The deadline for the IOCCG Summer Lecture Series is fast approaching (16 March 2012). This lecture series will focus on current critical issues in ocean colour science with lectures given by a number of distinguished scientists. A significant portion of the course will be dedicated to interactive discussions between the students and lecturers. Students will be encouraged to engage in in-depth discussions with leaders in the field on various topics, both those discussed in the lecture series, as well as their own scientific research interests.
The course will take place at the Laboratoire d’Océanographie de Villefranche (LOV) in Villefranche-sur-Mer, France from 2 – 14 July 2012. See ioccg.org/training/upcoming.html for further information on the course, and how to apply.
We are delighted to report that the IOCCG past-Chair, Prof. James A. Yoder from Woods Hole Oceanographic Institution, was recently nominated as the 2012 Fellow of The Oceanography Society (TOS) for his innovative and visionary application of satellite ocean colour technologies to interdisciplinary oceanography, and his extraordinary service to oceanography. This is a great achievement and we extend our congratulations to Jim on behalf of the IOCCG Committee.
A working group was recently established by the IOCCG to develop what is tentatively called “The International Network for Sensor Intercomparison and Uncertainty assessment for Ocean Color Radiometry (INSITU-OCR)” in support of the Committee on Earth Observations Ocean Colour Radiometry Virtual Constellation (OCR-VC). This working group, co-chaired by Giuseppe Zibordi (JRC, Ispra, Italy) and Sean Bailey (NASA GSFC, Greenbelt, MD, USA), was formed with the goal of consolidating a set of recommendations that highlight the essential activities necessary to ensure the effective continuation and development of ongoing and future ocean colour missions. These recommendations, which will take the form of a 15 to 20-page white paper, will be presented to the various international space agencies to garner support for a concerted inter-agency effort on activities relating to sensor inter-comparison and uncertainty assessment of data sets required for the generation of Essential Climate Variables from ocean colour.
The working group held a meeting at NASA’s Goddard Space Flight Center on February 15th and 16th, 2012 to discuss a wide range of issues under four major topics: Space Sensor Radiometric Calibration, Characterization and Temporal Stability; Development and Assessment of Satellite Products; In Situ Data; and Information Management and Support. A series of recommendations under each of these topics were agreed upon and will form the basis of the working group’s final report.
It is with deep regret that we inform you of the passing of our dear colleague, Dr. Andreas Neumann. He was one of the founding members of the IOCCG and was instrumental in forming the IOCCG working group on "Calibration of Ocean Colour Satellite Sensors". He served on the IOCCG Committee from 1997 to 2001 and also played a prominent role in working with data from the IRS-P3 MOS instrument (1996 – 2004), the first of the "new generation" of ocean colour sensors in the post-CZCS era. Andreas was an inspiration to many people and was a strong supporter of ocean colour science. On behalf of the IOCCG Committee we extend our deepest condolences to his family and friends.
The 2nd GOCI PI Workshop was held at KORDI (Ansan, Korea) on 11-12 Jan. 2012 to highlight scientific research using data from the geostationary GOCI mission. A large number of international research scientists as well as over 150 companies participated in the workshop. Presentations included GOCI validation and algorithm development, ocean environmental monitoring, turbid water studies and fisheries applications. An informative discussion session took place on the last day of the meeting. Suggestions included making aerosol data available, improvement in data transfer speed, Rayleigh-corrected algorithms, L2 batch processing in GDPS S/W, and sharing Cal/Val data. The Korea Ocean Satellite Center (KOSC) provided simultaneous interpretation and posted presentations on their website so that all participants could share and discuss their research achievements using GOCI data. The GOCI PI workshop will be held every two years.
Marcel Wernand and Winfried Gieskes recently published an overview of the history of the interpretation of natural water colouring entitled Ocean Optics from 1600 (Hudson) to 1930 (Raman). The book outlines the development of the understanding of natural water colour from the time of Henry Hudson (1600) to that of Chandrasekhara Raman (1930). They highlight reports of early explorers and scientists, as well as fishermen and sailors intrigued by ocean optics and the colour of the water, and also describe the early instruments developed to quantify water transparency and colour. The book represents an excellent introduction to aquatic optics as well as an overview of the maturing of marine optical research over the past few centuries. Contact the publishers, Union des océanographes de France (firstname.lastname@example.org) to order.
Several new positions have been added to the Employment Opportunities section of the IOCCG website. For further details see: www.ioccg.org/employment.html.
Since its launch from Vandenberg Air Force Base in California on 28 Oct. 2011, the NPP spacecraft and its five instruments have been undergoing initial checkout before starting regular science observations. VIIRS acquired its first measurements on 21 Nov. 2011 and recently two stunning new 'Blue Marble' images of the Earth (western and eastern hemisphere) were created by NASA scientists, using a number of swaths acquired by NPP-VIIRS on 4 and 23 January 2012. The NPP satellite was renamed Suomi National Polar-orbiting Partnership, or Suomi NPP on 24 Jan. 2012 to honour the late Verner E. Suomi, a meteorologist who is recognized as "the father of satellite meteorology." After the commissioning and a calibration/validation period, NPP data will be available from NOAA's Comprehensive Large Array-data Stewardship System at: www.class.noaa.gov.
NASA reports that the quality of the MODIS Aqua ocean colour products produced by the OBPG have degraded significantly over the past year, especially in the blue, due to unpredictable changes in the instrument radiometric calibration and limitations of the on-board calibration capabilities to track those changes.
The OBPG was previously using a cross-calibration of MODIS Aqua-to-SeaWiFS to augment the onboard calibration, but that capability ended with the demise of SeaWiFS. Recently, the MODIS Calibration Support Team (MCST) developed a similar approach using desert sites with good results. This desert-based correction is now being evaluated for application to the ocean colour time-series. A reprocessing of at least some portion of the MODIS Aqua ocean colour dataset is thus anticipated later this year. A decision following the MODIS Science Team Meeting in early May is anticipated.
The last few months have been very productive and many new references have been added to the IOCCG Recent References list. A new empirical algorithm was developed by Chuanmin Hu et al. (JGR, 2012) to estimate Chl in global low-Chl waters. The algorithm, based on a colour index (CI) defined as the difference between Rrs in the green and a reference formed linearly between Rrs in the blue and red, showed a better relationship between CI and in situ Chl than between traditional band ratios and in situ Chl. Overall, the CI-based algorithm showed improved performance in terms of reduced image noise and consistency between SeaWiFS and MODIS-Aqua because it is more tolerant to atmospheric correction errors and perturbations from Chl-independent particulate backscattering. The new algorithm may serve as a candidate for open-ocean Chl retrievals for all existing and planned sensors.
In another paper by Alvain et al. (Optics Express, 2012) the authors perform radiative transfer simulations in order to explain signals used to detect dominant phytoplankton groups in the PHYSAT method. Radiative transfer simulations were used along with in-situ measurements to understand the signals used in PHYSAT. Sensitivity analyses were performed to assess the impact of variability in phytoplankton and CDOM absorption, and particle backscattering on the reflectance anomalies. Particle scattering explained the largest portion of the spectral variability in reflectance anomalies although variations in CDOM and phytoplankton absorption coefficients can also have a large impact.
In a paper by Shi et al. (JGR, 2011) the authors demonstrate significant spring-neap tidal effects on variability of nLw, Kd(490) and TSM concentrations in the coastal regions of the Bohai, Yellow and East China Seas within a lunar cycle, using 8 years of MODIS-Aqua data. The magnitude of the spring-neap tidal effects is of the same order as the seasonal variations in the coastal region.
Variations of Kd(490) for various tidal phases during the spring season
Lastly, Melin et al. (2011, Opt. Exp.) published an assessment of the use of SeaDAS to process MERIS data, as an approach to minimize the differences in satellite data derived from the various ocean colour missions. SeaDAS offers the possibility of processing satellite ocean colour imagery from various missions in a common framework. A set of vicarious calibration coefficients were derived using in situ data from MOBY. The uncertainties associated with MERIS-derived reflectance spectra are then documented through comparison with field data collected in European waters.
A number of conferences and meetings are coming up that are of interest to ocean colour scientists including the 2012 Ocean Sciences Meeting in Salt Lake City, USA (20-24 February 2012) with a number of relevant Special Sessions including Sessions 03 (Biological Oceanography, Aquatic Biology); 121 (Remote Sensing of the Coastal Ocean Using Hyperspectral and Geostationary Satellite Imagers); 044 (Advancing Satellite Ocean Color Science for Global and Coastal Researh); 156 (Satellite Remote Sensing of the Physical and Biogeochemical Processes of the Ocean and Their Interactions) and Session 011 (Biology, Biogeochemistry, and Bio-optics of the Pacific Sector of the Arctic Ocean). Also, the 17th IOCCG Committee meeting will take place in Denpasar Indonesia (28 Feb - 1 March 2102), the Sentinel-3 Calibration and Validation Planning Meeting in Frascati, Italy (20-22 March 2012) and the Planet Under Pressure conference will take place in London, UK from 26 - 29 March 2012.
Material for possible inclusion in the IOCCG Newsletter should be submitted to the Project Scientist, Dr. Venetia Stuart
Subscription to the IOCCG Mailing List.
Participants receive a brief summary of the IOCCG Newsletter by e-mail (quarterly), as well as hard copies of IOCCG Reports as, and when, they become available.