Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ship exhaust makes oceanic thunderstorms more intense

08.09.2017

Thunderstorms directly above two of the world's busiest shipping lanes are significantly more powerful than storms in areas of the ocean where ships don't travel, according to new research.

A new study mapping lightning around the globe finds lightning strokes occur nearly twice as often directly above heavily-trafficked shipping lanes in the Indian Ocean and the South China Sea than they do in areas of the ocean adjacent to shipping lanes that have similar climates.


This is lightning behind an aircraft carrier in the Strait of Malacca. New research finds lightning strokes occurred nearly twice as often directly above heavily-trafficked shipping lanes in the Indian Ocean and the South China Sea year-round from 2005 through 2016.

Credit: pxhere.com; public domain

The difference in lightning activity can't be explained by changes in the weather, according to the study's authors, who conclude that aerosol particles emitted in ship exhaust are changing how storm clouds form over the ocean.

The new study is the first to show ship exhaust can alter thunderstorm intensity. The researchers conclude that particles from ship exhaust make cloud droplets smaller, lifting them higher in the atmosphere. This creates more ice particles and leads to more lightning.

The results provide some of the first evidence that humans are changing cloud formation on a nearly continual basis, rather than after a specific incident like a wildfire, according to the authors. Cloud formation can affect rainfall patterns and alter climate by changing how much sunlight clouds reflect to space.

"It's one of the clearest examples of how humans are actually changing the intensity of storm processes on Earth through the emission of particulates from combustion," said Joel Thornton, an atmospheric scientist at the University of Washington in Seattle and lead author of the new study in Geophysical Research Letters, a journal of the American Geophysical Union.

"It is the first time we have, literally, a smoking gun, showing over pristine ocean areas that the lightning amount is more than doubling," said Daniel Rosenfeld, an atmospheric scientist at the Hebrew University of Jerusalem who was not connected to the study. "The study shows, highly unambiguously, the relationship between anthropogenic emissions - in this case, from diesel engines - on deep convective clouds."

Mapping lightning and exhaust

All combustion engines emit exhaust, which contains microscopic particles of soot and compounds of nitrogen and sulfur. These particles, known as aerosols, form the smog and haze typical of large cities. They also act as cloud condensation nuclei - the seeds on which clouds form. Water vapor condenses around aerosols in the atmosphere, creating droplets that make up clouds.

Cargo ships crossing oceans emit exhaust continuously and scientists can use ship exhaust to better understand how aerosols affect cloud formation.

In the new study, co-author Katrina Virts, an atmospheric scientist at NASA Marshall Space Flight Center in Huntsville, Alabama, was analyzing data from the World Wide Lightning Location Network, a network of sensors that locates lightning strokes all over the globe, when she noticed a nearly straight line of lightning strokes across the Indian Ocean.

Virts and her colleagues compared the lightning location data to maps of ships' exhaust plumes from a global database of ship emissions. Looking at the locations of 1.5 billion lightning strokes from 2005 to 2016, the team found nearly twice as many lightning strokes on average over major routes ships take across the northern Indian Ocean, through the Strait of Malacca and into the South China Sea, compared to adjacent areas of the ocean that have similar climates.

More than $5 trillion of world trade passes through the South China Sea every year and nearly 100,000 ships pass through the Strait of Malacca alone. Lightning is a measure of storm intensity, and the researchers detected the uptick in lightning at least as far back as 2005.

"All we had to do was make a map of where the lightning was enhanced and a map of where the ships are travelling and it was pretty obvious just from the co-location of both of those that the ships were somehow involved in enhancing lightning," Thornton said.

Forming cloud seeds

Water molecules need aerosols to condense into clouds. Where the atmosphere has few aerosol particles - over the ocean, for instance - water molecules have fewer particles to condense around, so cloud droplets are large.

When more aerosols are added to the air, like from ship exhaust, water molecules have more particles to collect around. More cloud droplets form, but they are smaller. Being lighter, these smaller droplets travel higher into the atmosphere and more of them reach the freezing line, creating more ice, which creates more lightning. Storm clouds become electrified when ice particles collide with each other and with unfrozen droplets in the cloud. Lightning is the atmosphere's way of neutralizing that built-up electric charge.

Ships burn dirtier fuels in the open ocean away from port, spewing more aerosols and creating even more lightning, Thornton said.

"I think it's a really exciting study because it's the most solid evidence I've seen that aerosol emissions can affect deep convective clouds and intensify them and increase their electrification," said Steven Sherwood, an atmospheric scientist at the University of New South Wales in Sydney who was not connected to the study.

"We're emitting a lot of stuff into the atmosphere, including a lot of air pollution, particulate matter, and we don't know what it's doing to clouds," Sherwood said. "That's been a huge uncertainty for a long time. This study doesn't resolve that, but it gives us a foot in the door to be able to test our understanding in a way that will move us a step closer to resolving some of those bigger questions about what some of the general impacts are of our emissions on clouds."

###

The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing 60,000 members in 137 countries. Join the conversation on Facebook, Twitter, YouTube, and our other social media channels.

The preceeding press release and accompanying images can be found at: http://news.agu.org/press-release/ship-exhaust-makes-oceanic-thunderstorms-more-intense/

Ship exhaust makes oceanic thunderstorms more intense

AGU Press Contact:

Nanci Bompey
+1 (202) 777-7524
nbompey@agu.org

University of Washington Press Contact:

Hannah Hickey
+1 (206) 543-2580
hickeyh@uw.edu

Media Contact

Nanci Bompey
nbompey@agu.org
202-777-7524

 @theagu

http://www.agu.org 

Nanci Bompey | EurekAlert!

More articles from Earth Sciences:

nachricht Geochemists measure new composition of Earth’s mantle
17.09.2019 | Westfälische Wilhelms-Universität Münster

nachricht Low sea-ice cover in the Arctic
13.09.2019 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: 'Nanochains' could increase battery capacity, cut charging time

How long the battery of your phone or computer lasts depends on how many lithium ions can be stored in the battery's negative electrode material. If the battery runs out of these ions, it can't generate an electrical current to run a device and ultimately fails.

Materials with a higher lithium ion storage capacity are either too heavy or the wrong shape to replace graphite, the electrode material currently used in...

Im Focus: Stevens team closes in on 'holy grail' of room temperature quantum computing chips

Photons interact on chip-based system with unprecedented efficiency

To process information, photons must interact. However, these tiny packets of light want nothing to do with each other, each passing by without altering the...

Im Focus: Happy hour for time-resolved crystallography

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.

The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.

Im Focus: Modular OLED light strips

At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.

Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...

Im Focus: Tomorrow´s coolants of choice

Scientists assess the potential of magnetic-cooling materials

Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

 
Latest News

Quality control in immune communication: Chaperones detect immature signaling molecules in the immune system

20.09.2019 | Life Sciences

Moderately Common Plants Show Highest Relative Losses

20.09.2019 | Life Sciences

The Fluid Fingerprint of Hurricanes

20.09.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>