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Primeur weekly 2017-07-24

Focus

20th Birthday celebrating OpenMP still welcoming new members ...

Fujitsu's processor roadmap is hitting new targets for Deep Learning ...

Focus on Europe

New FPGA programming method delivers five times more computing power ...

Gazprom Neft to utilise capacity at the St Petersburg Polytechnic University supercomputer ...

Tenfold connectivity increase between Ukraine and European research and education network ...

Newly improved Brain Simulation Platform now online ...

Joeri van Leeuwen received a grant and in-kind expertise from the eScience Center for his astronomy project AA-ALERT ...

Middleware

Bright Computing and Brazil-based AMT sign partnership agreement ...

Hardware

7th International Women in HPC workshop ...

IBM scientists observe elusive gravitational effect in solid-state physics ...

New Supermicro Rack Scale Design (RSD) supports high-density, high-performance pooled NVMe storage ...

Inspur announced the new M5 series servers to get businesses ready for the new era of intelligent computing ...

Women, leadership and Flash - Panel and networking event ...

Applications

3D models help scientists gauge flood impact ...

Pulses of electrons manipulate nanomagnets and store information ...

Flashes of light on the dark matter ...

Titan simulations show importance of close 2-way coupling between human and Earth systems ...

A firefly's flash inspires new nanolaser light ...

Simulation reveals universal signature of chaos in ultracold reactions ...

Massive simulation shows HIV capsid interacting with its environment ...

ANSYS, Saudi Aramco and KAUST shatter supercomputing record ...

Scientists use "Piz Daint" simulations to track heavy summer precipitation from the Mediterranean ...

Fernanda Foertter elected SIG HPC Education Vice Chair ...

The Cloud

IBM expands global Cloud data centre presence with four new facilities ...

The Cloud comes to you: AT&T to power self-driving cars, AR/VR and other future 5G applications through edge computing ...

Teradata acquires San Diego-based start-up StackIQ to strengthen Teradata Everywhere and IntelliCloud capabilities ...

IBM mainframe ushers in new era of data protection ...

Solarflare lets server racks match connectivity of a human neuron ...

New high speed interface connects IBM Z to IBM storage systems ...

Oracle significantly expands Cloud at Customer with PaaS and SaaS services to help customers in their journey to the Cloud ...

Scientists use "Piz Daint" simulations to track heavy summer precipitation from the Mediterranean


After massive thunderstorms and rain, the Aare River flooded parts of the Swiss city Bern in August 2005. Image: Tomas Wüthrich.
19 Jul 2017 Lugano - Low-pressure weather systems that move northwards in the summer from Italy to central Europe bring with them dreaded downpours and flooding north of the Alps. But from where do they pick up this destructive moisture? The answer to that question has now been clarified by climate scientists in Bern by means of simulations they ran on CSCS's "Piz Daint" supercomputer.

Every few years, Europeans witness extreme weather events in summer: torrential precipitation on the northern side of the Alps and in central Europe often causes the Elbe, Danube and Rhine rivers to swell and flood their respective regions. These meteorological phenomena can be traced back to several factors, among which are special types of Mediterranean low-pressure systems known as Vb cyclones. From Genoa, these Vb cyclones move across the Po Valley or the northern Adriatic and then northwards, carrying with them vast amounts of moisture. But from where does that moisture originally come?

In previous studies, water in the soil, in the Atlantic Ocean, and in the Mediterranean Sea have all been considered and debated as factors contributing to one or another extreme weather event. However, the role those sources play as individual contributors to the total moisture content of a Vb cyclone has never been fully understood to date. But now, climate scientists at the University of Bern have used simulations run on the "Piz Daint" supercomputer to investigate five extreme events dating between 1979 and 2013 that were attributed to Vb cyclones. In this way, researchers were able to identify the principal moisture source.

Taking the available data from these five extreme events as their basis, the researchers tested three distinct sources of moisture. In separate simulations they varied the degree of soil moisture and the sea surface temperatures of the Atlantic and Mediterranean.

To identify the impact of soil moisture, the researchers defined three scenarios: no moisture at all; a low degree of moisture, such as is typical for Spain; and fully saturated soil. According to the study, the highly unrealistic experimental case of completely dried-out, unsaturated soil was the only one of those three variants that significantly affected the moisture content of the Vb cyclones. With this factor in play, average precipitation amounts in the five case studies reduced by 32 percent. Meanwhile, the two other soil moisture experiments showed only minor effects on the Vb cyclones under investigation.

In the investigation of the Atlantic, researchers altered the ocean's surface temperature by plus or minus 5 Kelvin relative to the present-day figure. Results showed that these changes barely affected the cyclones' moisture content. Only when the model was fed with changes in the Mediterranean Sea's surface temperature did the system show a notable change: when the sea surface temperature increased by 5 Kelvin, average precipitation amounts in the cyclones rose by 24 percent.

"Sensitivity studies like these on real events are an experiment where we look at how a system reacts to predefined changes", stated climate researcher Martina Messmer, lead author of the study which was recently published in the scientific journalEarth System Dynamics.

One of the weather events tested in the study was what has gone down in history as the "Central European flood" of August 2002. This particular Vb cyclone caused mass flooding especially around the Elbe and Oder rivers. Another event that the researchers put under the microscope was the severe weather and heavy precipitation of summer 2005, which flooded Switzerland in particular.

Through sensitivity studies of these actual events, Martina Messmer and her team of researchers came to understand that the system's response to a sea surface temperature change in the Mediterranean is a clear indication that these Vb cyclones responsible for heavy summer precipitation in central Europe take on most of their moisture from the Mediterranean. The simulations also showed that a Mediterranean sea surface temperature increase diverted precipitation eastward and away from the central Alps. Although, the researchers caution against projecting such an eastward shift under future global warming trends based on this research alone.

"The study gives us an indication of how the cyclones might alter their behaviour. However, since the complex climate system will change under the influence of future warming, no direct conclusions on climate change can be drawn from our sensitivity studies", stated climate scientist Christoph Raible, co-author of the study.

Studies like these are important because they establish a better understanding of the mechanisms behind such weather conditions, the researchers note, as well as about where the cyclones gather their moisture. Knowing now that the Mediterranean Sea is the primary moisture source, researchers prepare to take the next step in their plan, which is to investigate the future impact of global warming on the development and behaviour of the infamous Vb cyclones.

Messmer M., Gómez-Navarro J.J. & Raible C.C. are the authors of the paper titled " Sensitivity experiments on the response of Vb cyclones to sea surface temperature and soil moisture changes ". The study appeared inEarth System Dynamics, 8, 477-493, doi.org/10.5194/esd-8-477-2017, 2017.
Source: Swiss National Supercomputing Centre - CSCS

Back to Table of contents

Primeur weekly 2017-07-24

Focus

20th Birthday celebrating OpenMP still welcoming new members ...

Fujitsu's processor roadmap is hitting new targets for Deep Learning ...

Focus on Europe

New FPGA programming method delivers five times more computing power ...

Gazprom Neft to utilise capacity at the St Petersburg Polytechnic University supercomputer ...

Tenfold connectivity increase between Ukraine and European research and education network ...

Newly improved Brain Simulation Platform now online ...

Joeri van Leeuwen received a grant and in-kind expertise from the eScience Center for his astronomy project AA-ALERT ...

Middleware

Bright Computing and Brazil-based AMT sign partnership agreement ...

Hardware

7th International Women in HPC workshop ...

IBM scientists observe elusive gravitational effect in solid-state physics ...

New Supermicro Rack Scale Design (RSD) supports high-density, high-performance pooled NVMe storage ...

Inspur announced the new M5 series servers to get businesses ready for the new era of intelligent computing ...

Women, leadership and Flash - Panel and networking event ...

Applications

3D models help scientists gauge flood impact ...

Pulses of electrons manipulate nanomagnets and store information ...

Flashes of light on the dark matter ...

Titan simulations show importance of close 2-way coupling between human and Earth systems ...

A firefly's flash inspires new nanolaser light ...

Simulation reveals universal signature of chaos in ultracold reactions ...

Massive simulation shows HIV capsid interacting with its environment ...

ANSYS, Saudi Aramco and KAUST shatter supercomputing record ...

Scientists use "Piz Daint" simulations to track heavy summer precipitation from the Mediterranean ...

Fernanda Foertter elected SIG HPC Education Vice Chair ...

The Cloud

IBM expands global Cloud data centre presence with four new facilities ...

The Cloud comes to you: AT&T to power self-driving cars, AR/VR and other future 5G applications through edge computing ...

Teradata acquires San Diego-based start-up StackIQ to strengthen Teradata Everywhere and IntelliCloud capabilities ...

IBM mainframe ushers in new era of data protection ...

Solarflare lets server racks match connectivity of a human neuron ...

New high speed interface connects IBM Z to IBM storage systems ...

Oracle significantly expands Cloud at Customer with PaaS and SaaS services to help customers in their journey to the Cloud ...