Jones, M. Jr., Siskind, D. E., Drob, D. P., McCormack, J. P., Emmert, J. T., Dhadly, M. S., et al. (2020). Coupling from the middle atmosphere to the exobase: Dynamical disturbance effects on light chemical species. Journal of Geophysical Research: Space Physics, 125, e2020JA028331. https://doi.org/10.1029/2020JA028331
Coupling from the middle atmosphere to the exobase : dynamical disturbance effects on light chemical species
|Author:||Jones Jr., M.1; Siskind, D. E.1; Drob, D. P.1;|
1Space Science Division, U.S. Naval Research Laboratory,Washington, DC, USA
2Department of Applied Sciences, College of Arts and Sciences, Embry-Riddle Aeronautical University, Daytona Beach, FL, USA
3NASA Langley Research Center, Hampton, VA, USA
4Department of Physics and Astronomy, University ofWestern Ontario, London, Ontario, Canada
5Institute of Applied Physics, Microwave Physics, University of Bern, Bern, Switzerland
6Sodankylä Geophysical Observatory, University of Oulu, Sodankylä, Finland
7Department of Physics and Astronomy, University of Leicester, Leicester, UK
8Leipzig Institute for Meteorology, Universität Leipzig, Leipzig, Germany
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe202102023535
American Geophysical Union,
|Publish Date:|| 2021-03-23
This paper characterizes the impacts of sudden stratospheric warmings (SSWs) and mesospheric coolings (MCs) on the light species distribution (i.e., helium [He], and atomic hydrogen [H]) of the thermosphere using a combined data‐modeling approach. Performing a set of numerical experiments with a general circulation model whose middle atmospheric dynamical and thermodynamical fields were constrained using a numerical weather prediction system, we simulate the effects of SSWs and MCs on light chemical species, and via comparisons with two data sets taken from the mesosphere and thermosphere, we quantify the associated variability in light species abundances and mass density. Large depletions in the observed and modeled polar H abundance in the mesosphere and lower thermosphere (MLT) occur with MC onset, as opposed to SSW onset. Depletions in all light thermospheric species at high northern latitudes extend up to the exobase in our model simulations during the January 2013 SSW/MC period, with the largest depletions simulated for the lightest species. Further, our modeling work substantiates the paradigm of increased mixing in the MLT driven by a meridional residual circulation during SSWs resulting from enhanced small‐scale gravity wave and migrating semidiurnal tidal forcing; the former being the primary driver and the latter of secondary but notable importance in our model simulations. SSW/MC induced light species variability then gets projected upward into the thermosphere through molecular diffusion. Modeled light species variability during the January 2013 SSW/MC event suggests SSW/MC signatures could be present in the topside ionosphere and plasmasphere.
Journal of geophysical research. Space physics
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
115 Astronomy and space science
This work was supported by the NASA Heliophysics Supporting Research (NNH16ZDA001N‐HSR/ITM16_2‐0013) and Early Career Investigator (NNH18ZDA001N‐ECIP/18‐ECIP_2‐0018) Programs. D. E. Siskind and M. G. Mlynczak acknowledge support from the NASA/TIMED SABER project (Interagency Purchase Request NNG17PX04I to NRL). J. P. McCormack acknowledges support from NASA Grant NNH18ZDA001N. J. T. Emmert acknowledges support from the Chief of Naval Research. M. S. Dhadly acknowledges support from the NASA ECI and Living with s Star (NNH18ZDA001N/18‐LWS18_2‐0126) Programs. H. E. Attard was an NRC Postdoctoral Research Associate at the U.S. Naval Research Laboratory and was supported by the Chief of Naval Research.
The TIME‐GCM code is made available by contacting the National Center for Atmospheric Research. The TIE‐GCM code is available for download at https://www.hao.ucar.edu/modeling/tgcm/. The model output produced herein is reproducible from the TGCM model source code following the discussions and implementations of the nudging schemes and lower boundary conditions described thoroughly in sections 2 and 3, as well as the supporting information. Daily NCAR TGCMs outputs in netCDF format from this study are archived on the DoD HPCMP long‐term storage system. NAVGEM‐HA inputs used to constrain the stratosphere and mesosphere of the TIME‐GCM simulations performed herein are accessible at https://map.nrl.navy.mil (cd to map/pub/nrl/jgrspace2020/lightspecies/navgem/djfm1213 or map/pub/nrl/jgrspace2020/lightspecies/navgem/djfm1314). Data from the Sodankylä meteor radar (SGO) used herein are available at https://www.sgo.fi/pub/JGR_SSW_2013https://www.sgo.fi/pub(cd to JGR_SSW_2013/HWD_201301 or JGR_SSW_2013/HWD_201401). Access to data from the CMOR and Collm meteor radars is discussed in Stober et al. (2019). SABER atomic hydrogen data are available at http://saber.gats‐inc.com/data.php then by clicking on the ftp://saber.gats‐inc.com/Version2_0/Level2A/ link. Orbit‐derived global average mass density data and the GAMDM model parameters are available in the supporting information of Emmert (2015). The SSW epochs used to generate the superposed epoch analysis in Figure 5 herein are in the supporting information of Yamazaki et al. (2015). Finally, all model and satellite data shown in Figures S2–S7 can be accessed using the data links provided above.
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