All-Sky Measurements of the Mesospheric Frontal Events From Bear Lake Observatory, Utah

Studies of internal gravity waves in the earth\u27s upper atmosphere are of considerable interest. These waves play a very important role in the dynamics of the mesosphere and lower thermosphere (ML T) region where they can transfer large amounts of energy and momentum from the lower atmosphere via wave saturation and dissipation. In particular, small-scale short-period (50ms 1) . Another unusual characteristic of frontal events is an apparent reversal in contrast of the wave structures as imaged in the hydroxyl (OH) emission (peak altitude- 87 km) when compared with the oxygen (OJ) green line (557.7 nm) emission (peak altitude -96 km) that can sometimes occur. In one isolated case, observed from Haleakala, Hawaii, the bright wave crests in the OH emission appeared to propagated through a dark structureless sky, whereas in the OI emission the same waves appeared to propagate into a bright sky, leaving an apparently depleted emission in its wake. Recent theoretical studies based on noble measurements have shown that frontal events may be due to a bore-like intrusion that raises the OJ (557. 7 nm) layer by a few km and at the same time depresses the OH layer by a similar amount. However, studies of fronts and bores in the ML T region are exceptionally rare. I have discovered and analyzed 16 frontal events from image data recorded at Bear Lake Observatory, Utah ( 41.6°N, 111.6°W), over the past four years. I have investigated some of their properties such as their horizontal wavelengths, horizontal phase speeds, observed periods, and their directions of motion. In addition, I have made comparative measurements of their relative intensities in the OH and OI emissions. These studies provide the first extensive data set on such events detailing their morphology and dynamics and should provide important information necessary for a deeper understanding of their occurrence frequency and properties

Constraint on the solar Δm2\Delta m^2 using 4,000 days of short baseline reactor neutrino data

There is a well known 2$\sigma$ tension in the measurements of the solar $\Delta m^2$ between KamLAND and SNO/Super-KamioKANDE. Precise determination of the solar $\Delta m^2$ is especially important in connection with current and future long baseline CP violation measurements. Reference \cite{Seo:2018rrb} points out that currently running short baseline reactor neutrino experiments, Daya Bay and RENO, can also constrain solar $\Delta m^2$ value as demonstrated by a GLoBES simulation with a limited systematic uncertainty consideration. In this work, the publicly available data, from Daya Bay (1,958 days) and RENO (2,200 days) are used to constrain the solar $\Delta m^2$. Verification of our method through $\Delta m^2_{ee}$ and $\sin^2 \theta_{13}$ measurements is discussed in Appendix A. Using this verified method, reasonable constraints on the solar $\Delta m^2$ are obtained using above Daya Bay and RENO data, both individually and combined. We find that the combined data of Daya Bay and RENO set an upper limit on the solar $\Delta m^2$ of 18 $\times 10^{-5}$ eV$^2$ at the 95% C.L., including both systematic and statistical uncertainties. This constraint is slightly more than twice the KamLAND value. As this combined result is still statistics limited, even though driven by Daya Bay data, the constraint will improve with the additional running of this experiment.Comment: 8 pages, 6 figures, 2 tables. This paper is a follow up of a Monte Carlo study reported in arXiv:1808.09150 by two of the authors. The current paper uses actual data from Daya Bay and RENO that was not previously available and this is the 1st "combined" result using this new experimental data. A new figure is added. Some modifications of the tex

Exploring Solar Neutrino Oscillation Parameters with LCS at Yemilab and JUNO

We investigate the sensitivities of the liquid scintillator counter (LSC) at Yemilab and JUNO to solar neutrino oscillation parameters, focusing on $\theta_{12}$ and $\Delta m^2_{21}$. We compare the potential of JUNO with LSC at Yemilab utilizing both reactor and solar data in determining those parameters. We find that the solar neutrino data of LSC at Yemilab is highly sensitive to $\theta_{12}$ enabling its determination with exceptional precision. Our study also reveals that if $\Delta m^2_{21}$ is larger, with a value close to the best fit value of KamLAND, JUNO reactor data will have about two times better precision than the reactor LSC at Yemilab. On the other hand, if $\Delta m^2_{21}$ is smaller and closer to the best fit value of solar neutrino experiments, the precision of the reactor LSC at Yemilab will be comparable/better than JUNO.Comment: 22 pages, 11 figure