Brent Yarnal

The Pacific/North American Teleconnection Pattern and United States Climate. Part I: Regional Temperature and Precipitation Associations

An electrical circuit for limiting surge currents through incandescent indicator or display lamps is disclosed. It is essentially a constant current device having a current controlling transistor in the load circuit to limit the initial surge current to a first value after, which the lamp itself limits the current. Provision is made for testing of the lamp and circuit by maintenance personnel.

Who Wants to Reduce Greenhouse Gas Emissions

Objective. We examine cognitive, economic, and partisan heuristic theories of why some people express support for reducing greenhouse gas emissions. Methods. Data come from a mail survey of 623 residents of central Pennsylvania, a region in which mitigation costs exceed potential benefits from slowing the rate of global warming. Results. Ordinary least squares analysis shows that people who can accurately identify the causes of climate change and who expect bad consequences from climate change are likely to support both government anti‐fossil fuel initiatives and voluntary actions. Economic circumstances and anxieties are not important predictors, but the belief that environmental protection efforts do not threaten jobs for people like the respondent, limit personal freedoms, and hurt the economy is a strong predictor. Democrats are more likely than Republicans to support government efforts to reduce emissions. Conclusions. Cognitive explanations of support for reducing greenhouse gas emissions are more powerful than economic or partisan heuristic ones. People want to reduce emissions if they understand the causes of climate change, if they perceive substantial risks from climate change if average surface temperatures increase, and if they think climate change mitigation policies will not cost them their jobs.

Simulating the river-basin response to atmospheric forcing by linking a mesoscale meteorological model and hydrologic model system

Abstract The purpose of this article is to test the ability of a distributed meteorological/hydrologic model to simulate the hydrologic response to three single-storm events passing over the Upper West Branch of the Susquehanna River Basin. The high-resolution precipitation fields for three storms are provided by observations and by the Penn State–NCAR Mesoscale Meteorological Model (MM5) with three nested domains. The MM5 simulation successfully captures the storm patterns over the study area, although some temporal and spatial discrepancies exist between observed and simulated precipitation fields. Observed and simulated precipitation data for those storms are used to drive the Hydrologic Model System (HMS). The output from HMS is compared to the measured hydrographic streamflow at the outlet of the Upper West Branch. The Curve Number and Green-Ampt methods of rainfall-runoff partitioning are used in HMS and evaluated for streamflow simulation. The results of the hydrologic simulation compare well with observed data when using the Curve Number partitioning, but underestimate observed data when using the Green-Ampt. The likely cause is the lack of heterogeneity in hydraulic parameters. The simulated streamflow with the MM5-simulated precipitation is lower than the simulated streamflow with observed precipitation. The experiments suggest that the subgrid-scale spatial variability in precipitation and hydraulic parameters should be included in future model development

Feeling at risk matters: water managers and the decision to use forecasts.

Experts contend that weather and climate forecasts could have an important role in risk management strategies for community water systems. Yet, most water managers make minimal use of these forecasts. This research explores the determinants of the use of weather and climate forecasts by surveying managers of community water systems in two eastern American states (South Carolina and the Susquehanna River Basin of Pennsylvania). Assessments of the reliability of weather and climate forecasts are not driving their use as water managers who find forecasts reliable are no more likely to use them than are managers who find them unreliable. Although larger systems and those depending on surface water are more likely to use forecasts for some (but not all) purposes, the strongest determinant of forecast use is risk perceptions. Water managers who expect to face problems from weather events in the next decade are much more likely to use forecasts than are water managers who expect few problems. Their expectations of future problems are closely linked with past experience: water managers who have had problems with specific types of weather events (e.g., flood emergencies) in the last 5 years are likely to expect to experience problems in the next decade. Feeling at risk, regardless of the specific source of that weather-related risk, stimulates a decision to use weather and climate forecasts.

A procedure for blending manual and correlation‐based synoptic classifications

Manual and correlation-based (also known as Lund or Kirchhofer) classifications are important to synoptic climatology, but both have significant drawbacks. Manual classifications are inherently subjective and labour intensive, whereas correlation-based classifications give the investigator little control over the map-patterns generated by the computer. This paper develops a simple procedure that combines these two classification methods, thereby minimizing these weaknesses. The hybrid procedure utilizes a relatively short-term manual classification to generate composite pressure surfaces, which are then used as seeds in a long-term correlation-based computer classification. Overall, the results show that the hybrid classification reproduces the manual classification while optimizing speed, objectivity and investigator control, thus suggesting that the hybrid procedure is superior to the manual or correlation classifications as they are currently used. More specifically, the results demonstrate little difference between the hybrid procedure and the original manual classification at monthly and longer time-scales, with less internal variation in the hybrid types than in the subjective categories. However, the two classifications showed substantial differences at the daily level, not because of poor performance by the hybrid procedure, but because of errors introduced by the subjectivity of the manual classification.

A procedure for the classification of synoptic weather maps from gridded atmospheric pressure surface data

Abstract Although synoptic climatological research includes two stages, the classification of daily weather maps and the evaluation of the relationships of these synoptic type categories with local weather elements, most expenditures of time and money are on classification procedures. To alleviate this problem, a series of 6 FORTRAN programs for the classification of synoptic weather maps from gridded atmospheric pressure surface data is presented. An example illustrating the applicaton of the procedure is discussed.

Universities and Climate Change Mitigation: Advancing Grassroots Climate Policy in the US

Abstract While US climate change mitigation policy has stalled at the national level, local and regional actors are increasingly taking progressive steps to reduce their greenhouse gas emissions. Universities are poised to play a key role in this grassroots effort by targeting their own emissions and by working with other local actors to develop climate change mitigation programmes. Researchers at the Pennsylvania State University have collaborated with university administrators and personnel to inventory campus emissions and develop mitigation strategies. In addition, they have facilitated a stakeholder-driven climate change mitigation project in one Pennsylvania county and started an ongoing service-learning project aimed at reducing emissions in another county. These campus and community outreach initiatives demonstrate that university-based mitigation action may simultaneously achieve tangible local benefits and develop solutions to broader challenges facing local climate change mitigation efforts. Outcomes include improved tools and protocols for measuring and reducing local emissions, lessons learned about service-learning approaches to climate change mitigation, and methods for creating climate change governance networks involving universities, local governments and community stakeholders.

The vulnerability of the elderly to hurricane hazards in Sarasota, Florida

Although the elderly are commonly thought to be disproportionately vulnerable to natural hazards, the elderly populations of coastal communities are continuing to grow. Because there is little to no empirical hazards work specifically addressing the vulnerable elderly in coastal communities, this paper uses Sarasota County, Florida, as a case study to analyze how vulnerable the elderly are to hurricane hazards and whether all elderly people are equally vulnerable. To explore the spatial variations in degree and composition of vulnerability among this population, the analysis maps physical exposure to hurricane storm-surge inundation and precipitation-induced flooding and creates social vulnerability indices by applying principal components analysis to census block group data in a geographic information system. The results show that elderly inhabitants of barrier islands face a considerable physical threat from hurricane-induced storm surge and flooding but are less socially vulnerable because of their wealth; the elderly living inland are far less physically vulnerable but are poorer and consequently demonstrate high socioeconomic sensitivity and limited adaptive capacity to these hurricane hazards. The paper concludes that the elderly are not equally vulnerable: there are many different types of elderly living in many different locations, and their vulnerability varies by type and over space. Effective vulnerability reduction measures should account for these differences between the elderly populations.

USING SYNOPTIC CLIMATOLOGY TO DEFINE REPRESENTATIVE DISCHARGE EVENTS

Hydroclimatic modellers presently have no well-established methodology either to identify representative scenarios or to confirm that their model output agrees with observation. To fill this gap, this research presents a synoptic climatological framework that distinguishes typical storm systems associated with above-average discharge from Pennsylvanias Susquehanna River basin (SRB) and establishes the characteristic hydrographic responses to those systems. To determine the effect of basin scale on the results, these responses are stratified by sub-basin size. The results show that those storm systems tapping into Atlantic Ocean moisture usually produce above-average discharge in the SRB. Hydrographic responses vary with the storm trajectory and type. However, within a sub-basin scale and for any storm type, these hydrographic responses are the same from sub-basin to sub-basin. Thus, almost any basin is representative of its scale. Additional findings suggest that conventional single-day synoptic types are inappropriate for many types of research. Still, it is concluded that a synoptic climatological framework can be valuable for defining model scenarios and confirming model experiments.

Building a geocollaboratory: Supporting Human–Environment Regional Observatory (HERO) collaborative science activities

Abstract Collaboratories have been defined as centers without walls , virtual places where teams of scientists can undertake coordinated research. As part of the Human–Environment Regional Observatory (HERO) infrastructure project, we have been developing a geocollaboratory to support work by geographically distributed scientists about geographic problems. Our specific focus is on science teams developing and applying protocols for long-term study of the local and regional scale human impacts of global environmental change. The HERO geocollaboratory includes web and other Internet-based tools to enable same-time and different-time (thus synchronous and asynchronous) different-place collaboration. Methods and tools have been developed to support (1) synchronous distributed meetings that include video links and shared visual display of geospatial information; (2) asynchronous perspective comparison and consensus building activities; and (3) long-term information sharing and knowledge development. This paper introduces the research effort, sketches the conceptual framework within which the geocollaboratory is being developed, outlines progress thus far in the three collaboratory components listed above, and discusses our experiences using these tools for distributed science as well as our plans for continued development. We direct specific attention to three web-based, collaborative tools we have developed in support of components 2 and 3 above: an e-Delphi tool (supporting sharing and comparing of expert opinions), a concept-mapping tool that supports building, sharing, and comparing concept relationship diagrams linked to formal ontologies, and a web portal (called Codex) that provides a personal workspace, mechanisms for forming groups and accessing group resources, and methods for encoding knowledge objects that include geographic referencing.