scholarly journals Compositional variations of sea-salt-mode aerosol particles from the North Atlantic

1995 ◽  
Vol 100 (D11) ◽  
pp. 23063 ◽  
Author(s):  
Mihály Pósfai ◽  
James R. Anderson ◽  
Peter R. Buseck ◽  
Herman Sievering
Keyword(s):  
North Atlantic ◽  
Aerosol Particles ◽  
Sea Salt ◽  
The North ◽  
The North Atlantic ◽  
Compositional Variations

scholarly journals Decadal-scale progression of the onset of Dansgaard–Oeschger warming events

2019 ◽  
Vol 15 (2) ◽  
pp. 811-825 ◽  
Author(s):  
Tobias Erhardt ◽  
Emilie Capron ◽  
Sune Olander Rasmussen ◽  
Simon Schüpbach ◽  
Matthias Bigler ◽  
...  
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Ice Core ◽  
Sea Salt ◽  
Meridional Overturning Circulation ◽  
Proxy Records ◽  
The North ◽  
Decadal Scale ◽  
The North Atlantic ◽  
North Greenland

Abstract. During the last glacial period, proxy records throughout the Northern Hemisphere document a succession of rapid millennial-scale warming events, called Dansgaard–Oeschger (DO) events. A range of different mechanisms has been proposed that can produce similar warming in model experiments; however, the progression and ultimate trigger of the events are still unknown. Because of their fast nature, the progression is challenging to reconstruct from paleoclimate data due to the limited temporal resolution achievable in many archives and cross-dating uncertainties between records. Here, we use new high-resolution multi-proxy records of sea-salt (derived from sea spray and sea ice over the North Atlantic) and terrestrial (derived from the central Asian deserts) aerosol concentrations over the period 10–60 ka from the North Greenland Ice Core Project (NGRIP) and North Greenland Eemian Ice Drilling (NEEM) ice cores in conjunction with local precipitation and temperature proxies from the NGRIP ice core to investigate the progression of environmental changes at the onset of the warming events at annual to multi-annual resolution. Our results show on average a small lead of the changes in both local precipitation and terrestrial dust aerosol concentrations over the change in sea-salt aerosol concentrations and local temperature of approximately one decade. This suggests that, connected to the reinvigoration of the Atlantic meridional overturning circulation and the warming in the North Atlantic, both synoptic and hemispheric atmospheric circulation changes at the onset of the DO warming, affecting both the moisture transport to Greenland and the Asian monsoon systems. Taken at face value, this suggests that a collapse of the sea-ice cover may not have been the initial trigger for the DO warming.

scholarly journals Decadal-scale progression of Dansgaard-Oeschger warming events

2018 ◽  
Author(s):  
Tobias Erhardt ◽  
Emilie Capron ◽  
Sune Olander Rasmussen ◽  
Simon Schüpbach ◽  
Matthias Bigler ◽  
...  
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Environmental Changes ◽  
Ice Cores ◽  
Sea Salt ◽  
Meridional Overturning Circulation ◽  
Proxy Records ◽  
The North ◽  
Decadal Scale ◽  
The North Atlantic

Abstract. During the last glacial period, proxy records throughout the Northern Hemisphere document a succession of rapid millennial-scale warming events, called Dansgaard-Oeschger (DO) events. A range of different mechanisms have been proposed that can produce similar warming in model experiments, however the progression and ultimate trigger of the events is still unknown. Because of their fast nature, the progression is challenging to reconstruct from paleoclimate data due to the limited temporal resolution achievable in many archives and cross-dating uncertainties between records. Here we use new high-resolution multi-proxy records of sea-salt (derived from sea spray and sea ice over the North Atlantic) and terrestrial (derived from the Central Asian deserts) aerosol concentrations over the period 10–60 ka from the Greenland NGRIP and NEEM ice cores in conjunction with local precipitation and temperature proxies from one of the cores to investigate the progression of environmental changes at the onset of the warming events at annual to multi-annual resolution. Our results show on average a small lead of the changes in both local precipitation and terrestrial dust aerosol concentrations over the change in sea-salt aerosol concentrations and local temperature of approximately one decade. This suggests that, connected to the reinvigoration of the Atlantic Meridional Overturning Circulation and the warming in the North Atlantic, both synoptic and hemispheric atmospheric circulation change at the onset of the DO warming, affecting both the moisture transport to Greenland and the Asian monsoon systems. Taken at face value, this suggests that a collapse of the sea-ice cover was not the initial trigger for the DO events.

scholarly journals Influences of atmospheric transport pathways on radionuclide activities in aerosol particles from over the North Atlantic

1999 ◽  
Vol 104 (D17) ◽  
pp. 21301-21316 ◽  
Author(s):  
R. Arimoto ◽  
J. A. Snow ◽  
W. C. Graustein ◽  
J. L. Moody ◽  
B. J. Ray ◽  
...  
Keyword(s):  
North Atlantic ◽  
Atmospheric Transport ◽  
Aerosol Particles ◽  
Transport Pathways ◽  
The North ◽  
The North Atlantic

scholarly journals Impact of North America on the aerosol composition in the North Atlantic free troposphere

2017 ◽  
Vol 17 (12) ◽  
pp. 7387-7404 ◽  
Author(s):  
M. Isabel García ◽  
Sergio Rodríguez ◽  
Andrés Alastuey
Keyword(s):  
Organic Matter ◽  
North America ◽  
North Atlantic ◽  
North American ◽  
Sea Salt ◽  
Free Troposphere ◽  
Aerosol Composition ◽  
The North ◽  
The North Atlantic

Abstract. In the AEROATLAN project we study the composition of aerosols collected over  ∼  5 years at Izaña Observatory (located at  ∼  2400 m a.s.l. in Tenerife, the Canary Islands) under the prevailing westerly airflows typical of the North Atlantic free troposphere at subtropical latitudes and midlatitudes. Mass concentrations of sub-10 µm aerosols (PM10) carried by westerly winds to Izaña, after transatlantic transport, are typically within the range 1.2 and 4.2 µg m−3 (20th and 80th percentiles). The main contributors to background levels of aerosols (PM10 within the 1st–50th percentiles  =  0.15–2.54 µg m−3) are North American dust (53 %), non-sea-salt sulfate (14 %) and organic matter (18 %). High PM10 events (75th–95th percentiles  ≈  4.0–9.0 µg m−3) are prompted by dust (56 %), organic matter (24 %) and non-sea-salt sulfate (9 %). These aerosol components experience a seasonal evolution explained by (i) their spatial distribution in North America and (ii) the seasonal shift of the North American outflow, which migrates from low latitudes in winter (∼  32° N, January–March) to high latitudes in summer (∼  52° N, August–September). The westerlies carry maximum loads of non-sea-salt sulfate, ammonium and organic matter in spring (March–May), of North American dust from midwinter to mid-spring (February–May) and of elemental carbon in summer (August–September). Our results suggest that a significant fraction of organic aerosols may be linked to sources other than combustion (e.g. biogenic); further studies are necessary for this topic. The present study suggests that long-term evolution of the aerosol composition in the North Atlantic free troposphere will be influenced by air quality policies and the use of soils (potential dust emitter) in North America.

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