The Effects of Heat Advection on UK Weather and Climate Observations in the Vicinity of Small Urbanized Areas     

Richard Bassett  Xiaoming Cai  Lee Chapman  Clare Heaviside  John E. Thornes 《Boundary-Layer Meteorology》2017,165(1):181-196

Weather and climate networks traditionally follow rigorous siting guidelines, with individual stations located away from frost hollows, trees or urban areas. However, the diverse nature of the UK landscape suggests that the feasibility of siting stations that are truly representative of regional climate and free from distorting local effects is increasingly difficult. Whilst the urban heat island is a well-studied phenomenon and usually accounted for, the effect of warm urban air advected downwind is rarely considered, particularly at rural stations adjacent to urban areas. Until recently, urban heat advection (UHA) was viewed as an urban boundary-layer process through the formation of an urban plume that rises above the surface as it is advected. However, these dynamic UHA effects are shown to also have an impact on surface observations. Results show a significant difference in temperatures anomalies (\(p\,< \,0.001\)) between observations taken downwind of urban and rural areas. For example, urban heat advection from small urbanized areas (\(\sim \)1\(\,\hbox {km}^{2}\)) under low cloud cover and wind speeds of 2–3\(\,\hbox {m}\,\hbox {s}^{-1}\) is found to increase mean nocturnal air temperatures by 0.6\(\,^{\circ }\hbox {C}\) at a horizontal distance of 0.5 km. Fundamentally, these UHA results highlight the importance of careful interpretation of long-term temperature data taken near small urban areas.  相似文献   

Tracking the long-term responses of diatoms and cladocerans to climate warming and human influences across lakes of the Ring of Fire in the Far North of Ontario,Canada     

Kathryn E. Hargan  Clare Nelligan  Adam Jeziorski  Kathleen M. Rühland  Andrew M. Paterson  Wendel Keller  John P. Smol 《Journal of Paleolimnology》2016,56(2-3):153-172

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Contrasting Pliocene fluvial depositional systems within the rapidly subsiding South Caspian Basin; a case study of the palaeo-Volga and palaeo-Kura river systems in the Surakhany Suite,Upper Productive Series,onshore Azerbaijan     

Stephen J. Vincent  Clare E. Davies  Keith Richards  Elmira Aliyeva 《Marine and Petroleum Geology》2010

The South Caspian Basin contains major hydrocarbon reservoirs within the largely Early Pliocene Productive Series. This paper describes and contrasts outcrops of the uppermost ∼500 m of the series (the Surakhany Suite) deposited by two of the main fluvial systems that supplied the Azeri margin of the basin. Sedimentary facies and, for the first time from the Productive Series, palynological analyses document fluvial channel belt complexes, sheetflood overbank and flood plain to flood plain lake environments. The Productive Series on the Apsheron Peninsula, Azerbaijan, was supplied predominantly from the north by the palaeo-Volga river system. It displays an overall fining-upward trend, such that the Surakhany Suite at Lokbatan is dominated by mudstone. Siltstone and coarser-grained sediments make up 28% of the section. Channel bodies are on average 1.5 m thick and form 13% of the succession. In the sub-surface of the Apsheron Peninsula, ratty wireline log responses also indicate that siltstone and sandstone bodies are predominantly thin bedded, with SP-derived net-to-gross sand ratios of ∼0.35–0.40. The succession in the Kura Basin was sourced predominantly from the west by the palaeo-Kura river system. It displays a coarsening-upward trend, such that in the middle and upper Surakhany Suite at Babazanan siltstone and coarser sediments make up 52% of the section. It is characterised by numerous stacked and laterally continuous channel sandstone bodies that are on average 5.8 m thick and comprise 42% of the outcrop. In the sub-surface of the Kura Basin, wireline log responses of the Surakhany Suite have a blocky character and indicate SP-derived net-to-gross sand ratios of 0.26–0.38. These values are similar to calculated sandstone volumes at outcrop (44%). The palynological data, including multivariate analyses, show that the main controls on palynomorph distribution are the degree of fluvial or lacustrine influence, subaerial exposure and salinity. Despite their more lithic nature, Surakhany Suite sandstones derived from the palaeo-Kura river system along the Kurovdag-Babazanan-Neftchala trend have similar or better petrophysical properties than those derived from the palaeo-Volga river on the Apsheron Peninsula and its offshore continuation. This is probably due to their coarser-grain size. This, combined with their greater sandstone body thickness, would suggest that the axis of the Kura Basin forms the most promising part of the Azeri sector of the South Caspian Basin for exploration within the uppermost part of the Productive Series.  相似文献   

Oxygen consumption rates in pelagic sediments from the Central Pacific: First estimates from microelectrode profiles     

Clare E Reimers  Susan Kalhorn  Steven R Emerson  Kenneth H Nealson 《Geochimica et cosmochimica acta》1984,48(5):903-910

Oxygen profiles in pelagic sediments from the Manganese Nodule Program calcareous and siliceous ooze sites (MANOP sites C and S) in the central Pacific Ocean were measured with microelectrodes and are used to predict oxygen consumption rates beneath the sediment-water interface. We explain possible artifacts which occur during sample recovery and argue that minimum estimates of 0.083 and 0.025 μ moles $\text{O}{}_2\text{cm}{}^2\text{day}$ (C and S, respectively) can be calculated from the data. These oxygen consumption rates are in good agreement with in situ respirometer measurements previously reported for comparable sediments in the north Pacific, but previous estimates based on modeling of pore water nitrate profiles at both sites are two to five times smaller than our minimum fluxes. The differences in oxygen fluxes calculated by the two methods are probably in part due to uncertainty in the assumptions inherent in the nitrate model. However, non-steady state fluctuations in particulate organic matter fluxes could also be a reason for the disparity.  相似文献   

Some observations on the life history of the amphipod crustacean,Hyale nilssoni (Rathke), in New Hampshire     

Clare D. McBane  Robert A. Croker 《Estuaries and Coasts》1984,7(4):541-545

Hyale nilssoni is an intertidal amphipod at open coastal and estuarine habitats in New Hampshire. Two juvenile recruitment peaks occurred during the year (spring and summerfall), with these peaks occurring earlier in the estuary. The spring peak coincided with increasing water temperature at both locations. Body sizes at the two habitats tended to be inversely related to water temperature resulting in a greater body size on the open coast. Energy demands on the animal associated with the fluctuating water temperatures and salinities likely attributed to the smaller body size of the animal in the estuarine population.  相似文献   

A comparison of water-column macroinvertebrate communities in beds of differing submersed aquatic vegetation in the tidal freshwater Potomac River     

Angela G. Thorp  R. Christian Jones  Donald P. Kelso 《Estuaries and Coasts》1997,20(1):86-95

Macroinvertebrates are a major food source for fish species and macrophyte beds are hypothesized to harbor a rich community of these organisms. Macroinvertebrates inhabiting the water column in two macrophyte beds and an adjacent open area were sampled in a small embayment of the tidal freshwater Potomac River. One macrophyte bed consisted of an almost complete monoculture ofHydrilla verticillata, while the second community was a more diverse mixture of plant species. In samples with substantial amounts of submersed aquatic vegetation (SAV), macroinvertebrate density was two orders of magnitude higher than and substantially more taxa were found than at the open water site. Total macroinvertebrate abundance was significantly greater at theH. verticillata site than at the mixed site in July, but no significant difference was observed in August. Taxa richness did not vary between the two vegetated sites in July but was higher in the mixed bed in August. While the two vegetated sites shared similar taxa, they differed in their abundance. TheH. verticillata site harbored more hydrobiid snails, and the mixed site was characterized by more chironomids and hydroptilid caddisflies. Differences between July and August collections were even greater than between sites. Numbers of hydroptilid caddisflies, baetid mayflies, and coenagrionid damselflies were substantially higher in August, while oligochaetes, hydrobiids, and chironomids were reduced. Results support the hypothesis that water-column macroinvertebrates are greatly enhanced in the presence of macrophytes. The ecological significance of the less substantial differences in macroinvertebrates between macrophyte beds requires further study.  相似文献   

‘Signals’ from pre-crisis discourse: Lessons from UK flooding for global environmental policy change?     

Edmund Penning-Rowsell  Clare Johnson  Sylvia Tunstall 《Global Environmental Change》2006,16(4):323-339

This paper evaluates policy accelerations after past flood crises in the UK (in 1947, 1953, 1998 and 2000) and explores their value as surrogates or metaphors for how governments might respond with policy changes to the local expressions of global climate and environmental change in the future. We find that these past policy change accelerations were, in general, not based on the development of new ideas but on bringing forward existing ideas that were already the subject of widespread professional or public discourse. We suggest, therefore, that we may be able to detect now, as ‘signals’ within current policy discourse, the embryos of the policy shifts that are likely to come about as part of any crisis-response adaptation to future climate change. If this is the case, then we believe that those with policy responsibilities now may be able to begin carefully and proactively to prepare the ground for such policy changes ahead of the crisis events that will alone trigger their acceleration and adoption.  相似文献   

Working a fraction and making a fraction work: a rough guide for geographers in the academy     

Jacky Birnie  Clare Madge  Rachel Pain†  Parvati Raghuram‡  Gillian Rose‡ 《Area》2005,37(3):251-259

Little is known about the issues facing geographers working on fractional appointments in higher education institutions in the UK. This paper draws on a survey of UK geography departments and personal experiences to explore some of that territory for the first time. The purpose is both to set the agenda for institutional policy issues and to provide some immediate points of reflection for staff intending to take up fractional work. We consider the place of fractional working in the dominant discourses around paid work, problems of workload division and the impact on professional standing (including the RAE). We suggest that while personal 'life' reasons for fractional working are often positive, fractional workers in the academy risk professional marginalization.  相似文献   

Factors affecting dissolved organic matter dynamics in mixed-redox to anoxic coastal sediments   总被引：1，自引：0，他引：1  

Tomoko Komada  Clare E. Reimers  David J. Burdige 《Geochimica et cosmochimica acta》2004,68(20):4099-4111

Mixed-redox (suboxic, or oscillating between oxidizing and reducing conditions) to anoxic marine sediments from the Raritan -New York Bay complex and the Inner New York Bight of the eastern U.S. were studied to investigate the factors controlling the accumulation of pore-water dissolved organic carbon (DOC). DOC increased with depth at each of four study sites, but accumulation was generally limited in the mixed-redox zone relative to the anoxic zone. Humic-like fluorescence intensity also differed between mixed-redox and anoxic zones of the sediment, such that anoxic pore waters were relatively enriched in fluorescent, humic-like compounds.A pore-water DOC model was tested for its capacity to explain these geochemical patterns. Model results for a heavily irrigated and a non-bioturbated site both suggest that, excluding the uppermost few cm of the sediment column, pore-water DOC is predominantly comprised of poorly-reactive material with estimated degradation rate constants on the order of 10⁻³ yr⁻¹. Model results are also consistent with the suggestion that DOC accumulation is suppressed in the mixed-redox compared to the anoxic zones of the sediment due to rapid oxidation of high-molecular-weight DOC, and limited production and enhanced oxidation of the less reactive polymeric low-molecular-weight component of the DOC pool. An assessment of sorptive behavior of DOC in the surface sediments of the study area suggests that sorption can influence pore-water DOC distributions under conditions of high sedimentation and low bioirrigation.  相似文献   

Inclination- and dust-corrected galaxy parameters: bulge-to-disc ratios and size–luminosity relations     

Alister W. Graham  C. Clare Worley 《Monthly notices of the Royal Astronomical Society》2008,388(4):1708-1728

While galactic bulges may contain no significant dust of their own, the dust within galaxy discs can strongly attenuate the light from their embedded bulges. Furthermore, such dust inhibits the ability of observationally determined inclination corrections to recover intrinsic (i.e. dust-free) galaxy parameters. Using the sophisticated 3D radiative transfer model of Popescu et al. and Tuffs et al., together with the recent determination of the average face-on opacity by Driver et al. in nearby disc galaxies, we provide simple equations to correct (observed) disc central surface brightness and scalelengths for the effects of both inclination and dust in the B , V , I , J and K passbands. We then collate and homogenize various literature data sets and determine the typical intrinsic scalelengths, central surface brightness and magnitudes of galaxy discs as a function of morphological type. All galaxies have been carefully modelled in their respective papers with a Sérsic   R ^{1/ n}   bulge plus an exponential disc. Using the bulge magnitude corrections from Driver et al., we additionally derive the average, dust-corrected, bulge-to-disc flux ratio as a function of galaxy type. With values typically less than 1/3, this places somewhat uncomfortable constraints on some current semi-analytic simulations. Typical bulge sizes, profile shapes, surface brightness and deprojected densities are provided. Finally, given the two-component nature of disc galaxies, we present luminosity–size and (surface brightness)–size diagrams for discs and bulges. We also show that the distribution of elliptical galaxies in the luminosity–size diagram is not linear but strongly curved.  相似文献