<i>GHub</i>: Building a glaciology gateway to unify a community

Sperhac, Jeanette; Poinar, Kristin; Jones-Ivey, Renette; Briner, Jason P.; Csathó, Beáta; Nowicki, Sophie; Simon, Erika; Larour, Eric; Quinn, Justin; Patra, Abani

doi:10.1002/cpe.6130

Cited by 5 publications

(6 citation statements)

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“…We ran our analysis using Ghub, a science gateway providing browser-based access to data sets, analysis tools and super-computing resources for ice sheet science (). The Ghub gateway is built on the HUBzero platform (McLennan and Kennell, 2010) and hosts datasets, modeling workflows and community tools relevant for analyzing the ice sheets of Greenland and Antarctica (Sperhac and others, 2020). Through Ghub, users can develop, share and run tools that use community codes and hosted datasets.…”

Section: Methodsmentioning

confidence: 99%

Firn aquifer water discharges into crevasses across Southeast Greenland

et al. 2023

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In Southeast Greenland, summer melt and high winter snowfall rates give rise to firn aquifers: vast stores of meltwater buried beneath the ice-sheet surface. Previous detailed studies of a single Greenland firn aquifer site suggest that the water drains into crevasses, but this is not known at a regional scale. We develop and use a tool in Ghub, an online gateway of shared datasets, tools and supercomputing resources for glaciology, to identify crevasses from elevation data collected by NASA's Airborne Topographic Mapper across 29000 km2 of Southeast Greenland. We find crevasses within 3 km of the previously mapped downglacier boundary of the firn aquifer at 20 of 25 flightline crossings. Our data suggest that crevasses widen until they reach the downglacier boundary of the firn aquifer, implying that crevasses collect firn-aquifer water, but we did not find this trend with statistical significance. The median crevasse width, 27 meters, implies an aspect ratio consistent with the crevasses reaching the bed. Our results support the idea that most water in Southeast Greenland firn aquifers drains through crevasses. Less common fates are discharge at the ice-sheet surface (3 of 25 sites) and refreezing at the aquifer bottom (1 of 25 sites).

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Section: Methodsmentioning

confidence: 99%

Firn aquifer water discharges into crevasses across Southeast Greenland

et al. 2023

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“…VHub's architecture consists of a database server and webserver; an execution host that runs software containers for computational tools; and middleware-software that coordinates the container sessions with user sessions (Sperhac et al, 2021). HUBzero System Administrators handle user accounts and interaction, including registering and subsequently authenticating users, controlling access to tools and other hosted resources.…”

Section: Computer Infrastructure Platformmentioning

confidence: 99%

“…VHub enables members of the volcanology research community to deploy hazard map workflow tools that a user can interact with. VHub tools are maintained via a development lifecycle which guides users through a framework for publishing their tools on VHub; subversion control, testing, verification and review by domain scientists and HUBzero System Administrators prior to publication on the VHub website (Sperhac et al, 2021).…”

Section: Workflow Toolsmentioning

confidence: 99%

Workflows for Construction of Spatio-Temporal Probabilistic Maps for Volcanic Hazard Assessment

2022

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Probabilistic hazard assessments for studying overland pyroclastic flows or atmospheric ash clouds under short timelines of an evolving crisis, require using the best science available unhampered by complicated and slow manual workflows. Although deterministic mathematical models are available, in most cases, parameters and initial conditions for the equations are usually only known within a prescribed range of uncertainty. For the construction of probabilistic hazard assessments, accurate outputs and propagation of the inherent input uncertainty to quantities of interest are needed to estimate necessary probabilities based on numerous runs of the underlying deterministic model. Characterizing the uncertainty in system states due to parametric and input uncertainty, simultaneously, requires using ensemble based methods to explore the full parameter and input spaces. Complex tasks, such as running thousands of instances of a deterministic model with parameter and input uncertainty require a High Performance Computing infrastructure and skilled personnel that may not be readily available to the policy makers responsible for making informed risk mitigation decisions. For efficiency, programming tasks required for executing ensemble simulations need to run in parallel, leading to twin computational challenges of managing large amounts of data and performing CPU intensive processing. The resulting flow of work requires complex sequences of tasks, interactions, and exchanges of data, hence the automatic management of these workflows are essential. Here we discuss a computer infrastructure, methodology and tools which enable scientists and other members of the volcanology research community to develop workflows for construction of probabilistic hazard maps using remotely accessed computing through a web portal.

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Section: Use Casesmentioning

confidence: 99%

“…Sperhac et al 8 present GHub, a science gateway for glaciology and ice sheet science. GHub is designed to bring together the data and modeling communities around a common data storage, compute resource and tools so they may work more efficiently on the multiyear Ice Science Modeling Intercomparison Projects (ISMIP) that involves the preparation, evaluation, and curation of several terabytes of ice sheet model simulations and associated datasets.…”

Section: Use Casesmentioning

confidence: 99%