Eddy intrustion of hot plasma into the polar cap and formation of polar-cap arcs

Under the simple postulate that multiple large scale detachable magnetospheric convection eddies can exist in the vicinity of the convection reversal boundary and in the polar cap, by Kelvin-Helmholtz instability or otherwise, it is shown that a number of seemingly disconnected plasma and electric field observations in the polar cap can be organized into a theory of magnetosheath and plasmasheet plasma intrusion into the polar cap. Current theory of inverted V structures then predicts existence of similar, but weaker, structures at the eddy convection reversal boundaries in the polar cap. A possible consequence is that the polar cap auroras are natural offshoots from discrete oval arcs and evidently are formed by similar processes. The two arc systems can occassionally produce an optical image in the form of the theta aurora

Generation of the auroral kilometric radiation

For abstract, see A82-3554

Relativistic magnetospheric electrons: Lower ionospheric conductivity and long-term atmospheric variability

Long term observations of relativistic electrons in the earth's outer magnetosphere show a strong solar cycle dependence with a prominent intensity maximum during the approach to solar minimum. This population therefore closely corresponds to the presence of high speed solar wind streams emanating from solar coronal holes. Using a numerical code, the precipitating electron energy deposition in the earth's upper and middle atmosphere were calculated. Observed events (typically persisting several days) would have maximum effect in the 40 to 60 km altitude range with peak energy depositions greater than 110 keV/cu cm-s. It is suggested that this electron population could play an important long term role in modulating lower D region ionization and middle atmospheric ozone chemistry. Methods are described of observing middle atmospheric and lower ionospheric effects of the electrons including balloon, riometer, and space-based ozone sensor systems. A particularly promising approach may involve the monitoring of global Schumann resonance modes which are sensitive to global changes in the properties of the earth-ionosphere cavity. Present work indicates that Schumann resonance properties are moderately correlated with the flux of precipitating relativistic electrons thus offering the possibility of continuously monitoring this aspect of magnetosphere-atmosphere coupling

Modelling of auroral electrodynamical processes: Magnetosphere to mesosphere

Research conducted on auroral electrodynamic coupling between the magnetosphere and ionosphere-atmosphere in support of the development of a global scale kinetic plasma theory is reviewed. Topics covered include electric potential structure in the evening sector; morning and dayside auroras; auroral plasma formation; electrodynamic coupling with the thermosphere; and auroral electron interaction with the atmosphere

The ins and outs of keeping US service jobs at work

Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2006.Includes bibliographical references (p. 93-94).The purpose of this research is to discuss employment in the United States (US) service sector. The main concern is not pinpointing numerical estimates, but instead identifying trends which lead to job growth or job loss. Like manufacturing jobs that have been lost to offshore locations or productivity gains, so too are service jobs at risk. Offshoring - the outsourcing of business functions overseas - and automation have the same effect of displacing workers. What keeps a service job in the US and what makes it ideal to ship overseas or replace with a computer? Consumers have several choices between different product and service offerings. And, different products need varied levels of aftermarket service. What makes customers go out and spend money rather than completing tasks themselves? This thesis attacks these questions by outlining characteristics of products, services, and consumers which could help label jobs as "safe" or "at-risk." First is a discussion of these characteristics. Then, the range of product and service alternatives that consumers have to choose from is presented and applied to examples.(cont.) Overall, jobs which may be at-risk are those occupations that can be offshored, automated, or easily performed by consumers themselves. On the other hand, jobs that may prove safer are those with high barriers to self-service, those that offer a customized service or experience, and those that require physical contact to be performed.by Eric D. Gorney.S.M

Results of the 2013 Conner Prairie Biodiversity Survey, Hamilton County, Indiana

Conner Prairie is an interactive history park or a ‘‘living museum.’’ Located 6 km north of Indianapolis in Fishers, Indiana, the 850 acres that presently comprise Conner Prairie have a unique place in Indiana history. The property has been witness to many of the changes Indiana’s environment has undergone—from the glaciers that shaped much of the Hoosier landscape to the slow influx of humans over the past 12,000 years and the cultural changes they have made to the terrain. The first biodiversity survey (commonly called a BioBlitz) of Conner Prairie was conducted on 8–9 June 2013

Results of the 2014 Eagle Marsh Biodiversity Survey, Allen County, Indiana

Eagle Marsh, a 289.8 ha (716-acre) wetland nature preserve located on the southwest border of Fort Wayne, Indiana, is one of the largest wetland restorations ever undertaken in Indiana. The Little River Wetlands Project (LRWP) began acquisition, planning, and restoration in 2005 to 2007. The first biodiversity survey (also known as a bioblitz) of Eagle Marsh was conducted on 31 May and 1 June 2014. Over 125 scientists, naturalists, students, and other volunteers on thirteen different taxonomic teams observed and reported 728 taxa during the event. The thirteen taxonomic teams included aquatic macroinvertebrates, beetles, birds, butterflies, dragonflies and damselflies, fish, freshwater mussels, herpetofauna, small mammals, mushrooms/fungi, singing insects, snail-killing flies, and vascular plants. This manuscript presents both a brief history of Eagle Marsh and a summary overview of the results gathered by the thirteen taxonomic teams

Results of a Biodiversity Survey at Goose Pond Fish and Wildlife Area, Greene County, Indiana

Presented here are the results of a biodiversity survey held on July 16–18, 2011 at the Goose Pond Fish and Wildlife Area, Indiana Department of Natural Resources, in Greene County, southwestern Indiana. Fifteen teams (14 taxonomic teams and a biogeochemistry team) surveyed the flora and fauna of ponds, marshes, fields and forest of the ,8,000 acre site and reported 896 taxa: 862 species [20 amphibians and reptiles, 37 bees, 73 beetles, 122 birds, 48 butterflies, nine damselflies, 21 dragonflies, 39 species of fish, four freshwater mussels, five fungi and allies, 27 mammals, 74 moths, four snail-killing flies, 379 vascular plants), 16 families of aquatic macroinvertebrates, and 18 genera of plankton. A total of 215 new county records and numerous state-listed species were recorded. The baseline information provided by the survey will inform future management decisions and indicates that the restoration is maturing rapidly and successfully capturing the biological diversity of this portion of southwestern Indiana

When Less Is Best: Female Brown-Headed Cowbirds Prefer Less Intense Male Displays

Sexual selection theory predicts that females should prefer males with the most intense courtship displays. However, wing-spread song displays that male brown-headed cowbirds (Molothrus ater) direct at females are generally less intense than versions of this display that are directed at other males. Because male-directed displays are used in aggressive signaling, we hypothesized that females should prefer lower intensity performances of this display. To test this hypothesis, we played audiovisual recordings showing the same males performing both high intensity male-directed and low intensity female-directed displays to females (N = 8) and recorded the females' copulation solicitation display (CSD) responses. All eight females responded strongly to both categories of playbacks but were more sexually stimulated by the low intensity female-directed displays. Because each pair of high and low intensity playback videos had the exact same audio track, the divergent responses of females must have been based on differences in the visual content of the displays shown in the videos. Preferences female cowbirds show in acoustic CSD studies are correlated with mate choice in field and captivity studies and this is also likely to be true for preferences elucidated by playback of audiovisual displays. Female preferences for low intensity female-directed displays may explain why male cowbirds rarely use high intensity displays when signaling to females. Repetitive high intensity displays may demonstrate a male's current condition and explain why these displays are used in male-male interactions which can escalate into physical fights in which males in poorer condition could be injured or killed. This is the first study in songbirds to use audiovisual playbacks to assess how female sexual behavior varies in response to variation in a male visual display