Topology Can Help Us Find Patterns in Weather

By James Reinders

December 6, 2018

Topology–the study of shapes–seems to be all the rage. You could even say that data has shape, and shape matters. Shapes are comfortable and familiar concepts, so it is intriguing to see that many applications are being recast to use topology. For instance, looking for weather and climate patterns.

The Quest for Explainability

Interestingly, a key motivation for looking to topology is explainability (interpretability). One might say that, for many, the honeymoon period with “AI” (Artificial Intelligence, including machine learning) is over. Now, we hear talk of “XAI” (Explainable Artificial Intelligence). Goals for XAI expressed by researchers at DARPA (Defense Advanced Research Projects Agency) are to [1] produce more explainable models, while maintaining a high level of learning performance (prediction accuracy), and [2] enable human users to understand, appropriately trust, and effectively manage the emerging generation of artificially intelligent partners.

A goal of XAI is to enable human users to understand, appropriately trust, and effectively manage the emerging generation of artificially intelligent partners.

An XAI research area for this is called topological data analysis, and it offers us the opportunity to relate results of data analysis in terms of shapes.

Interest in Extreme Weather

Thanks to high-performance computing, weather predictions have become both more accurate and more precise (localized) in recent years. While this is true for most weather, it is far less the case for extreme weather events. It turns out that the extreme weather, such as thunderstorms, blizzards, heavy rains, dry spells, and hurricanes, are more challenging to forecast than more ordinary weather. The immediate and tangible benefits of better forecasting of extreme weather better are obvious. Additionally, there are longer-term trends to consider as well. In this vein, puzzling over the apparent supercharging of extreme weather events due to human activity is one of the youngest and most important branches of climate science.

Weather vs. Climate

Scientists speak distinctly of weather forecasts vs. climate forecasts. Today, the two types of modeling and forecasting use different mathematical modeling and computer programming. The fundamental reason for differences stem from the fact that computer resources are not unlimited in scope and speed. If we had infinitely fast computers at our command, the models for weather and climate would converge. As it is, we are very far from that, and thus weather and climate modeling are very different beasts in practice. Despite the differences in weather and climate modeling, techniques such as using topological data analysis will find a place in both weather and climate forecasting.

The concept of weather versus climate can be thought of this way: a weather forecast seeks to help us understand if it will rain on Thursday, while a climate forecast seeks to help us understand if a drought will continue for the next decade. A weather forecast for a hurricane in Central Florida should help us deploy emergency workers now, while a climate forecast for years of drought could guide planning for water rationing programs, longer-term investments in locating more sources, or reducing demand. It is not unusual for climate models to be run on supercomputers only when the computer is not being used for the first priority, which is weather forecasting. This makes sense when you consider there is no immediate risk if a climate computation takes a bit longer to run, but the timeliness of a weather forecast can be critical.

Patterns from Topological Analysis

Researchers at the University of Liverpool[1], working with researchers at Lawrence Berkeley National Laboratory, are exploring the use of topological data analysis for detecting and classifying patterns (shapes) in climate data.

A pattern of interest is that of events called atmospheric rivers. An atmospheric river is a long narrow high-moisture filament, resembling a river in many ways including their shape. They have been called “rivers in the sky.”

Given this “shape” thinking, it is not surprising that atmospheric rivers can have very different widths and lengths, but they have connectivity like a river and holes like small islands in the path of a river. We know from shapes the differences between a river and a string of unconnected lakes. Atmospheric rivers play a key role in water movement, with a strong atmospheric river having a flow seven to 15 times that of the flow at the mouth of the Mississippi River. Using topological analysis, atmospheric rivers can be identified and separated from events in the atmosphere that do not have the correct shape of an atmospheric river.

atmospheric rivers – have the shape of rivers in the sky; they can yield extreme rainfall and floods that takes away life, or normal rainfall that supports life

Atmospheric rivers that contain the largest amounts of water vapor and the strongest winds can lead to extreme rainfall and floods when they stall over watersheds vulnerable to flooding. Such events can disrupt travel, induce mudslides, and lead to catastrophic damage to life and property. Not all atmospheric rivers cause damage, the majority are simply responsible for the rain or snow that animals and plants depend upon for life.

Wet weather for Seattle: An Atmosphere River commonly called the Pineapple Express is easy to see in this image.

 

No Atmosphere Rivers in this image.
Shape tell the story: The familiar shape of a “river” jumps out in the first image, and is absent in the second image. It seems intuitive that the image with an apparent river will result in a lot of rainfall in the U.S. Pacific Northwest. The first image shows an atmospheric river (AR), this particular one is commonly called the “Pineapple Express” which is characterized by a strong flow of the moisture associated with the heavy precipitation originating from the close waters to the Hawaiian Islands. The second image is an example of a non-atmospheric river that does not form a narrow corridor of high concentrated atmospheric moisture in the atmosphere reaching the Pacific coast of North America. Both images are courtesy of [email protected] — they come from an integrated water vapor (IWV, kg/m^2) product of the version 5.1 of the Community Atmosphere Model (CAM 5.1) simulated at the National Energy Research Scientific Computing Center (NERSC), Lawrence Berkeley Lab, CA, USA.

The researchers combined ideas from topological data analysis with machine learning for detecting, classifying and characterizing extreme weather events, such as certain atmospheric rivers. While these researchers were developing their techniques to analyze climate model output, it will have applicability to weather model output as well. They have successfully demonstrated this approach on the Cori supercomputer. Cori, one of the world’s dozen most powerful supercomputers, with high performance Intel multicore processors, is operated by the National Energy Research Scientific Computing Center (NERSC).[2]

Researchers have published results showing that their accuracy (up to 90%) is higher than any prior published results for detection and classification of atmospheric rivers. They applied their algorithm to climate models, using data spanning nearly four decades of weather data, including four different spatial resolutions and two different temporal resolutions. Computing on up to 480 high-performance Intel Xeon (Haswell) processor cores, their typical run times for the analysis was on the order of 10 minutes for the topological analysis followed by a few hours for the classification algorithm. Their implementation used C++ code for the topological data analysis, and Python scikit-learn for the machine learning classification algorithm known as SVM (Support Vector Machine). For the SVM, good scaling was achieved because the Intel Data Analytics Acceleration Library (DAAL) was installed to accelerate Python.

Shape of Weather to Come

We all have a vested interest in seeing climate and weather models improve, and this is especially true for extreme weather which can literally be a matter of life or death. This particular work shows that thinking in terms of shapes via topological data analysis, combined with machine learning, may provide a uniquely powerful approach for identification and analysis of extreme weather. Aside from providing a more accurate method, the use of topological data analysis might lead to better interpretability of the predictions. Whether we are considering deploying a thousand emergency workers now, or considering a multi-billion-dollar infrastructure investment, we would like to be able to get explanations from those responsible for the forecast motivating our potential actions. Humans ultimately need to be able to defend their predictions, even if they come from “artificially intelligent partners” (AI programs). Topological data analysis offers to help scientists with this challenge, and do so in the familiar language of shapes.


[1] Machine Learning and Topological Data Analysis: Application to Pattern Classification in Fluid and Climate Simulations, by Vitaliy Kurlin and Grzegorz Muszynski from the University of Liverpool, plus Michael Wehner, Karthik Kashinath, and Prabhat from Lawrence Berkeley National Laboratory, presented at the Big Data Summit.

[2] Number 10 on the TOP500.org when the work was done, now #12 as of the November 2018 list.

James Reinders is an HPC enthusiast and author of eight books with more than 30 years of industry experience, including 27 years at Intel Corporation (retired June 2016).

Subscribe to HPCwire's Weekly Update!

Be the most informed person in the room! Stay ahead of the tech trends with industy updates delivered to you every week!

What’s New in HPC Research: Natural Gas, Precision Agriculture, Neural Networks and More

December 6, 2019

In this bimonthly feature, HPCwire highlights newly published research in the high-performance computing community and related domains. From parallel programming to exascale to quantum computing, the details are here. Read more…

By Oliver Peckham

On the Spack Track @SC19

December 5, 2019

At the annual supercomputing conference, SC19 in Denver, Colorado, there were Spack events each day of the conference. As a reflection of its grassroots heritage, nine sessions were planned by more than a dozen thought leaders from seven organizations, including three U.S. national Department of Energy (DOE) laboratories and Sylabs... Read more…

By Elizabeth Leake

Intel’s New Hyderabad Design Center Targets Exascale Era Technologies

December 3, 2019

Intel's Raja Koduri was in India this week to help launch a new 300,000 square foot design and engineering center in Hyderabad, which will focus on advanced computing technologies for the AI and exascale era. "Over th Read more…

By Tiffany Trader

AWS Debuts 7nm 2nd-Gen Graviton Arm Processor

December 3, 2019

The “x86 Big Bang,” in which market dominance of the venerable Intel CPU has exploded into fragments of processor options suited to varying workloads, has now encompassed CPUs offered by the leading public cloud serv Read more…

By Doug Black

Medical Imaging Gets an AI Boost

December 3, 2019

AI technologies incorporated into diagnostic imaging tools have proven useful in eliminating confirmation bias, often outperforming human clinicians who may bring their own prejudices. Another issue slowing progress is t Read more…

By George Leopold

AWS Solution Channel

Making High Performance Computing Affordable and Accessible for Small and Medium Businesses with HPC on AWS

High performance computing (HPC) brings a powerful set of tools to a broad range of industries, helping to drive innovation and boost revenue in finance, genomics, oil and gas extraction, and other fields. Read more…

IBM Accelerated Insights

AI Needs Intelligent HPC infrastructure

Artificial Intelligence (AI) has revolutionized entire industries and enables humanity to solve some of the most daunting challenges. To accomplish this, it requires massive amounts of data from heterogeneous sources that is processed it new ways that differs significantly from HPC applications. Read more…

Ride on the Wild Side – Squyres SC19 Mars Rovers Keynote

December 2, 2019

Reminding us of the deep and enabling connection between HPC and modern science is an important part of the SC Conference mission. And yes, HPC is a science itself. At SC19, Steve Squyres’ opening keynote recounting th Read more…

By John Russell

On the Spack Track @SC19

December 5, 2019

At the annual supercomputing conference, SC19 in Denver, Colorado, there were Spack events each day of the conference. As a reflection of its grassroots heritage, nine sessions were planned by more than a dozen thought leaders from seven organizations, including three U.S. national Department of Energy (DOE) laboratories and Sylabs... Read more…

By Elizabeth Leake

Intel’s New Hyderabad Design Center Targets Exascale Era Technologies

December 3, 2019

Intel's Raja Koduri was in India this week to help launch a new 300,000 square foot design and engineering center in Hyderabad, which will focus on advanced com Read more…

By Tiffany Trader

AWS Debuts 7nm 2nd-Gen Graviton Arm Processor

December 3, 2019

The “x86 Big Bang,” in which market dominance of the venerable Intel CPU has exploded into fragments of processor options suited to varying workloads, has n Read more…

By Doug Black

Ride on the Wild Side – Squyres SC19 Mars Rovers Keynote

December 2, 2019

Reminding us of the deep and enabling connection between HPC and modern science is an important part of the SC Conference mission. And yes, HPC is a science its Read more…

By John Russell

NSCI Update – Adapting to a Changing Landscape

December 2, 2019

It was November of 2017 when we last visited the topic of the National Strategic Computing Initiative (NSCI). As you will recall, the NSCI was started with an Executive Order (E.O. No. 13702), that was issued by President Obama in July of 2015 and was followed by a Strategic Plan that was released in July of 2016. The question for November of 2017... Read more…

By Alex R. Larzelere

Tsinghua University Racks Up Its Ninth Student Cluster Championship Win at SC19

November 27, 2019

Tsinghua University has done it again. At SC19 last week, the eight-time gold medal-winner team took home the top prize in the 2019 Student Cluster Competition Read more…

By Oliver Peckham

SC19: IBM Changes Its HPC-AI Game Plan

November 25, 2019

It’s probably fair to say IBM is known for big bets. Summit supercomputer – a big win. Red Hat acquisition – looking like a big win. OpenPOWER and Power processors – jury’s out? At SC19, long-time IBMer Dave Turek sketched out a different kind of bet for Big Blue – a small ball strategy, if you’ll forgive the baseball analogy... Read more…

By John Russell

How the Gordon Bell Prize Winners Used Summit to Illuminate Transistors

November 22, 2019

At SC19, the Association for Computing Machinery (ACM) awarded the prestigious Gordon Bell Prize to the Swiss Federal Institute of Technology (ETH) Zurich. The Read more…

By Oliver Peckham

Using AI to Solve One of the Most Prevailing Problems in CFD

October 17, 2019

How can artificial intelligence (AI) and high-performance computing (HPC) solve mesh generation, one of the most commonly referenced problems in computational engineering? A new study has set out to answer this question and create an industry-first AI-mesh application... Read more…

By James Sharpe

Cray Wins NNSA-Livermore ‘El Capitan’ Exascale Contract

August 13, 2019

Cray has won the bid to build the first exascale supercomputer for the National Nuclear Security Administration (NNSA) and Lawrence Livermore National Laborator Read more…

By Tiffany Trader

DARPA Looks to Propel Parallelism

September 4, 2019

As Moore’s law runs out of steam, new programming approaches are being pursued with the goal of greater hardware performance with less coding. The Defense Advanced Projects Research Agency is launching a new programming effort aimed at leveraging the benefits of massive distributed parallelism with less sweat. Read more…

By George Leopold

D-Wave’s Path to 5000 Qubits; Google’s Quantum Supremacy Claim

September 24, 2019

On the heels of IBM’s quantum news last week come two more quantum items. D-Wave Systems today announced the name of its forthcoming 5000-qubit system, Advantage (yes the name choice isn’t serendipity), at its user conference being held this week in Newport, RI. Read more…

By John Russell

Ayar Labs to Demo Photonics Chiplet in FPGA Package at Hot Chips

August 19, 2019

Silicon startup Ayar Labs continues to gain momentum with its DARPA-backed optical chiplet technology that puts advanced electronics and optics on the same chip Read more…

By Tiffany Trader

SC19: IBM Changes Its HPC-AI Game Plan

November 25, 2019

It’s probably fair to say IBM is known for big bets. Summit supercomputer – a big win. Red Hat acquisition – looking like a big win. OpenPOWER and Power processors – jury’s out? At SC19, long-time IBMer Dave Turek sketched out a different kind of bet for Big Blue – a small ball strategy, if you’ll forgive the baseball analogy... Read more…

By John Russell

Cray, Fujitsu Both Bringing Fujitsu A64FX-based Supercomputers to Market in 2020

November 12, 2019

The number of top-tier HPC systems makers has shrunk due to a steady march of M&A activity, but there is increased diversity and choice of processing compon Read more…

By Tiffany Trader

Crystal Ball Gazing: IBM’s Vision for the Future of Computing

October 14, 2019

Dario Gil, IBM’s relatively new director of research, painted a intriguing portrait of the future of computing along with a rough idea of how IBM thinks we’ Read more…

By John Russell

Leading Solution Providers

ISC 2019 Virtual Booth Video Tour

CRAY
CRAY
DDN
DDN
DELL EMC
DELL EMC
GOOGLE
GOOGLE
ONE STOP SYSTEMS
ONE STOP SYSTEMS
PANASAS
PANASAS
VERNE GLOBAL
VERNE GLOBAL

AMD Launches Epyc Rome, First 7nm CPU

August 8, 2019

From a gala event at the Palace of Fine Arts in San Francisco yesterday (Aug. 7), AMD launched its second-generation Epyc Rome x86 chips, based on its 7nm proce Read more…

By Tiffany Trader

Intel Debuts New GPU – Ponte Vecchio – and Outlines Aspirations for oneAPI

November 17, 2019

Intel today revealed a few more details about its forthcoming Xe line of GPUs – the top SKU is named Ponte Vecchio and will be used in Aurora, the first plann Read more…

By John Russell

Kubernetes, Containers and HPC

September 19, 2019

Software containers and Kubernetes are important tools for building, deploying, running and managing modern enterprise applications at scale and delivering enterprise software faster and more reliably to the end user — while using resources more efficiently and reducing costs. Read more…

By Daniel Gruber, Burak Yenier and Wolfgang Gentzsch, UberCloud

Supercomputer-Powered AI Tackles a Key Fusion Energy Challenge

August 7, 2019

Fusion energy is the Holy Grail of the energy world: low-radioactivity, low-waste, zero-carbon, high-output nuclear power that can run on hydrogen or lithium. T Read more…

By Oliver Peckham

Dell Ramps Up HPC Testing of AMD Rome Processors

October 21, 2019

Dell Technologies is wading deeper into the AMD-based systems market with a growing evaluation program for the latest Epyc (Rome) microprocessors from AMD. In a Read more…

By John Russell

SC19: Welcome to Denver

November 17, 2019

A significant swath of the HPC community has come to Denver for SC19, which began today (Sunday) with a rich technical program. As is customary, the ribbon cutt Read more…

By Tiffany Trader

When Dense Matrix Representations Beat Sparse

September 9, 2019

In our world filled with unintended consequences, it turns out that saving memory space to help deal with GPU limitations, knowing it introduces performance pen Read more…

By James Reinders

With the Help of HPC, Astronomers Prepare to Deflect a Real Asteroid

September 26, 2019

For years, NASA has been running simulations of asteroid impacts to understand the risks (and likelihoods) of asteroids colliding with Earth. Now, NASA and the European Space Agency (ESA) are preparing for the next, crucial step in planetary defense against asteroid impacts: physically deflecting a real asteroid. Read more…

By Oliver Peckham

  • arrow
  • Click Here for More Headlines
  • arrow
Do NOT follow this link or you will be banned from the site!
Share This