low-earth orbit view only a small fraction of the earth's surface at once so that many observations must be combined to obtain global-scale information. It is also a major technical and logistical challenge to keep calibrated photometers continuously in orbit on decadal timescales. The earthshine, or "ashen light", is the glow of the "dark" part of the lunar disk visible to a nighttime observer. It is sunlight reflected from the earth and retroflected from the lunar surface, and so offers an alternative route to studying the earth's reflectance. Earthshine data are complementary to existing satellite data in that the coverage is instantaneous and hemispheric in scale. Because the earth's phase as seen from the moon is supplementary to that of the moon seen from the earth (i.e., the earth is nearly "full" when the moon is a thin crescent), the instantaneous intensity of the earthshine near the new moon samples almost half of the earth. For over a quarter century, beginning in 1926, Danjon and his followers [Danjon, 1928[Danjon, , 1954Dubois, 1947] performed regular earthshine observations from France. We have reinvigorated and modernized this nearly forgotten way of measuring the earth's albedo.Our earthshine coronagraph is a 6-inch refractive telescope with a cooled AP-7 512x512 pixel CCD camera; our fiducial regions comprise about 100 pixels each. We mask the bright portion of the lunar disk (i.e., "moonshine") with a neutral density filter of transmission • 10 -5, and correct the measured earthshine intensity for the effects of moonshine scattered in the atmosphere and optical train.

[1] Since late 1998, we have been making sustained measurements of the Earth's reflectance by observing the earthshine from Big Bear Solar Observatory. Further, we have simulated the Earth's reflectance for both the parts of the Earth in the earthshine and for the whole Earth. The simulations employ scene models of the Earth from the Earth Radiation Budget Experiment, simulated snow/ice cover, and near-real-time satellite cloud cover data. Broadly, the simulations and observations agree; however, there are important and significant differences, with the simulations showing more muted variations. During the rising phase of the Moon we measure the sunlit world to the west of California, and during the declining lunar phase we measure the sunlit world to the east. Somewhat surprisingly, the one third of the Earth to the west and that to the east have very similar reflectances, in spite of the fact that the topographies look quite different. The part to the west shows less stability, presumably because of the greater variability in the Asian cloud cover. We find that our precision, with steady observations since December 1998, is sufficient to detect a seasonal cycle. We have also determined the annual mean albedos both from our observations and from simulations. To determine a global albedo, we integrate over all lunar phases. Various methods are developed to perform this integration, and all give similar results. Despite sizable variation in the reflectance from night to night and from season to season (which arises from changing cloud cover), we use the earthshine to determine annual albedos to better than 1%. As such, these measurements are significant for measuring climate variation and are complementary to satellite determinations.

[1] We have been making sustained observations of the earthshine from Big Bear Solar Observatory in California since late 1998. We also have intermittent observations from 1994-1995. We have reinvigorated and modernized a nearly forgotten way of measuring the Earth's albedo, and hence its energy balance, previously studied by A. Danjon and his followers for about 25 years early in the last century using their observations of the earthshine from France. This is the first in a series of papers covering observations and simulations of the Earth's reflectance from photometric and spectral observations of the Moon. Here, we develop a modern method of measuring, instantaneously, the large-scale reflectance of the Earth. From California we see the Moon reflecting sunlight from the third of the Earth to the west of us in our evening (before midnight, which is during the Moon's rising phase) and from the third of the Earth to our east in our morning (after midnight, which is during the Moon's declining phase). We have precisely measured the scattering from the Moon as a function of lunar phase, which enables us to measure, in a typical night's observations, the Earth's reflectance to an accuracy of 2.0% (equivalent to measuring the Earth's emission temperature to $0.8 K). We have also identified the lunar phase function as the major source of discrepancy between Danjon's estimates of the albedo and more recent measurements. The albedo is due to the interplay of cloud cover and different landscapes.

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We derive the neutrino flavor transition probabilities with the neutrino treated as a wave packet. The decoherence and dispersion effects from the wave-packet treatment show up as damping and phase-shifting of the plane-wave neutrino oscillation patterns. If the energy uncertainty in the initial neutrino wave packet is larger than around 0.01 of the neutrino energy, the decoherence and dispersion effects would degrade the sensitivity of reactor neutrino experiments to mass hierarchy measurement to lower than 3 σ confidence level.