A simple dynamical model of cumulus convection for data assimilation research

A simplified model for cumulus convection has been developed, with the aim of providing a computationally inexpensive, but physically plausible, environment for developing methods for convective-scale data assimilation. Key processes, including gravity waves, conditional instability and precipitation formation, are represented, and parameter values are chosen to reproduce the most important space and time scales of cumulus clouds. The model is shown to reproduce the classic life cycle of an isolated convective storm. When provided with a low amplitude noise source to trigger convection, the model produces a statistically steady state with cloud size and cloud spacing distributions similar to those found in radiative-convective equilibrium simulations using a cloud resolving model. Results are also shown for convection triggered by flow over an orgraphic obstacle, where depending on the wind speed two regimes are found with convection trapped over the mountain, or propagating downstream. The model features prognostic variables for wind and rain that can be used to compute synthetic observations for data assimilation experiments

Case-control study of arsenic in drinking water and lung cancer in California and Nevada.

Millions of people are exposed to arsenic in drinking water, which at high concentrations is known to cause lung cancer in humans. At lower concentrations, the risks are unknown. We enrolled 196 lung cancer cases and 359 controls matched on age and gender from western Nevada and Kings County, California in 2002-2005. After adjusting for age, sex, education, smoking and occupational exposures, odds ratios for arsenic concentrations ≥85 µg/L (median = 110 µg/L, mean = 173 µg/L, maximum = 1,460 µg/L) more than 40 years before enrollment were 1.39 (95% CI = 0.55-3.53) in all subjects and 1.61 (95% CI = 0.59-4.38) in smokers. Although odds ratios were greater than 1.0, these increases may have been due to chance given the small number of subjects exposed more than 40 years before enrollment. This study, designed before research in Chile suggested arsenic-related cancer latencies of 40 years or more, illustrates the enormous sample sizes needed to identify arsenic-related health effects in low-exposure countries with mobile populations like the U.S. Nonetheless, our findings suggest that concentrations near 100 µg/L are not associated with markedly high relative risks

Taxing the Opposition: Cactus League Attendance and the Efficiency of the \u27Cubs Tax\u27

In 2010, a plan to finance a new spring training stadium for the Cubs through a ticket surcharge on all games in the Cactus League was proposed. We find that the Cubs increase attendance when they are the away team by about 37%. Thus, the surcharge would be economically justified as long as the price elasticity of tickets is less than 0.32, which many prior studies find to be the case. This tax provides one of the few examples in which the cost of a subsidized stadium would be born primarily by the group that benefits the most from the arrival of the subsidized team

Measuring ambivalence about government in the 2006 ANES Pilot Study.

Although scholars increasingly recognize that people often possess multiple and even conflicting attitudes about a given topic, our understanding of the nature, causes, and consequences of such attitudinal ambivalence is limited by a lack of consensus as to how the concept should be operationalized. In this paper, we examine three separate measures (one subjective, two operative) of ambivalence regarding the federal government in Washington that were asked in the 2006 ANES Pilot Study. Our findings indicate that while the operative measures are less susceptible to question-order and response-order effects, none of the three indicators fares particularly well in various other tests of construct validity