Climate warming to boost major hurricanes in active Atlantic seasons

Posted on by Catherine Zandonella
oceans on map of world
oceans on map of world
Clouds from a HiFLOR global model simulation, showing three hurricanes in the Atlantic and one in West Pacific (Figure Remik Ziemlinski)

New NOAA research that looks at the devastating 2017 Atlantic hurricane season projects that if similar weather conditions occur in the future, it’s likely that the number of major hurricanes (category 3 and higher) would increase by two in a similar active year at the end of century.

This increase would be driven by predicted climate warming, according to the research appearing today in Science.

The finding was reported by a team at NOAA’s Geophysical Fluid Dynamics Laboratory (GFDL) that included lead author Hiroyuki Murakami, who conducted the research while an associate research scholar with the Program in Atmospheric and Oceanic Sciences at Princeton University

Last year’s six major Atlantic hurricanes included landfalling hurricanes Harvey, Irma and Maria that unleashed destruction on and caused loss of life in communities across Texas, Florida and Puerto Rico. The three hurricanes caused an estimated $265 billion in damages during a year that shattered all records for U.S. economic losses due to severe weather.

Global model identifies climate influence

Hiroyuki Murakami
Hiroyuki Murakami. Photo by Maria Setzer

Using a high-resolution global climate model called HiFLOR, developed at GFDL, scientists were able to accurately predict the active hurricane season in June 2017. Scientists then conducted additional experiments with HiFLOR that found it was a remarkably warm tropical Atlantic Ocean, relative to the global tropical ocean, which was the main driver of 2017 hurricane activity.

“This new method allows us to predict hurricane activity as the season is happening as well as take into consideration the likely contribution of climate warming,” said Murakami, a climate researcher at GFDL. NOAA scientists use ocean temperature data showing the relative warmth of the tropical Atlantic to help create vital hurricane season outlooks.

In addition to Murakami, the research team included Emma Levin of Paul D. Schreiber High School in Port Washington, NY, Thomas Delworth and Richard Gudgel of GFDL, and Pang-Chi Hsu of Nanjing University of Information Science and Technology, China.

The study, “Dominant Effect of Relative Tropical Atlantic Warming on Major Hurricane Occurrence,” by H. Murakami, E. Levin, T. L. Delworth, R. Gudgel and P-C Hsu, was published in the journal Science on Sept. 27, 2018.

Funding for this study was provided by the National Oceanic and Atmospheric Administration (NOAA).

Article courtesy of NOAA.

 

New model projects an increase in dust storms in the US

Posted on by Catherine Zandonella
Drifting dust burying farm abandoned farm equipment.
Drifting dust burying farm abandoned farm equipment in 1935. Image courtesy of NOAA.

By Pooja Makhijani for the Office of Communications

Could the storms that once engulfed the Great Plains in clouds of black dust in the 1930’s once again wreak havoc in the U.S.? A new statistical model developed by researchers at Princeton University and the National Oceanic and Atmospheric Administration (NOAA)’s Geophysical Fluid Dynamics Laboratory (GFDL) predicts that climate change will amplify dust activity in parts of the U.S. in the latter half of the 21st century, which may lead to the increased frequency of spectacular dust storms that have far-reaching impacts on public health and infrastructure.

The model, detailed in a study published July 17 in the journal Scientific Reports, eliminates some of the uncertainty found in previous dust activity models by using present-day satellite data such as dust optical depth, which measures to what extent dust particles block sunlight, as well as leafy green coverage over land and other factors.

“Few existing climate models have captured the magnitude and variability of dust across North America,” said Bing Pu, the study’s lead author and an associate research scholar in the Program in Atmospheric and Oceanic Sciences (AOS), a collaboration between Princeton and GFDL.

Dust storms happen when wind blows soil particles into the atmosphere. Dust storms are most frequent and destructive in arid climates with loose soil — especially on lands affected by drought and deforestation. Certain regions of the U.S., such as the southwestern deserts and the central plains, are dust-prone. Most importantly, existing climate models predict “unprecedented” dry conditions in the late-21st century due to an increase in greenhouse gases in these very areas.

It is this “perfect storm” of geography and predicted drought and drought-like conditions that led Pu and her colleague Paul Ginoux, a physical scientist at GFDL, to examine the influence of climate change on dust. They analyzed satellite data about the frequency of dust events and the land’s leafy green coverage over the contiguous U.S., as well as precipitation and surface wind speed, and reported that climate change will increase dust activity in the southern Great Plains from spring to fall in the late half of the 21st century due to reduced rainfall, increased land surface bareness and increased surface wind speed. Conversely, they predicted reduced dust activity in the northern Great Plains in spring during the same time period due to increased precipitation and increased surface vegetation.

Although it is still unclear if rising temperatures themselves trigger the release of yet more dust into the atmosphere, this research offers a glimpse of what the future might hold. “This is an early attempt to project future changes in dust activity in parts of the United States caused by increasing greenhouse gases,” Pu said. Nonetheless, these findings are important given the huge economic and health consequences of severe dust storms, as they can disrupt public transportation systems and trigger respiratory disease epidemics. “Our specific projections may provide an early warning on erosion control, and help improve risk management and resource planning,” she said.

The paper, “Projection of American dustiness in the late 21st century due to climate change,” was published July 17, 2017 in the journal Scientific Reports (doi 10.1038/s41598-017-05431-9 ) and is available online.

This research was supported by NOAA, Princeton University’s Cooperative Institute for Climate Science, and NASA grantNNH14ZDA001N-ACMAP.

Read more about the research in this GFDL Research Highlight.