Bibliography

Development and Validation of the Whole Atmosphere Community Climate Model With Thermosphere and Ionosphere Extension (WACCM-X 2.0)

Key developments have been made to the NCAR Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X). Among them, the most important are the self-consistent solution of global electrodynamics, and transport of O⁺ in the F-region. Other ionosphere developments include time-dependent solution of electron/ion temperatures, metastable O⁺ chemistry, and high-cadence solar EUV capability. Additional developments of the thermospheric components are improvements to the momentum and energy equation solvers to account for variable mean molecular mass and specific heat, a new divergence damping scheme, and cooling by O(³P) fine structure. Simulations using this new version of WACCM-X (2.0) have been carried out for solar maximum and minimum conditions. Thermospheric composition, density, and temperatures are in general agreement with measurements and empirical models, including the equatorial mass density anomaly and the midnight density maximum. The amplitudes and seasonal variations of atmospheric tides in the mesosphere and lower thermosphere are in good agreement with observations. Although global mean thermospheric densities are comparable with observations of the annual variation, they lack a clear semiannual variation. In the ionosphere, the low-latitude E \texttimes B drifts agree well with observations in their magnitudes, local time dependence, seasonal, and solar activity variations. The prereversal enhancement in the equatorial region, which is associated with ionospheric irregularities, displays patterns of longitudinal and seasonal variation that are similar to observations. Ionospheric density from the model simulations reproduces the equatorial ionosphere anomaly structures and is in general agreement with observations. The model simulations also capture important ionospheric features during storms.

Liu, Han-Li; Bardeen, Charles; Foster, Benjamin; Lauritzen, Peter; Liu, Jing; Lu, Gang; Marsh, Daniel; Maute, Astrid; McInerney, Joseph; Pedatella, Nicholas; Qian, Liying; Richmond, Arthur; Roble, Raymond; Solomon, Stanley; Vitt, Francis; Wang, Wenbin;

Published by: Journal of Advances in Modeling Earth Systems      Published on: 01/2018

YEAR: 2018     DOI: 10.1002/jame.v10.210.1002/2017MS001232

Whole Atmosphere Community Climate Model—eXtended Version 2.0 Scientific Description

Key developments have been made to the NCAR Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X). Among them the most

Liu, Han-Li; Bardeen, Charles; Foster, Benjamin; Lauritzen, Peter; Liu, Jing; Lu, Gang; Marsh, Daniel; Maute, Astrid; McInerney, Joseph; Pedatella, Nicholas; , others;

Published by:       Published on:

YEAR: 2018     DOI:

The NCAR TIE-GCM: A community model of the coupled thermosphere/ionosphere system

Qian, Liying; Burns, Alan; Emery, Barbara; Foster, Benjamin; Lu, Gang; Maute, Astrid; Richmond, Arthur; Roble, Raymond; Solomon, Stanley; Wang, Wenbin;

Published by: Modeling the Ionosphere-Thermosphere System      Published on:

YEAR: 2014     DOI:

Ionospheric symmetry caused by geomagnetic declination over North America

We describe variations in total electron content (TEC) in the North American sector exhibiting pronounced longitudinal progression and symmetry with respect to zero magnetic declination. Patterns were uncovered by applying an empirical orthogonal function (EOF) decomposition procedure to a 12 year ground-based American longitude sector GPS TEC data set. The first EOF mode describes overall average TEC, while the strong influence of geomagnetic declination on the midlatitude ionosphere is found in the second EOF mode (or the second most significant component). We find a high degree of correlation between spatial variations in the second EOF mode and vertical drifts driven by thermospheric zonal winds, along with well-organized temporal variation. Results strongly suggest a causative mechanism involving varying declination with longitude along with varying zonal wind climatology with local time, season, and solar cycle. This study highlights the efficiency and key role played by the geomagnetic field effect in influencing mesoscale ionospheric structures over a broad midlatitude range.

Zhang, Shun-Rong; Chen, Ziwei; Coster, Anthea; Erickson, Philip; Foster, John;

Published by: Geophysical Research Letters      Published on: 10/2014

YEAR: 2013     DOI: 10.1002/grl.v40.2010.1002/2013GL057933

geomagnetic field; midlatitude ionosphere; thermospheric winds; total electron content

Mesospheric Impact on Thermosphere and Ionosphere

Wu, Qian; Roble, Raymond; Foster, Benjamin;

Published by: 38th COSPAR Scientific Assembly      Published on:

YEAR: 2010     DOI:

Observations of a positive storm phase on September 10, 2005

In this study, we present multi-instrument observations of a strong positive phase of ionospheric storm, which occurred on September 10, 2005 during a moderate geomagnetic storm with minimum D_st=-60\ nT and maximum K_p=6\textendash. The daytime electron density measured by the Millstone Hill incoherent scatter radar (42.6\textdegreeN, 288.5\textdegreeE) increased after 13\ UT (\~8\ LT) compared with that before the storm. This increase is observed throughout the daytime, lasts for about 9\ h, and covers F-region altitudes above \~230\ km. At the altitude of 300\ km, the maximum increase in N_e reaches a factor of 3 by 19:30\textendash20:00\ UT and is accompanied by a \~1000\ K decrease in electron temperature, a \~100\textendash150\ K increase in ion temperature, and a strong upward drift. Observations by Arecibo ISR (18.3\textdegreeN, 293.3\textdegreeE) reveal similar features, with the maximum increase in electron density reaching a factor of 2.5 at 21:30\ UT, i.e. 1.5\textendash2\ h later than over Millstone Hill. The GPS TEC data show that the increase in electron density observed at Millstone Hill and Arecibo is only a part of a global picture reflected in TEC. The increase in TEC reaches a factor of 2 and covers middle and low latitudes at 19\ UT. At later times this increase moves to lower latitudes. A combination of mechanisms were involved in generation of positive phase. The penetration electric field resulted in N_e enhancements at subauroral and middle latitudes, the TAD/TID played an important role at middle and lower latitudes, and increase in O/N₂ ratio could contribute to the observed positive phase at middle and lower latitudes. The results show the importance of an upward vertical drift at \~140\textendash250\ km altitude, which is observed for sustained period of time and assists in the convergence of ionization into the F-region.

Goncharenko, L.P.; Foster, J.C.; Coster, A.J.; Huang, C.; Aponte, N.; Paxton, L.;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 07/2007

YEAR: 2007     DOI: 10.1016/j.jastp.2006.09.011

F-region; geomagnetic storm; Ionosphere; positive phase

October 2002 30-day incoherent scatter radar experiments at Millstone Hill and Svalbard and simultaneous GUVI/TIMED observations

A long-duration incoherent scatter radar (ISR) experiment was conducted at Millstone Hill and Svalbard from October 4\textendashNovember 4, 2002. Along with the simultaneous GUVI/TIMED neutral composition measurements, this 30-day run enabled us to study a number of thermosphere-ionosphere-magnetosphere phenomena. This paper focuses on the day-to-day variability and quasiperiodic oscillation of the ionosphere. The day-to-day variability under quiet magnetic conditions in electron density Ne, ion temperature Ti and electron temperature Te, respectively, changed with local time and height, with the largest variability in Ne and the smallest in Ti. Midnight through dawn was the period of largest variability. Quasiperiodic Ne oscillations were present with periods \>1 day. Some of these oscillations were correlated with changes in the neutral composition originating from geomagnetic activity, which altered the global atmospheric circulation as a result of high latitude heating processes as indicated in Svalbard ion temperature enhancements. However, the wave-type oscillation of Ne exhibits a downward phase progression which persists up to 600 km and prevails until a large storm appears to impose an upward phase progression.

Zhang, Shun-Rong; Holt, John; Erickson, Phil; Lind, Frank; Foster, John; van Eyken, Anthony; Zhang, Yongliang; Paxton, Larry; Rideout, William; Goncharenko, Larisa; Campbell, Glenn;

Published by: Geophysical Research Letters      Published on: 01/2005

YEAR: 2005     DOI: 10.1029/2004GL020732

Space Sciences-L01108 October 2002 30-day incoherent scatter radar experiments at Millstone Hill and Svalbard and simultaneous GUVI/TIMED observations (DOI 10.1029/2004GL020732)

Zhang, Shun-Rong; Holt, John; Erickson, Phil; Lind, Frank; Foster, John; van Eyken, Anthony; Zhang, Yongliang; Paxton, Larry; Rideout, William; Goncharenko, Larisa; , others;

Published by: Geophysical Research Letters      Published on:

YEAR: 2005     DOI:

Global ionospheric disturbances during super magnetic storms

Huang, C; Foster, J; Rideout, W; Zhang, Y; Paxton, L;

Published by:       Published on:

YEAR: 2005     DOI: