scholarly journals Long-range atmospheric transport of terrestrial biomarkers to the western North Atlantic

2002 ◽  
Vol 16 (4) ◽  
pp. 89-1-89-17 ◽  
Author(s):  
Maureen H. Conte ◽  
J. C. Weber
Keyword(s):  
Long Range ◽  
North Atlantic ◽  
Atmospheric Transport

scholarly journals Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC<sup>4</sup>A

2021 ◽  
Author(s):  
Leonie Villiger ◽  
Heini Wernli ◽  
Maxi Boettcher ◽  
Martin Hagen ◽  
Franziska Aemisegger
Keyword(s):  
Long Range ◽  
North Atlantic ◽  
Large Scale ◽  
Cold Front ◽  
Trade Wind ◽  
Long Range Transport ◽  
The North ◽  
Range Transport ◽  
The North Atlantic ◽  
The Tropics

Abstract. Shallow clouds in the trade-wind region over the North Atlantic contribute substantially to the global radiative budget. In the vicinity of the Caribbean island Barbados, they appear in different mesoscale organisation patterns with distinct net cloud radiative effects (CRE). Cloud formation processes in this region are typically controlled by the prevailing large-scale subsidence. However, occasionally weather systems from remote origin cause significant disturbances. This study investigates the complex cloud-circulation interactions during the field campaign EUREC4A (Elucidate the Couplings Between Clouds, Convection and Circulation) from 16 January to 20 February 2020, using a combination of Eulerian and Lagrangian diagnostics. Based on observations and ERA5 reanalyses, we identify the relevant processes and characterise the formation pathways of two moist anomalies above the Barbados Cloud Observatory (BCO), one in the lower (~1000–650 hPa) and one in the middle troposphere (~650–300 hPa). These moist anomalies are associated with strongly negative CRE values and with contrasting long-range transport processes from the extratropics and the tropics, respectively. The low-level moist anomaly is characterised by an unusually thick cloud layer, high precipitation totals and a strongly negative CRE. Its formation is connected to an “extratropical dry intrusion” (EDI) that interacts with a trailing cold front. A quasi-climatological (2010–2020) analysis reveals that EDIs lead to different conditions at the BCO depending on how they interact with the associated cold front. Based on this climatology, we discuss the relevance of the strong large-scale forcing by EDIs for the low-cloud patterns near the BCO and the related CRE. The second case study about the mid-tropospheric moist anomaly is associated with an extended and persistent mixed-phase shelf cloud and the lowest daily CRE value observed during the campaign. Its formation is linked to “tropical mid-level detrainment” (TMD), which refers to detrainment from tropical deep convection near the melting layer. The quasi-climatological analysis shows that TMDs consistently lead to mid-tropospheric moist anomalies over the BCO and that the detrainment height controls the magnitude of the anomaly. However, no systematic relationship was found between the amplitude of this mid-tropospheric moist anomaly and the CRE at the BCO. Overall, this study reveals the important impact of the long-range transport, driven by dynamical processes either in the extratropics or the tropics, on the variability of the vertical structure of moisture and clouds, and on the resulting CRE in the North Atlantic winter trades.

Evaluation of the Effect of Horizontal Diffusion on the Long-Range Atmospheric Transport Simulation with Chernobyl Data

1995 ◽  
Vol 34 (7) ◽  
pp. 1653-1665 ◽  
Author(s):  
Hirohiko Ishikawa
Keyword(s):  
Long Range ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Mean Square Displacement ◽  
Empirical Formulas ◽  
Measured Concentration ◽  
Transport Simulation ◽  
Horizontal Diffusion ◽  
Low Concentrations ◽  
Lagrangian Particle Transport

Abstract The effect of horizontal diffusion on the long-range transport simulation is examined with a Lagrangian particle transport model. The transport of radioactivity released from Chernobyl is simulated by the model with different values of horizontal diffusivity. The computed concentrations are statistically compared with measured concentration. The best simulation is found when the magnitude of the horizontal diffusivity is between 3.3 × 104 and 1.0 × 105 m2 s−1. The performance of empirical formulas of horizontal diffusion, in which mean-square displacement σy is specified as a function of time, is also examined. A part of measured concentrations, which are relatively low concentrations, cannot be explained by transport and diffusion only. It is shown that these measured concentrations can be explained by resuspension of deposited radioactivity.

Long-range atmospheric transport of PAHs, PCBs and PBDEs to the central and eastern Mediterranean and changes of PCB and PBDE congener patterns in summer 2010

2015 ◽  
Vol 111 ◽  
pp. 51-59 ◽  
Author(s):  
Marie D. Mulder ◽  
Angelika Heil ◽  
Petr Kukučka ◽  
Jan Kuta ◽  
Petra Přibylová ◽  
...  
Keyword(s):  
Long Range ◽  
Atmospheric Transport ◽  
Eastern Mediterranean ◽  
Pbde Congener

scholarly journals Decadal-scale variability in long-range atmospheric transport to the Summit of the Greenland Ice Sheet

1999 ◽  
Vol 26 (4) ◽  
pp. 481-484 ◽  
Author(s):  
Jonathan D. W. Kahl ◽  
Jennifer A. Galbraith ◽  
Dewayne A. Martinez
Keyword(s):  
Long Range ◽  
Atmospheric Transport ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Decadal Scale

scholarly journals Virus-Like Particle Production in Atmospheric Eubacteria Isolates

Atmosphere ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 417 ◽  
Author(s):  
Teigell-Perez ◽  
Gonzalez-Martin ◽  
Valladares ◽  
Smith ◽  
Griffin
Keyword(s):  
Sea Level ◽  
Long Range ◽  
Particle Production ◽  
Atmospheric Transport ◽  
Lower Atmosphere ◽  
Rates Of Evolution ◽  
Virus Like Particle ◽  
The Pacific ◽  
High Prevalence ◽  
Mid Atlantic Ridge

Culturable eubacterial isolates were collected at various altitudes in Earth’s atmosphere, including ~1.5 m above ground in Tallahassee, FL, USA; ~10.0 m above sea level over the mid-Atlantic ridge (~15° N); ~ 20 km above ground over the continental United States; ~20 km above sea level over the Pacific Ocean near southern California; and from the atmosphere of Carlsbad Cavern, Carlsbad Cavern National Park, NM, USA. Isolates were screened for the presence of inducible virus-like particles (VLP) through the use of mitomycin C and epifluorescent direct counts. We determined that 92.7% of the isolates carried inducible VLP counts in exposed versus non-exposed culture controls and that the relationship was statistically significant. Further statistical analyses revealed that the number of isolates that demonstrated VLP production did not vary among collection sites. These data demonstrate a high prevalence of VLP generation in isolates collected in the lower atmosphere and at extreme altitudes. They also show that species of eubacteria that are resistant to the rigors of atmospheric transport play a significant role in long-range atmospheric inter- and intra-continental dispersion of VLP and that long-range atmospheric transport of VLP may enhance rates of evolution at the microbial scale in receiving environments.

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