Sample template image
WACCM-X simulation of the "April Fools" geomagnetic storm in 2001, showing the global electron column density in units of 10^12 cm^-2. Note the "tongue of ionization" extending out of both the north and south auroral regions into the dayside low-latitudes, and the highly distorted equatorial ionosphere.

The Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X) is a comprehensive numerical model, spanning the range of altitude from the Earth’s surface to the upper thermosphere.

The scientific goals of the model include studying solar impacts on the Earth atmosphere, couplings between atmosphere layers through chemical, physical and dynamical processes, and the implications of the coupling for the climate and for the near space environment. The development of the model is inter-divisional collaboration that unifies certain aspects of the upper atmospheric modeling of HAO, the middle atmosphere modeling of ACOM, and the tropospheric modeling of CGD, using the NCAR Community Earth System Model (CESM) as a common numerical framework.


More Information:

    • WACCM-X information and tutorials at CESM:

-CESM main page
-CESM quick start guide
-WACCM-X Compsets
-CESM/WACCM-X description

    • Whole Atmosphere Working Group:


    • WACCM at ACOM:


    • Sign up for WACCM-X Mailing list


News and Updates:

    • Extended runs of WACCM-X v. 2.1 with specified dynamics forcing available for analysis


    • Climate change model output archived (Solomon et al., 2018; 2019)


    • WACCM-X v. 2.1, is released as part of the Community Earth System Model, v. 2.1, January 2019.

-Release Notes for WACCM-X v.2.1

    • WACCM-X v. 2.0, with fully-interactive ionosphere, is released as part of the Community Earth System Model, v. 2.0, June 2018.

-Release Notes for WACCM-X v.2.0

Recent Workshops and Symposia:

    • System Science Workshop 2018
-Toward a Whole Geospace Model

    • CEDAR Workshop 2018
-Hanli Liu's CEDAR Prize Lecture

    • Whole Atmosphere Modeling Workshop, June 13-15, 2018
  • Whole Atmosphere Data Assimilation in WACCMX+DART
  • CESM: A platform for atmospheric prediction from the surface to geospace
  • Whole Atmosphere Community Climate Model with Thermosphere/Ionosphere Extension (WACCM-X)
      • Whole Atmosphere Working Group Meeting, Feb. 12–14, 2018

      • WACCM-X Users Group tutorial session at the CEDAR Workshop, June 22, 2017

      • Whole Atmosphere Variability session at the CEDAR Workshop, June 22, 2017

      • Whole Atmosphere Working Group meeting at the CESM Workshop, June 20, 2017

    WACCM-X Highlights:

    Graphic image of SW2 amplitude in neutral temperature
    February 5, 2020

    We use the CESM2-WACCM, to study the importance of ozone in the vertical coupling between lower and upper atmosphere during SSWs.

    Graphic depicting three WACCM realizations
    January 7, 2020

    Simulations with the Community Earth System Model 2 using the Whole Atmosphere Community Climate Model configuration, known as CESM2(WACCM6), show evidence of dynamical coupling from the high latitudes of the winter middle atmosphere to the tropics and the middle and high latitudes of the summer

    Figure of 150-km echoes and WACCM-X simulated electron densities during the solar flare
    October 31, 2019

    A puzzling feature of the Earth’s equatorial upper atmosphere is the occurrence of enhanced VHF radar echoes near 150-km altitude. These so-called 150-km echoes have been observed for over 50-years, and occur nearly every day, making them a persistent feature of the equatorial ionosphere.

    Graph depicting global normalized root mean square error for wavenumbers 0-6
    July 15, 2019

    The ability to predict conditions in Earth’s ionosphere and thermosphere is of increasing societal relevance due to the growing dependence on, for example, satellite based communications and navigation (e.g., GPS) systems.

    Graph of global simulations
    May 9, 2019

    Solomon and colleagues conducted global simulations of temperature change due to emissions of trace gases due to human activity, that extended from the surface, throughout the atmosphere, to space.