We use a hierarchy of earth system models (from simple theoretical models to comprehensive dynamical models to AI earth system emulators) and leverage advanced statistics and machine learning techniques to model and understand the dynamics of the coupled ocean-land-atmosphere system and its impact on weather risk.
Department of Atmospheric Sciences, University of Hawai‘i at Mānoa
I ka wā ma mua, I ka wā ma hope
(look to the past to move forward)
"The real voyage of discovery consists not in seeking new landscapes but in having new eyes."
Marcel Proust, 1871-1922
WELCOME!
Our research group is based at the Department of Atmospheric Sciences at the University of Hawaiʻi at Mānoa.
The group is led by Prof. Christina Karamperidou [pronunciation] and focuses on ENSO dynamics and predictability, extreme events in response to large-scale climate variability, paleoclimate, and machine learning applications in environmental science and earth system model optimization.
News & Highlights
Congratulations, Olivia!
May 2026
Olivia Alderson, after succesfully completing her Undergraduate Degree in Atmospheric Sciences at UH Mānoa, will be joining the University of Southern California in Fall 2026 as a PhD student in the Department of Earth Sciences and is excited to continue exploring the intersection of atmospheric science and computational modeling.
AGU25: Karamperidou, Casselman, Murray, and Rivera Tello present new results
December 2025
Our group presented work spanning ENSO and Coastal El Niño dynamics, paleoclimate, atmospheric blocking/extremes, and heat-stress impacts relevant to people and infrastructure.
Karamperidou Research Group members participate in the NSF ERC EARTH Industry Forum and Site Visit in Lawrence, KS
October 2025
Christina Karamperidou, Jake Casselman, and Wasfia (Fia) Hoque joined hundreds of ERC EARTH Members in its first Industry Forum and Annual Site Visit at the University of Kansas, October 20-22, 2025
Our new paper reveals trends and pathways of water into the Equatorial Undercurrent
October 2025
In a new study, led by PhD student Wei-Bang He and published in Journal of Climate, we find that the contribution of the Southeastern Subtropical Pacific water to the Equatorial Undercurrent has increased, while its pathway has shifted and deepened, driven by intensified trades during recent decades.
Group member M. McKenna awarded Grau Fellowship
September 2025
Research Group member Madeline McKenna was awarded a 2025 Grau Fellowship with the Honolulu Office of Climate Change, Sustainability, and Resiliency (CCSR), working with the Coastal and Water Program team to implement the city’s adaptation strategy.
El Niño research brings global experts to UH Mānoa
March 2025
The University of Hawaiʻi at Mānoa hosted the ENSO Winter School 2025 from March 15 to 23, bringing together 32 students and 19 instructors from 16 countries. The program provided an immersive learning experience focused on El Niño-Southern Oscillation (ENSO), a climate pattern that influences global weather.
Gerardo Rivera Tello part of the first-place team at Aloha Data: AI Hackathon for Hawaiʻi’s Resilience
April 2025
The first-place team, Untrained Parameters, created the Hawaiʻi Climate Explorer—an interactive web app that visualizes temperature and rainfall data from the Hawaiʻi Climate Data Portal.
NSF News: A novel method to shed light on heat waves
November 2024
NSF News highlights our research on atmospheric blocking, a weather phenomenon linked to heat waves, cold spells and unusual rainfall events.
El Niño Enhances Exposure to Humid Heat Extremes
February 2025
In a new study published in Geophysical Research Letters, we find that El Niño events enhance humid heat stress metric exceedances regionally to levels expected under much warmer mean climatological conditions.
Deep learning illuminates atmospheric blocking events of past, future
October 2024
In a new study published in Nature Communications Earth & Environment, atmospheric scientist Christina Karamperidou used a deep learning model to infer the frequency of atmospheric blocking events over the past 1,000 years and shed light on how future climate change may impact these significant phenomena.
$26M grant fuels UH research on climate-friendly cooling
August 2024
We are excited to be part of ERC EARTH: UH is part of a team of six universities that has been awarded $26 million to establish EARTH, one of four new NSF Engineering Research Centers (ERC). EARTH will create a transformative, sustainable refrigerant lifecycle to reduce global warming from refrigerants while increasing the energy efficiency of heating, ventilation and cooling.
Group member Z. Menzo awarded the Ellen M. Koenig Award by the ARCS (Achievement Rewards for College Scientists) Foundation
March 2024
ARCS Foundation advances science and technology in the United States by providing financial awards to academically outstanding students who are U.S. citizens studying to complete degrees in science, engineering, math, technology, and medical research.
Dynamics, Predictability, and Impacts of ENSO Diversity in Past, Present, and Future Climates
November 2023
Click here to watch the invited talk at the Seminar Series of the Earth System Science Interdisciplinary Center (ESSIC), University of Maryland.
Assessing El Niño ‘flavors’ to unravel past variability, future impact
December 8, 2022
The new set of climate model simulations developed by Karamperidou and co-author Pedro DiNezio, associate professor at the University of Colorado Boulder, are the first to allow the study of changes in the frequency of El Niño flavors during the past 12,000 years. This enabled the researchers to test a hypothesis that Karamperidou and colleagues posed in 2015—that paleoclimate records across the Pacific could be explained by changes in El Niño flavors.
El Niño research earns Christina Karamperidou early career scientist award
November 10, 2022
Christina Karamperidou, SOEST associate professor of atmospheric sciences, was honored with an Early Career Scientist Award by the International Union of Geodesy and Geophysics (IUGG) for her “significant contributions to understanding El Niño spatiotemporal diversity and associated impacts, from paleoclimate to modern times through multidisciplinary international collaborations.”
Holocene hydroclimate variability in the tropical Pacific explained by changing ENSO diversity.
November 25, 2022
Our new paper is out in Nature Communications!
Past changes in climate variability across the tropical Pacific inferred from paleoclimate records can be explained by changes in both the frequency in which El Nino events with different spatial patterns occur, as well as their hydroclimatic impacts.
HAWAI‘I DROUGHT DURING EL NIÑO WINTER? NOT ALWAYS, ACCORDING TO NEW RESEARCH
January 7, 2021
Our paper on the impacts of Eastern and Central Pacific events on Hawaiian rainfall is published in the Journal of Climate. Read more on SOEST news, UH News, Environmental News Network, Mirage News, and Science Daily.
NEW BOOK ADVANCES KNOWLEDGE OF EL NINO IN A CHANGING CLIMATE
November 13, 2019
El Niño and La Niña events exert their influence worldwide, including in Hawaiʻi. Our participation in the international collaboration that led to this book continues the decades-long tradition of the University’s contributions to understanding and modeling ENSO.
COVERAGE OF THE IMPORTANCE OF ENSO FOR HAWAIʻI DROUGHT BY HPR
September 19, 2019
Ryan Finnerty of Hawaii Public Radio reports on drought, with Christina Karamperidou commenting on the role of ENSO in Hawaii's precipitation patterns.
July 24, 2019
Atmospheric Sciences graduate student Madeline McKenna is among the three students from the University of Hawai‘i at Mānoa who were awarded grants from Future Investigators in NASA Earth and Space Science and Technology (FINESST) program.
HIGH-RESOLUTION MODELING OF ENSO-INDUCED PRECIPITATION IN THE TROPICAL ANDES
January 2019
Our study published in Paleoceanography and Paleoclimatology highlights that in order to better interpret paleo-ENSO proxies in regions with complex terrain it is important to not only consider the large-scale impacts of different ENSO flavors but also how these impacts are modulated by regional and small-scale atmospheric circulation, as well as the terrain.
August 2016
MPR News reports on the Expert Witness Training Academy (EWTA). EWTA is funded in part by the Paleoclimate Program at the National Science Foundation and provides innovative workshops and training materials to scientists on how best to communicate scientific information in legal proceedings and other adversarial forums.
RESEARCH THEMES
INTERACTING DYNAMICS OF TROPICAL AND EXTRATROPICAL CLIMATE
Extratropical atmospheric circulation is influenced by the tropics, and in turn it may influence tropical ocean-atmosphere variability: our studies look into the interactions between tropical climate variability and midlatitude atmospheric dynamics, including blocking events, atmosperic response to volcanic eruptions, surface temperature contrasts etc.
MULTI-RESOLUTION PALEOCLIMATE MODEL-PROXY SYNTHESIS
Paleoclimate proxy records reflect large-scale signals as they are modulated by regional processes and terrain influences: our studies combine the use of global climate models, high-resolution regional models and statistical downscaling methods to improve interpretation of proxies recording ENSO variability.
CONSTRAINTS FOR CLIMATE CHANGE PROJECTIONS
Model uncertainty is a main source of uncertainty in climate projections, especially at multidecadal scales: our studies focus on using our understanding of tropical climate process to identify model biases and constrain intermodel spread of future projections of tropical and global climate.