Isotopic composition of rainwater nitrate at Bermuda: The influence of air mass source and chemistry in the marine boundary layer

Abstract. Ice nucleating particles (INPs) in the Arctic can influence climate and precipitation in the region; yet our understanding of the concentrations and sources of INPs in this region remain uncertain. In the following, we (1) measured concentrations of INPs in the immersion mode in the Canadian Arctic marine boundary layer during summer 2014 on board the CCGS Amundsen, (2) determined ratios of surface areas of mineral dust aerosol to sea spray aerosol, and (3) investigated the source region of the INPs using particle dispersion modelling. Average concentrations of INPs at −15, −20, and −25 ∘C were 0.005, 0.044, and 0.154 L−1, respectively. These concentrations fall within the range of INP concentrations measured in other marine environments. For the samples investigated the ratio of mineral dust surface area to sea spray surface area ranged from 0.03 to 0.09. Based on these ratios and the ice active surface site densities of mineral dust and sea spray aerosol determined in previous laboratory studies, our results suggest that mineral dust is a more important contributor to the INP population than sea spray aerosol for the samples analysed. Based on particle dispersion modelling, the highest concentrations of INPs were often associated with lower-latitude source regions such as the Hudson Bay area, eastern Greenland, or north-western continental Canada. On the other hand, the lowest concentrations were often associated with regions further north of the sampling sites and over Baffin Bay. A weak correlation was observed between INP concentrations and the time the air mass spent over bare land, and a weak negative correlation was observed between INP concentrations and the time the air mass spent over ice and open water. These combined results suggest that mineral dust from local sources is an important contributor to the INP population in the Canadian Arctic marine boundary layer during summer 2014.

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The North Atlantic Marine Boundary Layer Experiment(NAMBLEX). Overview of the campaign held at Mace Head, Ireland, in summer 2002

Atmospheric Chemistry and Physics ◽

10.5194/acp-6-2241-2006 ◽

2006 ◽

Vol 6 (8) ◽

pp. 2241-2272 ◽

Cited By ~ 48

Author(s):

D. E. Heard ◽

K. A. Read ◽

J. Methven ◽

S. Al-Haider ◽

W. J. Bloss ◽

...

Keyword(s):

Boundary Layer ◽

North Atlantic ◽

Marine Boundary Layer ◽

Numerical Models ◽

Measurement Data ◽

Air Mass ◽

The North ◽

Trace Species ◽

Wide Range ◽

The North Atlantic

Abstract. The North Atlantic Marine Boundary Layer Experiment (NAMBLEX), involving over 50 scientists from 12 institutions, took place at Mace Head, Ireland (53.32° N, 9.90° W), between 23 July and 4 September 2002. A wide range of state-of-the-art instrumentation enabled detailed measurements of the boundary layer structure and atmospheric composition in the gas and aerosol phase to be made, providing one of the most comprehensive in situ studies of the marine boundary layer to date. This overview paper describes the aims of the NAMBLEX project in the context of previous field campaigns in the Marine Boundary Layer (MBL), the overall layout of the site, a summary of the instrumentation deployed, the temporal coverage of the measurement data, and the numerical models used to interpret the field data. Measurements of some trace species were made for the first time during the campaign, which was characterised by predominantly clean air of marine origin, but more polluted air with higher levels of NOx originating from continental regions was also experienced. This paper provides a summary of the meteorological measurements and Planetary Boundary Layer (PBL) structure measurements, presents time series of some of the longer-lived trace species (O3, CO, H2, DMS, CH4, NMHC, NOx, NOy, PAN) and summarises measurements of other species that are described in more detail in other papers within this special issue, namely oxygenated VOCs, HCHO, peroxides, organo-halogenated species, a range of shorter lived halogen species (I2, OIO, IO, BrO), NO3 radicals, photolysis frequencies, the free radicals OH, HO2 and (HO2+Σ RO2), as well as a summary of the aerosol measurements. NAMBLEX was supported by measurements made in the vicinity of Mace Head using the NERC Dornier-228 aircraft. Using ECMWF wind-fields, calculations were made of the air-mass trajectories arriving at Mace Head during NAMBLEX, and were analysed together with both meteorological and trace-gas measurements. In this paper a chemical climatology for the duration of the campaign is presented to interpret the distribution of air-mass origins and emission sources, and to provide a convenient framework of air-mass classification that is used by other papers in this issue for the interpretation of observed variability in levels of trace gases and aerosols.

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The importance of alkyl nitrates and sea ice emissions to atmospheric NO<sub>x</sub> sources and cycling in the summertime Southern Ocean marine boundary layer

10.5194/acp-2021-519 ◽

2021 ◽

Author(s):

Jessica Mary Burger ◽

Julie Granger ◽

Emily Joyce ◽

Meredith Galanter Hastings ◽

Kurt Angus McDonald Spence ◽

...

Keyword(s):

Boundary Layer ◽

Southern Ocean ◽

Sea Ice ◽

Marine Boundary Layer ◽

Weddell Sea ◽

Alkyl Nitrates ◽

Air Mass ◽

Surface Ocean ◽

Alkyl Nitrate ◽

Atmospheric Nitrate

Abstract. Atmospheric nitrate originates from the oxidation of nitrogen oxides (NOx = NO + NO2) and impacts both tropospheric chemistry and climate. NOx sources, cycling, and NOx to nitrate formation pathways are poorly constrained in remote marine regions, especially the Southern Ocean where pristine conditions serve as a useful proxy for the preindustrial atmosphere. Here, we measured the isotopic composition (δ15N and δ18O) of atmospheric nitrate in coarse-mode (> 1 μm) aerosols collected in the summertime marine boundary layer of the Atlantic Southern Ocean from 34.5° S to 70° S, and across the northern edge of the Weddell Sea. The δ15N-NO3− decreased with latitude from −2.7 ‰ to −43.1 ‰. The decline in δ15N with latitude is attributed to changes in the dominant NOx sources: lightning at the low latitudes, oceanic alkyl nitrates at the mid latitudes, and photolysis of nitrate in snow at the high latitudes. There is no evidence of any influence from anthropogenic NOx sources or equilibrium isotopic fractionation. Using air mass back trajectories and an isotope mixing model, we calculate that oceanic alkyl nitrate emissions have a δ15N signature of −22.0 ‰ ± 7.5 ‰. Given that measurements of alkyl nitrate contributions to remote nitrogen budgets are scarce, this may be a useful tracer for detecting their contribution in other oceanic regions. The δ18O-NO3− was always less than 70 ‰, indicating that daytime processes involving OH are the dominant NOx oxidation pathway during summer. Unusually low δ18O-NO3− values (less than 31 ‰) were observed at the western edge of the Weddell Sea. The air mass history of these samples indicates extensive interaction with sea ice covered ocean, which is known to enhance peroxy radical production. The observed low δ18O-NO3− is therefore attributed to increased exchange of NO with peroxy radicals, which have a low δ18O, relative to ozone, which has a high δ18O. This study reveals that the mid- and high-latitude surface ocean may serve as a more important NOx source than previously thought, and that the ice-covered surface ocean impacts the reactive nitrogen budget as well as the oxidative capacity of the marine boundary layer.

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Measurements of35S in the marine boundary layer at La Jolla, California: A new technique for tracing air mass mixing during Santa Ana events

Journal of Geophysical Research Atmospheres ◽

10.1029/2011jd016878 ◽

2012 ◽

Vol 117 (D8) ◽

pp. n/a-n/a ◽

Cited By ~ 12

Author(s):

Antra Priyadarshi ◽

Jason Hill-Falkenthal ◽

Elena Coupal ◽

Gerardo Dominguez ◽

Mark H. Thiemens

Keyword(s):

Boundary Layer ◽

Marine Boundary Layer ◽

New Technique ◽

Air Mass ◽

Santa Ana ◽

A New Technique ◽

La Jolla

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The North Atlantic Marine Boundary Layer Experiment (NAMBLEX). Overview of the campaign held at Mace Head, Ireland, in summer 2002

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-5-12177-2005 ◽

2005 ◽

Vol 5 (6) ◽

pp. 12177-12254 ◽

Cited By ~ 1

Author(s):

D. E. Heard ◽

K. A. Read ◽

J. Methven ◽

S. Al-Haider ◽

W. J. Bloss ◽

...

Keyword(s):

Boundary Layer ◽

North Atlantic ◽

Marine Boundary Layer ◽

Numerical Models ◽

Measurement Data ◽

Air Mass ◽

The North ◽

Trace Species ◽

Wide Range ◽

The North Atlantic

Abstract. The North Atlantic Marine Boundary Layer Experiment (NAMBLEX), involving over 50 scientists from 12 institutions, took place at Mace Head, Ireland (53.32° N, 9.90° W), between 23 July and 4 September 2002. A wide range of state-of-the-art instrumentation enabled detailed measurements of the boundary layer structure and atmospheric composition in the gas and aerosol phase to be made, providing one of the most comprehensive in situ studies of the marine boundary layer to date. This overview paper describes the aims of the NAMBLEX project in the context of previous field campaigns in the Marine Boundary Layer (MBL), the overall layout of the site, a summary of the instrumentation deployed, the temporal coverage of the measurement data, and the numerical models used to interpret the field data. Measurements of some trace species were made for the first time during the campaign, which was characterised by predominantly clean air of marine origin, but more polluted air with higher levels of NOx originating from continental regions was also experienced. This paper provides a summary of the meteorological measurements and Planetary Boundary Layer (PBL) structure measurements, presents time series of some of the longer-lived trace species (O3, CO, H2, DMS, CH4, NMHC, NOx, NOy, PAN) and summarises measurements of other species that are described in more detail in other papers within this special issue, namely oxygenated VOCs, HCHO, peroxides, organo-halogenated species, a range of shorter lived halogen species (I2, OIO, IO, BrO), NO3 radicals, photolysis frequencies, the free radicals OH, HO2 and (HO2+ΣRO2), as well as a summary of the aerosol measurements. NAMBLEX was supported by measurements made in the vicinity of Mace Head using the NERC Dornier-228 aircraft. Using ECMWF wind-fields, calculations were made of the air-mass trajectories arriving at Mace Head during NAMBLEX, and were analysed together with both meteorological and trace-gas measurements. In this paper a chemical climatology is presented to interpret the distribution of air-mass origins and emission sources, and to provide a convenient framework of air-mass classification that is used by other papers in this issue for the interpretation of observed variability in levels of trace gases and aerosols.

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Hygroscopic behaviour of aerosol particles in the arctic marine boundary layer-relation to air mass history and mixing

Journal of Aerosol Science ◽

10.1016/s0021-8502(98)00081-0 ◽

1998 ◽

Vol 29 ◽

pp. S9-S10

Author(s):

E. Swietlicki ◽

J. Zhou ◽

O.H. Berg ◽

E.D. Nilsson ◽

P.P. Aalto ◽

...

Keyword(s):

Boundary Layer ◽

Marine Boundary Layer ◽

Aerosol Particles ◽

The Arctic ◽

Air Mass

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Use of Atmospheric Refraction to Determine Air Mass and Extinction Coefficients as Well as Temperature and Humidity Profiles in the Marine Boundary Layer

10.21236/ada627978 ◽

1997 ◽

Author(s):

George W. Kattawar

Keyword(s):

Boundary Layer ◽

Marine Boundary Layer ◽

Atmospheric Refraction ◽

Air Mass ◽

Extinction Coefficients ◽

Temperature And Humidity ◽

Humidity Profiles

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Key controls of water vapour isotopes during oceanic evaporation and their global impact

10.5194/egusphere-egu2020-13131 ◽

2020 ◽

Author(s):

Martin Werner ◽

Jean-Louis Bonne ◽

Alexandre Cauquoin ◽

Hans Christian Steen-Larsen

Keyword(s):

Boundary Layer ◽

Sea Ice ◽

Isotopic Composition ◽

Water Vapour ◽

Marine Boundary Layer ◽

Atmospheric Model ◽

Global Scale ◽

Data Sets ◽

Stable Water Isotopes ◽

New Findings

<p>Stable water isotopes are employed as hydrological tracers to quantify the diverse implications of atmospheric moisture for climate. In a recent study based on several years of in-situ isotope measurements in water vapour of the marine boundary layer it was shown that the isotope signal during evaporation is not modulated by wind speed, contrary to the commonly used theory, but controlled by relative humidity and sea surface temperature, only (Bonne et al., 2019). In sea ice covered regions, the sublimation of deposited snow on sea ice was found as another key process controlling the local water vapour isotopic composition. Here, we evaluate how these new findings will impact the stable water isotope signal both in vapour and precipitation on a global scale. For this purpose, the newly suggested parametrisations are included in two versions of the isotope-enabled atmospheric model ECHAM-wiso (Werner et al., 2016; Cauquoin et al., 2019) and a set of simulations is performed to disentangle the effects of the various controlling factors. Model results are evaluated against a compilation of short-term measurements of the isotopic composition in the marine boundary layer (Benetti et al., 2017), as well as data sets from several coastal stations (Steen-Larsen et al., 2014; 2015; 2017). In addition, the implications of the suggested parameterization changes for the interpretation of various isotope records in paleo-records will be discussed.</p>

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Reactive Halogens in the Marine Boundary Layer (RHaMBLe): the tropical North Atlantic experiments

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-1031-2010 ◽

2010 ◽

Vol 10 (3) ◽

pp. 1031-1055 ◽

Cited By ~ 51

Author(s):

J. D. Lee ◽

G. McFiggans ◽

J. D. Allan ◽

A. R. Baker ◽

S. M. Ball ◽

...

Keyword(s):

Boundary Layer ◽

North Atlantic ◽

Marine Boundary Layer ◽

Cape Verde ◽

Aerosol Composition ◽

Air Mass ◽

Mixing Ratios ◽

Tropical North Atlantic ◽

Halogen Species

Abstract. The NERC UK SOLAS-funded Reactive Halogens in the Marine Boundary Layer (RHaMBLe) programme comprised three field experiments. This manuscript presents an overview of the measurements made within the two simultaneous remote experiments conducted in the tropical North Atlantic in May and June 2007. Measurements were made from two mobile and one ground-based platforms. The heavily instrumented cruise D319 on the RRS Discovery from Lisbon, Portugal to São Vicente, Cape Verde and back to Falmouth, UK was used to characterise the spatial distribution of boundary layer components likely to play a role in reactive halogen chemistry. Measurements onboard the ARSF Dornier aircraft were used to allow the observations to be interpreted in the context of their vertical distribution and to confirm the interpretation of atmospheric structure in the vicinity of the Cape Verde islands. Long-term ground-based measurements at the Cape Verde Atmospheric Observatory (CVAO) on São Vicente were supplemented by long-term measurements of reactive halogen species and characterisation of additional trace gas and aerosol species during the intensive experimental period. This paper presents a summary of the measurements made within the RHaMBLe remote experiments and discusses them in their meteorological and chemical context as determined from these three platforms and from additional meteorological analyses. Air always arrived at the CVAO from the North East with a range of air mass origins (European, Atlantic and North American continental). Trace gases were present at stable and fairly low concentrations with the exception of a slight increase in some anthropogenic components in air of North American origin, though NOx mixing ratios during this period remained below 20 pptv (note the non-IUPAC adoption in this manuscript of pptv and ppbv, equivalent to pmol mol−1 and nmol mol−1 to reflect common practice). Consistency with these air mass classifications is observed in the time series of soluble gas and aerosol composition measurements, with additional identification of periods of slightly elevated dust concentrations consistent with the trajectories passing over the African continent. The CVAO is shown to be broadly representative of the wider North Atlantic marine boundary layer; measurements of NO, O3 and black carbon from the ship are consistent with a clean Northern Hemisphere marine background. Aerosol composition measurements do not indicate elevated organic material associated with clean marine air. Closer to the African coast, black carbon and NO levels start to increase, indicating greater anthropogenic influence. Lower ozone in this region is possibly associated with the increased levels of measured halocarbons, associated with the nutrient rich waters of the Mauritanian upwelling. Bromide and chloride deficits in coarse mode aerosol at both the CVAO and on D319 and the continuous abundance of inorganic gaseous halogen species at CVAO indicate significant reactive cycling of halogens. Aircraft measurements of O3 and CO show that surface measurements are representative of the entire boundary layer in the vicinity both in diurnal variability and absolute levels. Above the inversion layer similar diurnal behaviour in O3 and CO is observed at lower mixing ratios in the air that had originated from south of Cape Verde, possibly from within the ITCZ. ECMWF calculations on two days indicate very different boundary layer depths and aircraft flights over the ship replicate this, giving confidence in the calculated boundary layer depth.

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