The Australian nocturnal jet and diurnal variations of boundary-layer winds over Mt. Isa in North-eastern Australia

This volume provides the first detailed account of the Chroococcales of north-eastern Australia. It provides keys, morphological and ecological data for 6 families, 33 genera and 112 species, and photomicrographs and original illustrations to enable the identification of natural populations based on stable and recognizable characters observable with the aid of light microscopy. Distributional data are based on extensive surveys at 270 sites representing the major freshwater habitats including rivers and streams, palustrine and lacustrine wetlands, thermal springs, and man-made reservoirs in Queensland and the Northern Territory as well as a review of the Australian phycological literature.

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Some physical and chemical features of two upland crater lakes in tropical north-eastern Australia

Marine and Freshwater Research ◽

10.1071/mf97261 ◽

1999 ◽

Vol 50 (2) ◽

pp. 159 ◽

Cited By ~ 6

Author(s):

D. Walker

Keyword(s):

Thermal Stability ◽

Meteorological Data ◽

Euphotic Zone ◽

Open Water ◽

Crater Lakes ◽

Ground Temperatures ◽

Eastern Australia ◽

North Eastern ◽

Physical And Chemical ◽

Continuous Deposition

Lakes Barrine and Eacham, ~1.0 and 0.5 km2 area, 67 and 63 m depth respectively, lie at ~740 m a.s.l., ~17°S in north-eastern Australia. Seasonal changes in their volumes modelled from meteorological data correspond well with observations at Eacham. Temperature profiles through 6 years show summer stratification with a metalimnion at 20–30 m; in winter, near isothermy is usually attained. At Barrine, thermal stability varies between winter and summer (<500 and >4000 g-cm cm-2 respectively). Mixing is related to low ground temperatures during periods of generally low thermal stability; exceptionally it penetrates to >60 m. Oxygen saturation decreases from the surface to ~20% at the base of the euphotic zone (15–21 m) but oxygen is carried lower by mixing after which anoxia commonly rises to ~40 m. At Barrine, Fe-reducing redox (<200 mV) usually occurs below 50 m, but during mixing this boundary falls to within 1 m of the mud–water interface. The Barrine solution is dilute (total dissolved solids 55–58 mg L-1), and that of Eacham is more so. A concentrated monimolimnion has developed in the lowermost 2–3 m at Barrine but not at Eacham. Sedimentation at the middle of each lake results from the continuous deposition of open-water products punctuated by the redistribution of coarser detritus from the ‘shallows’ at times of deep mixing. The resultant laminations are preserved only at Barrine, protected by the chemical stability of the monimolimnion.

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Diel peroxy radicals in a semi industrial coastal area: nighttime formation of free radicals

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-19529-2012 ◽

2012 ◽

Vol 12 (8) ◽

pp. 19529-19570 ◽

Cited By ~ 1

Author(s):

M. D. Andrés-Hernández ◽

D. Kartal ◽

J. N. Growley ◽

V. Sinha ◽

E. Regelin ◽

...

Keyword(s):

Boundary Layer ◽

Trace Gases ◽

Peroxy Radical ◽

Industrial Area ◽

Diurnal Variations ◽

Peroxy Radicals ◽

Industrial Emissions ◽

Air Masses ◽

Volatile Organic ◽

Organic Trace

Abstract. Peroxy radicals were measured by a PeRCA (Peroxy Radical Chemical Amplifier) instrument in the boundary layer during the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) campaign at a coastal, forested site influenced by urban-industrial emissions in Southern Spain in late autumn. Total peroxy radicals (RO2* = HO2 + ΣRO2) generally showed a daylight maximum between 10 and 50 pptv at 13:00 UTC, with an average of 18 pptv over the 15 days of measurements. Emissions from the industrial area of Huelva often impacted the measurement site at night during the campaign. The processing of significant levels of anthropogenic organics leads to an intense nocturnal radical chemistry accompanied by formation of organic peroxy radicals at comparable levels to those of summer photochemical conditions with peak events up to 60–80 pptv. The RO2 production initiated by reactions of NO3 with organic trace gases was estimated to be significant but not sufficient to account for the concentrations of RO2* observed in air masses carrying high pollutant loading. The nocturnal production of peroxy radicals seems therefore to be dominated by ozonolysis of volatile organic compounds. RO2* diurnal variations were consistent with other HO2 measurements available at the site. HO2/RO2* ratios generally varied between 0.3 and 0.4 in all wind directions. Occasional HO2/RO2* ≥ 1 seemed to be associated with periods of high RO2* variability and with RO2 interferences in the HO2 measurement in air masses with high RO2 load.

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Lower Atmospheric Wind Dynamics as Measured by the 1290 MHz Wind Profiler Radar Located at Cardington (Lat. 52.10ºN, Long. 0.42ºE), UK and Their Comparisons with Near-by Radiosonde Instrument

Asian Journal of Advanced Research and Reports ◽

10.9734/ajarr/2020/v8i130190 ◽

2020 ◽

pp. 22-35

Author(s):

M. Satyavani ◽

P. S. Brahmanandam ◽

P. S. V. Subba Rao ◽

M. P. Rao

Keyword(s):

Remote Sensing ◽

Boundary Layer ◽

Wind Speed ◽

Universal Time ◽

Diurnal Variations ◽

Wind Profiler ◽

Independent Observations ◽

Wind Profiler Radar

This study reports diurnal variations of wind directions, wind speed of vector winds, and the evolution of boundary layer (BL) over a mid-latitude measured using a transportable 1290 MHz wind profiling radar located at Cardington (Lat. 52.10ºN; Long. 0.42ºE), Bedfordshire, UK from 17 to 28 April 2010. The horizontal winds show benign behavior during nighttime hours, while winds during daytime hours had magnitudes around, on average, 10-20 m/s, in the majority of the cases. The heights of the boundary layer (BL) varied from as low as ~1100 m to ~2600 km and BL height had shown to have evolved from 0700 universal time (UT) onwards and collapsed by 0000 UT. Besides, a comparison made between winds measured by the 1290 MHz radar and near-by radiosonde showed a moderate similitude between them, albeit a few discrepancies are found in wind directions and speeds. The possible reasons for these discrepancies could be different volume sensing of observations of these independent observations. An attempt is, therefore, made to calculate radiosonde balloon drifts [1] for the ascending node of the balloons, which had confirmed that the balloons often drifted horizontally as long as up to 100 km. The large drifts, most probably, are the possible reasons for the mismatching of winds measured by these two independent remote sensing instruments.

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