scholarly journals Freak waves - more frequent than rare!

2004 ◽  
Vol 22 (5) ◽  
pp. 1839-1842 ◽  
Author(s):  
P. C. Liu ◽  
U. F. Pinho
Keyword(s):  
Atlantic Ocean ◽  
Surface Waves ◽  
Key Words ◽  
Atmospheric Dynamics ◽  
South Atlantic Ocean ◽  
Freak Waves ◽  
Meteorology And Atmospheric Dynamics ◽  
Wave Measurements ◽  
Waves And Tides ◽  
Made In

Abstract. Contrary to the widely held notion that considers the occurrence of freak waves in the ocean as being rare, from an examination of five years of wave measurements made in the South Atlantic Ocean, we found the occurrence of freak waves is actually more frequent than rare. Key words. Meteorology and atmospheric dynamics (waves and tides) – Oceanography: physical (surface waves and tides; air-sea interaction)

scholarly journals Unexpectedly small semidiurnal tidal wind amplitudes in the mid-latitudemesopause region during September 2002

2004 ◽  
Vol 22 (2) ◽  
pp. 701-704 ◽  
Author(s):  
D. Kürschner ◽  
Ch. Jacobi
Keyword(s):  
Phase Transition ◽  
Key Words ◽  
Central Europe ◽  
Annual Cycle ◽  
Middle Atmosphere ◽  
Atmospheric Dynamics ◽  
Mesopause Region ◽  
Meteorology And Atmospheric Dynamics ◽  
Middle Atmosphere Dynamics ◽  
Waves And Tides

Abstract. The mesopause region monthly mean winds and semidiurnal tidal amplitudes and phases over Central Europe have been measured at Collm Observatory since September 1982. The regular annual cycle of the semidiurnal tidal amplitudes show maximum values during late August and September. In contrast to that, in autumn 2002 no enhancement of the tidal amplitudes was measured, while the autumn tidal phase transition occurred unusually early. Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides; climatology)

scholarly journals An explanation for some fallstreak clouds

2002 ◽  
Vol 20 (5) ◽  
pp. 711-715 ◽  
Author(s):  
R. M. Worthington
Keyword(s):  
Radar Data ◽  
Atmospheric Dynamics ◽  
Atmospheric Composition ◽  
Cloud Physics ◽  
Mountain Wave ◽  
Mountain Waves ◽  
Meteorology And Atmospheric Dynamics ◽  
Composition And Structure ◽  
Waves And Tides ◽  
Stratospheric Clouds

Abstract. Fallstreak cirrus clouds are associated with super-saturated air, together with waves, instabilities and/or turbulence; however, their precise cause is usually uncertain. This paper uses already-published satellite, radiosonde and radar data, reanalysed to study some large fallstreaks which had been previously overlooked. The fallstreaks – up to 60 km long with a parent cloud 20 km wide – are caused by lifting and/or turbulence from a mountain wave, rather than, for example, Kelvin-Helmholtz instabilities. If turbulent breaking of mountain waves affects ice particle formation, this may be relevant for the seeder-feeder effect on orographic rain, and the efficiency of mountain-wave polar stratospheric clouds for ozone depletion.Key words. Meteorology and atmospheric dynamics (turbulence; waves and tides) – Atmospheric composition and structure (cloud physics and chemistry)

scholarly journals Planetary wave activity in the lower ionosphere during CRISTA I campaign in autumn 1994 (October−November)

1998 ◽  
Vol 16 (8) ◽  
pp. 1014-1023 ◽  
Author(s):  
D. Pancheva ◽  
J. Laštovička
Keyword(s):  
Planetary Wave ◽  
Middle Atmosphere ◽  
Lower Ionosphere ◽  
Wave Activity ◽  
Atmospheric Dynamics ◽  
Planetary Scale ◽  
Meteorology And Atmospheric Dynamics ◽  
Wave Numbers ◽  
Dominant Period ◽  
Waves And Tides

Abstract. On the basis of MEM spectrum analysis, the main planetary scale fluctuations formed in the lower ionosphere are studied over a period of 3–25 days during the CRISTA campaign (October-November 1994). Three dominant period bands are found: 3–5, 6–8 and 15–23 (mainly 16–18) days. For 7–8 and 16–18 day fluctuations, propagation was eastward with wave numbers K = 3 and K = 1, respectively. The magnitude of planetary wave activity in the mid-latitudes of the Northern Hemisphere during the CRISTA campaign seems to be fairly consistent with the expected undisturbed normal/climatological state of the atmosphere at altitudes of 80–100 km.Key words. Ionosphere (ionosphere-atmosphere interactions) · Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides)

scholarly journals About the direction of motion, polarity and multiplicity of lightning flashes hitting towers: a comparative analysis of data gathered in Brazil and Switzerland

2003 ◽  
Vol 21 (5) ◽  
pp. 1209-1213 ◽  
Author(s):  
O. Pinto ◽  
D. G. Guedes ◽  
M. M. F. Saba ◽  
I. R. C. A. Pinto ◽  
M. Lacerda
Keyword(s):  
Comparative Analysis ◽  
Key Words ◽  
Atmospheric Electricity ◽  
Atmospheric Dynamics ◽  
Similar Data ◽  
Meteorology And Atmospheric Dynamics ◽  
Instruments And Techniques

Abstract. After 17 years of research at Morro do Cachimbo station (MC) in Brazil, 51 flashes with strokes higher than 2 kA were registered. The data are compared with similar data obtained from the Mount San Salvatore station (SS), Switzerland, in terms of the incidence of downward or upward flashes, polarity, and flash multiplicity. The comparison indicates that at MC the percentage of upward flashes and the multiplicity of negative downward flashes are higher than at SS, while the percentage of downward positive flashes is lower. Key words. Meteorology and atmospheric dynamics (atmospheric electricity; lightning; instruments and techniques)

scholarly journals Rapid increase in Asian bottles in the South Atlantic Ocean indicates major debris inputs from ships

2019 ◽  
Vol 116 (42) ◽  
pp. 20892-20897 ◽  
Author(s):  
Peter G. Ryan ◽  
Ben J. Dilley ◽  
Robert A. Ronconi ◽  
Maëlle Connan
Keyword(s):  
South America ◽  
Atlantic Ocean ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
The West ◽  
International Convention ◽  
To Come ◽  
Made In China ◽  
Central South ◽  
Made In

Most plastic debris floating at sea is thought to come from land-based sources, but there is little direct evidence to support this assumption. Since 1984, stranded debris has been recorded along the west coast of Inaccessible Island, a remote, uninhabited island in the central South Atlantic Ocean that has a very high macrodebris load (∼5 kg·m−1). Plastic drink bottles show the fastest growth rate, increasing at 15% per year compared with 7% per year for other debris types. In 2018, we examined 2,580 plastic bottles and other containers (one-third of all debris items) that had accumulated on the coast, and a further 174 bottles that washed ashore during regular monitoring over the course of 72 d (equivalent to 800 bottles·km−1·y−1). The oldest container was a high-density polyethylene canister made in 1971, but most were polyethylene terephthalate drink bottles of recent manufacture. Of the bottles that washed up during our survey, 90% were date-stamped within 2 y of stranding. In the 1980s, two-thirds of bottles derived from South America, carried 3,000 km by the west wind drift. By 2009, Asia had surpassed South America as the major source of bottles, and by 2018, Asian bottles comprised 73% of accumulated and 83% of newly arrived bottles, with most made in China. The rapid growth in Asian debris, mainly from China, coupled with the recent manufacture of these items, indicates that ships are responsible for most of the bottles floating in the central South Atlantic Ocean, in contravention of International Convention for the Prevention of Pollution from Ships regulations.

scholarly journals A juvenile Tristan albatross (Diomedea dabbenena) on land at the Crozet Islands

Polar Biology ◽  
2020 ◽  
Author(s):  
Alexander L. Bond ◽  
Christopher Taylor ◽  
David Kinchin-Smith ◽  
Derren Fox ◽  
Emma Witcutt ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Cytochrome B ◽  
Adult Male ◽  
Mitochondrial Gene ◽  
Small Population ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Tristan Da Cunha ◽  
Gough Island ◽  
Dispersal Events

AbstractAlbatrosses and other seabirds are generally highly philopatric, returning to natal colonies when they achieve breeding age. This is not universal, however, and cases of extraordinary vagrancy are rare. The Tristan Albatross (Diomedea dabbenena) breeds on Gough Island in the South Atlantic Ocean, with a small population on Inaccessible Island, Tristan da Cunha, ca 380 km away. In 2015, we observed an adult male albatross in Gonydale, Gough Island, which had been ringed on Ile de la Possession, Crozet Islands in 2009 when it was assumed to be an immature Wandering Albatross (D. exulans). We sequenced 1109 bp of the cytochrome b mitochondrial gene from this bird, and confirmed it to be a Tristan Albatross, meaning its presence on Crozet 6 years previous, and nearly 5000 km away, was a case of prospecting behaviour in a heterospecific colony. Given the challenges in identifying immature Diomedea albatrosses, such dispersal events may be more common than thought previously.

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