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Vic Klemas

Bio: Vic Klemas is an academic researcher from University of Delaware. The author has contributed to research in topics: Internal wave & Wind wave. The author has an hindex of 9, co-authored 15 publications receiving 557 citations.

Papers
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Journal ArticleDOI
04 Dec 1992-Science
TL;DR: Variabilities in sea-surface temperature and size of the Western Pacific Warm Pool were tracked with 10 years of satellite multichannel sea- Surface temperature observations from 1982 to 1991 and show that both annual mean sea- surface temperature and the size ofthe warm pool increased from 1983 to 1987 and fluctuated after 1987.
Abstract: Variabilities in sea-surface temperature and size of the Western Pacific Warm Pool were tracked with 10 years of satellite multichannel sea-surface temperature observations from 1982 to 1991. The results show that both annual mean sea-surface temperature and the size of the warm pool increased from 1983 to 1987 and fluctuated after 1987. Possible causes of these variations include solar irradiance variabilities, El Nino-Southern Oscillaton events, volcanic activities, and global warming.

253 citations

Journal ArticleDOI
TL;DR: In this article, the authors derived a theoretical model of a radar image for a Korteweg-de Vries type ocean internal soliton and validated the model using ocean internal wave signals taken from ERS-1 SAR and RADARSAT SAR images.
Abstract: This paper deals with the development of techniques for satellite synthetic aperture radar (SAR) ocean image interpretation. We derived a theoretical model of a radar image for a Korteweg-de Vries type ocean internal soliton and validated the model using ocean internal wave signals taken from ERS-1 SAR and RADARSAT SAR images. The results indicate that the model perfectly simulates ocean internal soliton signatures with double-sign variations of radar backscatter. On the basis of the model, we developed the curve fitting method and the peak-to-peak method for determining the internal soliton characteristic half widths, which then were used to calculate the internal soliton amplitudes. The test results indicate that ocean internal soliton amplitudes derived by the two methods agree with in situ data acquired on the Portuguese Continental Shelf and in the South China Sea with reasonable accuracy. The role that wind fields play in ocean radar remote sensing was also analyzed. Finally, the modulation ratio of ocean internal waves on radar images was quantitatively estimated.

128 citations

Journal ArticleDOI
TL;DR: In this paper, the internal wave field in the sample area has a three-level structure which consists of packet groups, packets, and solitons, and an average packet group wavelength of 17.5 km and average soliton wavelength of 0.6 km are measured.
Abstract: The internal waves on the continental shelf on the Middle Atlantic Bight seen on Space Shuttle photographs taken during the STS-40 mission in June 1991 are measured and analyzed. The internal wave field in the sample area has a three-level structure which consists of packet groups, packets, and solitons. An average packet group wavelength of 17.5 km and an average soliton wavelength of 0.6 km are measured. Finite-depth theory is used to derive the dynamic parameters of the internal solitons: the maximum amplitude of 5.6 m, the characteristic phase speed of 0.42 m/s, the characteristic period of 23.8 min, the velocity amplitude of the water particles in the upper and lower layers of 0.13 m/s and 0.030 m/s respectively, and the theoretical energy per unit crest line of 6.8 x 10 exp 4 J/m. The frequency distribution of solitons is triple-peaked rather than continuous. The major generation source is at 160 m water depth, and a second is at 1800 m depth, corresponding to the upper and lower edges of the shelf break.

46 citations

Journal ArticleDOI
TL;DR: In this paper, the authors recognized the sea surface signature of a coastal lee wave using ERS-1 synthetic aperture radar (SAR) images of the west side of the Taiwan Strait taken on December 8, 1994.
Abstract: Alternative dark-bright patterns on ERS-1 synthetic aperture radar (SAR) images of the west side of the Taiwan Strait taken on December 8, 1994, were recognized to be the sea surface signature of a coastal lee wave. Such waves are called coastal lee waves because they occur along the lee side of the coast. The coastal lee waves appeared in the form of a wave packet distributed within an offshore band 20–40 km wide. The first packet, which occurred in the northern portion of the observed area, contained six waves with variable wavelengths (defined as the spatial separation between two waves) from 1.7 to 2.7 km. The second packet, in the middle, contained 10 waves with a relatively uniform wavelength of 4.2 km. The third packet, in the southern portion, contained 17 waves with an average wavelength of 2.0 km. The crest lengths were from 20 to 80 km. Local meteorologic parameters observed simultaneously at Fuzhou, China, close to the imaged area, showed an offshore wind of 1.5–3.5 m/s and a land surface air temperature of 19°C, which was 4°C lower than the sea surface temperature (SST). Thus the lower atmospheric boundary conditions at imaging time were very favorable both for generating the land breeze circulation and small wind waves on the sea surface, which are in the Bragg-scattering wavelength band of the C band ERS-1 SAR. A physical model of a three-layer atmosphere was developed in order to explain how the land breeze circulation can generate the coastal lee waves. The results showed that the vertical velocity disturbance caused by the wind convergence at the land breeze frontal zone is of vital importance for the generation of coastal lee waves, and the model gave very good estimates of the processes observed. The SAR imaging mechanisms of the waves were analyzed in detail. The differences between coastal lee waves and ocean internal waves, which appear as similar alternative dark-bright patterns on SAR images, were also discussed.

45 citations

Journal ArticleDOI
TL;DR: In this paper, Tappert et al. analyzed the evolution of ocean internal solitary waves passing over a seamount in the Gulf of Aden and found that a surprisingly sharp recess of an internal solitary wave packet, imaged by the space shuttle Discovery, is a signature of spatial phase delay caused by thermocline shoaling over the seamount.
Abstract: Measurements of the upper ocean thermal structure show that on the continental shelves the thermocline depth may shoal or deepen generally depending on the bottom topography. Thermocline shoaling and deepening cause changes in the phase speeds of internal waves as described by linear wave theories. On the other hand, the ocean area where internal waves have variable phase speeds may be treated as a dynamically inhomogeneous medium. In this case, theories of nonlinear dispersive wave propagation in inhomogeneous media developed by Tappert and Zabusky [1971] may stand. We used these theories to analyze the evolution of ocean internal solitary waves passing over a seamount in the Gulf of Aden. The results indicate that a surprisingly sharp recess of an internal solitary wave packet, imaged by the space shuttle Discovery, is a signature of spatial phase delay caused by thermocline shoaling over the seamount. Soliton fission due to thermocline shoaling was also observed in the imagery. The observed number of transmitted solitons over the seamount agrees with theoretical predictions. Relative soliton amplitudes measured from the imagery also agree qualitatively with predictions.

35 citations


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09 Jan 2004
TL;DR: In this paper, Sea salt aerosol (SSA) particles interact with other atmospheric gaseous and aerosol constituents by acting as sinks for condensable gases and suppressing new particle formation, thus influencing the size distribution of other aerosols and more broadly influencing the geochemical cycles of substances with which they interact.
Abstract: Sea salt aerosol (SSA) exerts a major influence over a broad reach of geophysics. It is important to the physics and chemistry of the marine atmosphere and to marine geochemistry and biogeochemistry generally. It affects visibility, remote sensing, atmospheric chemistry, and air quality. Sea salt aerosol particles interact with other atmospheric gaseous and aerosol constituents by acting as sinks for condensable gases and suppressing new particle formation, thus influencing the size distribution of these other aerosols and more broadly influencing the geochemical cycles of substances with which they interact. As the key aerosol constituent over much of Earth's surface at present, and all the more so in pre-industrial times, SSA is central to description of Earth's aerosol burden.

603 citations

Journal ArticleDOI
TL;DR: In this paper, seasonal cycles of photic depth, primary production and accumulation (or loss) of algal biomass were obtained from the climatological CZCS chlorophyll field and other data, together with mixed layer depths, which can be grouped into eight models.

548 citations

Journal ArticleDOI
TL;DR: A range of evidence from geomorphology, palynology, biogeography and vegetation/climate modelling suggests that a north-south "savanna corridor" did exist through the continent of Sundaland through the Last Glacial Period (LGP) at times of lowered sea-level, as originally proposed by Heaney [1991] as discussed by the authors.

515 citations

Journal ArticleDOI
TL;DR: In the tropical southwestern Pacific, surface-ocean temperatures were depressed by 4-6°C during the Younger Dryas climatic event and rose episodically during the next 4000 years as mentioned in this paper.

477 citations

Journal ArticleDOI
Pinxian Wang1
TL;DR: In this article, the authors reviewed the recent progress in late Quaternary studies in five northwestern Pacific marginal seas, especially the South China Sea as an example, and showed that during glacial cycles, the sea-level-induced environmental signal was amplified in the marginal seas giving rise to drastic changes in areas and configurations of these seas, and to reorganization of sea water circulation in basins.

434 citations