73 resultados para Orcagna, fl. 1343-1368.
Resumo:
This data set contains grain size analyses of bottom sediments collected by scientists from the V.P. Zenkovich Laboratory of Shelf and Sea Coasts (P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences) during the Project ''Arctic Shelf of the Eurasia in the Late Quaternary'' in a number of expeditions to the Barents, Kara, East Siberian and Chukchi Seas on board the research vessels R/V Professor Shtokman, H/V Dmitry Laptev, H/V Malygin, and icebreaker Georgy Sedov since 1978. The analyses have been carried out according to the methods published by Petelin (1967) in the Analytical Laboratory of the P.P. Shirshov Institute of Oceanology. Archiving and electronic publication was performed through a data rescue by Evgeny Gurvich in 2003.
Resumo:
The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data set provides continuous measurements made with a WETLabs Eco-FL sensor mounted on the flowthrough system between June 4th, 2011 and March 30th, 2012. Data was recorded approximately every 10s. Two issues affected the data: 1. Periods when the water 0.2µm filtered water were used as blanks and 2. Periods where fluorescence was affected by non-photochemical quenching (NPQ, chlorophyll fluorescence is reduced when cells are exposed to light, e.g. Falkowski and Raven, 1997). Median data and their standard deviation were binned to 5min bins with period of light/dark indicated by an added variable (so that NPQ affected data could be neglected if the user so chooses). Data was first calibrated using HPLC data collected on the Tara (there were 36 data within 30min of each other). Fewer were available when there was no evident NPQ and the resulting scale factor was 0.0106 mg Chl m-3/count. To increase the calibration match-ups we used the AC-S data which provided a robust estimate of Chlorophyll (e.g. Boss et al., 2013). Scale factor computed over a much larger range of values than HPLC was 0.0088 mg Chl m-3/count (compared to 0.0079 mg Chl m-3/count based on manufacturer). In the archived data the fluorometer data is merged with the TSG, raw data is provided as well as manufacturer calibration constants, blank computed from filtered measurements and chlorophyll calibrated using the AC-S. For a full description of the processing of the Eco-FL please see Taillandier, 2015.
Resumo:
This data set contains chemical composition of bottom sediments collected by scientists from the V.P. Zenkovich Laboratory of Shelf and Sea Coasts (P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences) during the Project ''Arctic Shelf of the Eurasia in the Late Quaternary'' in a number of expeditions to the Barents, Kara, East Siberian and Chukchi Seas on board research vessels R/V Professor Shtokman, H/V Dmitry Laptev, H/V Malygin, and icebreaker Georgy Sedov between 1978 and 1990. The analyses have been carried out in the Analytical Laboratory of the P.P. Shirshov Institute of Oceanology. Archiving and electronic publication was performed through a data rescue by Evgeny Gurvich in 2003.
Resumo:
Coastal upwelling systems account for approximately half of global ocean primary production and contribute disproportionately to biologically driven carbon sequestration. Diatoms, silica-precipitating microalgae, constitute the dominant phytoplankton in these productive regions, and their abundance and assemblage composition in the sedimentary record is considered one of the best proxies for primary production. The study of the sedimentary diatom abundance (SDA) and total organic carbon content (TOC) in the five most important coastal upwelling systems of the modern ocean (Iberia-Canary, Benguela, Peru-Humboldt, California and Somalia-Oman) reveals a global-scale positive relationship between diatom production and organic carbon burial. The analysis of SDA in conjunction with environmental variables of coastal upwelling systems such as upwelling strength, satellite-derived net primary production and surface water nutrient concentrations shows different relations between SDA and primary production on the regional scale. At the global-scale, SDA appears modulated by the capacity of diatoms to take up silicic acid, which ultimately sets an upper limit to global export production in these ocean regions.