Validation of the IRI-2012 model with GPS-based ground observation over a low-latitude Singapore station by Kumar, Sanjay, Siingh, Devendraa, Tan, Eng Leong, Razul, Sirajudeen Gulam, See, Chong Meng Samson

“…For the year 2011, these two models showed agreement at all times with GPS-TEC only for the summer season, and for the period 11:00 to 24:00 UT hours (19:00 to 24:00 LT and 00:00 to 08:00 LT) during the winter and equinox seasons. The IRI-2012 model electron density profile showed agreement with constellation observing system for meteorology, ionosphere, and climate (COSMIC) radio occultation (RO)-based measurements around 250 to 300 km and was found to be independent of the options for topside density profiles. …”
Get full text
Get full text

The atmospheric circulation and dust activity in different orbital epochs on Mars by Newman, C, Lewis, SR, Read, P

“…The atmospheric circulation is stronger when l aligns with solstice rather than equinox, and there is also a bias from the martian topography, resulting in the strongest circulations when perihelion is at northern winter solstice. …”

Mid-infrared spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 1. Determination of the mean temperature structure of the upper troposphere and stratosphere by Orton, G, Fletcher, L, Moses, J, Mainzer, A, Hines, D, Hammel, H, Martin-Torres, F, Burgdorf, M, Merlet, C, Line, MR

“…On 2007 December 16-17, spectra were acquired of the disk of Uranus by the Spitzer Infrared Spectrometer (IRS), ten days after the planet's equinox, when its equator was close to the sub-Earth point. …”

Mid-infrared spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 1. Determination of the mean temperature structure of the upper troposphere and stratosphere by Orton, G, Fletcher, L, Moses, J, Mainzer, A, Hines, D, Hammel, H, Javier Martin-Torres, F, Burgdorf, M, Merlet, C, Line, MR

“…On 2007 December 16-17, spectra were acquired of the disk of Uranus by the Spitzer Infrared Spectrometer (IRS), ten days after the planet's equinox, when its equator was close to the sub-Earth point. …”

Assessment of tidal power opportunities in Indonesian waters by Firdaus, A

“…An assessment with a limited computational time should avoid the solstices and equinoxes in the simulation period.</p> <p>The interaction between the diurnal and semidiurnal components also creates an asymmetric tidal flow. …”

Uranus' cloud structure and seasonal variability from Gemini-North and UKIRT observations by Irwin, P, Teanby, N, Davis, G, Fletcher, L, Orton, G, Tice, D, Kyffin, A

“…Overall, Uranus appeared to be less convectively active in 2009 than in the previous 3years, which suggests that now the northern spring equinox (which occurred in 2007) is passed the atmosphere is settling back into the quiescent state seen by Voyager 2 in 1986. …”

Analysis Of Ionospheric Effects On Ground-Based Augmentation System (Gbas) At Klia, Malaysia by Zamzuri, Amira Nur’izzah

“…However, the data is enough to conduct studies on how ionospheric scintillation can affect the GBAS operation. An equinox month suspected of the ionospheric scintillation to occur was selected to ease the study. …”
Get full text

Science goals and new mission concepts for future exploration of Titan’s atmosphere, geology and habitability: titan POlar scout/orbitEr and in situ lake lander and DrONe explorer... by Rodriguez, Sébastien, Vinatier, Sandrine, Cordier, Daniel, Tobie, Gabriel, Achterberg, Richard K., Anderson, Carrie M., Badman, Sarah V., Barnes, Jason W., Barth, Erika L., Bézard, Bruno, Carrasco, Nathalie, Charnay, Benjamin, Clark, Roger N.

“…The ideal arrival time at Titan would be slightly before the next northern Spring equinox (2039), as equinoxes are the most active periods to monitor still largely unknown atmospheric and surface seasonal changes. …”
Get full text

Equatorial Ionospheric Anomaly (EIA) and comparison with IRI model during descending phase of solar activity (2005– 2009) by Singh, A.K., Kumar, Sanjay, Lee, Jiyun

“…It is found that the maximum TEC (EIA) near equatorial anomaly crest yield their maximum values during the equinox months and their minimum values during the summer. …”
Get full text
Get full text

Ozone Chemistry in the Lower Stratosphere: Drivers, Trends, and Impacts by Wilka, Catherine A.

“…This study shows a previously unrecognized mechanism in near-equinox months for dynamical influences on the spatial structures of atmospheric composition changes in the deep tropics. …”
Get full text

Seasonal evolution of Saturn's polar temperatures and composition by Fletcher, L, Irwin, P, Sinclair, J, Orton, G, Giles, R, Hurley, J, Gorius, N, Achterberg, R, Hesman, B, Bjoraker, G

“…We construct a near-continuous record of atmospheric variability poleward of 60° from northern winter/southern summer (2004, Ls=293°) through the equinox (2009, Ls=0°) to northern spring/southern autumn (2014, Ls=56°). …”

The effect of topography on the Martian atmospheric circulation and determining Pluto's atmospheric thermal structure from stellar occultations by Zalucha, Angela M. (Angela Marie)

Get full text

Mid-infrared spectroscopy of Uranus from the Spitzer infrared spectrometer: 2. Determination of the mean composition of the upper troposphere and stratosphere by Orton, G, Moses, J, Fletcher, L, Mainzer, A, Hines, D, Hammel, H, Martin-Torres, J, Burgdorf, M, Merlet, C, Line, MR

“…Mid-infrared spectral observations Uranus acquired with the Infrared Spectrometer (IRS) on the Spitzer Space Telescope are used to determine the abundances of C2H2, C2H6, CH3C2H, C4H2, CO2, and tentatively CH3 on Uranus at the time of the 2007 equinox. For vertically uniform eddy diffusion coefficients in the range 2200-2600cm2s-1, photochemical models that reproduce the observed methane emission also predict C2H6 profiles that compare well with emission in the 11.6-12.5μm wavelength region, where the υ9 band of C2H6 is prominent. …”

Mid-infrared spectroscopy of Uranus from the Spitzer infrared spectrometer: 2. Determination of the mean composition of the upper troposphere and stratosphere by Orton, G, Moses, J, Fletcher, L, Mainzer, A, Hines, D, Hammel, H, Martin-Torres, J, Burgdorf, M, Merlet, C, Line, MR

“…Mid-infrared spectral observations Uranus acquired with the Infrared Spectrometer (IRS) on the Spitzer Space Telescope are used to determine the abundances of C2H2, C2H6, CH3C2H, C4H2, CO2, and tentatively CH3 on Uranus at the time of the 2007 equinox. For vertically uniform eddy diffusion coefficients in the range 2200-2600 cm2 s-1, photochemical models that reproduce the observed methane emission also predict C2H6 profiles that compare well with emission in the 11.6-12.5 μm wavelength region, where the υ9 band of C2H6 is prominent. …”

Light-level geolocation reveals winter migration of the endangered Hutton’s Shearwater (Puffinus huttoni) by Martinez, I

“…The first result chapter is about the correction of latitudinal error around the equinoxes in GLS loggers. The second results chapter describes the previously unknown winter migration of the endangered Hutton's shearwater (Puffinus huttoni).…”

Equatorial waves and superrotation in the stratosphere of a Titan general circulation model by Lewis, NT, Lombardo, NA, Read, PL, Lora, JM

“…The existence of this "Rossby–Kelvin"-type wave appears to depend on strong meridional shear of the background zonal wind that occurs in the upper stratosphere at times away from the equinoxes. In the lower stratosphere, acceleration of superrotation occurs throughout the year and is partially induced by equatorial Rossby waves, which we speculate are generated by quasigeostrophic barotropic instability. …”

Extreme exospheric dynamics at Charon: Implications for the red spot by Teolis, B, Raut, U, Kammer, JA, Gimar, CJ, Howett, CJA, Gladstone, GR, Retherford, KD

“…Charon's exosphere may exhibit extreme seasonal dynamics, with centuries of quiescence punctuated by short lived (∼4 earth years) exospheric surges near the equinoxes, as spring sunrise bi-annually drives frozen methane off the polar night zones. …”

Millstone Hill Thomson Scatter Results for 1964 by Evans, J. V.

“…It is shown that this feature is strictly associated with the peak of the layer and that densities above 400-km altitude are highest at the equinoxes. No seasonal variations of temperature are found which might be large enough to account for the phenomenon. …”
Get full text

Seasonal changes in the vertical structure of ozone in the Martian lower atmosphere and its relationship to water vapor by Olsen, KS, Fedorova, AA, Trokhimovskiy, A, Montmessin, F, Lefèvre, F, Korablev, O, Baggio, L, Forget, F, Millour, E, Bierjon, A, Alday, J, Wilson, CF, Irwin, PGJ, Belyaev, DA, Patrakeev, A, Shakun, A

“…During solar occulations, the 003←000 band (3,000-3,060 cm−1) is observed with spectral sampling of ∼0.045 cm−1. Around the equinoxes in both hemispheres and over the southern winters, we regularly observe around 200–500 ppbv of O3 below 30 km. …”

Modelling the seasonal cycle of Uranus’s colour and magnitude, and comparison with Neptune by Irwin, PGJ, Dobinson, J, James, A, Teanby, NA, Simon, AA, Fletcher, LN, Roman, MT, Orton, GS, Wong, MH, Toledo, D, Pérez-Hoyos, S, Beck, J

“…We suggest that the increase in reflectivity of Uranus in both filters between the equinoxes in 1966 and 2007, noted by previous authors, might be related to Uranus&rsquo;s distance from the Sun and the production rate of dark photochemical haze products. …”