A Low-order Model of Water Vapor, Clouds, and Thermal Emission for Tidally Locked Terrestrial Planets

In the spirit of minimal modeling of complex systems, we develop an idealized two-column model to investigate the climate of tidally locked terrestrial planets with Earth-like atmospheres in the habitable zone of M-dwarf stars. The model is able to approximate the fundamental features of the climate obtained from three-dimensional (3D) atmospheric general circulation model (GCM) simulations. One important reason for the two-column model's success is that it reproduces the high cloud albedo of the GCM simulations, which reduces the planet's temperature and delays the onset of a runaway greenhouse state. The two-column model also clearly illustrates a secondary mechanism for determining the climate: the nightside acts as a ``radiator fin'' through which infrared energy can be lost to space easily. This radiator fin is maintained by a temperature inversion and dry air on the nightside, and plays a similar role to the subtropics on modern Earth. Since 1D radiative-convective models cannot capture the effects of the cloud albedo and radiator fin, they are systematically biased towards a narrower habitable zone. We also show that cloud parameters are most important for determining the day--night thermal emission contrast in the two-column model, which decreases and eventually reverses as the stellar flux increases. This reversal is important because it could be detected by future extrasolar planet characterization missions, which would suggest that the planet has Earth-like water clouds and is potentially habitable.Comment: The Astrophysical Journal (in press), 14 pages, 11 figures, 1 tabl

Teacher Contract Non-Renewal in the Rocky Mountains

Success for students in the 21st century increasingly relies on competencies and proficiencies typically available on]y through formal educational processes. Researchers have noted the paramount importance of quality teaching as the important criterion for student success (Haycock, 1998; Marzano, 2003). Recent reforms have increased the expectation that school principals energetically address teacher evaluations and subsequently remove ineffective teachers. These recent reforms tend to have common priorities, including emphasizing high quality teaching, evaluating teachers for merit pay purposes, and linking evaluation to student performance with an emphasis on the removal of ineffective teachers from the classroom