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Small-scale Patterns (small-scale + pattern)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

The climatology of small-scale orographic precipitation over the Olympic Mountains: Patterns and processes

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 633 2008
Justin R. Minder
Abstract The climatology of small-scale patterns of mountain precipitation is poorly constrained, yet important for applications ranging from natural hazard assessment to understanding the geologic evolution of mountain ranges. Synthesizing four rainy seasons of high-resolution precipitation observations and mesoscale model output (from the Penn State/NCAR MM5), reveals a persistent small-scale pattern of precipitation over the ,10 km wide, ,800 m high ridges and valleys of the western Olympic Mountains, Washington State, USA. This pattern is characterized by a 50,70% excess accumulation over the ridge crests relative to the adjacent valleys in the annual mean. While the model shows excellent skill in simulating these patterns at seasonal time-scales, major errors exist for individual storms. Investigation of a range of storm events has revealed the following mechanism for the climatological pattern. Regions of enhanced condensation of cloud water are produced by ascent in stable flow over the windward slopes of major ridges. Synoptically generated precipitation grows by collection within these clouds, leading to enhanced precipitation which is advected by the prevailing winds. Instances of atypical patterns of precipitation suggest that under certain conditions (during periods with a low freezing level, or convective cells) fundamental changes in small-scale patterns may occur. However, case-studies and composite analysis suggest that departures from the pattern of ridge-top enhancement are rare; the basic patterns and processes appear robust to changes in temperature, winds, and background rainfall rates. Copyright © 2008 Royal Meteorological Society [source]

Large-scale processes in ecology and hydrology

JOURNAL OF APPLIED ECOLOGY, Issue 2000
R.W.G. Caldow
1. Several papers published in the 1980s stressed the importance of scaling issues, the inter-relatedness of patterns and processes at different scales of time and space, to our understanding of ecological systems. Scaling issues are of major theoretical interest and increasingly are of considerable applied importance. 2. In recognition of this, the Natural Environment Research Council, in partnership with the Scottish Executive Rural Affairs Department, funded a Thematic Programme entitled ,Large-scale Processes in Ecology and Hydrology'. The principal aim of this Programme was to integrate recent major developments in information resources and technologies with current theory in order to improve understanding of large-scale patterns and processes and their relationship to patterns and processes at smaller scales. 3. The Thematic Programme, which ran from 1995 until 1999, funded six research projects that have generated a large body of published papers. This volume, dedicated to the findings of the Programme, brings together outputs from all six projects with the aim of ensuring a rapid and widespread dissemination of the Programme's findings. A brief résumé of each of the papers is presented. 4. The papers in this volume cover a wide variety of subjects ranging from ions to the flora and fauna of the United Kingdom. Nonetheless, each study has sought in various ways to quantify observed spatio-temporal patterns at a range of scales, to determine whether those patterns are consistent across scales and to identify the interactions between small-scale patterns and processes and those at larger scales. The importance of the spatial and temporal scales at which studies are conducted, the key role played by dispersal in spatial population dynamics, and the diversity of ways in which large-scale patterns and processes relate to those at smaller scales are highlighted in many of the papers. 4. All of the papers presented here have direct relevance to applied issues. These issues are diverse and include the control of invasive alien species, the conservation of declining, threatened or endangered species, the development of survey techniques, strategies for farmland, woodland and forestry management, and the assessment of pollution sensitivity. Thus, the Thematic Programme has addressed issues of considerable theoretical interest and has at the same time generated results and predictive models that are of considerable practical and policy relevance. [source]

High gene flow promotes the genetic homogeneity of the fish goby Pomatoschistus marmoratus (Risso, 1810) from Mar Menor coastal lagoon and adjacent marine waters (Spain)

MARINE ECOLOGY, Issue 2 2010
Carlos Vergara-Chen
Abstract The extreme environmental variability of coastal lagoons suggests that physical and ecological factors could contribute to the genetic divergence among populations occurring in lagoon and open-coast environments. In this study we analysed the genetic variability of lagoon and marine samples of the sand goby, Pomatoschistus marmoratus (Risso, 1810) (Pisces: Gobiidae), on the SW Spain coast. A fragment of mitochondrial DNA control region (570 bp) was sequenced for 196 individuals collected in five localities: Lo Pagan, Los Urrutias and Playa Honda (Mar Menor coastal lagoon), and Veneziola and Mazarrón (Mediterranean Sea). The total haplotype diversity was h = 0.9424 ± 0.0229, and the total nucleotide diversity was , = 0.0108 ± 0.0058. Among-sample genetic differentiation was not significant and small-scale patterns in the distribution of haplotypes were not apparent. Gene flow and dispersal-related life history traits may account for low genetic structure at a small spatial scale. The high genetic diversity found in P. marmoratus increases its potential to adapt to changing conditions of the Mar Menor coastal lagoon. [source]