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Geomagnetic storms are primarily driven by stream interaction regions (SIRs) and coronal mass ejections (CMEs). Since SIR and CME storms have different solar wind and magnetic field characteristics, the magnetospheric response may vary accordingly. Using FAST/TEAMS data, we investigate the variation of ionospheric O⁺and H⁺outflow as a function of geomagnetic storm phase during SIR and CME magnetic storms. The effects of storm size and solar EUV flux, including solar cycle and seasonal effects, on storm time ionospheric outflow, are also investigated. The results show that for both CME and SIR storms, the O⁺and H⁺fluences peak during the main phase, and then declines in the recovery phase. However, for CME storms, there is also significant increase during the initial phase. Because the outflow starts during the initial phase in CME storms, there is time for the O⁺to reach the plasma sheet before the start of the main phase. Since plasma is convected into the ring current from the plasma sheet during the main phase, this may explain why more O⁺is observed in the ring current during CME storms than during SIR storms. We also find that outflow fluence is higher for intense storms than moderate storms and is higher during solar maximum than solar minimum.

 

Maize (Zea mays ssp. mays) domestication began in southwestern Mexico ~9,000 calendar years before present (cal. BP) and humans dispersed this important grain to South America by at least 7000 cal. BP as a partial domesticate. South America served as a secondary improvement center where the domestication syndrome became fixed and new lineages emerged in parallel with similar processes in Mesoamerica. Later, Indigenous cultivators carried a second major wave of maize southward from Mesoamerica, but it is unclear whether the deeply divergent maize lineages underwent any subsequent gene flow between these regions. Here we report ancient maize genomes (2,300-1,900 cal. BP) from El Gigante rock-shelter, Honduras, that are closely related to ancient and modern maize from South America. Our findings suggest that genetic material from long-divergent South American maize was reintroduced to Central America. Direct radiocarbon dates and cob morphological data from the rock-shelter suggest that more productive maize varieties developed between 4,300 and 2,500 cal BP. We hypothesize that the hybridization of South and Central American maize may have been a source of genetic diversity and hybrid vigor as maize was becoming a staple grain in Central- and Meso- America. 

Factors related to two sources of energy input to the ionosphere, the Poynting flux associated with both quasistatic fields (S_dc) and Alfvénic fluctuations (S_ac), and the soft electron precipitation, are investigated to evaluate their correlations with the O⁺and the H⁺outflows in the dayside cusp region by using recalibrated FAST/Time‐of‐Flight Energy, Angle, and Mass Spectrograph (TEAMS) data during the 24–25 September 1998 geomagnetic storm studied by Strangeway et al. (2005,https://doi.org/10.1029/2004JA010829). The Poynting flux and the soft electron precipitation are well correlated with ion outflow flux in the dayside cusp region.S_dcshows the highest correlation with the O⁺outflows, while it is the electron number flux that correlates best with the H⁺outflows. The Alfvénic waves play an essential role in accelerating outflows. The averaged O⁺/H⁺flux ratio is 3.0 and is positively correlated to the Poynting flux, suggesting that the O⁺flux increases more strongly with the energy input.