Tropical Atmospheric Dynamics Group

NOAA GOES-17 imagery showing a double ITCZ, one ITCZ in each hemisphere, spanning the Pacific Ocean on 10 March 2018. Courtesy of NASA’s Earth Polychromatic Imaging Camera (EPIC) Team.

Welcome to the tropical atmospheric dynamics research group at Iowa State University! We are interested in atmospheric dynamical processes in the tropics and their interactions with higher latitudes. We study a variety of topics, including the Inter-Tropical Convergence Zone (ITCZ), the Madden-Julian Oscillation (MJO), the Hadley circulation, equatorial waves, tropical cyclones, El Niño-Southern Oscillation (ENSO), and tropical-extratropical teleconnection patterns. One of our primary goals is to improve understanding of observations of these complex phenomena using a hierarchy of models and theory. With this improved understanding, weather and climate prediction can be guided in the right direction.

We are also involved in science education and outreach, particularly at Iowa State University and in the local Iowa community. From bringing hands-on rotating tank geophysical experiments to K–12 and college classrooms to mentoring middle- and high-school students and teachers on research projects, we strive to motivate a generation of future scientists.

Prospective students interested in undergraduate research or pursuing an M.S. or Ph.D. are encouraged to contact Professor Alex Gonzalez at Note: Professor Gonzalez is not recruiting any new graduate students for Fall 2022.

Monday, August 23 2021 – Welcome, Fouzia and Travis!

The Tropical Atmospheric Dynamics Group welcomes new graduate students, Fouzia Fahrin and Travis Enzensperger. They both will be researching the east Pacific ITCZ and its associated climate model biases as a part of their Ph.D. and M.S. theses, respectively.


Monday, June 21 2021 – Katherine Hanson begins her Summer 2021 research on the ITCZ

We welcome Urbandale High School Chemistry and Physical Sciences teacher, Katherine Hanson, to our research group for Summer 2021. Katherine will work on studying east Pacific ITCZ events that occurred from 2013 to 2019 in NASA observational and reanalysis data for northern ITCZs, southern ITCZs, and double ITCZs. Katherine is supported by one of Alex’s NSF grants and ISU’s Summer Research Experience for Teachers Program. More info.


Tuesday, May 25 2021 – Alex hosts seminar at UNAM México City Seminar Series

Alex presented research entitled, “Interacciones de la dinámica y propagación de OMJ en simulaciones de modelos climáticos,” as a part of the Center for Atmospheric Sciences at UNAM México City Virtual Seminar Series (Ciencias Atmosféricas Para Quedarse En Casa). More info and seminar recording.


Monday, May 24 2021 – Marissa Osterloh begins her Summer 2021 research on the ITCZ

We welcome undergraduate student, Marissa Osterloh, to our research group for Summer 2021. Marissa will work on studying east Pacific ITCZ events that occurred during 1998 to 2012 in ECMWF and NASA observational and reanalysis data for northern ITCZs, southern ITCZs, and double ITCZs.


Wednesday, April 21 2021 – Allysa presents at ISU’s 15th Annual Undergraduate Research Symposium

Allysa Dallmann presented her Spring 2021 research at ISU’s 15th Annual Symposium on Undergraduate Research and Creative Expression. A recording of her talk entitled, “” can be viewed here: Congrats, Allysa!


Monday, December 21 2020 – Allysa receives LAS research award

Allysa Dallmann was awarded the Dean’s High Impact Awards for Undergraduate Research for Spring 2021. Each award is $1,200 per semester or $4,800 for summer. Allysa will be advised by Dr. Christina Patricola and co-advised by Alex. She will continue her senior thesis research on the influence of El Niño Southern Oscillation on past and future precipitation. Congrats, Allysa!


Wednesday, November 18 2020 – Allysa presents Senior Thesis at 28th Annual ISU Research Symposium

Allysa Dallmann presented her senior thesis project entitled, “The Influence of ENSO on Future Winter Precipitation and Temperature in the Southwestern United States,” at the 28th Annual Iowa State University Atmospheric Science Undergraduate Research Symposium. Allysa was advised by Dr. Christina Patricola and co-advised by Alex.


Wednesday, September 20 2020 – Alex hosts seminar at Fall 2020 Penn State Colloquia 

Alex presented research entitled, “Weather in the east Pacific ITCZ: The role of nonlinear dynamics in boreal spring submonthly ITCZ shifts,” at Penn State’s Meteorology and Atmospheric Science Colloquia. More info and seminar recording.


Thursday, August 13 2020 – James presents ITCZ research at ISU Summer Undergraduate Research Symposium

James Larson virtually presented his spring/summer research entitled, “How Climate Model Biases Depend on Weather: Case Studies in the East Pacific Ocean” at the 2020 ISU Summer Undergraduate Research Symposium. James’ poster and presentation can be found at this CyBox link. Congrats, James!


Friday, August 7 2020 – Ashley successfully defends her M.S. thesis and graduates

Ashley Heath successfully defended her M.S. thesis entitled, “Interactions of large scale dynamics in multi-model Madden-Julian Oscillation simulations” on July 6th via Webex. She officially graduated one month later and is working on publishing her research in the American Geophysical Union’s Journal of Advances in Modeling Earth Systems. Congrats, Ashley!



Friday, June 26 2020 – Fully funded, Graduate Research Assistantship opening for Fall 2021

There is a fully funded, Graduate Student Research Assistantship opening up in our Tropical Atmospheric Dynamics group for Fall 2021. We are seeking a bright and enthusiastic graduate student who has strong skills in applied mathematics and computer programming (FORTRAN, Python, NCL) with interests in numerical modeling of tropical storms, the Inter-Tropical Convergence Zone, and more generally, Earth’s climate system. More info here.


Monday, May 25 2020 – Natalie Kongable teaches fluid dynamics to middle schoolers using DIYnamics

Natalie Kongable was just recognized for her high school senior research project where she worked with our Tropical Atmospheric Dynamics group perfecting fluid experiments on extratropical cyclones using the DIYnamics Lego-based tank system and presenting said experiments at local middle schools in eastern Iowa. Congrats, Natalie! For more info, see the DIYnamics blog post.


Tuesday, April 21 2020 – Alex welcomed as core team member of multi-institutional DIYnamics Project

Alex and two other scientists were added as core team members of the DIYnamics Project, which is a multi-institutional project that develops affordable, accessible Earth science demonstration and teaching materials to K–12 and universities. For more info, see the DIYnamics blog post.


Tuesday, April 7 2020 – National Science Foundation grant funded on synoptic ITCZ shifts 

Alex’s grant entitled, “Nonlinear Dynamics of Daily-weekly Boreal Spring InterTropical Convergence Zone (ITCZ) Shifts over the Eastern Pacific Ocean” was awarded by the National Science Foundation’s Climate & Large-Scale Dynamics Program. Funding for this project will be for three years beginning in May 2020. See more details on our ITCZ Dynamics Research Page and the official Award Abstract on NSF’s website here.


Tuesday, January 21 2020 – James win research award through Iowa Space Grant Consortium

Undergraduate student, James Larson, won a Student Experiential Opportunities award through the Iowa Space Grant Consortium for January through June 2020. James will be assessing the accuracy of the Community Atmosphere Model (CAM) in simulating sub-monthly shifts in the eastern Pacific Ocean Inter-Tropical Convergence Zone (ITCZ) for October 2009–March 2010. Congrats and welcome to our research group, James!


Friday, December 13 2019 – Melissa wins Outstanding Senior Thesis Award

Undergraduate student, Melissa Piper, won the 2019 Outstanding Senior Thesis Award on her research entitled, “Evaluating Hurricane Harvey’s Rapid Intensification and Precipitation in the ERA5 Reanalysis.”


Thursday, December 12 2019 – Indrani wins NCAR Graduate Student Fellowship

Ph.D. student, Indrani Ganguly, won the National Center for Atmospheric Research (NCAR) NCAR’s Advanced Study Program’s Graduate Student Fellowship for summer 2020. Indrani will be working with Dr. Richard Neale in the Climate and Global Dynamics Division conducting research on double ITCZ biases in climate models through hindcast simulations. Congrats, Indrani!


Monday, December 9 2019 – Sara, Melissa, and Matt present at ISU Research Symposium

Sara Foernssler, Melissa Piper, and Matthew Statz all presented their senior thesis research at the 27th Annual Iowa State University Atmospheric Science Undergraduate Research Symposium. Congrats, Sara, Melissa, and Matt!


Thursday, December 5 2019 – Melissa featured in Inside LAS article

Melissa Piper’s reflects on her undergraduate experience in Meteorology at Iowa State in an article featured in Inside LAS:


Wednesday, November 27 2019 – Kevin, Matt, and Melissa win LAS research awards

Kevin Greene, Matthew Statz, and Melissa Piper were all awarded the Dean’s High Impact Awards for Undergraduate Research for Spring 2020. Each award is $1,200 per semester or $4,800 for summer. This is Kevin’s second time winning the award; he will be continuing his research on improving our understanding of the rainfall characteristics of Tropical Storm Hermine (2010) in the ERA5 reanalysis. Matt will continue work he conducted for his senior thesis on the impact of the Madden-Julian Oscillation and El Niño-Southern Oscillation on near-surface wind speeds over the Midwest U.S. using numerous reanalysis data sets and Iowa Mesonet surface station data. Melissa will be also be continuing work she conducted for her senior thesis on Hurricane Harvey and other large rain-producing Atlantic tropical cyclones in the ERA5 reanalysis.

Congrats, Kevin, Matt, and Melissa!


Monday, September 30 2019 – Melissa returns from East Pacific Ocean Field Campaign

Melissa Piper was one of five undergradauate students selected to participate in the National Science Foundation funded field experiment called the Organization of Tropical East Pacific Convection (OTREC) based in Costa Rica. Melissa helped launch radiosonde-equipped weather balloons that measured key atmospheric variables such as winds, temperature, and humidity. She also had to opportunity to be onboard for several research flights into tropical storms. For more information about OTREC, see the website Congrats, Melissa!