OceanObs'09 - Additional Contributions

Session: Information and Assessment (03A)

Ocean Data Stewardship
Conkright Gregg, Margarita1; Casey, Kenneth2; Ji, Ming3; Fox, Christopher4; Beard, Russ5; LeDuc, Sharon6; Levitus, Sydney2; Newlin, Michele7; Allegra, Andrew7; Boyer, Tim2; Roby, Eric8; Pissierssens, Peter9
1U.S. National Oceanographic Data Center, UNITED STATES;
2National Oceanographic Data Center, UNITED STATES;
3Oceans Prediction Center, UNITED STATES;
4National Geophysical Data Center, UNITED STATES;
5National Coastal Data Development Center, UNITED STATES;
6National Climatic Data Center, UNITED STATES;
7NOAA/National Oceanographic Data Center, UNITED STATES;
8National Coastal Development Center, NODC, UNITED STATES;
9IOC Project Office for IODE, BELGIUM

As the ocean community looks to the next decade of ocean observations, end to end data management must be considered as an integral part of the design. Ocean data stewardship plays a critical role in ensuring that coastal and ocean observations and information deliver maximum service to society. Ocean data stewardship means more than mere mechanical or electronic acts of data archiving and transfer. It consists of an integrated suite of functions to preserve and realize the full value of environmental data (see Figure 1). These functions must be successfully implemented to ensure optimal use of oceanographic data and information, both in current and in future, often unpredictable applications. The end to end management of data facilitates the ability to integrate data from multiple sources and sensors (i.e. satellites, in situ, and model data) (Figure 2). There are many challenges facing data stewardship in todays world. Issues such as ocean acidification and the effect on plankton and corals, hypoxia and harmful algal blooms in our coasts all illustrate the need for integrated oceanographic data, particularly the chemical, biological, and fisheries data. The complexity of data collected from increasingly more complicated systems, is becoming a challenge for archives to understand, provide stewardship for, and even use. This can stem from the data volumes, formats, lack of good metadata, and even just the complexity of the data itself. On top of this the archives need to be able to keep up with and issue of scalability. Being able to provide proper data stewardship of environmental data given all these associated complexities is a time consuming task for the archive centers. The data system should also allow for easier interoperability and analysis across disciplines. These and other large scale issues require large scale partnerships. Through partnerships in the ocean and coastal communities, we can ensure stewardship of all new data, develop the capability to provide increasingly complex data in a form that is usable for multiple purposes, and engage the user community to generate products that meet their needs.

Integration of Marine Environmental Data in support of the Stewardship of Living Marine Resources
Foley, David G.
Joint Institute for Marine and Atmospheric Research, University of Hawaii, UNITED STATES

There is an increasing emphasis on the employment of ecosystem-based management towards the stewardship of living marine resources. This inherently includes a requirement for the accessibility of timely descriptions of the aspects of marine environment that are relevant to a given ecosystem. In the past decade there has been a proliferation of publicly available oceanographic data sets derived from a variety of platforms and sensors. National, Provincial, and Municipal researchers and managers who are not necessarily expert in the production and distribution of oceanographic satellite data often face a bewildering, and seemingly contradictory, array of options when choosing data for use in their applications. The standards and data products stemming from the international components of the Global Earth Observing System of Systems (GEOSS) provide a mechanism that may serve to increase the accessibility of such products while improving their quality. We offer examples in which highly-derived products and dissemination systems are being employed on the North American Pacific Coast to support management of both fisheries and protected species.

Performance Assessment of ERS-2 and Envisat Ocean Altimetry Time Series
Faugere, Y1; Mertz, F1; Ollivier, A1; Femenias, P2; Picot, N3

Almost 14 years after its launch, ERS-2 is still flying and providing altimetric measurements. Due to the loss of the on-board register in 2003, the data coverage is now partial. Its successor, Envisat, launched in 2002, does not only ensure the continuity of the observations provided by ERS-2, it also significantly improves the data quality, allowing Envisat to reach the same high level of accuracy as other precise missions such as T/P and Jason-1. Data from these 2 missions are used by a various range of oceanic applications, from real time mesoscale modelling to fine climatology analysis.

The quality assessment of these data is routinely performed at the CLS Space Oceanography Division. This paper presents the main results in terms of ERS-2 and Envisat data quality and performance: verification of data availability and validity, monitoring of the most relevant altimeter and radiometer parameters, assessment of the altimeter systems performances.

This work includes a cross-calibration analysis of data with other flying precise altimetric missions. This step is essential to assess data quality and performances, and to allow combination of altimeter datasets as required by applications and operational oceanography. Envisat is also an important third point of comparison between the Jason-1 and -2. Finally, altimetry data are compared to a tide gauge data network. Comparisons with an independent data set are indeed of great interest to detect drifts and biases.

Mean Sea Level Trend Estimated From Envisat Altimetry Mission: Comparison with Jason-1 and In Situ Data
Faugere, Y1; Ollivier, A1; Ablain, M1; Valladeau, G1; Femenias, P2; Picot, N3

The global Mean Sea Level (MSL) derived from altimetry data, TOPEX/Poseidon and Jason-1 dataset in particular, are today used as the reference for climate studies (MSL aviso website http://www.jason.oceanobs.com/msl). Envisat altimeter system (RA2/MWR/DORIS) has the technical capacity of reaching the high accuracy needed for MSL studies. Extensive work has been done on the Envisat MSL which allows to identify the potential causes of the differences with the other satellites. The recent Envisat MSL studies henceforth show a certain confidence in the MSL evolution provided by Envisat after removing the first years.

First, a status on the current MSL seen by Envisat altimeter will be given and a cross comparison with Jason-1 will be performed. Notably, the impact of recent updates and sensitivity studies will be detailed. A list of all the possible causes of errors in the MSL Envisat computation will then be analysed: geophysical, instrumental and orbital potential sources will be listed. Secondly, the Ra-2 time series will be compared to in situ data a global tide gauge network and Temperature and Salinity (T/S) in-situ measurements. These two kinds of in situ measurements are complementary: TG in-situ data have a very good temporal sampling (1 hour) but a poor spatial repartition (only on coastal areas), while T/S profilers are very well spread out over the whole open ocean but with a temporal sampling close to 10 days. The objective of this comparison is on the one hand to detect jumps or drifts in the altimeter MSL, and on the other hand to estimate the performances of new standards in the altimeter products. This shall give to the users a quantification of the confidence that can be given to Envisat altimetric mission as a complementary source of data in climate studies.

Observation Requirements for Scientific Assessment of Operational Ocean Forecasting System, as Performed in GODAE
Hernandez, F.1; Martin, M2
1IRD/Mercator Ocean, FRANCE;

In the framework of GODAE, but also European funded project like MERSEA, several countries around the world have been developing an operational capacity for short term ocean dynamics prediction. Ocean forecasting systems rely on observations to provide more realistic hindcasts and forecasts, through assimilation procedures. Moreover, most of these operational groups have implemented Cal/Val procedures, based on scientific assessment of the system and products. These procedures aimed first to verify the realism of ocean estimates, and monitor the forecasting system in operation. Second, used in delayed mode, they provide a validation of numerical simulations as performed classically by the ocean modelling community.

This scientific assessment is based on standardized diagnostics - or metrics - that allow quantifying the error level of ocean products. They usually rely on observations, in-situ or from space. The diagnostic can be "independent" if the set of observation has not been previously used in the assimilation. Satellite observations of sea level (altimetry), sea surface temperature (radiometry), ocean colour (imagery) are frequently used to verify mesoscale and large scale signal of the upper ocean. At depth, one relies on in situ data for assessment of currents (e.g. from moored currentmeters, vessel mounted ADCP, drifters) or assessment of water masses (temperature or salinity from moored array, drifters or profiling floats, XBTs, CTDs, thermosalinograph...). Forcing fields errors are also verified in some cases, and other combined products are also used. An overview of observations used in GODAE-like assessment procedures is given, as well as some requirements in term of observing network for future implementations.

Towards a Long Term Monitoring of Water Discharge in Coastal Arid Climates: Changes by Natural and Human Influences
Lechuga-Devze, C.H.; Mendoza-Salgado, R.A.; Maldonado-Garca, M.C.; Aguilar-Jurez, M.A.
Centro de Investigaciones Biolgicas del Noroeste, MEXICO

Water sources in arid climates assure human settlements and productive activities, from subsistence to intensive agricultural practices. In southern Baja California a number of water sources (mainly oases) are characteristically spread out and funnel their water resources to a short watercourse eventually discharging to a central lagoon, surrounded typically by fresh water vegetation. The lagoons are typically nourished by a larger waterway, and the surface water is eventually lost by evaporation, by filtration, or sea discharge.

The chemical composition of the emerged water, its watercourse, and fate (whether oceanic, atmospheric or reincorporation to the ground) show variability driven by natural influences (type of soils, density of vegetation, insolation, and rain amount) or by human uses (agriculture, waste water discharges). Nitrogen and phosphorus enrichment is expected as a result of agriculture or urban activity. Along the waterway, salinity can be modified by the type of soil, evaporation or by its proximity to a marine inlet. The waterways are also a source of oceanic nitrogen, phosphorus and silicate discharges and affect the marine biota and, by consequence, the extent of variability of the flow discharge can promotes changes in the site marine primary productivity.

Those scenarios are important for arid zones such as Baja California, where a number of small and larger towns depend on the underground water. This research describes the water quality at the source, along the waterway, and at its discharge on the sea. This work (2004-2008) is part of a long term monitoring program reports of chemical data of some of the known oases in Baja California Sur. These sites are recommended for insertion into the new international net of Marine Observatories (Mexican-French agreement), starting in 2009. The purpose of which is to observe changes driven by increased human activity, and for developing indicators of change for French coasts, the Gulf of Mexico coast, the Caribbean Coast, and the Baja California coasts. The medians of first data are showed in table I.

World Ocean Database and World Ocean Atlas
Levitus, Sydney; Boyer, Tim P.; Antonov, John I.; Garcia, Hernan; Johnson, Daphne; Locarnini, Ricardo; Mishonov, Alexey; Seidov, Dan; Baranova, Olga; Smolyar, Igor; Zweng, Melissa; Levitus, Sydney; Boyer, Tim P.; Johnson, Daphne; Locarnini, Ricardo; Mishonov, Alexey; Seidov, Dan; Baranova, Olga; Zweng, Melissa

The World Ocean Database (WOD) is the largest collection of quality-controlled ocean profile data available without restriction. WOD is constructed and maintained by the U.S. National Oceanographic Data Center. The WOD contains data for 25 different variables including temperature, salinity, oxygen, nutrients, and tracers among others. These data have been measured with several different types of instrument systems including water bottle samplers, reversing thermometers, CTDs, XBTs, MBTs, profiling floats, gliders, moored buoys, and drifting buoys among others. The data in WOD and products based on WOD such as the World Ocean Atlas (WOA) climatologies have proven to be of great value to the oceanographic, climate, and geodetic communities. These products are used in ocean climate diagnostic studies, as boundary conditions in ocean circulation models, for ocean data assimilation studies, and as sea-truth for satellite altimetry studies among others. The effect of WOD and WOA can be quantified by a count of citations in the peer-reviewed scientific literature of the WOD and WOA atlases and their predecessor Climatological Atlas of the World Ocean. Figure 1 shows that since 1982 these products have been cited more than 5,900 times. It is clear that global compilations of oceanographic data and analyses of these compilations are of great value to the science community. The scientific community is advising governments about global climate variability and global climate change. Thus the community needs to have access to the most comprehensive ocean profile databases possible. All data from ocean observing systems need to be permanently archived with appropriate metadata.

"El Nino" Influences Fish Capture in La Paz Bay, Gulf of California: Eight years of Monitoring.
Maldonado-Garca, M.C.; Vzquez-Hurtado, M.; Lechuga-Devze, C.H.
Centro de Investigaciones Biolgicas del Noroeste, MEXICO

From 1998 to 2005, artisanal fish captures were analyzed from records provided by official sources. Monthly surface temperature of La Paz bay was obtained from satellite data. The fishing effort was estimated for 552 fishing boats of 20-foot length in the whole bay and the surrounding Gulf of California. From 1998 to 2000 the small annual variability of temperature showed "El Nino" influence. Starting 2001 this condition disappears and larger temperature variability was evident. During "El Nino" influence captures of Spotted rose snapper (Lutjanus guttatus), ocean whitefish (Caulolatilus princeps), flathead mullet (Mugil cephalus), and the yellow fin mojarra (Eucinostomus sp), were lower. After 2001 without "El Nino" influence, the captures of these species increased. The opposite trend was observed for tuna (Thunnus albacares), and no influence was evident for Pacific red snapper (Lutjanus peru), Leopard grouper (Mycteroperca sp.), and Crevalle Jack (Caranx sp.).

Observing Systems in Italian Waters
Manzella, G.1; Griffa, A.2; Santoleri, R.3; Zambianchi, E.4; Spezie, G.C.4; Marullo, S.5; Cervino, R.6; DeMarte, M.6; Masina, S.7; Vichi, M.7; Tunesi, L.8; Mosetti, R.9; Crise, A.9; Zincone, A.10; Ribera D'Alcal, M.10; Corsini, S.8; Manzella, Giuseppe1
10Stazione Zoologica, ITALY

In January 2009 it was established the Italian Oceanographic Commission (COI), having the role of a coordination body foreseen in IOC-Unesco statutory regulations. The commission is composed by representatives of the main Italian institutions working in the marine sciences: Consiglio Nazionale delle Ricerche, Consorzio Nazionale Interuniversitario per le Scienze del Mare, Ente per le Nuove tecnologie l'Energia e l'Ambiente, Istituto Idrografico della Marina, Istituto Nazionale di Geofisica e Vulcanologia, Istituto Superiore per la Protezione e la Ricerca Ambientale, Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Stazione Zoologica Anton Dorhn.

The commission has to address those issues that make more effective the participation to IOC activities.

COI collaborate with the Italian operational systems (GNOO) to consolidate and expand the concerted monitoring and forecasting systems. It aims to encourage national scientific research on monitoring, assessment activities and advances in scientific understanding of the Mediterranean Sea. The institutions represented in COI are managing observing networks on: sea level, waves, temperature and salinity profiles with ships of opportunity and research vessels, physical, chemical and biological parameters with buoys, currents and physical parameters with moorings. Also satellite data are operationally collected in order to provide sea surface temperatures, colour data, altimetric data, scatterometer data.

The COI institutions are actively participating to the following IOC programmes: Global Sea Level Observing System, Global Ocean Observing System, International Oceanographic Data Exchange, Joint IOC/WMO Commission on Marine Meteorology, Marine Environment, Tsunami, World Climate Research Programme.

OceanBIT: an International Coastal Ocean Observing and Forecasting System based in the Balearic Islands

OceanBIT (BIT for Balearic Islands Technologies) is a multi-platform distributed and integrated facility that will provide streams of oceanographic data and modelling services in support to operational oceanography in the Balearic Islands in a European and international frame, therefore also contributing to the needs of marine and coastal research in a global change context. Operational Oceanography is here understood in a wide sense, including both the systematic, long-term routine measurements of the seas and their interpretation and dissemination and also the sustained supply of multidisciplinary data to cover the needs of a wide range of scientific research priorities.

OceanBIT activities will be mostly (but not only) centred in the western Mediterranean, with focus in the Balearic Islands and adjacent sub-basins (specifically Algerian and Alboran/Gibraltar) and covering from the nearshore to the open ocean. Basic principles are: scientific and technological excellence through peer review; science, technology and society driven objectives; support to R&D activities in the Balearic Islands (existing and new ones); integration, coordinated multiplatform, multidisciplinary and sustained (systematic, long term and different scales) monitoring, partnership between institutions; free, open and quality controlled data streams; baseline data in adherence to community standards.

OceanBIT objectives are driven by state of the art international scientific and technological priorities but also, by specific interests from the Spanish and Balearic Islands society. The general objective is twofold: (1) to address and respond to international scientific, technological and strategic challenges for operational oceanography in the coastal ocean and (2) to vertebrate the coastal ocean operational oceanography research being carried out in the Balearic Islands, contributing to the consolidation of a well structured centre of excellence. Five specific objectives have been also identified: Scientific, Technological, Strategic (response to society needs), Transfer of Knowledge (including Outreach and Education) and Training and Mobility.

On a long term, our vision is to advance on the understanding of physical and multidisciplinary processes and their non linear interactions, to detect and quantify changes in coastal systems, to understand the mechanism that regulate them and to forecast their evolution and or adaptation under, for example, different IPCC scenarios. Ocean_BIT will specifically address the preservation and restoration of the coastal zone and its biodiversity, the analysis of its vulnerability under global change and consider new approaches, such as connectivity studies and Marine Protected Areas optimal design to advance and progressively establish a more science based and sustainable management of the coastal area (ICZN).

OceanBIT will be composed of three major subsystems: (1) an observing sub-system, (2) a forecasting and data assimilation sub-system and (3) a data management, visualization and dissemination sub-system. OceanBIT components will be constituted by a sustained, spatially distributed, heterogeneous, potentially relocatable and dynamically adaptive observing network that will be integrated through data management and numerical methodologies to exploit the synergies between both the observational network (moorings network, surface velocity drifters, ARGO profilers, HF radar, gliders, AUV's, R/V's, VOS, etc.) per se and between the observational network and the numerical models (physical-waves and currents at different scales- and biogeochemical coupling) and assimilation tools, with the aim to provide a complete and integrated description of the physical and biogeochemical properties of the marine environment.

OceanBIT will have both static and relocatable facilities (the facilities make the observations that are specified by the nodes that provide the objectives, in line with IMOS in Australia). The first ones will be mostly sustained in permanent locations (in response to operational and scientific needs) and will be open and internationally access free. The second, relocatable dynamic facilities will have adaptive capability in space and time to respond to specific scientific requests that will be allocated after an international peer reviewed process in response to open annual international calls.

OceanBIT is part of the Spanish Large Scale Infrastructure Facilities (ICTS). An international scientific advisory committee will be responsible for the implementation of a peer review evaluation process following the highest quality standards. It is no formally a new Consortium with legal entity, with approved funding, up to 36 million Euros, including 14 million Euro for scientific equipment and facilities, and 2 million Euros/year for running costs during 11 years (2011-2021). Activities planned for 2009 specifically include preparation of the implementation plan.

Potential improvement to the standard technique for calculating expandable bathythermographs fall-rate equation
Tchen, T

The presence of biases in Expandable Bathythermograph (XBT) is an issue currently unresolved which has implications on the estimation precision of the global ocean heat content, particularly in instances where historical XBT records are used for determining its change rate. The temperature values obtained from XBT are derived from the probes depth positions, which in turn are determined by applying a fall rate equation which initially was provided by the manufacturer. It was recognized that the calibration of the probe of which the intended design was the estimation of sound speed profiles by the Navy lacked sufficient precision for scientific research particularly of climatic type. Hanawa et al (1994) published a temperature-error-free method which was adopted by UNESCO as marine science standard method for calculating fall rate equation. The technique is widely used in comparative analysis of profiles from XBT collocated with reference instruments such as high accuracy CTD. The accuracy of the Hanawa technique is proven to be particularly effective in regions of the water column characterised by sufficiently varying temperature gradients. However, the ability of the method to accurately determine isotherm depth differences significantly degrades in situations where the temperature gradient is constant or where the XBT temperature profile does not present features well matched by the collocated reference profile (Hanawa et al 1994). Importantly, these situations represent a significantly large proportion in actual operational conditions, ie more than a third of all data in some of the cruises analysed. In order to overcome these shortcomings, a method based on signal signature and pattern recognition was tested which produced promising results. This study introduces the novel approach for testing the data and reports on the potential improvement to the standard method. The methodology consisted in an application of wavelet transform in combination with pattern recognition technique. Wavelet transform is commonly used in the image analysis field (Addison 2002). Here we applied the technique to data series of XBT and CTD. Specifically discrete wavelet transform (DWT) was used as the data consisted of sampled data. Firstly, a DWT was applied to the data of interest to give a wavelet representation. Secondly, in the wavelet space, the isotherm depth differences were treated as signal affected by noise. Subsequently a wavelet shrinkage denoising was applied to separate and remove the noise (Donoho et al, 1992). In this step, non-matching elements were eliminated as noise. Thirdly the denoised and deconvoluted data were assimilated through a pattern matching process and the resulting data aggregated into a least squares fit to produce the XBT fall rate equation. Figure 1 shows the flowchart of the methodology. Figure 1. Process flowchart. DWT: discrete wavelet transform; WSD: wavelet shrinkage denoising; LSF: least squares fit The study examined a series of collocated XBT and CTD data collated by the NODC and identified a number of cases where the standard technique failed to produce reliable results. The new technique was applied to these series to produce significantly greater accuracies. Figure 2 shows an example of isotherm displacement plot for a series (NODC31025260) of collocated XBT and CTD. The left plot shows the depth-errors produced by application of the standard method and the right plot shows the depth-errors obtained by applying the new technique. Figure 2. The new method (right-hand figure) produced a significantly better fit than the standard method. MSE was reduced from 115 to 69. Analytical tools. The core engine of the analysis software was coded in Objective-C. The code is POSIX and X11 compliant. Graphic output was produced using Matlab. For details, contact: tvtchen@LogicFour.com.au. Conclusion. By taking into consideration data series as a whole instead of arbitrary sections, this powerful method enabled an improved estimation of the fall rate equation and the conservation of continuity over regions exhibiting either low temperature gradient change or lacking highly matching features. The novel technique is not exposed to biasing nor to over-weighing related to low signal-to-noise ratios, hence offers potential improvement to the standard technique. It emulates the results of visual inspection whilst lending well to automation. The novel technique could be advantageously be deployed in batch calibration for achieving greater accuracy in future XBT deployments. References Hanawa, K., Rual, P., Bailey, R., Sy, A., Szabados, M. (1994). Calculation of New Depth Equations for Expandable Bathythermographs Using a Temperature-Error Free Method. Unesco Technical Paper Marine Science, 67. Donoho, D.L., Johnstone, I.M. (1992). Minimax estimation via wavelet shrinkage. Stanford Univ. Dept. Stat, National Science Foundation (U.S.). Addison, P.S. (2002). The Wavelet Transform Handbook, Springer.

An ocean monitoring system for fisheries in waters around Japan
Watanabe, Tomowo; Shimizu, Manabu; Setou, Takashi; Kuroda, Hiroshi; Masujima, Masachika; Okazaki, Makoto
National Research Institute of Fisheries Science, FRA, JAPAN

The waters around Japan are known as a densely observed area in the world. Fisheries institutes in Japan are playing an important role in the continuation of the ocean monitoring from the 1910fs. The monitoring system operated by fisheries institutes has definite purpose to provide oceanographic information to fisheries communities. The work was done by using the handwriting systems and real mail system in the past. Numerical modeling systems are necessary for integration of various sorts of observation data in the present time. An ocean forecast model, FRA-JCOPE, was developed under the cooperation of JAMSTEC and is operated by Fisheries Research Agency for the monitoring system. The monitoring system has advantages that can use oceanographic data obtained by fisheries institutes for data assimilation. While ARGO data and satellite SSH data are very important in the model, the data are less available in the coastal region which is quite important for fisheries. This insufficiency is expected to be compensated by the oceanographic data obtained by fisheries institutes in the monitoring system. Requests for improvement of the accuracy of oceanographic products in the coastal region occupy main position of the subject list of the monitoring system. The three-dimensional data produced by the monitoring system are provided to member institutes for diagnosing the oceanographic conditions and for providing fisheries information to their tax payer. The data are also applied to the fisheries researches. For example, the drift of Giant Jellyfishes in the East China Sea is calculated by using the forecasted surface currents. Transport experiment of bluefin tuna larvae near the continental shelves is performed in order to investigate the mechanisms of the recruitment of young bluefin tuna.