- CISL Feature Story
- Allocated dedicated time on NCAR's 624-processor 4.7-TFLOPS supercomputer bluevista for colloquium participants
- Oriented the new users to the NCAR computing facility
- Provided training tailored to the project
- Presented a lecture on the challenges of employing massively parallel processing technology
- Implemented a new job queue for the project
- Issued user names and one-time password devices to new users
- Produced daily usage reports for the project
- Provided laptops for some of the participants
CISL Supports NCAR ASP ColloquiumCISL provided cyberinfrastructure and consulting support to a 2008 NCAR Advanced Study Program (ASP) colloquium entitled Numerical Techniques for Global Atmospheric Models. The colloquium, which was jointly supported by NSF, NASA, and the Department of Energy, was held at NCAR on 1-13 June in Boulder, Colorado. This working group of graduate students, model developers, and scientists tested and analyzed 13 dynamical cores that are being considered for next-generation atmospheric models. The dynamical core solves, loosely speaking, the governing equations on resolved scales. The efficiency of the dynamical core is critical for large, high-resolution models to complete runs in a practical amount of time. ASP colloquium participants performed hundreds of test runs to analyze these 13 cores, and this gave insight into the advantages and disadvantages of different approaches for designing dynamical cores.
CISL's people, technology, and facilities played a key role in the colloquium. The results and methodology from the workshop are available to the research community via a new science gateway developed collaboratively by the Earth System Curator and Earth System Grid (ESG) projects in CISL. The effort was also supported by NCAR's Cyberinfrastructure Strategic Initiative, which seeks to develop a Science Gateway Framework that can be used to develop a variety of different portals. The teams jointly extended the Earth System Grid portal by adding structured information, or metadata, about the scientific and technical properties of the dynamical cores and by building new tools, such as comparison tables, that utilize that metadata. Modelers who examine the portal will find not just datasets for download, but a rich store of semantic information that enables them to better understand how and why results were obtained. This ASP colloquium attracted graduate students with backgrounds in atmospheric science, applied mathematics, and/or computer science, and it introduced them to the latest developments in weather and climate modeling. An elite group of lecturers, model developers, and mentors provided input and guidance for the two weeks of intensive work. A total of 38 students, 4 organizers, 13 modeling mentors, and 18 lecturers participated in this event that produced significant benefits for both the attendees and the atmospheric research community. The graduate students received education and experience in atmospheric science, modeling, and computer architectures, and they performed and archived more than 350 simulations from models that incorporated the 13 dynamical cores. The organizers now have a large archive of data for their research. The modeling community has a rich and timely intercomparison dataset—described in detail using metadata and available through a science gateway—that may be used to improve the dynamical cores and create new standards. The limitations of past supercomputers required separate development paths for regional-scale weather models and global-scale climate models. Current supercomputers operating at tens of teraflops—and the coming petascale systems running at thousands of teraflops—will allow a single type of model to simulate atmospheric phenomena on multiple scales, from local to global. The key to this new type of model is an efficient and accurate dynamical core, the central component of every climate and weather research model. Research in dynamical cores faces many scientific and computational challenges. Increasing grid resolution puts strong demands on the computational efficiency of the numerical algorithms. This is especially true on the massively parallel computer architectures being developed to incorporate hundreds of thousands of processors. Pathways for sharing the data and metadata
The goal of the NSF-funded Curator project is to contribute to comprehensive science portals in which model source code, simulations, datasets, and individual model components are linked through metadata. This benefits model intercomparison projects, which require that modelers have information about the algorithms and codes they are analyzing. A specific benefit to modelers is the effort to standardize how datasets are linked to models: how they were generated, what flags were set, which input datasets were used, what initial conditions were used, and so on. Collaborators working on other aspects of the Curator project include the Georgia Institute of Technology, the Massachusetts Institute of Technology, Princeton University, and the European MetaFor effort (Common Metadata For Climate Modelling Digital Repositories). Rather than trying to build a computing environment from scratch, the Curator project enhanced the Earth System Grid portal, which had an initial ontology—a structured collection of metadata—in place. Sylvia Murphy of Earth System Curator coordinated the joint effort, organized the development of new metadata with Luca Cinquini of ESG, and was the primary point of contact for the colloquium organizers. CISL software engineer Julien Chastang created several specialized tools for use with the enhanced metadata. One is a "trackback" page that details the model configuration associated with a particular dataset. It shows the scientific and technical properties for a model as a whole, and for each constituent component in the model. A second tool enables modelers to dynamically create comparison tables for a select set of models or components and a select set of properties. For the ASP colloquium, these tools helped participants track and understand the characteristics of each core, including information on the resolution, time step, spatial filtering, and input datasets that were used for each simulation. Since Earth System Grid will be a primary portal for hosting IPCC Fifth Assessment data, and the enhancements from Curator will be folded into the main ESG portal, the improvements in metadata and tools arising from this ASP colloquium will benefit the next IPCC assessment. More CISL contributionsCISL deployed a new science portal for archiving data and metadata for the colloquium. Building on CISL's strategic effort to develop a flexible Science Gateway Framework, the new portal was developed jointly by CISL staff working on the Earth System Curator and Earth System Grid projects. For this colloquium alone, the NCAR Mass Storage System (MSS) received a 1.1 TB archive of model output. CISL staff wrote software to automatically load the data from the MSS onto the new portal, publish it to the web, and upload the metadata for each test case.
Supporting 38 new users and providing the appropriate cyberinfrastructure for the project required a significant commitment from CISL: OutcomesThe four primary colloquium organizers will prepare a research paper for publication describing how this approach to testing dynamical cores can benefit the field (the full test case formulation used in the colloquium will be available as a NCAR technical report shortly). Christiane Jablonowski (University of Michigan) and Peter H. Lauritzen (NCAR, ESSL, CGD) created a specific set of idealized test cases designed to highlight strengths and find weaknesses in the cores. Christiane and Peter are now analyzing the data generated during the colloquium to understand how both the test suite and the cores performed. The testing approach used for the colloquium has the potential to become a community standard for testing dynamical cores. The ongoing analysis and their paper will further develop this idea. Also, the organizers are editing a book based on contributions from the colloquium lecturers that is going to be published in the Springer series Lecture Notes in Computational Science and Engineering.
On the webPortal
URL: http://dycore.ucar.edu/ About NCAR's Advanced Study ProgramNCAR's Advanced Study Program encourages the development of young scientists in the fields of atmospheric and related science, and it directs attention to timely scientific areas needing special emphasis. The ASP also helps to organize new science initiatives, supports interactions with universities, and promotes continuing education at NCAR. Sponsored by the National Science Foundation and NASA, the 2008 ASP summer colloquium's primary organizers were Peter H. Lauritzen (NCAR, ESSL, CGD), Christiane Jablonowski (University of Michigan), Mark Taylor (Sandia National Laboratories), and Ramachandran D. Nair (NCAR, CISL, IMAGe). Four distinguished lecturers presented the four keynotes: Professor John Thuburn, Professor of Applied Mathematics in the School of Engineering, Computer Science, and Mathematics at the University of Exeter, U.K.; Professor Dale Durran, Professor and Chair of Atmospheric Sciences, Adjunct Professor of Applied Mathematics, Atmospheric Sciences at the University of Washington; Dr. Todd Ringler, Climate, Ocean, and Sea Ice Modeling Group, Theoretical Division at the Los Alamos National Laboratory; and Professor David A. Randall, Department of Atmospheric Science at Colorado State University.
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