Student Makes El Niño Discovery After Shifting Her Focus From the Earth to its Climate

Krishna Borhara came to Utah State University with a master’s in geology and the expectation that she’d be earning a doctorate in the same field. Now she is preparing to graduate with a Ph.D. in climate science, and instead of studying the inner workings of the Earth, she’s made a significant contribution to understanding how global warming will affect El Niño and La Niña in the Pacific — and by extension, much of the planet.

Originally from Tanzania, Borhara earned her bachelor’s and master’s degrees in Ohio before coming to USU with plans to continue her focus on earthquake sciences. Three years into the program, however, she decided to switch majors. The decision wasn’t made lightly.

“It’s different changing majors at the Ph.D. level than at an undergraduate level,” Borhara said. “All I did for 10 years was work to have a future in geology. And then I entered a field where I had no experience at all, not even basic knowledge.”

At first, Borhara wasn’t sure if she wanted to continue in higher education. But then she met Professor Simon Wang in the Plants, Soils and Climate Department.

“He was the first person who really listened to me,” Borhara said. “We talked, and from that very first day when I met him, I knew that under his advising, I would be able to make it through a new field, and I had the confidence that I could put the pieces of my life back together.”

The work of being a climate scientist is very different from geology. Instead of studying rocks under a microscope and doing chemical analyses, Borhara needed to learn computer programming to manage massive amounts of atmospheric and oceanic data. However, Wang gave Borhara the materials and guidance to catch up in the field, and within only a couple months, Borhara felt she could make it in her new major. That was fortunate, because Borhara was also expected to teach an undergraduate climate science class at the same time.

“I was studying things one week and then teaching a chapter on them the next,” Borhara said. “It was a lot of learning in a short period of time, but that helped me grow faster than if I was just reading a textbook on my own.”

Borhara did more than just stay ahead of her students. She was named USU Graduate Student Teacher of the Year in 2022, and she is in the process of coauthoring an undergraduate textbook. But as her recent publication in the journal Climate Dynamics attests, she has not let research fall by the wayside.

Most of Borhara’s work focuses on the El Niño-Southern Oscillation (ENSO), a cycle of warm and cold water in the eastern Pacific Ocean near the equator. El Niño refers to when there are unusually warm waters in this area, and it can affect weather and climate patterns across the globe. In the United States, it often means higher temperatures, drought, or flooding depending on the region and other factors.

Along with Wang and USU alumnus Boniface Fosu, who is currently an assistant professor at Mississippi State University, Borhara examined the relationship between El Niño and sea surface temperatures in the western Pacific near Japan and the Philippines, going as far back as 1890. While unusually cold winter sea surface temperatures in that part of the ocean were already known to predict the start of El Niño around one year later, Borhara and her coauthors found that rising global temperatures have already enhanced this effect, and that trend is likely to continue.

“The influence of these extratropical processes is becoming stronger in the formation of El Niño events, even more so than before we reached today’s level of warming,” Borhara said. “They have always influenced ENSO events, but their impact is becoming stronger.”

On one hand, Borhara’s findings will make predicting future El Niño events easier. While the unusually warm surface waters that define El Niño have historically occurred in the eastern Pacific, Borhara’s research shows that warming has and will continue to shift those anomalies west, and that knowledge is of great value to climate scientists. However, her research also offers further proof of what scientists already know: The planet’s climate is changing, and with those changes come unpredictable weather.

“The patterns are becoming more erratic in the Pacific,” Borhara said. “As the effects of warming have become stronger, the patterns of El Niños are becoming more complex. Our predictions need to consider that, because the situation is becoming more complicated.”

Unexpected flooding, droughts and other weather patterns shaped by El Niño can have huge impacts on agriculture, wildlife and the economy, making Borhara’s research especially relevant. Reflecting on his student’s work, Wang praised Borhara for being the sort of scientist the world needs now.

"As her adviser, I am filled with pride for Krishna's remarkable achievements and unwavering perseverance in the face of adversity,” Wang said. “Her inspiring story serves as a true testament to the power of hard work and dedication in achieving one's goals. Such qualities are precisely what we need to tackle the pressing climate challenges of our time.”