Arizona researchers probe seabed for clues about monsoons

Nov 4, 2018, 4:15 AM
Monsoon storms move into the metro area as the dark clouds release heavy rains Wednesday, July 11, ...

Monsoon storms move into the metro area as the dark clouds release heavy rains Wednesday, July 11, 2018, in Phoenix. (AP Photo/Ross D. Franklin)

(AP Photo/Ross D. Franklin)

TUCSON – Thunder and lightning. Dust and wind. Flash floods. These hallmarks of the North American monsoon are well-known to Arizonans, and new research indicates these impressive storms have been a part of the Southwest’s climate for millions of years.

Jessica Tierney, a geologist and associate professor at the University of Arizona, leads a research team that’s analyzing mud samples taken from the seafloor in the Gulf of California.

“What we are interested in knowing about is how the monsoon is going to change in the future, and how we can prepare,” Tierney said. “But in order to do that, we have to actually go back and look in the past.”

It’s impossible to predict when and where monsoon storms will strike. But Tierney and her team’s work could help climatologists better understand the power of the North American monsoon, which hits the Southwest from June through September, and what its intensity may be like in the future.

Deep-sea mud contains chemical signatures that hold secrets about the earth’s past. One area the team is looking at are the waxes that plants secrete to hold in moisture and control evaporation.

“The waxes that are growing on plants that receive more monsoon rain have a special chemical signature versus plants that were growing in times that had more winter rain,” Tierney said.

“By measuring the chemistry of these plant waxes, we can actually go back in the past and tell you how much summer versus winter rain there was.”

Tierney is more interested in summer rain because that’s when Arizona’s monsoon occurs. If her team can get a better idea of how much rain fell during the summer months of the latest ice age, they can conclude how intense the monsoon was back then.

The team has already found that the North American monsoon was suppressed but not completely gone during the latest ice age, which ended more than 11,000 years ago. Tierney said its research also suggests the monsoon has been a persistent feature of the Southwest’s climate.

The research has stirred up interest of other scientists.

“If they can go down to deeper layers where it was a warmer period and interglacial, something where we had similar kind of CO₂ that we have now, and they can see how was the monsoon consistent then, was it more intense or was it less intense, that will be very useful information,” said Nancy Selover, Arizona state climatologist.

“Right now, global climate models don’t do a good job predicting precipitation from the monsoon,” she said, noting that the monsoon might be 10 percent wetter or 10 percent drier. “If we can get a good idea of whether the monsoon will be more or less intense, we will really have a good idea of which it will be.”

Tierney, who will be one of the authors of the Intergovernmental Panel on Climate Change report expected in 2021, hopes the study can be useful for policymakers.

“Our work that is done here could be very useful for water resource management. If we have a better idea on the how the monsoon could behave, it could certainly help people in the Southwest plan for future drought.”

The team is looking to collect mud compounds from even deeper layers in the floor of the Gulf of California, also known as the Sea of Cortez. Tierney said that could help them answer how the monsoon acted millions of years ago, when the planet was as warm as it is today.

Monsoons aren’t just felt here in Arizona, but in South America, Africa and Asia. They are classified as a seasonal change in the winds in the upper atmosphere. The North American monsoon can be described as a formation of upper-level clockwise circulation, also known as high pressure, over the mountains of Mexico, New Mexico and west Texas.

This formation creates atmospheric rivers from the Gulf of Mexico and the Gulf of California, which bring in high levels of moisture to the deserts. The mountains across the area lift the intensive heat at the surface into the atmosphere, giving way to enormous thunderstorms.

Lifetime Windows & Doors

We want to hear from you.

Have a story idea or tip? Pass it along to the KTAR News team here.

Arizona News

(Facebook Photo/Phoenix Police Department)...

Phoenix police releases body cam footage of fatal shooting from man throwing rocks

Phoenix police released the body cam footage from the fatal shooting that left a man dead after he was throwing rocks at patrol cars.
16 hours ago
Tim Commerford, Brad Wilk, Zack de la Rocha (seated) and Tom Morello of Rage Against the Machine pe...
Kevin Stone

Long-awaited Phoenix-area Rage Against the Machine shows canceled

Rage Against the Machine scrapped the rest of their reunion tour, including two Glendale shows, after singer Zack de la Rocha injured his leg.
16 hours ago
Murad Dervish (University of Arizona Police Department Photo)...
Associated Press

Ex-grad student held without bond in fatal shooting of Arizona professor

A judge ruled there was enough evidence to try Murad Dervish on charges of first degree murder and aggravated assault.
16 hours ago
(Twitter Photo/@CaesarsPalace)...

Bobby’s Burgers by chef Bobby Flay coming to Phoenix Sky Harbor Airport

Handcrafted burgers from Bobby Flay will be served at a new restaurant concept coming to Phoenix Sky Harbor International Airport.
16 hours ago
Arizona Secretary of State Republican candidate Mark Finchem listens to instructions prior to debat...
Kevin Stone

Arizona GOP secretary of state candidate Mark Finchem explains prior use of early voting

Mark Finchem, the GOP nominee for Arizona secretary of state, explained Thursday why he regularly voted early until this year.
16 hours ago
This undated photo released by the Arizona Attorney General's Office shows Guillermina Fuentes. A Y...
Associated Press

Character witnesses testify for Arizona woman seeking leniency for ballot harvesting

A parade of character witnesses provided a judge Thursday with glowing reports about a southern Arizona woman who admitted collecting four voted early ballots in the 2020 primary election.
16 hours ago

Sponsored Articles

Quantum Fiber

How high-speed fiber internet can improve everyday life

Quantum Fiber supplies unlimited data with speeds up to 940 mbps, enough to share 4K videos with coworkers 20 times faster than a cable.
Children’s Cancer Network

Children’s Cancer Network celebrates cancer-fighting superheroes, raises funds during September’s Childhood Cancer Awareness Month

Jace Hyduchak was like most other kids in his kindergarten class: He loved to play basketball, dress up like his favorite superheroes and jump as high as his pint-sized body would take him on his backyard trampoline.
Day & Night Air Conditioning, Heating and Plumbing

Most plumbing problems can be fixed with regular maintenance

Instead of waiting for a problem to happen, experts suggest getting a head start on your plumbing maintenance.
Arizona researchers probe seabed for clues about monsoons