Whole Atmosphere Community Climate Model
This is an excerpt from Applying the science and technology of data assimilation by Brian Bevirt 07/11/2017 as part of a CISL News series describing the many ways CISL improves modeling beyond providing supercomputing systems and facilities.
These plots show measured and modeled zonal mean temperatures between 70N and 90N during the January 2009 sudden warming of the stratosphere. The bottom plot shows the observed temperatures (in degrees Kelvin, see legend at right), the center plot shows how this state of the atmosphere was simulated by the specified-dynamics version of the WACCM model, and the top plot shows WACCM’s improved result after using DART to assimilate middle atmosphere observations.
The key point in this figure is that WACCM+DART captures both the stratosphere warming and mesosphere cooling that are seen in the observations. Also seen in the specified-dynamics version of WACCM, the elevated stratopause that forms at high altitudes around day 30 descends too fast compared to the observations. The elevated stratopause is maintained at a high altitude in the WACCM+DART simulation. This has implications for the descent of species from the mesosphere into the stratosphere. Accurate representation of the mesosphere dynamics is important for the ionosphere variability during sudden stratosphere warming events. (Figure courtesy of Nick Pedatella, HAO)
Nick Pedatella, firstname.lastname@example.org
Hanli Liu, email@example.com
Jing Liu, firstname.lastname@example.org
Laskar, F. I., Pedatella, N. M., Codrescu, M. V., Eastes, R. W., Evans, J. S., Burns, A. G., & McClintock, W., 2021 Impact of GOLD retrieved thermospheric temperatures on a whole atmosphere data assimilation model.
Journal of Geophysical Research: Space Physics, 126, e2020JA028646. doi.org/10.1029/2020JA028646
Pedatella, N. M., H.‐L. Liu, D. R. Marsh, K. Raeder, J. L. Anderson, J. L. Chau, L. P. Goncharenko and T. A. Siddiqui, 2018 Analysis and Hindcast Experiments of the 2009 Sudden Stratospheric Warming in WACCMX+ DART.
Journal of Geophysical Research: Space Physics, 123, 3131-3153, doi:10.1002/2017JA025107