21 research outputs found

    Measurement of Sea Wave Spatial Spectra from High- Resolution Optical Aerospace Imagery

    Get PDF
    The chapter is devoted to the development of methods for remote measurement of spatial spectra of waves arising on marine and ocean surface. It is shown that in most natural conditions of optical image formation, a nonlinear modulation of the brightness field occurs by slopes of water surface elements. Methods for reconstructing the spectra of surface waves from optical image spectra with allowance for such modulation are proposed. The methods are based on the numerical simulation of water surface taking into account wave formation conditions and conditions of light entering the sea surface from the upper and lower hemispheres. Using the results of numerical simulation, special operators are built to retrieve wave spectra from the spectra of aerospace images. These retrieving operators are presented in the form of analytical expressions, depending on the sets of parameters, which are determined by the conditions for the formation of images. The results of experimental studies of the sea wave spectra in various water areas using satellite optical images of high spatial resolution are presented. In the experimental studies, the spatial spectral characteristics of sea waves estimated from remote sensing data were compared with the corresponding characteristics measured by contact assets under controlled conditions

    Submerged turbulence detection with optical satellites

    Full text link
    During fall periods in 2002, 2003 and 2004 three major oceanographic expeditions were carried out in Mamala Bay, Hawaii. These were part of the RASP Remote Anthropogenic Sensing Program. Ikonos and Quickbird optical satellite images of sea surface glint revealed ~100 m spectral anomalies in km^2 averaging patches in regions leading from the Honolulu Sand Island Municipal Outfall diffuser to distances up to 20 km. To determine the mechanisms behind this phenomenon, the RASP expeditions monitored the waters adjacent to the outfall with an array of hydrographic, optical and turbulence microstructure sensors in anomaly and ambient background regions. Drogue tracks and mean turbulence parameters for 2x10^4 microstructure patches were analyzed to understand complex turbulence, fossil turbulence and zombie turbulence near-vertical internal wave transport processes. The dominant mechanism appears to be generic to stratified natural fluids including planet and star atmospheres and is termed beamed zombie turbulence maser action (BZTMA). Most of the bottom turbulent kinetic energy is converted to ~100 m fossil turbulence waves. These activate secondary (zombie) turbulence in outfall fossil turbulence patches that transmit heat, mass, chemical species, momentum and information vertically to the sea surface for detection in an efficient maser action. The transport is beamed in intermittent mixing chimneys.Comment: 8 pages, 7 figures, SPIE Optics+Photonics 2007 Coastal Ocean Remote Sensing Aug. 27, San Diego, CA, see http://sdcc3.ucsd.edu/~ir11

    Energetics of the Beamed Zombie Turbulence Maser Action Mechanism for Remote Detection of Submerged Oceanic Turbulence

    Get PDF
    Sea surface brightness spectral anomalies from a Honolulu municipal outfall have been detected from space satellites in 200 km2 areas extending 20 km from the wastewater diffuser (Leung and Gibson 2004, Bondur 2005, Keeler et al. 2005, Gibson et al. 2006). Dropsonde and towed body microstructure measurements show greatly enhanced viscous and temperature dissipation rates above the outfall trapping-layer. Fossil-turbulencewaves (FTWs) and secondary zombie-turbulence-waves (ZTWs) break as they propagate near-vertically and then break again near the surface to produce wind-ripple smoothing with narrow-wavelength λ patterns from the soliton-like internal waves that supply turbulence energy to advected outfall fossils and to the ZTWs they radiate. The λ = 30-250 m solitons reflect an efficient maser-action conversion of horizontal tidal and current kinetic energy by bottom boundary layer turbulence events to near-vertical FTWs with λ the Ozmidov scale of the events at fossilization. Secondary (zombie) turbulence amplifies, channels in chimneys, and near-vertically beams ambient internal wave energy at scales λ just as energized metastable molecules amplify and beam quantum wavelengths in astrophysical lasers and masers around stars. Kilowatts of buoyancy power from the treatment plant produce fossil turbulence patches trapped below the thermocline. Beamed zombie turbulence maser action (BZTMA) in mixing chimneys amplifies these kilowatts into the megawatts of surface turbulence dissipation required to affect brightness on wide sea surface areas. The BZTMA vertical mixing mechanism appears critical to vertical oceanic transport of information, heat, mass and momentum, and to the conversion of barotropic tides to baroclinic tides

    Pan-Eurasian Experiment (PEEX) Program : An Overview of the First 5 Years in Operation and Future Prospects

    Get PDF
    The Pan-Eurasian Experiment (PEEX) program was initiated as a bottom-up approach by the researchers coming from Finland and Russia in October 2012. The PEEX China kick off meeting was held in November 2013. During its five years in operation, the program has established a governance structure and delivered a science plan for the Northern Eurasian region. PEEX has also introduced a concept design for a modelling platform and ground-based in situ observation systems for detecting land-atmosphere and ocean-atmosphere interactions. Today, PEEX has an extensive researcher’s network representing research communities coming from the Nordic countries, Russia and China. PEEX is currently carrying out its research activities on a project basis, but is looking for more coordinated funding bases, especially in Russia and in China. The near-future challenge in implementing the PEEX research agenda is to achieve a successful integration and identification of the methodological approaches of the socio-economic research to environmental sciences. Here we give insight into these issues and provide an overview on the main tasks for the upcoming years.The Pan-Eurasian Experiment (PEEX) program was initiated as a bottom-up approach by the researchers coming from Finland and Russia in October 2012. The PEEX China kick off meeting was held in November 2013. During its five years in operation, the program has established a governance structure and delivered a science plan for the Northern Eurasian region. PEEX has also introduced a concept design for a modelling platform and ground-based in situ observation systems for detecting land-atmosphere and ocean-atmosphere interactions. Today, PEEX has an extensive researcher’s network representing research communities coming from the Nordic countries, Russia and China. PEEX is currently carrying out its research activities on a project basis, but is looking for more coordinated funding bases, especially in Russia and in China. The near-future challenge in implementing the PEEX research agenda is to achieve a successful integration and identification of the methodological approaches of the socio-economic research to environmental sciences. Here we give insight into these issues and provide an overview on the main tasks for the upcoming years.The Pan-Eurasian Experiment (PEEX) program was initiated as a bottom-up approach by the researchers coming from Finland and Russia in October 2012. The PEEX China kick off meeting was held in November 2013. During its five years in operation, the program has established a governance structure and delivered a science plan for the Northern Eurasian region. PEEX has also introduced a concept design for a modelling platform and ground-based in situ observation systems for detecting land-atmosphere and ocean-atmosphere interactions. Today, PEEX has an extensive researcher’s network representing research communities coming from the Nordic countries, Russia and China. PEEX is currently carrying out its research activities on a project basis, but is looking for more coordinated funding bases, especially in Russia and in China. The near-future challenge in implementing the PEEX research agenda is to achieve a successful integration and identification of the methodological approaches of the socio-economic research to environmental sciences. Here we give insight into these issues and provide an overview on the main tasks for the upcoming years.Peer reviewe

    Overview: Recent advances in the understanding of the northern Eurasian environments and of the urban air quality in China – a Pan-Eurasian Experiment (PEEX) programme perspective

    Get PDF
    The Pan-Eurasian Experiment (PEEX) Science Plan, released in 2015, addressed a need for a holistic system understanding and outlined the most urgent research needs for the rapidly changing Arctic-boreal region. Air quality in China, together with the long-range transport of atmospheric pollutants, was also indicated as one of the most crucial topics of the research agenda. These two geographical regions, the northern Eurasian Arctic-boreal region and China, especially the megacities in China, were identified as a "PEEX region". It is also important to recognize that the PEEX geographical region is an area where science-based policy actions would have significant impacts on the global climate. This paper summarizes results obtained during the last 5 years in the northern Eurasian region, together with recent observations of the air quality in the urban environments in China, in the context of the PEEX programme. The main regions of interest are the Russian Arctic, northern Eurasian boreal forests (Siberia) and peatlands, and the megacities in China. We frame our analysis against research themes introduced in the PEEX Science Plan in 2015. We summarize recent progress towards an enhanced holistic understanding of the land-atmosphere-ocean systems feedbacks. We conclude that although the scientific knowledge in these regions has increased, the new results are in many cases insufficient, and there are still gaps in our understanding of large-scale climate-Earth surface interactions and feedbacks. This arises from limitations in research infrastructures, especially the lack of coordinated, continuous and comprehensive in situ observations of the study region as well as integrative data analyses, hindering a comprehensive system analysis. The fast-changing environment and ecosystem changes driven by climate change, socio-economic activities like the China Silk Road Initiative, and the global trends like urbanization further complicate such analyses. We recognize new topics with an increasing importance in the near future, especially "the enhancing biological sequestration capacity of greenhouse gases into forests and soils to mitigate climate change" and the "socio-economic development to tackle air quality issues".Peer reviewe

    Detection and Analysis of the Causes of Intensive Harmful Algal Bloom in Kamchatka Based on Satellite Data

    No full text
    In this paper, the causes of the anomalous harmful algal bloom which occurred in the fall of 2020 in Kamchatka have been detected and analyzed using a long-term time series of heterogeneous satellite and simulated data with respect to the sea surface height (HYCOM) and temperature (NOAA OISST), chlorophyll-a concentration (MODIS Ocean Color SMI), slick parameters (SENTINEL-1A/B), and suspended matter characteristics (SENTINEL-2A/B, C2RCC algorithm). It has been found that the harmful algal bloom was preceded by temperature anomalies (reaching 6 °C, exceeding the climatic norm by more than three standard deviation intervals) and intensive ocean level variability followed by the generation of vortices, mixing water masses and providing nutrients to the upper photic layer. The harmful algal bloom itself was manifested in an increase in the concentration of chlorophyll-a, its average monthly value for October 2020 (bloom peak) approached 15 mg/m3, exceeding the climatic norm almost four-fold for the region of interest (Avacha Gulf). The zones of accumulation of a large amount of biogenic surfactant films registered in radar satellite imagery correlate well with the local regions of the highest chlorophyll-a concentration. The harmful bloom was influenced by river runoff, which intensively brought mineral and biogenic suspensions into the marine environment (the concentration of total suspended matter within the plume of the Nalycheva River reached 10 mg/m3 and more in 2020), expanding food resources for microalgae
    corecore