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Strong 2015 El Niño Led To Large-Scale Antarctic Melting, Study Says

An illustration shows the number of days in Jan. 2016 that surface melt on the West Antarctic Ice Sheet was detected from passive microwave satellite observations.
Julien Nicolas/OSU
An illustration shows the number of days in Jan. 2016 that surface melt on the West Antarctic Ice Sheet was detected from passive microwave satellite observations.
Strong 2015 El Niño Led To Large-Scale Antarctic Melting, Study Says
Strong 2015 El Niño Led To Large-Scale Antarctic Melting, Study Says GUEST: Ryan Scott, Ph.D. candidate, Scripps Institution of Oceanography

Just collect more data on the effects of global warming, the picture becomes worrying. Scientists with the Scripps Institution of Oceanography and have information about how El Niño affects this I shelf with and they looked at a landmass larger than Mexico. One who collected the data was our guest, Ryan Scott. He was a graduate of Scripps Institution of Oceanography. Thank you for being here . Thank you. Tell us how long did you spend in Antarctica? I was there for a total of three months. We witnessed the melt event for five weeks. We were there to study the service energy balance and how much energy it receives and the properties of clouds and we hope to determine that energy. It drives melting. Tell us about how you took the measurements. How did you find out the data? We had a large measurement program. It is sponsored by the department of energy. They have instruments that they send out from place to place. We were lucky enough to get to deploy those instruments for the first time since 1967. Are you taking ice course? Yes. This is an old ice core site. They drilled several miles down to the eyes and you can reconstruct past climate history and look at the aerosols plan doesn't in the ice. What did it look like? Was there evidence from the service of ice melting? Not where we were. We felt affects me neurologically. The temperature jumped from minus 4 degrees Fahrenheit up to 30 degrees Fahrenheit. We were's -- that was warm because ice melts around 32. Low lying areas, they were warmer and that is where a huge melting event occurred. That time period was a hot period, right? That is right. That El Niño set up the atmosphere circulation patterns that drove the warm air to the area. Brought low level clouds to enhance air energy input. Tell us what you found. You just finished crunching the numbers here what was the results? The biggest result, we can understand what was happening at the surface. In the past, we had satellite observations that tell us the events occur but we do not know what is driving the melting and what physical process is involved and whether or not it is radiation from the sun or the atmosphere or it is turbulent mixing of heat, we have not had a direct picture of what is happening until now. We were extremely lucky that we had any pet this large with instruments that we had. They were really unprecedented and sophisticated and it has never been there before. Was this a more dramatic melt? Absolutely, yes. What did you discover in terms -- you say you did not know what was causing about what did you conclude? One thing that was interesting, the fact that as the warm air mass was transferred ported over the ice sheet, there was a low-level liquid containing clouds. They were thin enough to allow sunlight through them. The sunlight could penetrate through the service and heated up. At the same time, they are opaque enough that they were able to absorb energy that is omitted from the surface and readmit the energy back down to the service and prevent it from:. The clouds have a maximum radiated effectiveness in warming the surface. I understand the melting did refreeze again when the temperature dropped. Did all of it refreeze? We are not sure. The area was so large. There were portions close to the coast that we have just learned that developed ponds. Masjid this, we believe that most of the melt water was probably soaked up into the snow and probably re-froze. This particular event did not affect the balance in any massive way but we are worried that it will happen in the future. Back in January 2017, the sunlight showed a similar event that also occurred. In the same area? Exactly. Thank you for coming in. Thank you.

El Niño events are having a greater influence on ice melting in Antarctica than before, according to a joint study announced today by the Scripps Institution of Oceanography at UC San Diego and Ohio State University.

Researchers were able to record substantial melting on the West Antarctic Ice Sheet during the 2015-16 El Nino episode with ground instruments for the first time. Prior melting was observed via satellite.

The ice sheet is larger than the land mass of Mexico, according to the scientists. They said melted snow was spotted over most of the Ross Ice Shelf, a thick platform of floating ice that channels about a third of the ice flowing from the West Antarctic Ice Sheet into the ocean.

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One of the largest El Niños in 50 years likely delivered to the region relatively warm air and clouds, which help seal in heat, according to the study, published in the journal Nature Communications.

"We were extraordinarily fortunate to be able to deploy state-of-the art equipment to West Antarctica just before this large melt event occurred,'' said Dan Lubin, a research physicist at Scripps. "These atmospheric measurements will help geophysical scientists develop better physical models for projecting how the Antarctic ice sheet might respond to a changing climate and influence sea level rise.''

Scientists believe that climate change could result in more frequent El Niños, which are characterized by an unusually warm mass of water in the Pacific Ocean. The phenomenon affects weather globally, and often brings wetter conditions to Southern California.

Warmer air gravitates toward Antarctica in El Nino, but are often counteracted by westerly winds, the scientists said.

"In West Antarctica, we have a tug-of-war going on between the influence of El Niños and the westerly winds, and it looks like the El Niños are winning,'' said study co-author David Bromwich, professor of geography at Ohio State. "It's a pattern that is emerging. And because we expect stronger, more frequent El Niños in the future with a warming climate, we can expect more major surface melt events in West Antarctica.''

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Scientists from Brookhaven National Laboratory in New York, Argonne National Laboratory in Illinois, Penn State University, the Australian Bureau of Meteorology and Los Alamos National Laboratory in New Mexico assisted with the study.

Funding was provided by the U.S. Department of Energy and National Science Foundation.