Tyler O'Neal, Staff Editor ASTRONOMY

ECMWF moves towards a policy of open data

From 7 October 2020, hundreds of ECMWF forecast charts will become free and accessible to all.

Medium-range, extended-range, and long-range forecast charts of temperature, wind, precipitation, clouds, and ocean waves are just some of the products that are becoming available. With ECMWF’s focus on ensemble prediction, charts also cover probability-based information, which provides a guide to forecasting confidence. The likelihood of extreme conditions, as well as tropical and extratropical cyclone activity, are also included.

Up to now, full access to these forecast charts was restricted to national meteorological and hydrological services of ECMWF’s Member and Co-operating States, World Meteorological Organisation (WMO) members, and commercial customers. Access was subject to a range of bespoke licenses and often incurred charges for customers. Only a few charts were freely available.

Making these hundreds of charts free and open means that, not only is there no charge for the information, but users can also share, redistribute and adapt the information as they require, even for commercial applications, as long as they acknowledge the source as ECMWF. The charts are available under the Creative Commons license (CC-BY 4.0).

The changes also mean a move to an open data policy for historical information in ECMWF’s huge data repository – the Meteorological Archival and Retrieval System, or MARS. MARS contains hundreds of petabytes of data including recent and past forecasts, analyses, climatological data, and research experiments; it represents the largest archive of such data in the world. Making these MARS data open will simplify and expand their use and, importantly, allow their re-use, thus stimulating further research and the development of applications related to weather and beyond. Charts cover medium, extended and long-range forecast information.{module INSIDE STORY}

These changes are part of broader developments across Europe to encourage the wider use of public sector data – for the benefit of all.

Rolf Brennerfelt, Chair of ECMWF Policy Advisory Committee, commented: “The ECMWF Member States have been keen for the Centre’s data to be open and free for a while. The societal benefits associated with free and open data are big. We are aware that the move comes with its financial challenges, but the benefits outweigh those challenges. We are in a period of transition, and this first batch of data being made freely available is a very good start and illustrates well our commitment to this principle.”

This phased move towards free and open data aims to support creativity and innovation in the field of scientific research as well as weather applications. Whilst today’s announcement only represents the first step, it has the potential to already increase accountability and transparency, and enable more necessary and critical scientific, social, and economic advances.

The EU Copernicus Earth observation program, several elements of which are implemented by ECMWF, has operated a policy of free, open data since its inception. With many thousands of users, the program offers a host of examples of the benefits that open data can bring.

Adrian Tompkins, a research scientist at the International Centre for Theoretical Physics (ICTP), commented: "ICTP has a long history of working with scientists in both academia and government agencies in developing countries and one issue repeatedly raised is the lack of easy access to leading global forecasting systems and climate information. This move by ECMWF to open their catalog of graphical products, combined with the continued development of the excellent Copernicus climate data store, has the potential to supercharge research efforts in developing countries, particularly in the continent of Africa, where weather and climate information has utmost societal importance."

At the start of the COVID-19 pandemic, a group of Italian epidemiologists used atmospheric pollution data from the EU Copernicus Atmospheric Monitoring Service (CAMS) to investigate links between the level of pollution in a given area, and the rate and seriousness of COVID infection. The open data policy meant that the group was able to quickly and easily access the data they needed. The Copernicus Climate Change Service (C3S) has developed an application that allows health authorities and epidemiology centers to explore whether temperature and humidity affect the spread of the coronavirus.

Climate reanalyses provide a globally complete, consistent picture of the climate system stretching back in time, being derived from a blend of observations and model data. They are one of the most used datasets provided by C3S and represent a cornerstone of the development of climate services across Europe. Reanalyses provide vital information for monitoring how the climate is changing and for understanding impacts across a whole range of sectors such as transport, utilities, finance, and agriculture. Wind, solar radiation, and ocean wave data from reanalyses are being used, for example, to help plan and safeguard renewable energy developments.

Data from all past ECMWF forecasts stretching back to the early 1980s are just some of the billions of fields within ECMWF’s vast MARS data repository. The epitome of the term ‘big data’, MARS offers immense opportunities for machine learning, where a supercomputer uses observations or other data, to ‘learn’ relationships between different variables. If there are sufficient data for training, machine learning can be used to develop numerical tools that can mimic complex systems. In fact, researchers are using machine learning to investigate the development of a ‘digital twin’ of the Earth system. Reanalyses and simulated satellite data from the MARS repository have been key to this work.

MARS data coupled with non-meteorological ‘big data’ offers the potential for almost limitless applications through machine learning - from weather effects on financial markets or consumer behavior to phenomena in the natural world such as bird migration.

As part of its formal agreement with the WMO, ECMWF is designated as a World Meteorological Centre (WMC). The change in policy at ECMWF will mean simplified access to ECMWF forecasts for the national meteorological and hydrological services (NMHSs) of WMO Members. NMHS forecasters rely on WMCs for the information they need to carry out their operational activities and in particular to warn citizens of severe weather events.

These are only a few examples, but they show how much is already being achieved through free and open data, and offer a glimpse of how much more could be possible.

Andy Morse, Professor of Climate Impacts at the University of Liverpool, commented: "The potential uses and benefits these products bring for a range of users and sectors are vast and particularly key in less economically developed countries. Now that remote internet access is widespread through modern mobile phone networks; the availability of this information is likely to be a game-changer for many small enterprises. In my experience, people in these most remote parts of the world are hungry for such information."

Why is ECMWF moving more towards open data?

The EU and ECMWF Member and the Co-operating States are themselves moving towards an open data policy.

In the EU, a Directive on open data and the re-use of public sector information, also known as the 'Open Data Directive'entered into force on 16 July 2019. It focuses on the economic aspects of the re-use of information and it encourages the EU Member States to make as much information available for re-use as possible. The Directive also introduces the concept of high-value datasets (which includes weather data), the re-use of which is associated with particularly important benefits for society and the economy.

Scientists discover new clues deciphering the shape of black holes

Tyler O'Neal, Staff Editor ASTRONOMY

Black holes are one of the most fascinating objects in the Universe. At their surface, known as the 'event horizon', gravity is so strong that not even light can escape from them. Usually, black holes are quiet, silent creatures that swallow anything getting too close to them; however, when two black holes collide and merge together, they produce one of the most catastrophic events in the Universe: in a fraction of a second, a highly-deformed black hole is born and releases tremendous amounts of energy as it settles to its final form. This phenomenon gives astronomers a unique chance to observe rapidly changing black holes and explore gravity in its most extreme form.

Although colliding black holes do not produce light, astronomers can observe the detected gravitational waves--ripples in the fabric of space and time--that bounce off them. Scientists speculate that, after a collision, the behavior of the remnant black hole is key to understanding gravity and should be encoded in the emitted gravitational waves.

In the article published in an academic journal, a team of scientists led by OzGrav alumnus Prof. Juan Calderón Bustillo--now 'La Caixa Junior Leader - Marie Curie Fellow' at the Galician Institute for High Energy Physics (Santiago de Compostela, Spain)--has revealed how gravitational waves encode the shape of merging black holes as they settle to their final form. 

Graduate student and co-author Christopher Evans from the Georgia Institute of Technology said, "We performed simulations of black-hole collisions using supercomputers and then compared the rapidly changing shape of the remnant black hole to the gravitational waves it emits. We discovered that these signals are far more rich and complex than commonly thought, allowing us to learn more about the vastly changing shape of the final black hole." CAPTION Artist's illustration of a black hole cusp. CREDIT C. Evans; J.C. Bustillo.{module INSIDE STORY}

The gravitational waves from colliding black holes are very simple signals known as 'chirps'. As the two black holes approach each other, they emit a signal of increasing frequency and amplitude that indicates the speed and radius of the orbit. According to Prof. Calderón Bustillo, 'the pitch and amplitude of the signal increases as the two black holes approach faster and faster. After the collision, the final remnant black hole emits a signal with a constant pitch and decaying amplitude--like the sound of a bell being struck'. This principle is consistent with all gravitational-wave observations so far when studying the collision from the top.

However, the study found something completely different happens if the collision is observed from the 'equator' of the final black hole. "When we observed black holes from their equator, we found that the final black hole emits a more complex signal, with a pitch that goes up and down a few times before it dies,' explains Prof. Calderón Bustillo. 'In other words, the black hole actually chirps several times."

The team discovered that this is related to the shape of the final black hole, which acts as a kind of gravitational-wave lighthouse: "When the two original, 'parent' black holes are of different sizes, the final black hole initially looks like a chestnut, with a cusp on one side and a wider, smoother back on the other,' says Bustillo. "It turns out that the black hole emits more intense gravitational waves through its most curved regions, which are those surrounding its cusp. This is because the remnant black hole is also spinning and its cusp and back repeatedly point to all observers, producing multiple chirps."

Co-author Prof. Pablo Laguna, former chair of the School of Physics at Georgia Tech and now Professor at the University of Texas at Austin pointed out "while a relationship between the gravitational waves and the behavior of the final black hole has been long conjectured, our study provides the first explicit example of this kind of relation."

Australian scientists debunk long-held theory of Moon’s magnetic crust

Tyler O'Neal, Staff Editor ASTRONOMY

New international research into the Moon provides scientists with insights as to how and why its crust is magnetized, essentially ‘debunking’ one of the previous longstanding theories.

Australian researcher and study co-author Dr. Katarina Miljkovic, from the Curtin Space Science and Technology Centre, located within the School of Earth and Planetary Sciences at Curtin University, explained how the new research, published by Science Advances, expands on decades of work by other scientists.

“There are two long term hypotheses associated with why the Moon’s crust might be magnetic: One is that the magnetization is the result of an ancient dynamo in the lunar core, and the other is that it’s the result of an amplification of the interplanetary magnetic field, created by meteoroid impacts,” Dr. Miljkovic said.

“Our research is a deep numerical study that challenges that second theory – the impact-related magnetization –  and it essentially ‘debunks’ it. We found that meteoroid impact plasmas interact much more weakly with the Moon compared to the magnetization levels obtained from the lunar crust.

“This finding leads us to conclude that a core dynamo is the only plausible source of the magnetization of the Moon’s crust.”

To carry out her portion of the research, Dr. Miljkovic provided the team with numerical estimates of the vapor formation that occurred during large meteoroid impact bombardment on the Moon approximately 4 billion years ago.

“When we look at the Moon with the naked eye, we can see these large craters caused by ancient meteoroid impacts. They are now filled with volcanic maria, or seas, causing them to look darker on the surface,” Dr Miljkovic said.

“During these impact events, the meteoroids hit the Moon at a very high speed, causing displacement, melting, and vaporization of the lunar crust. Pixabay moon{module INSIDE STORY}

“My work calculated the mass and thermal energy of the vapor emitted during these impacts. That was then used as input for further calculations and investigation of the behavior of the ambient magnetic field at the Moon, following these large impact events.

“Basically, we made a much more inclusive, high fidelity, and high-resolution investigation that led to debunking of the older hypothesis.”

The study’s lead researcher Dr. Rona Oran, a research scientist in the Department of Earth, Atmospheric and Planetary Sciences (EAPS) at the Massachusetts Institute of Technology (MIT), said the impact simulations, combined with plasma simulations, harness the latest developments in scientific codes and supercomputing power and allowed the team to perform the first simulations that could realistically capture and test this long-proposed mechanism.

Using such tools was key to allowing the team to look at many different scenarios, and in this way to rule out this mechanism under any feasible conditions that could have existed during the impact. This refutation could have important implications to determine what did magnetize the Moon and even other objects in the solar system with unexplainable magnetized crusts.

“In addition to the Moon, Mercury, some meteorites, and other small planetary bodies all have a magnetic crust. Perhaps other equivalent mechanical dynamo mechanisms, such as those we now believe to have been in operation on the Moon, could have been in effect on these objects as well,” Dr. Oran said.