Nutrient Dynamics in the North Basin of Lake Biwa: I. Changes in the Vertical Distribution of Nutrients Due To an Internal Surge Induced by a Strong Typhoon

1996 ◽  
Vol 22 (2) ◽  
pp. 331-340 ◽  
Author(s):  
Toyoaki Aoki ◽  
Yuichi Hayami ◽  
Tateki Fujiwara ◽  
Hiroshi Mukai ◽  
Yoshimitsu Tanaka
Keyword(s):  
Vertical Distribution ◽  
Nutrient Dynamics ◽  
Lake Biwa ◽  
The North ◽  
The Vertical Distribution

scholarly journals Vertical distribution of sub-micron aerosol chemical composition from North-Western Europe and the North-East Atlantic

2009 ◽  
Vol 9 (2) ◽  
pp. 9117-9150
Author(s):  
W. T. Morgan ◽  
J. D. Allan ◽  
K. N. Bower ◽  
G. Capes ◽  
J. Crosier ◽  
...  
Keyword(s):  
Organic Matter ◽  
Chemical Composition ◽  
Vertical Distribution ◽  
Western Europe ◽  
Vertical Profiles ◽  
East Atlantic ◽  
Air Masses ◽  
North East ◽  
The North ◽  
The Vertical Distribution

Abstract. A synthesis of UK based airborne in-situ measurements of aerosol properties representing air masses from North-West Europe and the North-East Atlantic is presented. The major focus of the study is the vertical distribution of sub-micron aerosol chemical composition. Vertical profiles are derived from a Quadrupole Aerosol Mass Spectrometer (Q-AMS). Background sub-micron aerosol vertical profiles are identified and are primarily composed of organic matter and sulphate aerosol. Such background conditions occurred predominantly during periods associated with long-range air mass transport across the Atlantic. These instances may serve as useful model input of aerosol to Western Europe. Increased mass concentration episodes are coincident with European outflow and periods of stagnant/recirculating air masses. Such periods are characterised by significantly enhanced concentrations of nitrate aerosol relative to those of organic matter and sulphate. Periods of enhanced ground level PM2.5 loadings are coincident with instances of high nitrate mass fractions measured on-board the aircraft, indicating that nitrate is a significant contributor to regional pollution episodes. The vertical structure of the sulphate and organic aerosol profiles were shown to be primarily driven by large-scale dynamical processes. The vertical distribution of nitrate is likely determined by both dynamic and thermodynamic processes, with chemical partitioning of gas phase precursors to the particle phase occurring at lower temperatures at the top of the boundary layer. Such effects have profound implications for the aerosol's lifetime and subsequent impacts, highlighting the requirement for accurate representation of the aerosol vertical distribution.

Vertical distribution of cephalopods at 40°N, 53°N and 60°N at 20°W in the North Atlantic

1975 ◽  
Vol 55 (1) ◽  
pp. 143-163 ◽  
Author(s):  
C. C. Lu ◽  
M. R. Clarke
Keyword(s):  
Vertical Distribution ◽  
North Atlantic ◽  
The North ◽  
The North Atlantic ◽  
The Mediterranean ◽  
The 1960S ◽  
The Vertical Distribution

Little work on vertical distribution of cephalopods was possible before the development, in the 1960s, of sophisticated opening-closing devices usable on midwater trawls such as the 10 ft Isaacs Kidd trawl (IKMT; Foxton, 1963; Aron et al. 1964) and the series of rectangular midwater trawls developed by the Institute of Oceanographic Sciences (previously the National Institute of Oceanography) (Clarke, 1969 a; Baker et al. 1973). These developments have resulted in three papers on vertical distribution of cephalopods in the North Atlantic (Clarke, 1969 ft; Gibbs & Roper, 1970; Clarke & Lu, 1974) and one for the Mediterranean (Roper, 1972). The present paper describes the vertical distribution of cephalopods caught at 40° N 20° W, 53° N 20° W and 60° N 20° W in the North Atlantic based upon day and night series of horizontal hauls between the surface and 2000 m using the RMT combination net (Baker et al. 1973).

Vertical distribution, seasonality and troposphericity of ice-supersaturated air masses in the northern mid-latitudes from regular in-situ observations by passenger aircraft

2020 ◽  
Author(s):  
Andreas Petzold ◽  
Susanne Rohs ◽  
Mihal Rütimann ◽  
Patrick Neis ◽  
Berkes Florian ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Vertical Distribution ◽  
North Atlantic ◽  
Observation Data ◽  
European Research ◽  
Air Masses ◽  
The North ◽  
The North Atlantic ◽  
Passenger Aircraft ◽  
The Vertical Distribution

<p>The vertical distribution and seasonal variation of water vapour volume mixing ratio (H<sub>2</sub>O VMR), relative humidity with respect to ice (RH<sub>ice</sub>) and particularly of regions with ice-supersaturated air masses (ISSR) in the extratropical upper troposphere and lowermost stratosphere are investigated at northern mid-latitudes over the regions Eastern North America, the North Atlantic and Europe for the period 1995 to 2010.</p><p>Observation data originate from regular and continuous long-term measurements of H<sub>2</sub>O VMR, temperature and RH<sub>ice</sub> by instrumented passenger aircraft in the framework of the European research program MOZAIC which is continued as European research infrastructure IAGOS (from 2011; see www.iagos.org). The observation data are analysed with respect to the thermal and dynamical tropopauses, as provided by ERA-Interim. Additionally, collocated O<sub>3</sub> observations from MOZAIC are used as tracer for stratospheric air masses.</p><p>Our key results provide in-depth insight into seasonal and regional variability and tropospheric nature of ice-supersaturated air masses at various distances from the tropopause layer. For the vertical distribution and seasonal variation of ISSR occurrence we show a comparison of our results to radio soundings and to satellite observations of cirrus cloud occurrence from AIRS and TOVs Path B instruments. Finally, for all three regions, we investigate the trends and the dependencies of ISSR occurrence on the North Atlantic Oscillation (NAO) index.</p>

Observations on the Vertical Distribution of the Genus Acanthephyra (Crustacea: Decapoda) in the eastern North Atlantic, with particular reference to Species of the ‘purpurea’ Group.

1972 ◽  
Vol 73 ◽  
pp. 301-313 ◽  
Author(s):  
P. Foxton
Keyword(s):  
Vertical Distribution ◽  
North Atlantic ◽  
South Atlantic ◽  
The North ◽  
Mesopelagic Zone ◽  
Vertical Distributions ◽  
The North Atlantic ◽  
Eastern North Atlantic ◽  
The Vertical Distribution ◽  
Mesopelagic Species

SynopsisThe vertical distribution of pelagic decapods has been investigated at six positions, each located approximately at 10° interval of latitude between 11°N and 60°N in the eastern North Atlantic. An account of the day and night depth distribution of four mesopelagic species, Acanthephyra purpurea, A. pelagica, A. sexspinosa and A. acanthitelsonis, and four bathypelagic species, A. prionota, A. curtirostris, A. acutifrons and A. stylorostratis, is presented. The four mesopelagic species have vertical distributions which vary latitudinally in association with geographical gradients in temperature, the mesopelagic zone from about the latitude of 28°N cooling both polewards and equatorwards. It is concluded that environmental temperature is a major factor in controlling the vertical ranges of these species although other physical variables, principally light, must also be involved.A faunal boundary exists in the region of 18°N, where the North Atlantic species A. purpurea and A.pelagica are replaced by the Central and South Atlantic species A. sexspinosa and A. acanthitelsonis. The nature of the physical boundary is not clear, but it is tentatively proposed that it represents a relatively broad area where the North Atlantic Central Water and South Atlantic Central Water meet.

scholarly journals The vertical distribution and abundance of Chthamalus stellatus Poli and Chthamalus montagui Southward (Crustacea, Cirripedia) at two localities of the Istrian peninsula coast (North Adriatic)

2017 ◽  
Vol 58 (1) ◽  
pp. 77-88
Author(s):  
Nataša Dolenc-Orbanić ◽  
Claudio Battelli
Keyword(s):  
Vertical Distribution ◽  
Adriatic Sea ◽  
Spatial Scales ◽  
Tidal Range ◽  
Rocky Shores ◽  
Tidal Level ◽  
The North ◽  
Chthamalus Montagui ◽  
The Vertical Distribution ◽  
North Adriatic Sea

Two species of chthamalid barnacles are well established from the upper to the lower limit of the midlittoral zone on the rocky shores of the North Adriatic Sea: Chthamalus stellatus, Poli and Chthamalus montagui, Southward. The present study deals with the vertical distribution and abundance for each species at two localities of the Istrian peninsula coast (North Adriatic Sea). For this purpose chthamalid populations were monitored in 2015 along the Slovenian marine coast (Bay of Koper, Gulf of Trieste) and along the Croatian marine coast, near Rovinj (west Istrian coast), both on limestone. The main aim of the study was to establish if there was a relationship between the vertical distribution and abundance of these two species at different spatial scales: small (between sites, about 1 kilometer) and large (between localities, 10s of kilometers). The selected localities are slightly different in tidal range, in orientation and wave exposure. Three sites were randomly selected at each locality and two transects per tidal level (upper, middle and lower) were chosen on each site. The abundance of each chthamalids species in 1 dm2 plots was determined at three different tidal levels along each transect. The results indicated that the vertical distribution of C. montagui and C. stellatus was very similar between localities and even among sites, but their abundance varied. At both localities, C. montagui was more abundant in the upper and middle tidal levels, while C. stellatus was more abundant at the lower tidal level. It was also found that C. montagui was more abundant in sheltered conditions (Bay of Koper), while C. stellatus on the coast more exposed to the wave action (near Rovinj), at all tidal levels.

Distribution of DDTs in the Sediment of Lake Biwa

1992 ◽  
Vol 25 (11) ◽  
pp. 93-98
Author(s):  
K. Kawabe ◽  
A. Maegawa ◽  
S. Yamanaka ◽  
K. Nomura
Keyword(s):  
Vertical Distribution ◽  
Lake Biwa ◽  
Southern Basin ◽  
The Past ◽  
Northern Basin ◽  
The Vertical Distribution

An investigation was carried out to determine the residual tendency of DDT and its derivatives in the sediment of Lake Biwa, Japan, where the banning of DDT took effect some 15 years ago. Of the two basins shaping Lake Biwa, the frequency of detection of DDT was higher in the Northern Basin than in the Southern Basin. In the Southern Basin, the area of DDT detection was more confined than that of DDE detection. Therefore, it is reasonable to assume that DDT has been decomposing more rapidly in the Southern Basin than in the Northern Basin. Based on the profile obtained for the vertical distribution of DDTs, it can be inferred also that the amount of DDT and DDE flowing in from land has been decreasing in the past years. DDT has hardly been decomposing into DDE at the deeper part of the Lake.

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