EOL Seminar: Moisture Transport by Shallow Clouds: Insights from the EUREC4A Field Experiment

Tuesday, February 16, 2021 - 15:30 to 16:30
Virtual (Webcast link provided below)
Contact Name: 
Melissa Ward
Contact Email: 
Contact Phone: 

SPEAKER: Dr. Adriana Raudzens Bailey - NCAR EOL Research Aviation Facility

DATE: February 16, 2021

Time: 3:30 - 4:30 pm MST

WEBCAST: https://operations.ucar.edu/live-eol

QUESTIONS: Slido will be used to answer your questions during the seminar.



Shallow clouds in the tropics continue to contribute large uncertainties to our predictions of future climate. To better study these clouds in the context of their mesoscale environment, scientists from across Europe, the United States, and the Caribbean, came together to launch EUREC4A — or ElUcidating the RolE of Clouds-Circulation Coupling in ClimAte — a field experiment that took place in early 2020 in the western tropical Atlantic.

Using the long-term Barbados Cloud Observatory as its base, EUREC4A also supported an impressive fleet of mobile research platforms, including 4 research aircraft, 4 ocean-going research vessels, and numerous unmanned airborne and ocean-going measurement systems. The experiment also exploited novel sampling methods to estimate key quantities, like the large-scale moisture flux divergence, which are typically derived from model output.

In this talk, we focus on one major aspect of EUREC4A: the role of shallow clouds in mixing moisture up and out of the boundary layer. This process, which is known to accelerate with sea surface warming, is believed responsible for moistening the lower free troposphere, amplifying water vapor feedbacks, and for drying the boundary layer sufficiently to impede cloud growth, ultimately reducing low-level cloud cover and increasing Earth’s climate sensitivity. However, models disagree about just how important this shallow convective mixing process is.

Using data from NCAR’s new fast water vapor isotopic analyzer, which flew on the NOAA hurricane hunter Miss Piggy, we’ll discuss how much moisture trade cumuli export from the boundary layer and match this export to large-scale and mesoscale conditions in order to identify potential controls on the strength of shallow convective mixing and its impact on cloudiness. We’ll also discuss ongoing efforts to extend the analysis globally using satellite retrievals of water vapor’s hydrogen isotope ratio.


Adriana Bailey is an atmospheric scientist who studies the processes that control humidity, cloudiness, and precipitation. Using the isotopic composition of water molecules as a tracer (both in the real world and in numerical simulations), she tracks moisture as it moves through the atmosphere and exchanges with the ocean and land. She is especially interested in understanding the sensitivity of moisture transport to climate variability, how efficiently clouds form precipitation, and the role of vertical mixing between the boundary layer and free troposphere in affecting water cycle feedbacks and pollution transport.

As a staff scientist with NCAR’s Research Aviation Facility, Adriana supports measurements of water isotope ratios (in water vapor, cloud droplets, and ice particles) and airborne measurements of winds and turbulence. Prior to becoming an atmospheric scientist, Adriana worked as a Science News Writer for the University of Colorado and NOAA’s Cooperative Institute for Research in Environmental Sciences. She credits writing about science, which requires asking lots (and lots) of questions, for stoking her interest in scientific inquiry. Adriana is also one of 125 AAAS If/Then Ambassadors nationwide working to share her career story and inspire girls to become the next pioneers in STEM.