scholarly journals Ice-nucleating ability of aerosol particles and possible sources at three coastal marine sites

2018 ◽  
Vol 18 (21) ◽  
pp. 15669-15685 ◽  
Author(s):  
Meng Si ◽  
Victoria E. Irish ◽  
Ryan H. Mason ◽  
Jesús Vergara-Temprado ◽  
Sarah J. Hanna ◽  
...  
Keyword(s):  
Particle Size ◽  
Aerosol Particles ◽  
Freezing Temperature ◽  
The Arctic ◽  
Labrador Sea ◽  
Sea Spray ◽  
Site Density ◽  
Coastal Marine ◽  
Surface Active ◽  
Surface Area Basis

Abstract. Despite the importance of ice-nucleating particles (INPs) for climate and precipitation, our understanding of these particles is far from complete. Here, we investigated INPs at three coastal marine sites in Canada, two at mid-latitude (Amphitrite Point and Labrador Sea) and one in the Arctic (Lancaster Sound). For Amphitrite Point, 23 sets of samples were analyzed, and for Labrador Sea and Lancaster Sound, one set of samples was analyzed for each location. At all three sites, the ice-nucleating ability on a per number basis (expressed as the fraction of aerosol particles acting as an INP) was strongly dependent on the particle size. For example, at diameters of around 0.2 µm, approximately 1 in 106 particles acted as an INP at −25 ∘C, while at diameters of around 8 µm, approximately 1 in 10 particles acted as an INP at −25 ∘C. The ice-nucleating ability on a per surface-area basis (expressed as the surface active site density, ns) was also dependent on the particle size, with larger particles being more efficient at nucleating ice. The ns values of supermicron particles at Amphitrite Point and Labrador Sea were larger than previously measured ns values of sea spray aerosols, suggesting that sea spray aerosols were not a major contributor to the supermicron INP population at these two sites. Consistent with this observation, a global model of INP concentrations under-predicted the INP concentrations when assuming only marine organics as INPs. On the other hand, assuming only K-feldspar as INPs, the same model was able to reproduce the measurements at a freezing temperature of −25 ∘C, but under-predicted INP concentrations at −15 ∘C, suggesting that the model is missing a source of INPs active at a freezing temperature of −15 ∘C.

scholarly journals Ice-nucleating efficiency of aerosol particles and possible sources at three coastal marine sites

2018 ◽  
Author(s):  
Meng Si ◽  
Victoria E. Irish ◽  
Ryan H. Mason ◽  
Jesús Vergara-Temprado ◽  
Sarah Hanna ◽  
...  
Keyword(s):  
Aerosol Particles ◽  
Freezing Temperature ◽  
The Arctic ◽  
Labrador Sea ◽  
Sea Spray ◽  
Site Density ◽  
Coastal Marine ◽  
Sea Spray Aerosol ◽  
Surface Active ◽  
Surface Area Basis

Abstract. Despite the importance of ice-nucleating particles (INPs) for climate and precipitation, our understanding of these particles is far from complete. Here, we investigated INPs at three coastal marine sites in Canada, two at mid-latitude (Amphitrite Point and Labrador Sea), and one in the Arctic (Lancaster Sound). At all three sites, the ice-nucleating efficiency on a per number basis (expressed as the fraction of aerosol particles acting as an INP) was strongly dependent on the size. For example, at diameters of around 0.2 µm, approximately 1 in 106 particles acted as an INP at −25 ºC, while at diameters of around 8 µm, approximately 1 in 10 particles acted as an INP at −25 ºC. The ice-nucleating efficiency on a per surface area basis (expressed as the surface active site density, ns) was also dependent on the size, with larger particles being more efficient at nucleating ice. The ns values of supermicron particles at Amphitrite Point and Labrador Sea were larger than previously measured ns values of sea spray aerosol, suggesting that sea spray aerosol was not a major contributor to the supermicron INP population at these two sites. Consistent with this observation, a global model of INP concentrations under-predicted the INP concentrations when assuming only marine organics as INPs. On the other hand, assuming only K-feldspar as INPs, the same model was able to reproduce the measurements at a freezing temperature of −25 ºC, but under-predicted INP concentrations at −15 ºC, suggesting that the model is missing a source of INPs active at a freezing temperature of −15 ºC.

scholarly journals Measurement report: Ice nucleating abilities of biomass burning, African dust, and sea spray aerosol particles over the Yucatan Peninsula

2020 ◽  
Author(s):  
Fernanda Córdoba ◽  
Carolina Ramirez-Romero ◽  
Diego Cabrera ◽  
Graciela B. Raga ◽  
Javier Miranda ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Aerosol Particles ◽  
Air Masses ◽  
African Dust ◽  
Site Density ◽  
Sea Spray Aerosol ◽  
Surface Active ◽  
Field Campaigns ◽  
Aerosol Types ◽  
Aerosol Type

Abstract. Most precipitation from deep clouds over the continents and in the intertropical convergence zone is strongly influenced by the presence of ice crystals, whose formation requires the presence of ice nucleating particles (INP). Although there are a large number of INP sources, the ice nucleating abilities of aerosol particles emitted from oceans, deserts, and wildfires are poorly described at tropical latitudes. To fill this gap in knowledge, the UNAM-MicroOrifice Uniform Deposit Impactor-Droplet Freezing Technique (UNAM-MOUDI-DFT) was built. Aerosol samples were collected in Sisal and Merida, Yucatan (Mexico) under the influence of cold fronts, biomass burning (BB), and African dust (AD), during five short-term field campaigns between January 2017 and July 2018. The three different aerosol types were distinguished by characterizing their physicochemical properties. Marine aerosol (MA), BB, and AD air masses were found to contain INP; the highest concentrations were found for AD (from 0.071 L−1 to 36.07 L−1), followed by MA (from 0.068 L−1 to 18.90 L−1), and BB (from 0.063 L−1 to 10.21 L−1). However, MA had the highest surface active site density (ns) between −15 °C and −30 °C. Additionally, supermicron particles contributed more than 72 % of the total INP concentration independent of aerosol type; MA had the largest contribution from supermicron particles.

Substrate-Deposited Sea Spray Aerosol Particles: Influence of Analytical Method, Substrate, and Storage Conditions on Particle Size, Phase, and Morphology

2015 ◽  
Vol 49 (22) ◽  
pp. 13447-13453 ◽  
Author(s):  
Olga Laskina ◽  
Holly S. Morris ◽  
Joshua R. Grandquist ◽  
Armando D. Estillore ◽  
Elizabeth A. Stone ◽  
...  
Keyword(s):  
Particle Size ◽  
Analytical Method ◽  
Aerosol Particles ◽  
Storage Conditions ◽  
Sea Spray ◽  
Sea Spray Aerosol ◽  
And Storage

Effect of grain size on the vapour phase hydration of monoclinic and triclinic modifications of tricalcium silicate; role of high temperature activation

1991 ◽  
Vol 56 (10) ◽  
pp. 1993-2008
Author(s):  
S. Hanafi ◽  
G. M. S. El-Shafei ◽  
B. Abd El-Hamid
Keyword(s):  
Particle Size ◽  
Vapour Phase ◽  
Tricalcium Silicate ◽  
Active Centers ◽  
Thermally Activated ◽  
Grain Sizes ◽  
Intermediate Size ◽  
Surface Active ◽  
Temperature Activation

The hydration of tricalcium silicate (C3S) with three grain sizes of monoclinic (M) and triclinic (T) modifications and on their thermally activated samples were investigated by exposure to water vapour at 80°C for 60 days. The products were investigated by XRD, TG and N2 adsorption. The smaller the particle size the greater was the hydration for both dried and activated samples from (M). In the activated samples a hydrate with 2θ values of 38.4°, 44.6° and 48.6° could be identified. Hydration increased with particle size for the unactivated (T) samples but after activation the intermediate size exhibited enhanced hydration. Thermal treatment at 950°C of (T) samples increased the surface active centers on the expense of those in the bulk. Changes produced in surface texture upon activation and/or hydration are discussed.

scholarly journals Effects of SO<sub>2</sub> oxidation on ambient aerosol growth in water and ethanol vapours

2005 ◽  
Vol 5 (3) ◽  
pp. 767-779 ◽  
Author(s):  
T. Petäjä ◽  
V.-M. Kerminen ◽  
K. Hämeri ◽  
P. Vaattovaara ◽  
J. Joutsensaari ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Sulphuric Acid ◽  
Cloud Condensation Nuclei ◽  
Aerosol Particles ◽  
The Arctic ◽  
Ambient Conditions ◽  
Similar Chemical ◽  
Ethanol Vapours ◽  
Hygroscopic Particles ◽  
Ultrafine Aerosol

Abstract. Hygroscopicity (i.e. water vapour affinity) of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic particles is expected to increase their hygrocopicity and hence their cloud condensation nuclei formation potential. In this study, differences in the hygroscopic and ethanol uptake properties of ultrafine aerosol particles in the Arctic air masses with a different exposure to anthropogenic sulfur pollution were examined. The main discovery was that Aitken mode particles having been exposed to polluted air were more hygroscopic and less soluble to ethanol than after transport in clean air. This aging process was attributed to sulphur dioxide oxidation and subsequent condensation during the transport of these particle to our measurement site. The hygroscopicity of nucleation mode aerosol particles, on the other hand, was approximately the same in all the cases, being indicative of a relatively similar chemical composition despite the differences in air mass transport routes. These particles had also been produced closer to the observation site typically 3–8 h prior to sampling. Apparently, these particles did not have an opportunity to accumulate sulphuric acid on their way to the site, but instead their chemical composition (hygroscopicity and ethanol solubility) resembled that of particles produced in the local or semi-regional ambient conditions.

Inside versus Outside: Ion Redistribution in Nitric Acid Reacted Sea Spray Aerosol Particles as Determined by Single Particle Analysis

2013 ◽  
Vol 135 (39) ◽  
pp. 14528-14531 ◽  
Author(s):  
Andrew P. Ault ◽  
Timothy L. Guasco ◽  
Olivia S. Ryder ◽  
Jonas Baltrusaitis ◽  
Luis A. Cuadra-Rodriguez ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Single Particle ◽  
Aerosol Particles ◽  
Particle Analysis ◽  
Sea Spray ◽  
Single Particle Analysis ◽  
Sea Spray Aerosol

Rapid measurement of particle hygroscopicity and CCN activity using broad scanning supersaturation (BS2)-CCNC: calibration and intercomparison

2021 ◽  
Author(s):  
Najin Kim ◽  
Yafang Cheng ◽  
Nan Ma ◽  
Mira Pöhlker ◽  
Thomas Klimach ◽  
...  
Keyword(s):  
Particle Size ◽  
Time Resolution ◽  
Calibration Curve ◽  
Aerosol Particles ◽  
High Time ◽  
Activity Measurement ◽  
High Time Resolution ◽  
Chemical Compositions ◽  
Monotonic Relation ◽  
Ccn Activity

&lt;p&gt;For understanding and assessing aerosol-cloud interactions and their impact on climate, reliable measurement data of aerosol particle hygroscopicity and cloud condensation nuclei (CCN) activity are required. Furthermore, aerosol liquid water, mainly controlled by hygroscopicity, affects heterogeneous and multiphase reactions of aerosol particles. The CCN activity of aerosol particles can be determined by scanning particle size and supersaturation (S) in the CCN measurement. Compared to the existing CCN activity measurement, a broad supersaturation scanning CCN (BS2-CCN) system, in which particles are exposed to a range of S simultaneously, can measure particle hygroscopicity and CCN activity with a high-time resolution. Based on a monotonic relation between the activation supersaturation of aerosol particles (S&lt;sub&gt;aerosol&lt;/sub&gt;) &amp;#160;and the activation fraction (F&lt;sub&gt;act&lt;/sub&gt;) of the BS2-CCN measurement, we can derive &amp;#954;, a single hygroscopicity parameter, directly.&lt;/p&gt;&lt;p&gt;Here, we describe how the BS2-CCN system can be effectively calibrated and which factors can affect the calibration curve (F&lt;sub&gt;act&lt;/sub&gt; - S&lt;sub&gt;aerosol&lt;/sub&gt;). For calibration, size-resolved CCN measurements with ammonium sulfate (AS) and sodium chloride particles are performed under the three different thermal gradient (dT) conditions (dT=6, 8, and 10). First, the shape of the calibration curve is primarily influenced by S&lt;sub&gt;max&lt;/sub&gt;, maximum S in the activation tube. We need to determine appropriate S&lt;sub&gt;max&lt;/sub&gt; depending on particle size and &amp;#954; to be investigated. To minimize the effect of double/multiple charged particles, small&amp;#160; D&lt;sub&gt;g &lt;/sub&gt;and &amp;#963;&lt;sub&gt;g&lt;/sub&gt;&amp;#160; in number size distribution are recommended when generating the calibration aerosols. Sheath-to-aerosol-flow ratio (SAR) is the third factor to be considered. BS2-CCNC system uses a low SAR with a wider inlet compared to the typical CCN measurement, which can make a monotonic relation between F&lt;sub&gt;act&lt;/sub&gt; and S&lt;sub&gt;aerosol&lt;/sub&gt;. Lastly, F&lt;sub&gt;act &lt;/sub&gt;is affected by particle number concentration and has a decreasing rate of 0.02/100 cm&lt;sup&gt;-3&lt;/sup&gt; (within N&lt;sub&gt;CN&lt;/sub&gt; ~ 300 cm&lt;sup&gt;-3&lt;/sup&gt; for AS) due to the water consumption in the chamber. For evaluating the BS2-CCN system, inter-comparison experiments between typical DMA-CCN and BS2-CCN measurement were performed with the laboratory-generated aerosol mixture and ambient aerosols. Statistically good agreements of &amp;#954; values between DMA-CCN and BS2-CCN measurements for both inter-comparison experiments imply that the BS2-CCN system can measure particle hygroscopicity and CCN activity well compared to the existing measurement. We expect that this new system can be applied to aircraft and ship measurements that require a high-time resolution as well as ground measurement for a broad range of hygroscopicity distribution. Because hygroscopicity is closely related to the fraction of organics/inorganics in aerosol particles, our method can also serve as a complementary approach for fast detection/estimation of aerosol chemical compositions.&amp;#160;&lt;/p&gt;

scholarly journals Anomalous blocking over Greenland preceded the 2013 extreme early melt of local sea ice

2017 ◽  
Vol 59 (76pt2) ◽  
pp. 181-190 ◽  
Author(s):  
Thomas J. Ballinger ◽  
Edward Hanna ◽  
Richard J. Hall ◽  
Thomas E. Cropper ◽  
Jeffrey Miller ◽  
...  
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Circulation Pattern ◽  
The Arctic ◽  
Labrador Sea ◽  
First Year ◽  
Tropospheric Circulation ◽  
Blocking Index

ABSTRACTThe Arctic marine environment is undergoing a transition from thick multi-year to first-year sea-ice cover with coincident lengthening of the melt season. Such changes are evident in the Baffin Bay-Davis Strait-Labrador Sea (BDL) region where melt onset has occurred ~8 days decade−1 earlier from 1979 to 2015. A series of anomalously early events has occurred since the mid-1990s, overlapping a period of increased upper-air ridging across Greenland and the northwestern North Atlantic. We investigate an extreme early melt event observed in spring 2013. (~6σ below the 1981–2010 melt climatology), with respect to preceding sub-seasonal mid-tropospheric circulation conditions as described by a daily Greenland Blocking Index (GBI). The 40-days prior to the 2013 BDL melt onset are characterized by a persistent, strong 500 hPa anticyclone over the region (GBI >+1 on >75% of days). This circulation pattern advected warm air from northeastern Canada and the northwestern Atlantic poleward onto the thin, first-year sea ice and caused melt ~50 days earlier than normal. The episodic increase in the ridging atmospheric pattern near western Greenland as in 2013, exemplified by large positive GBI values, is an important recent process impacting the atmospheric circulation over a North Atlantic cryosphere undergoing accelerated regional climate change.

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