The vertical distribution of large aerosols in the marine atmospheric surface layer

1999 ◽  
Vol 30 ◽  
pp. S59-S60 ◽  
Author(s):  
Alexander M.J. van Eijk ◽  
Gerrit De Leeuw ◽  
Stuart G. Gathman
Keyword(s):  
Surface Layer ◽  
Vertical Distribution ◽  
Atmospheric Surface Layer ◽  
The Vertical Distribution

scholarly journals Linking Meteorology, Turbulence, and Air Chemistry in the Amazon Rain Forest

2016 ◽  
Vol 97 (12) ◽  
pp. 2329-2342 ◽  
Author(s):  
Jose D. Fuentes ◽  
Marcelo Chamecki ◽  
Rosa Maria Nascimento dos Santos ◽  
Celso Von Randow ◽  
Paul C. Stoy ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Surface Layer ◽  
Vertical Distribution ◽  
Rain Forest ◽  
Forest Canopy ◽  
Cloud Condensation Nuclei ◽  
Chemical Species ◽  
Chemical Transformations ◽  
Condensation Nuclei ◽  
The Vertical Distribution

Abstract We describe the salient features of a field study whose goals are to quantify the vertical distribution of plant-emitted hydrocarbons and their contribution to aerosol and cloud condensation nuclei production above a central Amazonian rain forest. Using observing systems deployed on a 50-m meteorological tower, complemented with tethered balloon deployments, the vertical distribution of hydrocarbons and aerosols was determined under different boundary layer thermodynamic states. The rain forest emits sufficient reactive hydrocarbons, such as isoprene and monoterpenes, to provide precursors of secondary organic aerosols and cloud condensation nuclei. Mesoscale convective systems transport ozone from the middle troposphere, enriching the atmospheric boundary layer as well as the forest canopy and surface layer. Through multiple chemical transformations, the ozone-enriched atmospheric surface layer can oxidize rain forest–emitted hydrocarbons. One conclusion derived from the field studies is that the rain forest produces the necessary chemical species and in sufficient amounts to undergo oxidation and generate aerosols that subsequently activate into cloud condensation nuclei.

scholarly journals AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun†

2016 ◽  
Vol 74 (9) ◽  
pp. 2342-2353 ◽  
Author(s):  
Maxime Geoffroy ◽  
Finlo R Cottier ◽  
Jørgen Berge ◽  
Mark E Inall
Keyword(s):  
Surface Layer ◽  
Vertical Distribution ◽  
Autonomous Vehicles ◽  
Autonomous Underwater Vehicle ◽  
Atlantic Water ◽  
The Arctic ◽  
Backscatter Signal ◽  
Spatial Coverage ◽  
Acoustic Instruments ◽  
The Vertical Distribution

Abstract An autonomous underwater vehicle (AUV) carrying 614 kHz RDI acoustic doppler current profilers (ADCPs) was deployed at four locations over the West Spitsbergen outer shelf in July 2010. The backscatter signal recorded by the ADCPs was extracted and analysed to investigate the vertical distribution and patchiness of pelagic organisms during midnight sun. At the northernmost locations (Norskebanken and Woodfjorden), fresher and colder water prevailed in the surface layer (0–20 m) and scatterers (interpreted as zooplankton and micronekton) were mainly distributed below the pycnocline. In contrast, more saline and warmer Atlantic Water dominated the surface layer at Kongsfjordbanken and Isfjordbanken and scatterers were concentrated in the top 20 m, above the pycnocline. Pelagic scatterers formed patchy aggregations at all locations, but patchiness generally increased with the density of organisms and decreased at depths >80 m. This study contributes to our understanding of the vertical distribution of pelagic organisms in the Arctic, and the spatial coverage of the AUV has extended early acoustic studies limited to Arctic fjords from 1D observations to a broader offshore coverage. Neither synchronized nor unsynchronized vertical migrations were detected, but autonomous vehicles with limited autonomy (<1 day) may not be as effective as long-term mooring deployments or long-range AUVs to study vertical migrations. Short-term AUV-based acoustic surveys of the pelagic communities are nonetheless highly complementary to Eulerian studies, in particular by providing spatial measurements of patchiness. Compared with ship-based or moored acoustic instruments, the 3D trajectory of AUVs also allows using acoustic instruments with higher frequencies and better size resolution, as well as the detection of organisms closer to the surface.

scholarly journals The Vertical Distribution of Sediment Archaeal Community in the “Black Bloom” Disturbing Zhushan Bay of Lake Taihu

Archaea ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xianfang Fan ◽  
Peng Xing
Keyword(s):  
Surface Layer ◽  
Vertical Distribution ◽  
Lake Taihu ◽  
Archaeal Community ◽  
Cyanobacterial Blooms ◽  
Bloom Formation ◽  
Significant Difference ◽  
Different Depths ◽  
Biomass Transformation ◽  
The Vertical Distribution

Using the Illumina sequencing technology, we investigated the vertical distribution of archaeal community in the sediment of Zhushan Bay of Lake Taihu, where the black bloom frequently occurred in summer. Overall, the Miscellaneous Crenarchaeotal Group (MCG), Deep Sea Hydrothermal Vent Group 6 (DHVEG-6), andMethanobacteriumdominated the archaeal community. However, we observed significant difference in composition of archaeal community among different depths of the sediment. DHVEG-6 dominated in the surface layer (0–3 cm) sediment.Methanobacteriumwas the dominating archaeal taxa in the L2 (3–6 cm) and L3 (6–10) sediment. MCG was most abundant in the L4 (10–15 cm) and L5 (15–20 cm) sediment. Besides, DHVEG-6 was significantly affected by the concentration of total phosphorus (TP). And loss on ignition (LOI) was an important environmental factor forMethanobacterium. As the typical archaeal taxa in the surface layer sediment, DHVEG-6 andMethanobacteriummight be more adapted to abundant substrate supply from cyanobacterial blooms and take active part in the biomass transformation. We propose that DHVEG-6 andMethanobacteriumcould be the key archaeal taxa correlated with the “black bloom” formation in Zhushan Bay.

scholarly journals Study of vertical distribution of zooplankton in Zaporozhskoye Reservoir aiming to calculate bighead carp stocking

2018 ◽  
Vol 3 (3) ◽  
pp. 57-69
Author(s):  
V. A. Yakovenko ◽  
E. Yu. Zaychenko
Keyword(s):  
Surface Layer ◽  
Vertical Distribution ◽  
Vertical Section ◽  
Stocking Density ◽  
Planktivorous Fish ◽  
Bighead Carp ◽  
Economic Losses ◽  
Forage Base ◽  
The Vertical Distribution ◽  
Zooplankton Production

The article focuses on the vertical distribution of zooplankton because of its importance for calculation of bighead carp stocking the Zaporozhskoye Reservoir. The reservoir is a water-body of complex use with fish catching being one of the priorities of the reservoir. Zooplankton is an important component of fish forage base, so accurate quantitation of zooplankton development is necessary for improving efficiency of forage base use of the reservoir by means of appropriate stocking with fish. These indicators depend significantly on the depth of the reservoir and can vary through the vertical section. At the same time, almost all investigations of the reservoir were aimed at studying the indicators of zooplankton development in the surface layer which can led to inaccurate calculations concerning the stocking of the reservoir with planktivorous fish. Therefore, the purpose of this work was not only to study the vertical distribution of zooplankton of the Zaporozhskoye Reservoir, but also to calculate the zooplankton production and the corresponding rates of stocking the reservoir with bighead carp. In summer and autumn periods, the heterogeneous vertical distribution of zooplankton was found in both parts of the reservoir. In the upper part of the reservoir, the maximum values of zooplankton development were observed in the surface and near-bottom layers whereas in the lower part of the reservoir – in the surface layer and at the depth of 10 m. Since conditions of the upper part of the reservoir are unfavorable for bighead carp, and the estimated value of the stocking density (0.3 spec.·ha-1) is negligible, no stocking of this part of the reservoir with the indicated planktivorous fish is expected. When calculating the stocking based on the zooplankton production in the surface layer only, but not in the whole water column, almost double overvaluation obtained (excess would be 246.8 thousand specimens) would lead to economic losses because of the wasteful expenditure of stocked material due to a lack of food resources. For effective utilization of zooplankton as the food base it is advisable to stock the lower part of the reservoir with two-year-old bighead carps with the stocking density of 19.1 spec.·ha-1.

EVALUATIONS OF INVENTORY AND ACTIVITY CONCENTRATION OF RADIOCESIUM IN SOIL AT A RESIDENTIAL HOUSE 3 YEARS AFTER THE FUKUSHIMA NUCLEAR ACCIDENT

2019 ◽  
Vol 184 (3-4) ◽  
pp. 518-522
Author(s):  
M Hosoda ◽  
W Hozumi ◽  
N Akata ◽  
A Endo ◽  
K Kelleher ◽  
...  
Keyword(s):  
Surface Layer ◽  
Vertical Distribution ◽  
Surface Runoff ◽  
Activity Concentration ◽  
Lower Layer ◽  
Ground Surface ◽  
Soil Samples ◽  
Short Period ◽  
Residential House ◽  
The Vertical Distribution

Abstract Soil samples from the surface to a 5 cm depth were collected at a residential house in Koriyama City, Fukushima Prefecture using a scraper plate every three months from March 2014 to September 2014 to evaluate the vertical distribution profiles and inventories of 134Cs and 137Cs in soil. The vertical distribution profiles of radiocesium (134Cs and 137Cs) in soil showed that greater than 86% of the total radiocesium was absorbed in the upper 2 cm 3 years after the accident. Radiocesium in the surface layer seems to move to the lower layer over time. The migration of radiocesium in surface layer might be influenced by the ground surface runoff by rainfall. Radiocesium inventories in June increased significantly over the short period between March and June. In contrast, the radiocesium inventories in September did not increase significantly compared to the values in June. Radiocesium resuspension and deposition caused by decontamination work and meteorological events might be one possible reason for the increased radiocesium inventories observed in June.

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