The modern Forel-Ule scale: a ‘do-it-yourself’ colour comparator for water monitoring

The colour comparator Forel-Ule scale has been used to estimate the colour of natural waters since the 19th century, resulting in one of the longest oceanographic data series. This colour index has been proven by previous research to be related to water quality indicators such as chlorophyll and coloured dissolved organic material. The aim of this study was to develop an affordable, ‘Do-it-Yourself’ colour scale that matched the colours of the original Forel-Ule scale, to be used in water quality monitoring programs by citizens. This scale can be manufactured with high-quality lighting filters and a white frame, an improvement with respect to the materials employed to manufacture the original scale from the 19th century, which required the mixing of noxious chemicals. The colours of the new scale were matched to the original colours using instrumental and visual measurements carried out under controlled lighting conditions, following the standard measurement protocols for colour. Moreover, the colours of the scale are expressed in Munsell notations, a standard colour system already successfully used in water quality monitoring. With the creation of this Modern Forel-Ule scale, as a ‘Do-it-yourself’ kit, the authors foresee a possible use of the Forel-Ule number as a water quality index that could be estimated by means of participatory science and used by environmental agencies in monitoring programs

The Forel-Ule scale revisited spectrally: preparation protocol, transmission measurements and chromaticity

Within the EC-funded project CITLOPS (Citizens' Observatory for Coast and Ocean Optical Monitoring), with its main goal to empower endusers, willing to employ community-based environmental monitoring, our aim is to digitalize the colours of the Forel-Ule scale to establish the colour of natural waters through smartphone imaging. The objective of this study was to reproduce the Forel-Ule scale following the original recipes, measure the transmission of the solutions and calculate the chromaticity coordinates of the scale as Wernand and Van der Woerd did in 2010, for the future development of a smartphone application. Some difficulties were encountered when producing the scale, so a protocol for its consistent reproduction was developed and is described in this study. Recalculated chromaticity coordinates are presented and compared to measurements conducted by former scientists. An error analysis of the spectral and colourimetric information shows negligible experimental errors

Towards a spatially and temporally constant Karakorum fault slip rate

Abstract HKT-ISTP 2013 A

L'initiative européenne "Suivi global pour l'environnement et la sécurité'' et le protocole de Kyoto

International audienceEn 1992 la Convention Cadre des Nations Unies pour le Contrôle du Changement du Climat (UNFCCC) a montré la prise de conscience internationale des effets néfastes de l'accumulation dans l'atmosphère des gaz à effet de serre, conduisant à un réchauffement climatique, sous l'effet direct ou indirect des activités anthropiques. Le Protocole de Kyoto, adopté en 1997, a fixé des engagements quantitatifs que les parties signataires s'engageaient à respecter. Ceci suppose des moyens d'observation afin de comprendre, modéliser, mesurer l'évolution des sources et des puits de gaz à effet de serre, et tout particulièrement celles sur lesquelles l'Homme peut avoir une influence directe. Conjointement aux mesures in situ, l'observation de la Terre par satellite s'avère un moyen puissant pour répondre à cet objectif. L'Europe, comme le rappelle le "Manifeste de Baveno" adopté par un certain nombre d'agences impliquées dans les activités spatiales, dispose d'atouts majeurs pour remplir de tels objectifs. Le présent article s'efforce de donner une vue synthétique des différentes informations à rassembler pour le suivi des clauses du Protocole de Kyoto, de l'UNFCCC et de leurs conséquences globales sur le changement climatique, mettant en évidence les résultats obtenus, les moyens à entreprendre, les recherches restant à mener, pour atteindre ces buts

Spectroscopic Study of SU UMa-type Dwarf Nova YZ Cnc during its 2002 Superoutburst

We report time-resolved spectroscopic observations of the SU Ursae Majoris dwarf nova, YZ Cnc, for 2 nights over 11 hrs during its 2002 January superoutburst. The spectra only show absorption-line profiles in the first day. But the lines display blue and red troughs, with ``W'' profiles in the second day. The radial velocity curve of the absorption troughs and emission peaks of H$\beta$ has an amplitude of $49\pm10$ km s$^{-1}$ and a phase offset of $-0.07\pm0.04$, which are very similar to those measured in quiescence; however, the $\gamma$ velocity deviates strongly from the systemic velocity measured in quiescence, showing variation of the order of $\pm$60 km s$^{-1}$. And large shifts of $\sim$70 km s$^{-1}$ and $\sim$0.09, for the orbital-averaged velocity and phase respectively, are also found in our observations. All these phenomena can be well explained with a precession of an eccentric disk and we conclude that these phenomena are the characteristic products of an eccentric accretion disk.Comment: 11 pages, 4 figures, accepted for publication in ChJA