Information content of OCO-2 oxygen A-band channels for retrieving marine liquid cloud properties

Information content analysis is used to select channels for a marine liquid cloud retrieval using the high-spectral-resolution oxygen A-band instrument on NASA's Orbiting Carbon Observatory-2 (OCO-2). Desired retrieval properties are cloud optical depth, cloud-top pressure and cloud pressure thickness, which is the geometric thickness expressed in hectopascals. Based on information content criteria we select a micro-window of 75 of the 853 functioning OCO-2 channels spanning 763.5–764.6 nm and perform a series of synthetic retrievals with perturbed initial conditions. We estimate posterior errors from the sample standard deviations and obtain ±0.75 in optical depth and ±12.9 hPa in both cloud-top pressure and cloud pressure thickness, although removing the 10 % of samples with the highest χ2 reduces posterior error in cloud-top pressure to ±2.9 hPa and cloud pressure thickness to ±2.5 hPa. The application of this retrieval to real OCO-2 measurements is briefly discussed, along with limitations and the greatest caution is urged regarding the assumption of a single homogeneous cloud layer, which is often, but not always, a reasonable approximation for marine boundary layer clouds

Parental rearing style as a predictor of attachment and psychosocial adjustment during young adulthood

Parental rearing-styles are crucial for psychosocial adjustment both during childhood and adulthood. The current study examined whether: (a) parental rearing-styles predicted psychosocial adjustment in young-adulthood, (b) this relationship was mediated by attachment styles , and ( c ) gender differences occur in these relationships. Two hundred and forty (103 male and 132 female) university students completed measures assessing parental rearing-style , current attachment style, romantic relationship satisfaction, friendship quality, self-esteem, and social competence. Multigroup structural equation modelling, conducted separately by gender, revealed that parental rearing-style predicted psychosocial adjustment during young-adulthood. Further, there was also evidence of gender differences and that self-models and other-models of attachment mediated this relationship. Together, these findings reinforce the importance of perceived parental rearing-style for subsequent psychosocial adjustment

The effect of ring distortions on buckling of blunt conical shells

A rigorous analytical study of cones stiffened by many thin-gage, open-section rings is presented. The results are compared with data previously obtained from uniform pressure tests of the Viking mission flight aeroshell and of the Viking structural prototype aeroshells. A conventional analysis, in which the rings are modeled as discrete rigid cross sections, is shown to lead to large, unconservative strength predictions. A more sophisticated technique of modeling the rings as shell branches leads to much more realistic strength predictions and more accurately predicts the failure modes. It is also shown that if a small initial imperfection proportional to the shape of the buckling mode is assumed, the critical buckling modes from analysis and test are in agreement. However, the reduction in buckling strength from the perfect-shell predictions is small

Magnetic Braking and Viscous Damping of Differential Rotation in Cylindrical Stars

Differential rotation in stars generates toroidal magnetic fields whenever an initial seed poloidal field is present. The resulting magnetic stresses, along with viscosity, drive the star toward uniform rotation. This magnetic braking has important dynamical consequences in many astrophysical contexts. For example, merging binary neutron stars can form "hypermassive" remnants supported against collapse by differential rotation. The removal of this support by magnetic braking induces radial fluid motion, which can lead to delayed collapse of the remnant to a black hole. We explore the effects of magnetic braking and viscosity on the structure of a differentially rotating, compressible star, generalizing our earlier calculations for incompressible configurations. The star is idealized as a differentially rotating, infinite cylinder supported initially by a polytropic equation of state. The gas is assumed to be infinitely conducting and our calculations are performed in Newtonian gravitation. Though highly idealized, our model allows for the incorporation of magnetic fields, viscosity, compressibility, and shocks with minimal computational resources in a 1+1 dimensional Lagrangian MHD code. Our evolution calculations show that magnetic braking can lead to significant structural changes in a star, including quasistatic contraction of the core and ejection of matter in the outermost regions to form a wind or an ambient disk. These calculations serve as a prelude and a guide to more realistic MHD simulations in full 3+1 general relativity.Comment: 20 pages, 19 figures, 3 tables, AASTeX, accepted by Ap

Developing learning progressions to support mathematical reasoning in the middle years - algebraic reasoning

As part of the Reframing Mathematical Futures II Project on Mathematical Reasoning, algebraic reasoning was identified as one of the three areas to be investigated. This involved developing a hypothetical learning progression for algebra to inform the design of assessment tasks to test the progression. The assessment forms were then sent to trial schools and the data was analysed using Rasch analysis. This paper reports on the analysis of preliminary data received and outlines some implications for teaching

Reframing Mathematical Futures II Project: Development of a draft learning progression for algebraic reasoning

Curriculum documents make a clear distinction between algebraic skills and algebraic reasoning, where the development of the former is far more readily articulated than the latter. While there are many studies of algebraic reasoning, these are usually topic specific and/or highly contextual. What are the big ideas of algebraic reasoning and is it possible to map their learning trajectory? This paper reports on the preliminary phase of a large national study in Australia which is designed to move beyond the hypothetical and to provide an evidence-based foundation for a learning progression. Using rich assessment tasks designed for middle years students of mathematics, this paper reports on the method of analysis used and some preliminary findings