Results of the Caspian Sea satellite survey: internal wave climate

Results of satellite observations of surface manifestations of internal waves in the Caspian Sea are presented. Our work produced data on a spatial and temporal variability of internal waves of non-tidal origin via their surface manifestations. By using high-resolution satellite data, we were able to get a clear picture of generation, propagation and interaction of internal wave packets and significantly broadened our insights on the physics and geography of internal waves in the World Ocean. The large amount of the data available allowed us to make some generalizations and obtain statistically significant results on a spatial and temporal variability of various internal wave surface manifestations in satellite images. We discovered numerous diverse instances of internal wave manifestations in satellite images of the Caspian Sea. We further demonstrated that this observed diversity of internal wave behavior is due to a diversity of their generation mechanisms and indicates the complexity of the dynamic environment in the region. We put together a detailed map of spatial distribution of surface manifestations of the internal waves in the Caspian Sea. We revealed a seasonal and inter-annual variability of wave activity, identified main regions of the internal wave localization for each season and revealed causes of a spatial inhomogenity of internal wave packet manifestations. Possible factors leading to the generation of non-tidal internal waves are determined on the basis of joint analysis of available satellite remote sensing data of the sea surface in microwave, visible (VIS) and infra-red (IR) ranges complemented by contact measurements.

[1]  L. Mysak,et al.  Waves in the ocean , 1978 .

[2]  Martin Gade,et al.  Remote Sensing of the European Seas , 2008 .

[3]  Werner Alpers,et al.  The role of the critical angle in brightness reversals on sunglint images of the sea surface , 2010 .

[4]  Hiroshi Kawamura,et al.  Fine structure of laboratory wind-wave surfaces studied using an optical method , 1987 .

[5]  J. Apel,et al.  Signatures of surface wave/internal wave interactions: experiment and theory , 1988 .

[6]  Marina I. Mityagina,et al.  Multi-sensor survey of seasonal variability in coastal eddy and internal wave signatures in the north-eastern Black Sea , 2010 .

[7]  Generation of baroclinic wave signatures by moving atmospheric fronts , 1997 .

[8]  W. Alpers.  Theory of radar imaging of internal waves , 1985 .

[9]  V. Klemas.  Remote Sensing of Ocean Internal Waves: An Overview , 2012 .

[10]  A. Voronovich,et al.  Theoretical model for scattering of radar signals in K u - and C-bands from a rough sea surface with breaking waves , 2001 .

[11]  L. Brekhovskikh,et al.  Short-period internal waves in the sea , 1975 .

[12]  Study of internal wave generation and propagation features in non-tidal seas based on satellite synthetic aperture radar data , 2011 .

[13]  Heinrich Hühnerfuss,et al.  Wind‐wave tank measurements of bound and freely propagating short gravity‐capillary waves , 1998 .

[14]  I. Robinson,et al.  Role of surface films in ERS SAR signatures of internal waves , 1998 .

[15]  B. Hughes.  The effect of internal waves on surface wind waves 2. Theoretical analysis , 1978 .

[16]  A. New,et al.  On the structure and propagation of internal solitary waves generated at the Mascarene Plateau in the Indian Ocean , 2011 .

[17]  K. Prasad,et al.  Space borne SAR observations of oceanic internal waves in North Bay of Bengal , 2011 .

[18]  Leonid Mitnik,et al.  Ocean Internal Waves Observed in the Lombok Strait , 2005 .

[19]  J. Lorenzzetti,et al.  Internal Solitary Waves in the Brazilian SE Continental Shelf: Observations by Synthetic Aperture Radar , 2013 .

[20]  A. Bidokhti,et al.  The layered structure in exchange flows between two basins (Middle and Southern basins of the Caspian Sea) , 2011 .

[21]  R. Nerzic,et al.  Observations and predictability of internal solitons in the northern Andaman Sea , 2005 .

[22]  Y. Kravtsov,et al.  Signatures of resonant and non-resonant scattering mechanisms on radar images of internal waves , 2002 .

[23]  J. Johannessen,et al.  On radar imaging of current features: 1. Model and comparison with observations , 2005 .