Michael Lautenschlager

Documenting Climate Models and Their Simulations

The results of climate models are of increasing and widespread importance. No longer is climate model output of sole interest to climate scientists and researchers in the climate change impacts and adaptation fields. Now nonspecialists such as government officials, policy makers, and the general public all have an increasing need to access climate model output and understand its implications. For this host of users, accurate and complete metadata (i.e., information about how and why the data were produced) is required to document the climate modeling results. Here we describe a pilot community initiative to collect and make available documentation of climate models and their simulations. In an initial application, a metadata repository is being established to provide information of this kind for a major internationally coordinated modeling activity known as CMIP5 (Coupled Model Intercomparison Project, Phase 5). It is expected that for a wide range of stakeholders, this and similar community-managed metad...

The Earth System Grid Federation: delivering globally accessible petascale data for CMIP5

The fifth Coupled Model Intercomparison Project (CMIP5) will involve the global production and analysis of petabytes of data. The Program for Climate Model Diagnosis and Intercomparison (PCMDI), with responsibility for archival for CMIP5, has established the global “Earth System Grid Federation” (ESGF) of data producers and data archives to support CMIP5. ESGF will provide a set of globally synchronised views of globally distributed data – including some large cache replicants which will be persisted for (at least) decades. Here we describe the archive requirements and key aspects of the resulting architecture. ESGF will stress international networks, as well as the data archives themselves – but significantly less than would have been the case of a centralised archive. Developing and deploying the ESGF has exploited good will and best efforts, but future developments are likely to require more formalised architecture and management.

A Global Repository for Planet-Sized Experiments and Observations

AbstractWorking across U.S. federal agencies, international agencies, and multiple worldwide data centers, and spanning seven international network organizations, the Earth System Grid Federation (ESGF) allows users to access, analyze, and visualize data using a globally federated collection of networks, computers, and software. Its architecture employs a system of geographically distributed peer nodes that are independently administered yet united by common federation protocols and application programming interfaces (APIs). The full ESGF infrastructure has now been adopted by multiple Earth science projects and allows access to petabytes of geophysical data, including the Coupled Model Intercomparison Project (CMIP)—output used by the Intergovernmental Panel on Climate Change assessment reports. Data served by ESGF not only include model output (i.e., CMIP simulation runs) but also include observational data from satellites and instruments, reanalyses, and generated images. Metadata summarize basic infor...

Atmospheric response to a hypothetical Tibetan ice sheet

Abstract The atmospheric response to a hypothetical Tibetan ice sheet was tested with the T21 Atmospheric General Circulation Model (AGCM) of the European Centre for Medium-Range Weather Forecasts (ECMWF). The model response is discussed in terms of an “autocycle” hypothesis of the ice ages proposed by Kuhle. According to this hypothesis, ice-albedo feedbacks associated with the growth and retreat of the Tibetan ice sheet are the mechanism that amplifies the variation of solar insolation on astronomical time scales, producing conditions that favor glaciation or deglaciation in North America and Eurasia. The imposed Tibetan ice sheet forcing did not increase the annual snow balance at the locations of the Laurentide and Eurasian ice sheets. Analysis of the seasonal cycle results indicated that there were small areas of locally significant temperature decreases in July (at the ice sheet locations), but no corresponding precipitation increases in January. The upper-tropospheric response to the elevated Tibet...

A Framework for Extended Persistent Identification of Scientific Assets

Several scientific communities relying on e-science infrastructures are in need of persistent identifiers for data and contextual information. In this article, we present a framework for persistent identification that fundamentally supports context information. It is installed as a number of low-level requirements and abstract data type descriptions, flexible enough to envelope context information while remaining compatible with existing definitions and infrastructures. The abstract data type definitions we draw from the requirements and exemplary use cases can act as an evaluation tool for existing implementations or as a blueprint for future persistent identification infrastructures. A prototypic implementation based on the Handle System is briefly introduced. We also lay the groundwork for establishing a graph of persistent entities that can act as a base layer for more sophisticated information schemas to preserve context information.

A European Network for Earth System Modeling

The increasing complexity of Earth system models and the computing facilities needed to run those models put a heavy technical burden on research teams active in climate modeling. To ease this burden, a European collaborative venture called PRISM was initiated in December 2001 to organize a network of experts in order to share the development, maintenance, and support of Earth system modeling software tools and community standards. PRISM was recently reorganized, and a new Web portal (http://prism.enes.org) was unveiled in July 2006. The PRISM network was developed with the hope that advancing specific common standards and tools will reduce the technical development efforts of individual research teams, facilitate the assembling, running, and postprocessing of Earth system models based on state-of-the-art component models, and hence facilitate scientific collaboration between the different research groups in Europe and elsewhere.

Actionable Persistent Identifier Collections

Persistent Identifiers (PIDs) have lately received a lot of attention from scientific infrastructure projects and communities that aim to employ them for management of massive amounts of research data and metadata objects. Such usage scenarios, however, require additional facilities to enable automated data management with PIDs. In this article, we present a conceptual framework that is based on the idea of using common abstract data types (ADTs) in combination with PIDs. This provides a well-defined interface layer that abstracts from both underlying PID systems and higher-level applications. Our practical implementation is based on the Handle System, yet the fundamental concept of PID-based ADTs is transferable to other infrastructures, and it is well suited to achieve interoperability between them.

Atarrabi - A Workflow System for the Publication of Environmental Data

In a research project funded by the German Research Foundation, meteorologists, data publication experts, and computer scientists optimised the publication process of meteorological data and developed software that supports metadata review. The project group placed particular emphasis on scientific and technical quality assurance of primary data and metadata. At the end, the software automatically registers a Digital Object Identifier at DataCite. The software has been successfully integrated into the infrastructure of the World Data Center for Climate, but a key objective was to make the results applicable to data publication processes in other sciences as well.

Semantic oriented data access and storage at MPIM/DKRZ

Problems in data access may be caused by large amounts of data as for climate research or Earth observation and by interdisciplinary data usage. Data organisation in files on the operating system level is not sufficient to fit the requirements of access performance and easy to use data extraction. Semantic oriented data handling is suggested as an alternative. Data access and storage are formulated within the semantics of the data model neglecting the details of physical storage.