The Advantage of Accessibility to Goods and People: Transportation and Georgia's Economic Development

This report describes how transportation affects Georgia's economic development at present and what is likely in the future, and makes a set of recommendations for the direction of state transportation policy

Residential Mobility, Migration and Georgia's Labor Force

Abstract not available. Report #6

The deep atmospheric composition of Jupiter from thermochemical calculations based on Galileo and Juno data

The deep atmosphere of Jupiter is obscured beneath thick clouds. This causes direct observations to be difficult, and thermochemical equilibrium models fill in the observational gaps. This research uses Galileo and Juno data together with the Gibbs free energy minimization code GGCHEM to update the gas phase and condensation equilibrium chemistry of the deep atmosphere of Jupiter down to 1000 bars. Specifically, the Galileo data provides helium abundances and, with the incorporated Juno data, we use new enrichment values for oxygen, nitrogen, carbon and sulphur. The temperature profile in Jupiter’s deep atmosphere is obtained following recent interior model calculations that fit the gravitational harmonics measured by Juno. Following this approach, we produced pressure–mixing ratio plots for H, He, C, N, O, Na, Mg, Si, P, S and K that give a complete chemical model of all species occurring to abundances down to a 10−20 mixing ratio. The influence of the increased elemental abundances can be directly seen in the concentration of the dominant carriers for each element: the mixing ratio of NH3 increased by a factor of 1.55 as compared with the previous literature, N2 by 5.89, H2O by 1.78, CH4 by 2.82 and H2S by 2.69. We investigate the influence of water enrichment values observed by Juno on these models and find that no liquid water clouds form at the oxygen enrichment measured by Galileo, EH2O = 0.47, while they do form at higher water abundance as measured by Juno. We update the mixing ratios of important gas phase species, such as NH3, H2O, CO, CH4 and H2S, and find that new gas phase species, such as CN−, (NaCN)2, S2O and K+, and new condensates, namely H3PO4 (s), LiCl (s), KCl (s), NaCl (s), NaF (s), MgO (s), Fe (s) and MnS (s), form in the atmosphere

The deep atmospheric composition of Jupiter from thermochemical calculations based on Galileo and Juno data

The deep atmosphere of Jupiter is obscured beneath thick clouds. This causes direct observations to be difficult, and thermochemical equilibrium models fill in the observational gaps. This research uses Galileo and Juno data together with the Gibbs free energy minimization code GGCHEM to update the gas phase and condensation equilibrium chemistry of the deep atmosphere of Jupiter down to 1000 bars. Specifically, the Galileo data provides helium abundances and, with the incorporated Juno data, we use new enrichment values for oxygen, nitrogen, carbon and sulphur. The temperature profile in Jupiter’s deep atmosphere is obtained following recent interior model calculations that fit the gravitational harmonics measured by Juno. Following this approach, we produced pressure–mixing ratio plots for H, He, C, N, O, Na, Mg, Si, P, S and K that give a complete chemical model of all species occurring to abundances down to a 10−20 mixing ratio. The influence of the increased elemental abundances can be directly seen in the concentration of the dominant carriers for each element: the mixing ratio of NH3 increased by a factor of 1.55 as compared with the previous literature, N2 by 5.89, H2O by 1.78, CH4 by 2.82 and H2S by 2.69. We investigate the influence of water enrichment values observed by Juno on these models and find that no liquid water clouds form at the oxygen enrichment measured by Galileo, EH2O = 0.47, while they do form at higher water abundance as measured by Juno. We update the mixing ratios of important gas phase species, such as NH3, H2O, CO, CH4 and H2S, and find that new gas phase species, such as CN−, (NaCN)2, S2O and K+, and new condensates, namely H3PO4 (s), LiCl (s), KCl (s), NaCl (s), NaF (s), MgO (s), Fe (s) and MnS (s), form in the atmosphere.Publisher PDFPeer reviewe

The interaction of energetic particles with the winds of cool stars

Energetic particles, such as stellar energetic particles and Galactic cosmic rays, are an important part of space weather for exoplanets orbiting cool stars and the young Earth. Energetic particles bombard exoplanetary atmospheres, leading to unique chemical effects that may be detectable with JWST. The flux of energetic particles reaching an exoplanet depends on the stellar wind properties which vary with stellar age, as the star spins down. This means it is important to constrain the stellar wind properties of other stars. I will present our results which modelled the energetic particle flux reaching Earth at different ages, such as when life is thought to have begun (approximately 3.8Gyr ago). I will discuss how, at this time, our model shows that stellar energetic particles dominated over Galactic cosmic rays up to GeV energies. At these energies, energetic particles can cause particle showers in the planet atmosphere that can reach the surface of the planet. At the same time, to connect with upcoming observations we need to consider exoplanets orbiting stars with well-constrained stellar winds. For instance, the stellar mass-loss rate is important in determining the size of the astrosphere. Thus, I will also discuss our recent results for the Galactic cosmic ray fluxes reaching the habitable zone and exoplanets of a number of nearby stars. Finally, I will discuss our ongoing efforts to connect these energetic particle fluxes closely to upcoming JWST observations