Quantifying importance and scaling effects of atmospheric deposition of inorganic fixed nitrogen for the eutrophic Black Sea

Wet atmospheric depositions have been collected in a rural (Katsiveli) and urban (Sevastopol) location at the Crimean coast of the Black Sea from 2003 to 2008. Samples, 217 from Katsiveli and 228 from Sevastopol, have been analysed for inorganic fixed nitrogen (nitrate, nitrite, and ammonium). Data have revealed almost equal contributions of ammonium (44–45 %) and nitrate (52–53 %) and minor contribution of nitrite (2–4 %) for both rural and urban samples. The volume weight mean concentration of inorganic fixed nitrogen (IFN) in urban samples (2.51 mg N L^&minus;1) is about 2-fold of that content in rural samples (1.16 mg N L^&minus;1). Seasonal variations in volume weight mean monthly concentrations have been revealed for both locations with maximum concentrations in winter and minimum values in summer, but intra-annual variations are statistically significant for only urban samples. <br><br> The average annual deposition of IFN with atmospheric precipitations on the surface of the Black Sea is about 0.31 × 10⁶ t N yr⁻¹ (0.75 t N km⁻² yr⁻¹), which is on average 39 % of the riverine input. It does vary in space and time. The relative importance of the atmospheric input increases from coastal to open areas and from winter to summer. Deposition of IFN with wet atmospheric precipitations proportionally increases the concentration of chlorophyll <i>a</i>, as it is traced from satellite data. The traced increase in the concentration of chlorophyll <i>a</i> has reached 1.5-fold for mesoscale processes. In case of individual rain events supporting up to 50–60 mg N m^&minus;2, the influence of IFN deposition is up to 5 % at the north-western shelf of the Black Sea, where most of the river-born IFN is loaded. In the central areas of the sea, where the amount of IFN in summer is low, the contribution of individual rainfall can reach 35 %. The input of IFN to the Black Sea has potential to enhance 2-fold the level of primary production

Manifestation of the mesoscale phenomena in surface roughness, altimetry, optical and thermal properties of the upper layer

Medium and high resolution optical data (MODIS, MERIS, TM, ETM+), altimetry and radar data together with meteorological re-analysis are used for investigation of eddies, upwellings and internal wave manifestation in the Black Sea and Strait of Gibraltar. The next topics are discussed: 1. Sea surface roughness by optical scanners data – upwelling, eddies, pollutions and internal waves manifestation in sun glitter pattern. 2. Coastal upwelling - thermal and optical properties and impact on sea level and surface roughness. 3. Eddies manifestation in variation of the upper layer properties - different remote sensing sensors. 4. Statistic for 1994-2010 years and properties of eddies in the Black Sea, impact of the wind forcing – altimetry and meteorological data analysis

Studies of Sub-Mesoscale Variability of the Ocean Upper Layer Based on Satellite Observations Data

Purpose. The approach represented in the article is applied to analysis of satellite scanner optical images of high spatial resolution for identifying and quantitative determining the characteristics of the sub-mesoscale dynamic processes in the ocean upper layer. Methods and Results. The Envisat AATSR and MERIS SAR-images are used as the satellite data, which permit to determine the ocean surface temperature and surface brightness in the visible range, respectively. Variations in the sea surface glitter contrasts are associated with modulations of the sea surface roughness (rms slope of short waves) on the currents. It is shown that the surface roughness contrasts correlate with the spatial inhomogeneities of the ocean surface temperature, tracing sub-mesoscale processes in the ocean (spiral eddies, filaments, local shears of currents). The described model of formation of surface manifestations is based on interaction between the Ekman current and the main flow vorticity. Conclusions. Possibility of detecting and quantitative assessing the intense current gradients in the vicinity of sub-mesoscale fronts is shown. These gradients are manifested in the optical satellite images through the ocean surface roughness modulations. The proposed approach makes it possible to study and to assess quantitatively the dynamic processes taking place in the vicinity of the sub-mesoscale fronts. These processes, in their turn, affect the exchange of momentum, heat and gases between the ocean and the atmosphere. The prospects of applying the sub-mesoscale variability defined from the satellite measurements, to development of the models and the systems for the ocean global observations and monitoring are discussed

Wind driven upwelling along the African coast of the Strait of Gibraltar

Regular remote sensing data from various sensors are used here for the study of the wind driven upwelling phenomenon along the African coast of the Strait of Gibraltar. It is shown for an extended summer period (May 15 till September 15, 2003) that sea surface temperature (SST) data in the strait are correlated with NCEP winds, each westward wind increase being followed by a clear surface temperature decrease. Local surface temperature of about 22degreesC at that time drops down to 15degreesC, value corresponding to the 80 - 120 m depth conditions. The analysis of subsequent images indicates that the cold upwelling plume typically moves first to the Atlantic during wind forcing, and then to the Mediterranean after the wind event. The presence of the northern coast of the strait is taken as responsible for a rise of a cross-strait sea level gradient and the enhancement of the associated westward geostrophic current that explains the first stage of the plume deployment. Sea level difference measured between Tarifa (European coast) and Ceuta (African coast), well described by a linear equation in term of the westward wind component, supports this idea as well as the subsequent remotely sensed SST distributions

Anticyclonic eddies in the deep eastern Black Sea in summer-autumn 1999 (satellite and ship-borne observations

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