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Storm Activity (storm + activity)

Distribution by Scientific Domains
Earth and Environmental Science100%

Selected Abstracts

Dunefoot dynamics along the Dutch coast

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2002
B. G. Ruessink
Abstract The dynamics of the dunefoot along a 160 km portion of the Dutch coast has been investigated based on a data set of annual surveys dating back to as early as 1850. The linearly detrended (or residual) dunefoot positions comprise an alongshore uniform and an alongshore non-uniform component. The former is expressed as 10 to 15 m of landward retreat along extensive (>10 km) stretches of coast during years with severe storm surges and as up to 5 m of seaward advance during years without significant storm activity. The latter, alongshore non-uniform component is organized in sandwave-like patterns, which may have a longevity of decades to up to the duration of the entire data set (150 years). Their wavelengths vary along the coast, from 3·5 to 10 km; migration rates are 0,200 m a,1. Dunefoot sandwaves are shown to be the shoreward extensions of similar sandwave patterns in the beach position. The non-uniform dunefoot behaviour constitutes at least 80 per cent of the total residual dunefoot dynamics, implying that along the Dutch coast residual dunefoot variability is controlled by temporal and spatial variability in beach characteristics, and not by storm-induced uniform erosion. Various potential mechanisms causing beach sandwaves are discussed. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Predictability of seasonal east coast winter storm surge impacts with application to New York's Long Island

METEOROLOGICAL APPLICATIONS, Issue 2 2008
Arthur T. DeGaetano
Abstract The characteristics of seasons with enhanced east coast winter storm (ECWS) and storm surge activity are identified from among a set of global atmospheric circulation indices and local land and sea surface temperature (SST) anomalies. Without regard for storm strength or surge potential, the most active ECWS seasons occur in association with El Niño events. There is also some indication that such seasons are preferred under the positive phase of the Pacific decadal oscillation (PDO). In terms of storm surge potential, forecasts of strong ECWS activity are more skillful than direct forecasts of the number of extreme surge events. In both cases, SSTs off the southeast US coast and in the Gulf of Mexico differentiate high seasonal activity from relatively inactive seasons. Warmer-than-normal SSTs in both regions during summer provide a measure of storm activity in the subsequent winter. The results provide a means of anticipating seasonal ECWS activity, and to some degree impacts, that is similar to widely used forecasts of tropical storm activity. From a predictive standpoint, forecasts of active strong storm seasons and low surge activity exhibit fairly high false alarm ratios. However, the false alarm rate for forecasts of low storm activity or high surge activity is less than 10%. Copyright © 2008 Royal Meteorological Society [source]

Geophysical evidence for Holocene lake-level change in southern California (Dry Lake)

BOREAS, Issue 1 2010
BROXTON W. BIRD
Bird, B. W., Kirby, M. E., Howat, I. M. & Tulaczyk, S. 2009: Geophysical evidence for Holocene lake-level change in southern California (Dry Lake). Boreas, 10.1111/j.1502-3885.2009.00114.x. ISSN 0300-9483. Ground penetrating radar (GPR) data are used in combination with previously published sediment cores to develop a Holocene history of basin sedimentation in a small, alpine lake in southern California (Dry Lake). The GPR data identify three depositional sequences spanning the past 9000 calendar years before present (cal. yr BP). Sequence I represents the first phase of an early Holocene highstand. A regression between <8320 and >8120 cal. yr BP separates Sequence I from Sequence II, perhaps associated with the 8200 cal. yr BP cold event. Sequence II represents the second phase of the early-to-mid Holocene highstand. Sequence IIIa represents a permanent shift to predominantly low lake stands beginning ,5550 cal. yr BP. This mid-Holocene shift was accompanied by a dramatic decrease in sedimentation rate as well as a contraction of the basin's area of sedimentation. By ,1860 cal. yr BP (Sequence IIIb), the lake was restricted to the modern, central basin. Taken together, the GPR and core data indicate a wet early Holocene followed by a long-term Holocene drying trend. The similarity in ages of the early Holocene highstand across the greater southern California region suggests a common external forcing , perhaps modulation of early Holocene storm activity by insolation. However, regional lake level records are less congruous following the initial early Holocene highstand, which may indicate a change in the spatial domain of climate forcing(s) throughout the Holocene in western North America. [source]