Applications of Fourier analysis to broadening of stellar line profiles

Turbulence dominated by eddies of a finite size produces effects on a line profile which are similar to both macro- and micro-turbulence but which are at the same time neither. It is suggested that one of these effects in the Fourier transform domain, namely the narrowing of the first natural sidelobe relative to the width of the main lobe, can be used as an indicator of the dominance of finite-sized eddies (mesoturbulence). An examination of some existing solar data shows that finitesized eddy models fit the observed sidelobe widths better than do models computed with any reasonable combination of micro- and macro-turbulent broadenings (Paper III).     

Galactic mass determinations from incomplete rotation curves

Given an incomplete rotation curve of a spiral galaxy, various assumptions about the Galaxy beyond the last observed point are made: (A) the force falls off as 1/r ², (B) the mass density is zero, and (C) the mass density falls off as 1/r ³. The msss distributions obtained from each of these assumptions are all well behaved, and it is impossible to choose the correct curve from considerations of the resulting mass distributions alone. The correct mass distribution in the disk system of a galaxy cannot be deduced from an incomplete rotation curve.     

Estimation of spatially distributed soil information: dealing with data shortages in the Western Bug Basin,Ukraine

Integrated watershed models require spatially differentiated soil information. However, in many regions of the world the limited availability of soil data hinders an appropriate simulation of hydro-ecological processes. Such circumstances lead to unsupported statements, poor statistics, misrepresentations, and, ultimately, to bad resource management. The Western Bug catchment in west Ukraine is an example of such a region. In the former Soviet Union, soil classification primarily focused on soils of agricultural importance, whereas, forested, urban, industrial, and shallow soil territories were left underrepresented in the classification and soil maps. Spatially differentiated soil texture data are required to predict soil hydraulic properties using pedotransfer functions (PTFs), along with soil maps. Furthermore, the Ukrainian soil texture scheme does not match the particle size classes commonly used with PTFs. To overcome these shortcomings, a fuzzy logic methodology was applied, based on terrain and vegetation/land use analysis and soil sampling, to close the information gaps. For the application of PTFs, a procedure was tested to estimate missing values of soil texture distribution. Applied methods were evaluated using recent soil surveys, measured soil texture, and water retention properties, while having in consideration the limitations brought by scarce soil data for integrated watershed modelling purposes.     

Weather conditions associated with the passage of precipitation type transition regions over eastern Newfoundland

Abstract

The passage of a winter storm is accompanied by changes in many surface and near‐surface parameters including temperature, humidity, wind, pressure, precipitation rate and type, cloud base height, visibility and accretion. These parameters were measured in association with the passage of precipitation‐type transitions over Newfoundland during the Canadian Atlantic Storms Program II field experiment. Three simple summaries of the observed weather events were developed. These summaries depend on the observed large‐scale synoptic conditions, which include warm fronts, a cold front and a trough.     

Long-term ecosystem monitoring at Huntington Forest: Integrating hydrology,biogeochemistry and climatic controls on watershed processes

Located in the Adirondack Mountains of northern New York State, Huntington Wildlife Forest (HWF) is a 6000-ha research and education facility operated by SUNY ESF (State University of New York, College of Environmental Science and Forestry) with continuous long-term monitoring (LTM) programs spanning over six decades. One of the ‘cradles’ of acid rain research in North America, HWF was in the first cohort of National Atmospheric Deposition Program (NADP) sites beginning in 1978. HWF is currently the only location (NY-20) in New York with the full suite of NADP programs in operation, including atmospheric mercury speciation (AMNet), along with EPA CASTNET. Nearby to NY-20 at HWF, Arbutus Lake and its forested watershed have been the focus of intensive LTM since installation of v-notch weirs at the lake outlet and inlet in 1991 and 1994, respectively. Discharge at these locations has been monitored continuously at 15-min intervals since 1999. Lake outlet water chemistry samples were collected starting in 1983. Weekly sampling of water chemistry at both weirs began in 1995 and was expanded to include two headwater streams and groundwater wells in 2007. More recently, LTM programs at HWF have been augmented by participation in the PhenoCam Network since 2008, collection of high-resolution LiDAR in 2009, and installation of a precision NY Mesonet weather station in 2016. In 2018, we installed sensor networks that continuously monitor soil microclimate and snow depth. Lastly, we improved data access via a new website ( www.adk-ltm.org ) where users can create custom queries and visualize outputs.     

Process-based snowmelt modeling: does it require more input data than temperature-index modeling?

Modeling snow hydrology for cold regions remains a problematic aspect of many hydro-environmental models. Temperature-index methods are commonly used and are routinely justified under the auspices that process-based models require too many input data. To test this claim, we used a physical, process-based model to simulate snowmelt at four locations across the conterminous US using energy components estimated from measured daily maximum and minimum temperature, i.e. using only the same data required for temperature-index models. The results showed good agreement between observed and predicted snow water equivalents, average R²>0.9. We duplicated the simulations using a simple temperature-index model best fitted to the data and results were poorer, R²<0.8. At one site we applied the process-based model without substantial parameter estimation, and there were no significant (=0.05) differences between these results and those obtained using temperature-estimated parameters, despite relatively poorly predicted specific energy budget components (R²<0.8). These results encourage the use of mechanistic snowmelt modeling approaches in hydrological models, especially in distributed hydrological models for which landscape snow distribution may be controlled by spatially distributed components of the environmental energy budget.     

La Frontera and Beyond: Geography and Demography in Mexican American History*

The recent publication of an expansive national dataset, the Integrated Public Use Microdata Sample, allows for new analyses of the historical geography and settlement of various immigrant and ethnic groups in the United States. The present research explores the growth, development, and geographic dispersion of the ethnic Mexican population, and outlines some of the demographic and social characteristics within significant clusters of this population in the United States across the first half of the twentieth century. The analysis does not attempt to overturn other geographies and ethnographies in Mexican American history, but through its ability to elucidate broad, national patterns it is able to create a more dynamic view of settlement, demonstrating the role of immigrants and of women immigrants in particular. Results indicate that place matters: the geographical context of arrival and settlement were key factors in differentiating communities and the lives of those who lived in them.     

Polynomial approximate solutions to the Boussinesq equation

We provide closed-form approximate solutions to models of horizontal infiltration described by the Boussinesq equation in a semi-infinite aquifer that is initially dry. The approximations preserve such important qualitative properties as scaling and wetting fronts. They are applicable to four types of boundary conditions, two on head and two on flux, enumerated in the paper. All the considered problems admit self-similar variables that allow reduction to boundary value problems for a nonlinear ordinary differential equation. This work extends recent results by Lockington et al. [Lockington DA, Parlange J-Y, Parlange MB, Selker J. Similarity solution of the Boussinesq equation. Adv Water Resour 2000;23(7):725–9] and Telyakovskiy et al. [Telyakovskiy AS, Braga GA, Furtado F. Approximate similarity solutions to the Boussinesq equation. Adv Water Resour 2002;25(2):191–4], with new approximations developed for two of the four cases and a new extension of a previously existing method for a third case. Numerical results extending the work of Shampine [Shampine LF. Some singular concentration dependent diffusion problems. ZAMM 1973;53:421–2] provide a basis for assessing the accuracy of the new methods.