Introduction to special section on Recent Advances in the Study of Optical Variability in the Near-Surface and Upper Ocean

Optical variability occurs in the near-surface and upper ocean on very short time and space scales (e.g., milliseconds and millimeters and less) as well as greater scales. This variability is caused by solar, meteorological, and other physical forcing as well as biological and chemical processes that affect optical properties and their distributions, which in turn control the propagation of light across the air-sea interface and within the upper ocean. Recent developments in several technologies and modeling capabilities have enabled the investigation of a variety of fundamental and applied problems related to upper ocean physics, chemistry, and light propagation and utilization in the dynamic near-surface ocean. The purpose here is to provide background for and an introduction to a collection of papers devoted to new technologies and observational results as well as model simulations, which are facilitating new insights into optical variability and light propagation in the ocean as they are affected by changing atmospheric and oceanic conditions

GLOBAL OBSERVATION OF DIFFERENT PHYTOPLANKTON GROUPS USING PHYTODOAS WITH SCIAMACHY AND GOME-2 DATA

In order to understand the marine phytoplanktons role in the global marine ecosystem, it is necessary to derive global information on the distribution of major functional phytoplankton types (PFT) in the world oceans. So far only the dominant PFTs can be analysed from ocean color sensors such as CZCS, SeaWiFS, MODIS or MERIS. In our study we use PhytoDOAS, a method of Differential Optical Absorption Spectroscopy (DOAS) specialized for phytoplankton, to retrieve the absorption spectra and concentrations of various phytoplankton groups from high spectrally resolved satellite data of SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Cartography) on ENVISAT and GOME-2 (Global Ozone Measurement Experiment 2) on Meteosat. In-situ measured phytoplankton absorption spectra were used to identify these characteristic absorption spectra in SCIAMACHY data in the range of 430-500 and 530-590 nm. Pigment concentrations of in situ measurements were used to validate the satellite data, which showed a good agreement with the collocated in-situ measurements and with the NASA Ocean Biogeochemical Model. Results are of great importance for global modelling of marine ecosystems and climate change studies. http://www.sgmeet.com/aslo/nice2009/viewabstract2.asp?AbstractID=541

Determination of the absorption coefficient of chromophoric dissolved organic matter from underway spectrophotometry

Measurements of the absorption coefficient of chromophoric dissolved organic matter (a(y)) are needed to validate existing ocean-color algorithms. In the surface open ocean, these measurements are challenging because of low a(y) values. Yet, existing global datasets demonstrate that a(y) could contribute between 30% to 50% of the total absorption budget in the 400-450 nm spectral range, thus making accurate measurement of ay essential to constrain these uncertainties. In this study, we present a simple way of determining ay using a commercially-available insitu spectrophotometer operated in underway mode. The obtained a(y) values were validated using independent collocated measurements. The method is simple to implement, can provide measurements with very high spatio-temporal resolution, and has an accuracy of about0.0004 m(-1) and a precision of about 0.0025 m(-1) when compared to independent data (at 440 nm). The only limitation for using this method at sea is that it relies on the availability of relatively large volumes of ultrapure water. Despite this limitation, the method can deliver the a(y) data needed for validating and assessing uncertainties in ocean-colour algorithms. (C) 2017 Optical Society of Americ

PREDICTIVE VALUE OF IG/TR AND BCR/ABL1 PCR-BASED MINIMAL RESIDUAL DISEASE MONITORING IN PH plus PEDIATRIC ALL TREATED WITH IMATINIB IN THE ESPHALL STUDY

International audience21st Congress of the European-Hematology-Associatio