽  
Author(s):  
Cornelia Baumann ◽  
Inga Beck
Keyword(s):  
Climate Change ◽  
Scientific Information ◽  
Environmental Research ◽  
Background Information ◽  
High Mountain ◽  
Research Station ◽  
Human Beings ◽  
Mountain Areas ◽  
The Alps

&lt;p&gt;Education is key in order to create a generation that thinks and acts sustainable and that considers nature as one of the most important good.Within the three years Interreg Project &amp;#8216;KlimaAlps&amp;#8217; (www.klimaalps.eu) &amp;#8211; making climate change visible - one major task is the establishment of a training for educators, to become a certified &amp;#8216;Climate-Pedagogue&amp;#8217; for the alpine region. The &amp;#8216;Climate-Pedagogue&amp;#8217;-training contains background information of climate change in the Alps and a variety of innovative educational tools and methods. It covers aspects of the high mountain areas, rivers and lakes, human beings, agriculture as well as moors. &amp;#160;The project is managed by the &amp;#8216;Energiewende Oberland&amp;#8217;; five additional partners from Austria and Bavaria are responsible for e. g. a high quality of the taught scientific information (Environmental Research Station Schneefernerhaus), the didactical input (University of Innsbruck, Department of Geography), the outreach activities and the implementation (Naturpark Karwendel, Klimab&amp;#252;ndnis Ober&amp;#246;sterreich, Landratsamt Garmisch-Partenkirchen).&amp;#160;During the last one and half years, the concept for the &amp;#8216;Climate-Pedagogue&amp;#8217;- training was worked out in cooperation with other environmental facilities and in March 2021 the first lectures of a pilot run with over 30 selected participants were held. In total there will be two runs in 2021 in order to evaluate the recent version of the training as good as possible.&amp;#160;The next and long-term steps will be the firm establishment of a chargeable &amp;#8216;Climate-Pedagogue&amp;#8217; &amp;#8211; Training for every interested person for at least the coming ten years, as well as the strengthening and growing of the network.&amp;#160;The presentation will give a short overview about the entire project as well as details about the &amp;#8216;Climate-Pedagogue&amp;#8217; &amp;#8211; Training and some first impressions of the already hold lectures in 2021.&lt;/p&gt;

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