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Bridging the world through weather

March 24, 2023

ASU expert says World Meteorological Organization — which turns 150 — was 1st attempt at true international cooperation

Before the League of Nations and the United Nations, it’s a little-known fact that advanced scientific cooperation on a global scale had already commenced. 

The issue that brought nations together: weather. 

This year, the World Meteorological Organization turns 150.

More than a century ago, 50 meteorologists met at a scientific weather meeting in Leipzig, Poland, laying the groundwork of what would become a global body of scientists made up of 193 countries and territories that provide data on our changing climate and its impacts to people around the globe. The organization names hurricanes, tracks extreme weather and works to improve communication of weather dangers.   

ASU News spoke to Randy Cerveny, the keeper of the world’s records of weather for the World Meteorological Organization (WMO) for nearly two decades and a President’s Professor in ASU’s School of Geographical Sciences and Urban Planning, to talk about the history of the WMO, his involvement with the agency and how weather has changed in the last 150 years.

Portrait of ASU Professor Randy Cerveny

Photo of Randy Cerveny by Deanna Dent/Arizona State University

Question: How did the World Meteorological organization originate? 

Answer: We tend to think of the United Nations and the League of Nations as the first big chance for nations to come together. But all the way back, nearly 50 years before, in 1873, nations got together and they realized that meteorology was important on a global scale.

It wasn't called the World Meteorological Organization back then, it was called the International Meteorological Organization. It's gone through some changes since. But, what I found intriguing is that it's kind of the first attempt at true international cooperation. 

Q: Why is it important to have a standardized way to record and measure weather? 

A: Having measurements that are made the same way, in exactly the right fashion, can put a lot more faith in using that information for things involving climate change.

To me, it was surprising that early in the 1870s they decided that yes, they needed to do it. But that was also when (countries) were into shipping and sea travel across the world. A captain of a sailing vessel needed to know what kind of weather was going to be at the next port compared to what he had left. Having the right set of information made that all a whole lot easier. 

Q: Back 150 years ago, what was the process of stardizing weather measurements like? Did it take a long time? 

A: Yes, and even today, we're still debating on how to do certain things. For example, when we're measuring temperature, it has to be measured at a height of roughly 1.5 meters off the ground. 

That means when places use satellite measurements and record temperatures that are much hotter than what we've measured, like in the Sahara, we don't accept those as being records because they're not made at that official height. The difference of the temperature you measure on the ground is going to be different from what it is 5 feet up. Even today, we're still having to address those kinds of issues. But by having a set of standards, it keeps the playing field level across the entire world.

Q: What does the WMO do today? 

A: The thing that most people would recognize is that the WMO names hurricanes. If I say that hurricane 17B is coming towards you, you're probably not going to take as much action as if I said Hurricane Katrina is coming towards you. So we came up with this idea of having standardized lists of names for storms around the world.

Another thing that the WMO does is that they, together with another branch of the United Nations, are in charge of the Intergovernmental Panel on Climate Change (IPCC). The IPCC puts out periodical reports on the state of our climate.

One of the really important things that they're doing now is trying to improve weather forecasting and (distribution of) weather information across the entire globe. The WMO is working in Africa to improve communication so that storms and natural disasters can be mitigated or even prevented by getting word out to people ahead of time. 

And one of the things that I particularly am involved with is measuring (weather) extremes. 

Q: Tell us more about measuring world records of weather for the WMO. How did you get involved? 

A: I got into it by accident. I had been watching the (news) coverage in 2005 about Hurricane Katrina and a commentator on TV said that Hurricane Katrina was the worst hurricane of all time. Katrina was bad, over 2,000 people died, but no way was it the worst hurricane of all time. It pales in comparison to a tropical cyclone that hit what is now called Bangladesh, where 300,000 people died.

I wondered if there's anybody that could tell them the right answers. There are groups like the Guinness Book of World Records, but they're not official. So I said, "Maybe we should have something official." I presented the idea to the WMO back in 2006, and we started the archive project in 2007. We've come up with an official list of verified world extremes. I'm continuing to serve in that role.

Q: Can you give us some examples?

A: Things like the hottest temperature ever recorded (134 degrees Fahrenheit, Death Valley, California) to the fastest wind gust (253 mph, Barrow Island, Australia) to the highest mortality from a single tornado (estimated 1,300 individuals, Bangladesh). We've come up with that list, and it's a list that has been verified by meteorologists. And whenever we get a new record, we examine that record and make a determination if it is actually valid or not.

Right now, we started a new investigation. Down in the southern hemisphere, there has been a tropical cyclone named Freddy that was born on Feb. 3. It was born off the north coast of Australia. Over the last month, it has been slowly working its way across the Indian Ocean. The old record for the longest lasting tropical cyclone was a storm that moved across the Pacific Ocean called John that lasted for 31 days. Freddy has already lasted 32 days. We are currently getting a team of scientists together to investigate.

Q: Going back to the anniversary, how has the world's weather changed in 150 years?

A: The technology has gotten a lot better; we've been monitoring the weather as precisely as we possibly can. And, yes, the weather has also changed. For example, with temperatures, the last cold temperature record that we have verified dates back to the early 1990s. The last warmest world record temperature that we're currently evaluating is a record that occurred in Death Valley just a year ago where it got up to more than 130 degrees Fahrenheit. We're seeing a lot more record high temperatures than we are record low temperatures. It’s one of the easiest ways to say, “Yeah, the climate is changing.”

Q: Is there anything that you're hopeful for in the future, for weather monitoring or extreme records for the WMO?

A: We're always learning new stuff about science simply by monitoring (weather) extremes. To me, having a chance to work with brilliant people on a committee — I mix some of the old masters together with some of the new geniuses — and seeing that interchange take place in the discussions that I can get between those people, has been one of the greatest pluses of this whole thing for me. 

I am hoping, because I'm starting to get old, that there will be people that will continue this process going on. I would love to have this project still be going on decades into the future here. That, to me, would be a good indication that we came up with something that's a good idea.

Top image courtesy Pixabay

David Rozul

Media Relations Officer , Media Relations and Strategic Communications


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The flash that lasts

June 26, 2020

ASU researcher verifies two new world records of lightning flashes

Apparently, lightning is more than just a flash. 

Two new world records of lightning — the horizontal distance a bolt travels and the time duration of the flash — have been recorded by the World Meteorological Organization (WMO). 

The new records for “megaflashes,” verified with new satellite lightning imagery technology, more than double the previous records measured in the U.S. and France, according to the WMO.  

WMO’s Committee on Weather and Climate Extremes, which maintains official records of global, hemispheric and regional extremes found that: 

  • The world’s longest lightning flash covered over a horizontal distance of 441 miles plus or minus 5 miles (709 km plus or minus 8 km) across parts of southern Brazil on Oct. 31, 2018. This is equivalent to slightly farther than the distance from Phoenix to Los Angeles.
  • The greatest time duration for a single lightning flash is now 16.73 seconds from a flash that developed continuously over northern Argentina on March 4, 2019.

“These extraordinary records are from single lightning flash events,” said Randy Cerveny, an Arizona State University professor in the School of Geographical Sciences and Urban Planning and the “chief rapporteur” of weather and climate extremes for WMO. “Environmental extremes are living measurements of what nature is capable of on this planet.

Randy Cerveny

President's Professor Randy Cerveny

“This will provide valuable information for establishing limits to the scale of lightning — including megaflashes — for engineering, safety and scientific concerns,” Cerveny added. 

The previous record for the longest detected distance for a single lightning flash was almost 200 miles (321 km) on June 20, 2007, across Oklahoma. The previous record for duration of a single lightning flash lasted continuously for 7.74 seconds on Aug. 30, 2012, over Provence-Alpes-Côte d'Azur, France.

Space-based technology

The previous assessments that established the flash duration and extent records used data collected by ground-based lightning mapping array (LMA) networks. Many scientists acknowledged that there are upper limits for the scale of lightning that could be observed by any existing LMA. Identifying megaflashes beyond these extremes would require a lightning mapping technology with a larger observation domain. 

Recent advances in space-based lightning mapping offer the ability to measure flash extent and duration continuously over broader geospatial domains. These new instruments include the geostationary lightning mappers on the R-series geostationary operational environmental satellites that recorded the new lighting records, and their orbiting counterparts from Europe and China. 

“This dramatic augmentation of our space-based remote sensing capabilities has allowed the detection of previously unobserved extremes in lightning occurrence, known as ‘megaflashes,’ which are defined as horizontal mesoscale lightning discharges that reach hundreds of kilometers in length,” said evaluation committee member Michael Peterson, of the Space and Remote Sensing Group at Los Alamos National Laboratory in New Mexico.

The space-based instruments provide near-global coverage of total lightning (both intracloud flashes and cloud-to-ground flashes). This includes lightning hot spots in the Americas like the Great Plains in North America, and La Plata basin in South America.

“It is likely that even greater extremes exist, and that we will be able to observe them as lightning-detection technology improves,” Cerveny said. “This also reinforces the important 30-30 lightning rule: If the time between the lightning flash and the thunder is 30 seconds or less, go inside and then wait until 30 minutes after the storm has passed before resuming outdoor activities.”

The findings were published by the American Geophysical Union’s Geophysical Research Letters ahead of International Lightning Safety Day on June 28, 2020.

The WMO Archive of Weather and Climate Extremes maintains official records of the world, hemispheric and regional extreme records associated with a number of specific types of weather. Presently, the archive lists extremes for temperature, pressure, rainfall, hail, wind and lightning as well as two specific types of storms, tornadoes and tropical cyclones.

Top photo courtesy Pixabay 

Director , Media Relations and Strategic Communications