PNNL

Samson Hagos

Samson Hagos, an atmospheric scientist at Pacific Northwest National Laboratory, is the newest recipient of the American Meteorological Society's Clarence Leroy Meisinger Award. The award citation recognizes Hagos for his "novel use of observation, theory, and modeling to advance understanding of tropical convection and its interactions with the large-scale circulation."

Hagos is the first researcher to receive this honor while at PNNL. With family, friends, and colleagues in attendance, he accepted the award January 9, 2019, during the AMS 99th annual meeting in Phoenix, Arizona. 

The award, established in 1938, is given to an individual in recognition of research achievement that concerns the observation, theory, and modeling of atmospheric motions on all scales. Since Hagos joined PNNL in 2009, his body of work totals nearly 50 published research papers—17 as first author.

Reflecting on the contributions of past award winners, Hagos said he was surprised and humbled to receive the honor. "Now I think I have to work harder," he said.

A Passion for Precipitation

Hagos earned his PhD in atmospheric sciences from Cornell University in 2008. He was a postdoctoral research associate at the University of Miami, Rosenstiel School of Marine and Atmospheric Science before joining PNNL. His research reflects his passion: tropical precipitation processes across scales, from individual clouds to monsoon systems.

"I grew up in Northeast Africa during the Sahel droughts of the 1980s," he said, "with some awareness of how climate variability and availability of water affect every aspect of our lives. Political stability, food security, health—you name it."

One of his specific areas of interest is the Madden-Julian Oscillation, or MJO. This large storm system forms periodically over the Indian Ocean and propagates through the Maritime Continent and on to the Pacific Ocean. It affects weather patterns around the globe.

Some of Hagos’ research uses data from a Department of Energy field campaign called the ARM Madden-Julian Oscillation Investigation Experiment. This photo shows convective clouds forming off the coast of Gan Island in the Maldives, where instrumentation took continuous atmospheric measurements between 2011 and 2012.

Current Events

Hagos is the principal investigator for a yearlong field campaign in Indonesia called Diurnal Cycle Interactions with Madden-Julian Oscillation Propagation, or DIMOP. Funded by the U.S. Department of Energy, instrumentation placed on the island of Borneo will measure clouds, precipitation, and radiative energy to characterize MJO systems as they pass through the area. Researchers will compare these data against long-term satellite measurements to examine the forces that control the MJO's strength and frequency.

DIMOP is part of a larger international effort called Years of the Maritime Continent. Its goal is to use observations and modeling exercises to expedite improved understanding and prediction of local multiscale variability of the Maritime Continent weather-climate system and its global impact, including U.S. climate.

Another research effort led by Hagos further examines the processes that govern the progress of the MJO. This study, Modulation of MJO-Diurnal Cycle Interaction over the Maritime Continent, seeks to isolate the factors that move the MJO across the Maritime Continent islands—or not. Researchers will use MJO data gathered during the Years of the Maritime Continent effort to run simulations and test their hypotheses. The three-year project began in 2017 and is funded by the National Oceanic and Atmospheric Administration.

Hagos is a member of the AMS, the American Geophysical Union, and the European Geosciences Union. He is also a current member of the AGU Fall Meeting Program Committee, the AMS Climate Variability Committee, the World Meteorological Organization MJO Task Force, and the U.S. CLIVAR Process Study and Model Improvement Panel.