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The Climate Simulation Laboratory (CSL), which was established in 1995, represents CISL’s premier opportunity for researchers seeking high-performance computing and data storage systems to support extremely demanding, high-profile climate simulations. Such simulations require high resolution, span many centuries of simulated time, encompass large numbers of ensembles, integrate new physics or models, or address national and international scientific priorities.
CSL projects’ large-scale, long-running simulations typically require millions of core-hours to complete and usually produce many terabytes of model output that must be stored for analysis and comparison with other simulations and with observations. Approximately 70 million core-hours are allocated to four to six CSL projects each year.
Requests must meet or exceed the minimum request size of 10 million core-hours on Yellowstone. Very large projects, if awarded, may be required to consume their allocation approximately evenly over the course of the allocation period.
For purposes of the CSL, the Earth's climate system is defined as the coupled atmosphere, oceans, land, cryosphere, and associated biogeochemistry and ecology, studied on time scales ranging from seasons to centuries. The CSL encourages collaborations with scientists involved in policy development, including impacts, mitigation, and adaptation options for climate change as well as short-term climate variations.
The CSL computational facilities are operated and maintained by the NCAR Computational and Information Systems Laboratory (CISL) and supported by the NSF.
CSL proposals must address and discuss the following eligibility criteria in their allocation requests.
Requesters must complete the online CSL Allocation Request Form and attach a Request Summary document (PDF format).
The Request Summary document must provide a self-contained description of your project and allocation request. The Request Summary may be no more than eight (8) pages for Sections A-D below; Sections E-G must be included in the same uploaded document and are permitted an additional five (5) pages. The page limits apply to all requests, and it is strongly recommended that you follow the template below to help the panel locate required information within your request.
The format for CSL requests closely follows the format for CHAP/University Large Allocation requests. CSL requests are allowed three (3) extra pages due to the additional scrutiny that these projects receive and the expectations for significant progress in a short period. These instructions call out suggestions for topics to which requesters should devote those extra pages. The CSL Review Considerations provide further detail on considerations the review panel uses in identifying meritorious CSL requests.
A. Project Information
B. Overview of Project . The overview of the project should typically be less than half a page and should summarize:
C. Science Objectives . The science objectives must be described with sufficient information for understanding the computational plan in Section D and the need for a large-scale CSL allocation. Please keep in mind that a collection of unrelated activities that are assembled to reach the minimum CSL allocation size does not constitute a valid CSL request.
Advice for preparing your request. CSL requesters may want to provide greater detail on their scientific objectives, as compared to university allocation requests. The strength of the scientific justification will come into play if the panel cannot give adequate resources to all meritorious CSL requests and can recommend only a subset of requests for award. In addition, requesters may want to describe in this section the nature of any multi-institutional or multi-investigator collaboration and how the team members contribute to the pursuit of the scientific objectives and the computational effort. However, an elaborate justification of the scientific objectives does not replace the need for a strong justification of the computational need, so this section still should be no longer than 2½ to 3 pages.
D. Computational Experiments and Resource Requirements The bulk of the Request Summary should focus on Section D. Discuss your planned computational experiments and the resources needed to conduct the work in this section.
Advice for preparing your request. Given the large-scale nature of CSL projects, ensure that the description of your computational experiments explicitly justifies why your large-scale request is both necessary and sufficient to accomplish the scientific objectives. The panel will likely downgrade requests that appear to have been padded with unnecessary work or use unnecessarily complex runs to address the science questions. Furthermore, CSL requests must demonstrate to the panel—that is, not merely claim, but provide sufficient supporting information, such as benchmark runs and scaling data—that the codes to be used are production-ready on Yellowstone.
Provide a table summarizing the resources required for each experimental configuration and the complete set of computational experiments. This must include the number of core-hours needed and the terabytes of data destined for HPSS if such storage is required. The table should be accompanied by a narrative that elaborates on how you arrived at the numbers in the table and describes any needs for project disk space or data analysis and visualization resources as detailed below. Failure to provide such a table will reduce your chances of being recommended for an allocation.
With the Yellowstone system’s ability to generate vast amounts of data, CSL allocation requests require users to consider their data workflows and to justify their long-term storage resource use. Requesters should note that the CSL Review Considerations also apply to requests for allocated storage resources—that is, HPSS archive use and GLADE project spaces. The reviewers do not expect lengthy justifications; in most cases, a paragraph that demonstrates forethought commensurate with the scale of anticipated need will suffice. As requests approach hundreds of terabytes (or more!), longer justifications become appropriate. In addressing the criteria with respect to storage resources, justify the project’s need to retain the data to be stored, the project’s rationale for which data will be stored, and the project’s work plan for minimizing temporary data migration from disk to tape. While some statement of storage resource needs is expected in Section D, you may choose to provide details in Section E (Data Management Plan) to keep Sections A-D within the five-page limit. Please note that temporary data that never move beyond scratch disk space need not be justified in the project's allocation request.
1. HPC. The table must give the core-hours per simulated year or appropriate time period and the total core-hours needed for each experimental configuration as well as the total core-hours for the request. Describe how you arrived at the number of core-hours for each proposed computational experiment. To help reviewers evaluate whether the resources sought are justified and will be used efficiently, you must include details on how HPC resource requirements are estimated if they are not provided elsewhere.
Calculating or estimating Yellowstone core-hours. Performing benchmark runs on Yellowstone or using published timings from runs on Yellowstone are the strongly preferred methods for estimating CSL resource needs. The core-hours for a job are calculated from the number of nodes used multiplied by the 16 cores per node and by the wall-clock duration in hours. Because Yellowstone jobs have exclusive use of the batch nodes, core-hour calculations should assume the number of cores will always be a multiple of 16; requests should also assume all jobs will run in the regular queue. (For estimating Yellowstone core-hours based on earlier Bluefire runs, you can assume that 1 GAU is equivalent to 0.47 core-hours on Yellowstone. That is, GAUs x 0.47 = Yellowstone core-hours. Users with benchmark runs from other systems should contact email@example.com to determine a proper conversion to Yellowstone.)
2. HPSS archive. If your data storage in CISL’s HPSS archive during the life of this project will be less than 20 TB, stating “<20 TB” is sufficient and no detailed justification is required. Otherwise, in the table showing core-hours include a column for the terabytes of HPSS space that will be required for each experimental configuration and include the total terabytes stored. Projects with larger anticipated archival storage needs must include a description of how the estimate was calculated. If this request is a continuation of a previous request on the same project, please include a separate entry in the table for current data stored in HPSS.
Justifying HPSS requests. A successful justification for HPSS archive space would describe, for example, that the data have a meaningful purpose beyond initial post-processing steps; that variables or time steps not needed for planned analyses will be filtered out; and that HPC and analysis stages are interleaved where practical to minimize the need for temporary data to occupy tape. From the review criteria, it should be clear that a simple summation of all bytes generated by all proposed HPC runs may set an upper limit on HPSS needs but will not automatically constitute a sufficient justification in and of itself. Where appropriate, the justification should also describe how the project will reduce HPSS holdings in subsequent years (for example, a project may have a larger need during peak activity that will be reduced in out-years). As with computational justifications, the detail for storage justifications should grow commensurately with the project’s anticipated need.
3. Project file space. CSL projects can request dedicated large-scale disk space on the GLADE resource. The justification for GLADE project space must describe how the requested size was determined, how other available resources (such as /glade/scratch, /glade/p/work, and HPSS) will be used to minimize the size of the project space needed, why other storage options are not well suited for all of the project's needs, and how the requested project space will benefit or accelerate the project. Project file spaces must be for needs greater than 5 TB. Again, projects do not need to request or justify access to scratch or work file spaces, which are available to all users.
Justifying project space requests. A successful justification for GLADE project space must demonstrate your understanding of the unique capability offered by project spaces and show that the project will also make efficient use of scratch space and work spaces when possible. As with HPSS requests, a simple summation of all bytes generated by all proposed HPC runs may set an upper limit on overall disk use but almost certainly will not constitute a sufficient justification for dedicated project space. A description of how a project will adapt its workflow to leverage project space (along with scratch and work space) and improve its overall efficiency will strengthen the justification. Where applicable, the justification may also describe how a project space allocation will permit a project to substantially reduce its use of HPSS. As with computational justifications, the detail for storage justifications should grow commensurately with the project’s anticipated need.
4. Data analysis and visualization. Describe any planned need for CISL’s Geyser and Caldera clusters to analyze or visualize your results. For standard interactive access to these clusters, the number of users expected to use the DAV clusters will serve as sufficient justification for up to 5,000 core-hours per user. Projects with more extensive plans for use of the clusters (for example, long-duration, multi-node batch runs) must justify their needs in a manner similar to their HPC requests.
Special Requirements. Please specify any resource requirements that fall outside of the default environment limits, such as the need for longer job runtime limits, that may affect your ability to complete the proposed computational experiments.
Sections E through G together must be no more than five additional pages.
E. Data Management Plan. Consistent with NSF’s requirement that all proposals include a Data Management Plan, summarize your plan for managing the data resulting from this computational work. This section can be used to provide additional details or justification for the storage resource needs, to describe plans for sharing the project’s data, and to summarize any anticipated long-term storage needs beyond the lifetime of the supporting NSF award. A well-justified data management plan becomes more critical as a project's planned output approaches a hundred terabytes or more.
F. Accomplishment Report. The Accomplishment Report should encompass computations performed using CISL resources by the principal investigator or project lead. Clearly distinguish accomplishments on this project (i.e., for prior use associated with the same NSF award) and accomplishments from all past use of CISL resources. Related work performed on CISL resources by other members of a larger research group may be described, if relevant to this request. Briefly describe the calculations and scientific accomplishments that were completed. Include publications submitted or published that resulted from the use of CISL resources. List graduate students who used these computational resources and indicate if these resources supported their thesis or dissertation research. If so, please include the thesis or dissertation title(s).
G. References. Please limit to those directly related to the proposed project and referenced in your Request Summary document.
H. Figures and captions. Optional. Figures may be embedded within the main body of the Request Summary; embedded figures count against the five-page limit. Figures and charts at the end of the Request Summary will not count against the five-page limit.