72 research outputs found

    LargeScale Precursors to Major Lake Effect Snowstorms Lee of Lake Erie

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    Lake‐effect snowstorms are primarily a mesoscale feature; however, major lakeeffect snowstorms are linked closely to their synoptic environment. Thus, a lakeeffect system which lasts for more than 24 h cannot only be explained by the boundary layer; it is also associated with the upper tropospheric flow. This research will address whether major lake‐effect snow events off of Lake Erie can also be associated with large‐scale planetary features several days prior to event onset. The goal is to aid in the forecast process by increasing the accuracy and leadtime of lake‐effect snow forecasts. This study includes 31 cases recorded from the National Weather Service at Buffalo’s lake effect database. These 31 cases were then stratified into categories depending on its: length, the time of year, and the type of event. This categorization allowed for comparison of the state of the atmosphere in the days prior to different types of events. In order to assess the large‐scale pattern, teleconnections were used as a proxy for the state of the atmosphere. For cases that lasted for greater than 42 hours, there was a correlation to the phase Madden Julian oscillation eight days prior to onset. The cases that occurred during the positive and negative states of the Arctic Oscillation had two different upper level trough patterns, the former originating in Southern Canada and the latter over the Southwestern United States

    Differences Between High Shear / Low CAPE Environments in the Northeast US Favoring Straight-Line Damaging Winds versus Tornadoes

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    High shear / low CAPE (HSLC) environments are common in the Northeast US and can occur at any time of year. Severe weather in HSLC environments is notoriously hard to predict, often catching both forecasters and the general public off-guard. The goal of this project is to help forecasters to identify HSLC environments favorable for severe weather in the Northeast US, and to discriminate between HSLC environments that are supportive of tornadoes versus those that favor straight-line damaging winds (SDW). A 10-year HSLC severe weather environmental climatology was created for the Northeast US (New England, New York, New Jersey, Pennsylvania). This climatology includes 54 different parameters that can be used to identify and describe severe weather environments. HSLC criteria was defined as surface-based CAPE (SBCAPE) ≤ 500 J kg−1, most unstable parcel CAPE (MUCAPE) and mixed-layer CAPE (MLCAPE) ≤ 1000 J kg−1, and 0–6-km wind shear ≥ 18 m s−1 (Sherburn et al. 2016). Events included in the climatology consisted of numerous (≥5) straight-line damaging wind reports, or at least 1 tornado report. Each event was classified by the season in which it occurred and the mode (discrete, cluster of cells, quasi-linear convective system (QLCS)) of the storm which produced the reports. Results show that warm-season HSLC severe events typically occurred either at the beginning or at the tail end of an event in an environment where CAPE values were predominantly too large to meet the HSLC criteria. Storm mode was variable for warm-season events, but cool-season events were dominated by QLCSs. Results show lifted condensation levels (LCLs) as well as low-level shear and wind direction as some of the most skillful parameters at discriminating between tornadic and non-tornadic events. There are various other useful parameters, including but not limited to, surface relative humidity, effective shear magnitude, and convective inhibition. The usefulness of these, and other parameters, at discriminating between HSLC environments favorable for SDW versus tornadoes will be discussed

    The theory of the firm and its critics: a stocktaking and assessment

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    Includes bibliographical references."Prepared for Jean-Michel Glachant and Eric Brousseau, eds. New Institutional Economics: A Textbook, Cambridge, Cambridge University Press.""This version: August 22, 2005."Since its emergence in the 1970s the modern economic or Coasian theory of the firm has been discussed and challenged by sociologists, heterodox economists, management scholars, and other critics. This chapter reviews and assesses these critiques, focusing on behavioral issues (bounded rationality and motivation), process (including path dependence and the selection argument), entrepreneurship, and the challenge from knowledge-based theories of the firm

    Provenance of Cretaceous through Eocene strata of the Four Corners region: Insights from detrital zircons in the San Juan Basin, New Mexico and Colorado

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    Cretaceous through Eocene strata of the Four Corners region provide an excellent record of changes in sediment provenance from Sevier thin-skinned thrusting through the formation of Laramide block uplifts and intra-foreland basins. During the ca. 125–50 Ma timespan, the San Juan Basin was flanked by the Sevier thrust belt to the west, the Mogollon highlands rift shoulder to the southwest, and was influenced by (ca. 75–50 Ma) Laramide tectonism, ultimately preserving a >6000 ft (>2000 m) sequence of continental, marginal-marine, and offshore marine sediments. In order to decipher the influences of these tectonic features on sediment delivery to the area, we evaluated 3228 U-Pb laser analyses from 32 detrital-zircon samples from across the entire San Juan Basin, of which 1520 analyses from 16 samples are newly reported herein. The detrital-zircon results indicate four stratigraphic intervals with internally consistent age peaks: (1) Lower Cretaceous Burro Canyon Formation, (2) Turonian (93.9–89.8 Ma) Gallup Sandstone through Campanian (83.6–72.1 Ma) Lewis Shale, (3) Campanian Pictured Cliffs Sandstone through Campanian Fruitland Formation, and (4) Campanian Kirtland Sandstone through Lower Eocene (56.0–47.8 Ma) San Jose Formation. Statistical analysis of the detrital-zircon results, in conjunction with paleocurrent data, reveals three distinct changes in sediment provenance. The first transition, between the Burro Canyon Formation and the Gallup Sandstone, reflects a change from predominantly reworked sediment from the Sevier thrust front, including uplifted Paleozoic sediments and Mesozoic eolian sandstones, to a mixed signature indicating both Sevier and Mogollon derivation. Deposition of the Pictured Cliffs Sandstone at ca. 75 Ma marks the beginning of the second transition and is indicated by the spate of near-depositional-age zircons, likely derived from the Laramide porphyry copper province of southern Arizona and southwestern New Mexico. Paleoflow indicators suggest the third change in provenance was complete by 65 Ma as recorded by the deposition of the Paleocene Ojo Alamo Sandstone. However, our new U-Pb detrital-zircon results indicate this transition initiated ∼8 m.y. earlier during deposition of the Campanian Kirtland Formation beginning ca. 73 Ma. This final change in provenance is interpreted to reflect the unroofing of surrounding Laramide basement blocks and a switch to local derivation. At this time, sediment entering the San Juan Basin was largely being generated from the nearby San Juan Mountains to the north-northwest, including uplift associated with early phases of Colorado mineral belt magmatism. Thus, the detrital-zircon spectra in the San Juan Basin document the transition from initial reworking of the Paleozoic and Mesozoic cratonal blanket to unroofing of distant basement-cored uplifts and Laramide plutonic rocks, then to more local Laramide uplifts.National Science Foundation (NSF grant EAR-1649254

    Economic Analysis of Labor Markets and Labor Law: An Institutional/Industrial Relations Perspective

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    Dictator Games: A Meta Study

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    Behavioral agency theory: new foundations for theorizing about executive compensation

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    This article describes new micro-foundations for theorizing about executive compensation, drawing on the behavioral economics literature and based on a more realistic set of behavioral assumptions than those that have typically been made by agency theorists. We call these micro-foundations “behavioral agency theory.” In contrast to the standard agency framework, which focuses on monitoring costs and incentive alignment, behavioral agency theory places agent performance at the center of the agency model, arguing that the interests of shareholders and their agents are most likely to be aligned if executives are motivated to perform to the best of their abilities. We develop a line of argument first advanced by Wiseman and Gomez-Mejia and put the case for a more general reassessment of the behavioral assumptions underpinning agency theory. A model of economic man predicated on bounded rationality is proposed, adopting Wiseman and Gomez-Mejia’s assumptions about risk preferences, but incorporating new assumptions about time discounting, inequity aversion, and the trade-off between intrinsic and extrinsic motivation. We argue that behavioral agency theory provides a better framework for theorizing about executive compensation, an enhanced theory of agent behavior, and an improved platform for making recommendations about the design of executive compensation plans
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