In his work, the Stony Brook University professor focuses on remote sensing, instrument development, and mentoring
Editor’s note: This is the seventh and final article in the 2023–2024 series of profiles on members of the ARM User Executive Committee (UEC).
In January 2023, eight scientists joined the Atmospheric Radiation Measurement (ARM) user facility’s User Executive Committee (UEC). Among them was Zhien Wang, professor and Empire Innovation Scholar at the Stony Brook University School of Marine and Atmospheric Sciences on Long Island, New York.
Each UEC member brings a unique perspective and diverse research background to the committee and is tasked with providing objective feedback to ARM leadership about the user experience. Wang brings extensive expertise in atmospheric remote sensing, cloud physics, aerosol and cloud distributions, airborne Raman lidars, and instrument engineering.
Last year, 2023, was a busy one for Wang. It included transitioning from the University of Colorado Boulder to Stony Brook University. Now, Wang is eager to help ARM better serve the needs of the user community.
Wang participates in two UEC subgroups focused on enhancing outreach to the satellite community and communicating measurement calibrations and uncertainty estimates.
“I expect to increase my contributions to the UEC,” he says. “I want to use my knowledge and experience in remote sensing and instrument development to better represent the user community.”
“I hope to improve the impacts of ARM remote sensing capabilities and help new users and young researchers use ARM data and resources to study atmospheric processes.”
Having relied on ARM data since his days as a PhD student, Wang’s goals as a UEC member are clear. “I hope to improve the impacts of ARM remote sensing capabilities and help new users and young researchers use ARM data and resources to study atmospheric processes.”
Well-Defined Research
In his research, Wang seeks to enhance measurement capabilities for profiling the atmospheric boundary layer (ABL)—the bottom layer of the troposphere, which is the lowest 10 to 20 kilometers (6.2 to 12.4 miles) of the atmosphere and where most weather occurs. He also studies tropospheric phenomena, such as aerosols, clouds, and precipitation.
By advancing process-level understanding, Wang aims to improve parameterizations—simplified representations—of ABL- and cloud-related processes in weather and climate models, ultimately contributing to model accuracy and predictive capabilities.
Four pivotal themes guide Wang’s work. He is focused on the advancement of airborne instrumentation, leveraging lidar technologies to transform ABL observation capabilities and improve cloud observation capabilities through multisensor integration.
Wang also seeks to explore the intricacies of ABL structure, processes, and parameterization in diverse environmental contexts, spanning both terrestrial and marine domains. He will deploy a multi-function airborne Raman lidar system with biological aerosol detection capabilities on a mobile van to better characterize aerosols in urban and coastal regions.
Furthermore, Wang endeavors to deepen the understanding of cloud properties and processes, with particular interest in mixed-phase clouds, which contain both ice and liquid water.
Lastly, he studies aerosol properties and distributions globally with space-based lidar.
Opening Doors to Atmospheric Science
Statements of science missions and goals are far removed from Wang’s childhood experience growing up in a village of just a couple hundred people in the Anhui province of southeast China. In those days, it was a poor, agricultural region where most children spent a limited time in school before returning to work on the farm.
“My father only attended school for 20 days, and my mother never went to school at all,” he says, adding that even though they didn’t have a formal education, his parents “valued education highly and did their best to support me, and that kept me focused.”
After primary and middle school, Wang was selected to attend a “normal school,” which is designed to train teachers. “If I had been like most graduates from that school, I would have gone back to the countryside to be an elementary school teacher,” he says with a smile, adding, “But sometimes, you get lucky.”
Just one of 200 graduates was allowed to advance to a “normal university” and become a high school or college teacher. Wang was that graduate, but for him, it meant a chance to study physics—a topic in which he excelled.
It was a fast-changing period. In 1990, the year Wang graduated with a Bachelor of Science degree from Anhui Normal University, China dramatically modified graduate admission policies.
It was a change that altered Wang’s career path. Soon, he was in graduate school at the Chinese Academy of Sciences, studying optical engineering rather than electrical engineering in Shanghai.
“It wasn’t my choice to study optical engineering,” he recalls, “but I worked hard and got good training that would help me later in my career.”
Wang received a Master of Science in optics in 1994, and then, at an international lidar conference in Japan, he met his future PhD advisor and mentor, Kenneth Sassen of the University of Utah.
Of Lidars and Meteorology
Wang’s next stop took him across the Pacific to Salt Lake City, Utah, where he studied under Sassen. “Like me, he was a lidar guy studying meteorology,” Wang says of Sassen (now retired), who was also a science team participant in several ARM field campaigns in the 1990s and early 2000s.
Recognizing Wang’s potential, Sassen offered him the chance to pursue his burgeoning interest in remote sensing.
In atmospheric science, remote sensing is crucial, employing active and passive sensors across different wavelengths from ground, aircraft, or satellite to probe atmospheric properties and structures. This technique proves invaluable in studying a range of atmospheric phenomena, including clouds, precipitation, aerosols, and trace gases.
“His dedication and passion for science is what really motivated me,” Wang says of Sassen, adding that “he impacted my life in many ways. He guided me from engineering to atmospheric research and presented me with cutting-edge cloud remote sensing opportunities by working with ARM observations and supporting (NASA’s) CloudSat mission.”
Under Sassen, Wang honed his “hybrid” skills, working with lidar and other observations, evaluating and improving models, and “exploring science, which is the mode of my research efforts,” he says.
“My career benefited from the support and guidance of many teachers and scientists, but Ken is special, not only in my academic career but also in my personal life,” says Wang. “I had a colon cancer diagnosis in my second year of PhD studies. Had I stayed in China at that time, it could have remained undetected and ended my life early. Thus, his offer to study with him not only changed my career but also gave me a second life.”
Wang received his PhD in meteorology from the University of Utah in 2000. He remained in academia, serving as a postdoctoral research associate at Utah and then becoming a professor at the University of Wyoming, where he was the remote sensing group leader and the chief scientist of the university’s King Air research aircraft.
Venturing Into Entrepreneurship
While at Wyoming (2013–2018), Wang co-founded Alpenglow Instruments LLC. As chief scientist, Wang put his engineering skills to work, innovating compact lidar systems for aerosol, cloud, and gas measurements.
Throughout his career, in fact, Wang has innovated, built, and employed remote sensing instruments in the field.
“Creating and using new cutting-edge instruments allows you to see a new dimension of the natural world, which is critical to advance science, especially for atmospheric science,” says Wang. “The building and innovating process is enjoyable when you achieve the goal, but it is a long, challenging, and dedicated process.”
Wang says that using instruments “off the shelf” meet many routine observational needs, but they are not adequate for many emerging and future research requirements. “Continually improving observational capabilities is an imperative for atmospheric science.”
Alpenglow dissolved during the COVID pandemic after Wang moved to the University of Colorado Boulder as a professor. In the fall of 2023, Wang joined Stony Brook University.
User of ARM Data, Contributor to ASR Science
Since collaborating with Sassen in Utah, Wang has been an active user of ARM data, engaging in several ARM campaigns and projects for the U.S. Department of Energy’s Atmospheric System Research (ASR) program.
He contributed to a 1997 Integrated Intensive Operational Period campaign at ARM’s Southern Great Plains (SGP) atmospheric observatory in Oklahoma. The campaign provided data for several of his papers.
During subsequent multiyear efforts (2002–2010), he used radar, lidar, and radiometer measurements to classify cloud type, retrieve ice cloud properties, and study middle-level mixed-phase cloud properties.
“Cloud observations are challenging, and no single instrument observation is adequate,” says Wang, describing the 2002–2010 work. “This series of studies demonstrated that combining radar, lidar, and radiometer measurements provides improved capabilities for quantifying cloud vertical structures, phase, and microphysical properties with ARM observations. Now, the multisensor synergy is the essential strategy for cloud observations from ground, aircraft, and space.”
Wang notes that the multisensor cloud algorithms developed based on ARM measurements were later adopted and improved for NASA satellite measurements.
Wang’s career includes numerous ASR projects as a participant, co-investigator, and principal investigator. The most recent, “Understanding Processes Controlling the Temporal and Spatial Variations of PBL Structures Over the ARM SGP Site” (2019–2024), takes advantage of ARM’s recent investment in ABL observations and modeling to understand vital physical processes controlling convective mixed layer development and water vapor transport.
“This project demonstrated that combined ARM Raman lidar and Doppler lidar measurements can quantify the diurnal evolution of PBL (planetary boundary layer) structures over land—from the daytime convective boundary layer to nighttime residual and stable layers,” says Wang. “Using multisite and multiyear ARM Doppler lidar measurements, we revealed that there are significant spatial convective boundary layer heterogeneities over the SGP supersite. Further analyses showed that low tropospheric stability, surface energy budgets, and PBL heights are significant factors controlling convective boundary layer developments.”
A Passion for Advancing Science
“We need the next generation of scientists to carry on the mission and to innovate and discover by building on existing knowledge.”
Achieving the goals of reliable weather and climate forecasts requires multigenerational efforts. Atmospheric observations are entering a new era with diverse techniques and a massive amount of data while facing new demands for advanced observations, says Wang.
“We need the next generation of scientists to carry on the mission and to innovate and discover by building on existing knowledge,” says Wang, explaining why supporting early career scientists is so important. “Mentoring is critical for a young researcher to stand in the frontier of observations to advance science. Personally, I benefited from mentoring by many teachers and scientists, and that motivates me to mentor others today.”
With such a spirit of contribution, it’s little surprise that Wang is now a part of ARM’s UEC. “I just try to do everything the best I can do,” he says.
Read UEC profiles of current and past members.
# # #Author: Mike Wasem, Staff Writer, Pacific Northwest National Laboratory
ARM is a DOE Office of Science user facility operated by nine DOE national laboratories.