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IQuOD Project Proposal To produce and make publically available, the highest-quality standard possible historical subsurface ocean temperature (salinity) global database, along with the most complete metadata and formal error measurements. To be achieved through global coordination and support. I nternational Qu ality-controlled O cean D atabase Tim Boyer (GDAC leader) US National Oceanographic Data Center (on behalf of the CLIVAR/GSOP workshop team and international partners) Expert Center Expert Center Data Provider Global Data Assembly Center Manual Quality Control Performed Automatic Quality Control Flags Applied Expert Center Data and quality information IQuOD Information Stream Data User An agreed upon standard set of automated QC procedures will be developed to be quickly applied to any temperature profile type (currently groups are applying their automatic procedures to test datasets of known quality for comparison and assessment).. Automatic QC will identify the portion of profiles that need additional manual expert review. In the case of current WOD QC, this is ~7.5% of the temp. profiles (in the case of QuOTA, ~32%, Gronell et al. 2008) Number of profiles Each suspect temperature profile will be examined and final QC decisions made. Centers of expertise will be designated based on institutional knowledge of the temperature structure of geographic regions, familiarity with instrumentation and QC challenges of historical observational periods (e.g., wire angle depth errors in bottle casts pre-World War II). Centers of expertise will communicate and compare QC decisions to reach an equilibrium between standardization and specialized knowledge. Tools similar to Mquest (Gronell et al. 2008) will be shared to facilitate manual QC. 1.A Global Data Assembly Center to both supply data to the IQUOD system and quickly and easily disseminate results. 2.A standardized internationally agreed upon set of automatic quality control for in situ ocean profile data. 3.A network of centers of excellence with specialized local knowledge in specific temperature profile data and the ability to produce high-quality reliable data sets. 4.A uniform quality controlled baseline historical temperature profile database with uncertainty estimates for oceanographic and climate studies. MRI, MIRC, JODC & TOHOKU UNIVERSITY CSIRO, ACE CRC IMOS & BOM INCOIS & NIO UNIVERSITY OF HAMBURG WHOI IFREMER UK MET OFFICE & BAS SHIRSHOV INSTITUTE SHN UFBA USNODC SCRIPPS ISDM MNODC AOML More details: http://www.clivar.org/organization/gsop/activities/clivar-gsop-coordinated-quality-control-global-subsurface-ocean-climate 1. Global Data Assembly Center 2. Automatic Quality Control 3. Manual Quality Control A globally-coordinated effort to ‘clean up’ the ocean temperature profile database The World Ocean Database (WOD) ideal starting database ( >18,000 datasets consolidated in one format) Huge QC challenge due to numerous sources/instrument (accuracies/biases) contribution over the years. First IQuOD phase is to focus on the period pre-1990. Coordinated QC efforts such as Argo will be used and their QC decisions heeded. WOD will also be the reassembly point, storing and posting final data and QC flags for IQuOD public dissemination. Gaussian Tail for positive depth error is much bigger Josh Willis and Ann Thresher QC Problems (XBT data) Missing XBT metadata & bias corrections Ocean temperature/salinity data are essential to the understanding of variability and change in the Earth's energy/water cycle, and to discriminate between natural and anthropogenic drivers, particularly now in the context of climate change. The historical archive contains a large fraction of biased, duplicated and substandard quality data. So, efforts to analyse past ocean change and variability can be confounded, as can be the use of ocean data assimilation systems. Despite great effort by many groups in rescuing original profiles and metadata, refining quality, and reducing instrumental biases, there is no internationally sanctioned “climate-standard” ocean profile dataset. Presently, a number of institutions perform various levels of quality control, redoing the same job over many times in slightly different ways. In addition, no single group has the expertise and resources to do the complete quality control (QC ) job. International cooperation is required. With that in mind, attendees of a recent CLIVAR/GSOP workshop and interested parties from across the globe are formulating a coordinated approach to quality control ocean temperature (>13 million profiles) and salinity (in the near future) observations. The aim is to maximize the availability and consistency of these valuable and irreplaceable historical ocean subsurface data and to include proper characterization of uncertainty. Source: Abraham et al. (2013, Rev. Geophys.) Credit: Josh Willis (??)
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