Seasonal Variations in Western North Atlantic Remote Marine Aerosol Properties

2019 ◽  
Vol 124 (24) ◽  
pp. 14240-14261 ◽  
Author(s):  
P.K. Quinn ◽  
T.S. Bates ◽  
D.J. Coffman ◽  
L. Upchurch ◽  
J.E. Johnson ◽  
...  
Keyword(s):  
North Atlantic ◽  
Seasonal Variations ◽  
Marine Aerosol ◽  
Aerosol Properties

scholarly journals Marine boundary layer aerosol in the eastern North Atlantic: seasonal variations and key controlling processes

2018 ◽  
Vol 18 (23) ◽  
pp. 17615-17635 ◽  
Author(s):  
Guangjie Zheng ◽  
Yang Wang ◽  
Allison C. Aiken ◽  
Francesca Gallo ◽  
Michael P. Jensen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Atlantic ◽  
Seasonal Variations ◽  
Dimethyl Sulfide ◽  
Marine Boundary Layer ◽  
Sulfide Oxidation ◽  
Aerosol Size Distribution ◽  
Eastern North Atlantic ◽  
Aitken Mode ◽  
Aerosol Properties

Abstract. The response of marine low cloud systems to changes in aerosol concentration represents one of the largest uncertainties in climate simulations. Major contributions to this uncertainty are derived from poor understanding of aerosol under natural conditions and the perturbation by anthropogenic emissions. The eastern North Atlantic (ENA) is a region of persistent but diverse marine boundary layer (MBL) clouds, whose albedo and precipitation are highly susceptible to perturbations in aerosol properties. In this study, we examine MBL aerosol properties, trace gas mixing ratios, and meteorological parameters measured at the Atmospheric Radiation Measurement Climate Research Facility's ENA site on Graciosa Island, Azores, Portugal, during a 3-year period from 2015 to 2017. Measurements impacted by local pollution on Graciosa Island and during occasional intense biomass burning and dust events are excluded from this study. Submicron aerosol size distribution typically consists of three modes: Aitken (At, diameter Dp<∼100 nm), accumulation (Ac, Dp within ∼100 to ∼300 nm), and larger accumulation (LA, Dp>∼300 nm) modes, with average number concentrations (denoted as NAt, NAc, and NLA below) of 330, 114, and 14 cm−3, respectively. NAt, NAc, and NLA show contrasting seasonal variations, suggesting different sources and removal processes. NLA is dominated by sea spray aerosol (SSA) and is higher in winter and lower in summer. This is due to the seasonal variations of SSA production, in-cloud coalescence scavenging, and dilution by entrained free troposphere (FT) air. In comparison, SSA typically contributes a relatively minor fraction to NAt (10 %) and NAc (21 %) on an annual basis. In addition to SSA, sources of Ac-mode particles include entrainment of FT aerosols and condensation growth of Aitken-mode particles inside the MBL, while in-cloud coalescence scavenging is the major sink of NAc. The observed seasonal variation of NAc, being higher in summer and lower in winter, generally agrees with the steady-state concentration estimated from major sources and sinks. NAt is mainly controlled by entrainment of FT aerosol, coagulation loss, and growth of Aitken-mode particles into the Ac-mode size range. Our calculation suggests that besides the direct contribution from entrained FT Ac-mode particles, growth of entrained FT Aitken-mode particles in the MBL also represent a substantial source of cloud condensation nuclei (CCN), with the highest contribution potentially reaching 60 % during summer. The growth of Aitken-mode particles to CCN size is an expected result of the condensation of sulfuric acid, a product from dimethyl sulfide oxidation, suggesting that ocean ecosystems may have a substantial influence on MBL CCN populations in the ENA.

scholarly journals Marine boundary layer aerosol in Eastern North Atlantic: seasonal variations and key controlling processes

2018 ◽  
Author(s):  
Guangjie Zheng ◽  
Yang Wang ◽  
Allison C. Aiken ◽  
Francesca Gallo ◽  
Mike Jensen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Atlantic ◽  
Seasonal Variations ◽  
Dimethyl Sulfide ◽  
Marine Boundary Layer ◽  
Cloud Condensation Nuclei ◽  
Sulfide Oxidation ◽  
Aerosol Size Distribution ◽  
Eastern North Atlantic ◽  
Aerosol Properties

Abstract. The response of marine low cloud systems to changes in aerosol concentration represents one of the largest uncertainties in climate simulations. Major contributions to this uncertainty derive from poor understanding of aerosol under natural conditions and the perturbation by anthropogenic emissions. The Eastern North Atlantic (ENA) is a region of persistent but diverse marine boundary layer (MBL) clouds, whose albedo and precipitation are highly susceptible to perturbations in aerosol properties. In this study, we examine MBL aerosol properties, trace gas mixing ratios, and meteorological parameters measured at the Atmospheric Radiation Measurement Climate Research Facility’s ENA site on Graciosa Island, Azores, Portugal from 2015 to 2017. Measurements impacted by local pollutions on Graciosa Island and during occasional intense biomass burning and dust events are excluded from this analysis. Submicron aerosol size distribution typically consists of three modes: Aitken (At), Accumulation (Ac), and Larger Accumulation (LA) modes, with average number concentrations (denoted as NAt, NAc and NLA below) of 330, 114, and 14 cm−3, respectively. NAt, NAc and NLA show contrasting seasonal variations, suggesting different sources and removal processes. NLA is dominated by sea spray aerosol (SSA), and is higher in winter and lower in summer. This is due to the seasonal variations of SSA production, coalescence scavenging, and dilution by entrained free troposphere (FT) air. In comparison, SSA typically contributes a relatively minor fraction to NAt (10 %) and NAc (21 %) on an annual basis. In addition to SSA, sources of Ac mode particles include entrainment of FT aerosols and condensation growth of At mode particles inside MBL, while coalescence scavenging is the major sink of NAc. The observed seasonal variation of NAc, being higher in summer and lower in winter, generally agrees with the estimate based on the major sources and sink. NAt is mainly controlled by entrainment of FT aerosol, coagulation loss, and growth of At mode particles into Ac mode size range. Our calculation suggests besides the direct contribution from entrained FT Ac mode particles, growth of entrained FT At mode particles in the MBL also represent a substantial source of cloud condensation nuclei (CCN), with the highest contribution potentially reaching nearly 60 % during summer. The growth of At mode particles to CCN size is expected a result of the condensation of sulfuric acid from dimethyl sulfide oxidation, suggesting that ocean ecosystems may have a substantial influence on MBL CCN populations in ENA.

scholarly journals Growth and Seasonal Variations in Distribution of Chauliodus Sloani and C. Danae (Pisces) from the mid North Atlantic

1987 ◽  
Vol 57 (2) ◽  
pp. 164-182 ◽  
Author(s):  
W.L. van Utrech ◽  
C.N. van Utrecht-Cock ◽  
A.M.J. de Graaf
Keyword(s):  
North Atlantic ◽  
Vertical Migration ◽  
Seasonal Variations ◽  
Food Preference ◽  
Northern Limit

In the mid North Atlantic Chauliodus sloani is caught mainly between 55° and 29° N, while the majority is caught north of 35° N. The greatest density is found around 40° N. Chauliodus danae has the northern limit of its distribution at about 45° N. C. danae, in particular the smaller specimens, shows clear vertical migration and has food preference, while C. sloani does not show such migration and is most probably a random feeder. In both species there is a significant increase in length from south to north.

scholarly journals Investigating Primary Marine Aerosol Properties: CCN Activity of Sea Salt and Mixed Inorganic–Organic Particles

2012 ◽  
Vol 46 (19) ◽  
pp. 10405-10412 ◽  
Author(s):  
Stephanie M. King ◽  
Andrew C. Butcher ◽  
Thomas Rosenoern ◽  
Esther Coz ◽  
Kirsten I. Lieke ◽  
...  
Keyword(s):  
Sea Salt ◽  
Marine Aerosol ◽  
Organic Particles ◽  
Aerosol Properties ◽  
Ccn Activity

scholarly journals Determining the link between hygroscopicity and composition for semi-volatile aerosol species

2018 ◽  
Vol 11 (7) ◽  
pp. 4361-4372 ◽  
Author(s):  
Joel Alroe ◽  
Luke T. Cravigan ◽  
Marc D. Mallet ◽  
Zoran D. Ristovski ◽  
Branka Miljevic ◽  
...  
Keyword(s):  
Sampling Technique ◽  
Organic Aerosol ◽  
Marine Aerosol ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Coastal Marine ◽  
Bypass Line ◽  
Sea Spray Aerosol ◽  
Aerosol Properties ◽  
Cape Grim

Abstract. Internally and externally mixed aerosols present significant challenges in assessing the hygroscopicity of each aerosol component. This study presents a new sampling technique which uses differences in volatility to separate mixtures and directly examine their respective composition and hygroscopic contribution. A shared thermodenuder and unheated bypass line are continuously cycled between an aerosol mass spectrometer and a volatility and hygroscopicity tandem differential mobility analyser, allowing real-time comparative analysis of heated and unheated aerosol properties. Measurements have been taken of both chamber-generated secondary organic aerosol and coastal marine aerosol at Cape Grim, Australia, to investigate system performance under diverse conditions. Despite rapidly changing aerosol properties and the need to restrict analysis to a narrow size range, the former experiment separated the hygroscopic influences of ammonium sulfate and two distinct organic components with similar oxygen to carbon ratios but different volatilities. Analysis of the marine aerosol revealed an external mixture of non-sea-salt sulfates and sea spray aerosol, which likely shared similar volatile fractions composed of sulfuric acid and a non-hygroscopic organic component.

Finding linkages between ocean ecosystems and natural marine aerosols in the minimally polluted North Atlantic atmosphere

2020 ◽  
Author(s):  
Patricia Quinn ◽  
Tim Bates ◽  
Eric Saltzman ◽  
Tom Bell ◽  
Mike Behrenfeld
Keyword(s):  
North Atlantic ◽  
Cloud Condensation Nuclei ◽  
Sea Spray ◽  
Marine Aerosols ◽  
Condensation Nuclei ◽  
Surface Ocean ◽  
Cloud Properties ◽  
Sea Spray Aerosol ◽  
Ocean Ecosystems ◽  
Aerosol Properties

&lt;p&gt;The emission of sea spray aerosol (SSA) and dimethylsulfide (DMS) from the ocean results in marine boundary layer aerosol particles that can impact Earth&amp;#8217;s radiation balance by directly scattering solar radiation and by acting as cloud condensation nuclei (CCN), thereby altering cloud properties. The surface ocean is projected to warm by 1.3 to 2.8&amp;#176;C globally over the 21&lt;sup&gt;st&lt;/sup&gt; century. Impacts of this warming on plankton blooms, ocean ecosystems, and ocean-to-atmosphere fluxes of aerosols and their precursor gases are highly uncertain. A fundamental understanding of linkages between surface ocean ecosystems and ocean-derived aerosols is required to address this uncertainty. One approach for improved understandings of these linkages is simultaneous measurements of relevant surface ocean and aerosol properties in an ocean region with seasonally varying plankton blooms and a minimally polluted overlying atmosphere. The western North Atlantic hosts the largest annual phytoplankton bloom in the global ocean with a large spatial and seasonal variability in plankton biomass and composition. Periods of low aerosol number concentrations associated with unpolluted air masses allow for the detection of linkages between ocean ecosystems and ocean-derived aerosol.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Five experiments were conducted in the western North Atlantic between 2014 and 2018 with the objective of finding links between the bloom and marine aerosols. These experiments include the second Western Atlantic Climate Study (WACS-2) and four North Atlantic Aerosol and Marine Ecosystem Study (NAAMES) cruises. This series of cruises was the first time the western North Atlantic bloom was systematically sampled during every season with extensive ocean and atmosphere measurements able to assess how changes in the state of the bloom might impact ocean-derived aerosol properties. Measurements of unheated and heated number size distributions, cloud condensation nuclei (CCN) concentrations, and aerosol composition were used to identify primary and secondary aerosol components that could be related to the state of the bloom. Only periods of clean marine air, as defined by radon, particle number concentration, aerosol light absorption coefficient, and back trajectories, were included in the analysis.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;CCN concentrations at 0.1% supersaturation were best correlated (r&lt;sup&gt;2&lt;/sup&gt; = 0.73) with accumulation mode nss SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;=&lt;/sup&gt;. Sea spray aerosol (SSA) was only correlated with CCN during November when bloom accumulation had not yet occurred and dimethylsulfide (DMS) concentrations were at a minimum. The fraction of CCN attributable to SSA was less than 20% during March, May/June, and September, indicating the limited contribution of SSA to the CCN population of the western North Atlantic atmosphere. The strongest link between the plankton bloom and aerosol and cloud properties appears to be due to biogenic non-seasalt SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;=&lt;/sup&gt;.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Seasonal variations in physiological parameters of phytoplankton across the North Atlantic

1998 ◽  
Vol 20 (1) ◽  
pp. 17-42 ◽  
Author(s):  
Margareth N. Kyewalyanga ◽  
Trevor Platt ◽  
Shubha Sathyendranath ◽  
Vivian A. Lutz ◽  
Venetia Stuart
Keyword(s):  
North Atlantic ◽  
Seasonal Variations ◽  
Physiological Parameters ◽  
The North ◽  
The North Atlantic
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