The NASA ACTIVATE Mission

Bulletin of the American Meteorological Society, vol. 106, pp. E1517–E1538

Abstract

Abstract The NASA Aerosol Cloud Meteorology Interactions over the Western Atlantic Experiment (ACTIVATE) conducted 162 joint flights with two aircraft over the northwest Atlantic to study aerosol–cloud interactions (ACIs), which represent the largest uncertainty in estimating total anthropogenic radiative forcing. The combination of a high-flying King Air and low-flying HU-25 Falcon, equipped with remote sensing and in situ instruments, characterized trace gases, aerosol particles, clouds, and meteorological variables with data collected nearly simultaneously below, within, and above marine boundary layer (MBL) clouds. Flights spanning warm and cold seasons across 3 years (2020–22) provided a broad range of conditions associated with aerosol particles, cloud properties (including particle size and phase), and meteorology, ideally suited for robust ACI calculations and assessing how well models simulate a wide range of MBL clouds from stratiform to cumulus. ACTIVATE data suggest that drivers of cloud droplet number concentration N d , including aerosol particles and MBL dynamics, vary between winter and summer months with a stronger potential to convert aerosol particles into cloud droplets in winter. Models of varying complexity not only highlight some skills in simulating winter and summer cloud types but also identify challenges that still need to be addressed such as treatment of turbulence, wet scavenging, and mesoscale organization. Remote sensing advances range from new retrieval methods for N d , cloud phase classification, vertically resolved aerosol and cloud condensation nuclei number concentration, and ocean surface wind speed. This work describes these scientific and technological advances along with efforts in outreach and open data science. Significance Statement Depending on the number and type of aerosol particles there are in the air, the properties of cloud droplets can vary in number concentration, size, and lifetime, and this leads to varying effects of clouds on climate and weather. We took an ambitious approach to investigate aerosol–cloud interactions, which represent the largest uncertainty in estimating human impacts on climate change. The NASA ACTIVATE mission conducted 162 joint airborne flights over the northwest Atlantic with two spatially coordinated planes making measurements relevant to understanding clouds spanning the continuum from stratiform to cumulus clouds. Along with newfound knowledge of how clouds evolve and interact with aerosol particles, extensive technological advancements were made assisted by the carefully designed sampling strategy.

Authors 42

1. Armin Sorooshian corresponding

   University of Arizona

   Affiliation as printed

   Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, Arizona;

   Department of Hydrology and Atmospheric Sciences, The University of Arizona, Tucson, Arizona;

   Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ

   Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ

2. Leong Wai Siu

   University of Arizona

   Affiliation as printed

   Department of Hydrology and Atmospheric Sciences, The University of Arizona, Tucson, Arizona;

   Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ

3. Michael A. Brunke

   University of Arizona

   Affiliation as printed

   Department of Hydrology and Atmospheric Sciences, The University of Arizona, Tucson, Arizona;

   Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ

4. Brian Cairns

   Goddard Institute for Space Studies

   Affiliation as printed

   NASA Goddard Institute for Space Studies, New York, New York;

   NASA Goddard Institute for Space Studies, New York, NY

5. Seethala Chellappan

   Langley Research Center · Analytical Mechanics Associates (United States)

   Affiliation as printed

   Analytical Mechanics Associates, Hampton, Virginia;

   NASA Langley Research Center, Hampton, Virginia;

   Analytical Mechanics Associates, Hampton, VA

   NASA Langley Research Center, Hampton, VA

6. Jingyi Chen

   Pacific Northwest National Laboratory · Nanjing University of Information Science and Technology

   Affiliation as printed

   Atmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, Washington;

   School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing, China;

   Atmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, WA

   School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing, China

7. Yonghoon Choi

   Langley Research Center · Analytical Mechanics Associates (United States)

   Affiliation as printed

   Analytical Mechanics Associates, Hampton, Virginia;

   NASA Langley Research Center, Hampton, Virginia;

   Analytical Mechanics Associates, Hampton, VA

   NASA Langley Research Center, Hampton, VA

8. Ewan Crosbie

   Langley Research Center · Analytical Mechanics Associates (United States)

   Affiliation as printed

   Analytical Mechanics Associates, Hampton, Virginia;

   NASA Langley Research Center, Hampton, Virginia;

   Analytical Mechanics Associates, Hampton, VA

   NASA Langley Research Center, Hampton, VA

9. Joshua Paul DiGangi

   Langley Research Center

   Affiliation as printed

   NASA Langley Research Center, Hampton, Virginia;

   NASA Langley Research Center, Hampton, VA

10. Glenn S. Diskin

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

11. R. A. Ferrare

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

12. Johnathan W. Hair

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

13. C. A. Hostetler

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

14. Simon Kirschler

    Johannes Gutenberg University Mainz · Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

    Affiliation as printed

    Institute of Atmospheric Physics, German Aerospace Center, Cologne, Germany;

    Institute of Atmospheric Physics, University Mainz, Mainz, Germany;

    Institute of Atmospheric Physics, German Aerospace Center, Germany

    Institute of Atmospheric Physics, University Mainz, Germany

15. Mary M. Kleb

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

16. Xiangyu Li

    Pacific Northwest National Laboratory

    Affiliation as printed

    Atmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, Washington;

    Atmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, WA

17. Hongyu Liu

    Langley Research Center · National Institute of Aerospace

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    National Institute of Aerospace, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

    National Institute of Aerospace, Hampton, VA

18. Allison C. McComiskey

    NSF National Center for Atmospheric Research

    Affiliation as printed

    NSF National Center for Atmospheric Research, Boulder, Colorado;

    NSF National Center for Atmospheric Research, Boulder, CO

19. Soodabeh Namdari

    University of Arizona

    Affiliation as printed

    Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, Arizona;

    Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ

20. David Painemal

    Langley Research Center · Analytical Mechanics Associates (United States)

    Affiliation as printed

    Analytical Mechanics Associates, Hampton, Virginia;

    NASA Langley Research Center, Hampton, Virginia;

    Analytical Mechanics Associates, Hampton, VA

    NASA Langley Research Center, Hampton, VA

21. Joseph Simon Schlosser

    Langley Research Center · National Aeronautics and Space Administration

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Postdoctoral Program, NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

    NASA Postdoctoral Program, NASA Langley Research Center, Hampton, VA

22. Taylor Shingler

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

23. Michael A. Shook

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

24. Sam James Silva

    University of Southern California

    Affiliation as printed

    Department of Earth Sciences, University of Southern California, Los Angeles, California;

    Department of Earth Sciences, University of Southern California, Los Angeles, CA

25. Kenneth Sinclair

    Goddard Institute for Space Studies · Columbia University

    Affiliation as printed

    Center for Climate Systems Research, Columbia University, New York, New York;

    NASA Goddard Institute for Space Studies, New York, New York;

    Center for Climate Systems Research, Columbia University, New York, NY

    NASA Goddard Institute for Space Studies, New York, NY

26. William L. Smith

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

27. Cassidy Soloff

    University of Arizona

    Affiliation as printed

    Department of Hydrology and Atmospheric Sciences, The University of Arizona, Tucson, Arizona;

    Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ

28. Snorre Stamnes

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

29. Shuaiqi Tang

    Pacific Northwest National Laboratory · Nanjing University

    Affiliation as printed

    Atmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, Washington;

    School of Atmospheric Sciences, Nanjing University, Nanjing, China;

    Atmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, WA

    School of Atmospheric Sciences, Nanjing University, Nanjing, China

30. Kenneth Lee Thornhill

    Langley Research Center · Analytical Mechanics Associates (United States)

    Affiliation as printed

    Analytical Mechanics Associates, Hampton, Virginia;

    NASA Langley Research Center, Hampton, Virginia;

    Analytical Mechanics Associates, Hampton, VA

    NASA Langley Research Center, Hampton, VA

31. Florian Tornow

    Goddard Institute for Space Studies · Columbia University

    Affiliation as printed

    Center for Climate Systems Research, Columbia University, New York, New York;

    NASA Goddard Institute for Space Studies, New York, New York;

    Center for Climate Systems Research, Columbia University, New York, NY

    NASA Goddard Institute for Space Studies, New York, NY

32. George Tselioudis

    Goddard Institute for Space Studies

    Affiliation as printed

    NASA Goddard Institute for Space Studies, New York, New York;

    NASA Goddard Institute for Space Studies, New York, NY

33. Bastiaan van Diedenhoven Aachen SRON Netherlands Institute for Space Research

    Space Research Organisation Netherlands

    Affiliation as printed

    SRON Netherlands Institute for Space Research, Leiden, Netherlands;

    SRON Netherlands Institute for Space Research, Leiden, the Netherlands

34. Christiane Voigt

    Johannes Gutenberg University Mainz · Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

    Affiliation as printed

    Institute of Atmospheric Physics, German Aerospace Center, Cologne, Germany;

    Institute of Atmospheric Physics, University Mainz, Mainz, Germany;

    Institute of Atmospheric Physics, German Aerospace Center, Germany

    Institute of Atmospheric Physics, University Mainz, Germany

35. Holger Vömel

    NSF National Center for Atmospheric Research

    Affiliation as printed

    NSF National Center for Atmospheric Research, Boulder, Colorado;

    NSF National Center for Atmospheric Research, Boulder, CO

36. Hailong Wang

    Pacific Northwest National Laboratory

    Affiliation as printed

    Atmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, Washington;

    Atmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, WA

37. Edward L. Winstead

    Langley Research Center · Analytical Mechanics Associates (United States)

    Affiliation as printed

    Analytical Mechanics Associates, Hampton, Virginia;

    NASA Langley Research Center, Hampton, Virginia;

    Analytical Mechanics Associates, Hampton, VA

    NASA Langley Research Center, Hampton, VA

38. Yike Xu

    University of Arizona

    Affiliation as printed

    Department of Hydrology and Atmospheric Sciences, The University of Arizona, Tucson, Arizona;

    Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ

39. Xubin Zeng

    University of Arizona

    Affiliation as printed

    Department of Hydrology and Atmospheric Sciences, The University of Arizona, Tucson, Arizona;

    Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ

40. Bo Zhang

    Langley Research Center · National Institute of Aerospace

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    National Institute of Aerospace, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

    National Institute of Aerospace, Hampton, VA

41. Luke D. Ziemba

    Langley Research Center

    Affiliation as printed

    NASA Langley Research Center, Hampton, Virginia;

    NASA Langley Research Center, Hampton, VA

42. Paquita Zuidema

    University of Miami

    Affiliation as printed

    Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, Miami, Florida

    Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, Miami, FL