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Weather Patterns (weather + pattern)
Selected AbstractsThe Effect of Weather on HeadacheHEADACHE, Issue 6 2004Patricia B. Prince MD Objectives.,To assess headache patients' beliefs about how strongly weather affects their headaches; To objectively investigate the influence of multiple weather variables on headache. Design and Methods.,Our sample consisted of 77 migraineurs seen in a headache clinic, who provided headache calendars for a period ranging from 2 to 24 months. Our study was divided into two phases. First, each patient was given a questionnaire assessing their beliefs about how strongly (if so) weather affected their headaches. Second, weather data were collected from the National Weather Service, from three reporting stations central to the residences of the study participants. Analysis was performed on 43 variables to generate three meteorological factors. Linear regression was used to assess the relationship between headache and these three factors. Factor 1 represents a function of absolute temperature and humidity. Factor 2 represents a changing weather pattern. Factor 3 represents barometric pressure. Results.,Of the 77 subjects in the study, 39 (50.6%), were found to be sensitive to weather, but 48 (62.3%) thought they were sensitive to weather conditions (P < 0.05). Thirty (38.9%) were sensitive to one weather factor and 9 (11.7%) to two factors. Twenty-six (33.7%) were sensitive to factor 1; 11 (14.3%) to factor 2; 10 (12.9%) to factor 3. Conclusions.,Our study supports the influence of weather variables on headache. We showed that patients are susceptible to multiple weather variables and that more patients thought weather was a trigger than was the case. [source] Reconstruction of winter climate variations during the 19th century in JapanINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 11 2008Junpei Hirano Abstract An attempt was made to reconstruct winter climate conditions in Japan for the period 1810/1811 to 1858/1859 on the basis of daily weather records documented in old diaries. Daily weather maps for each winter were drawn using 19th century weather records collected by our research group. Maps were divided into five types by classifying daily snowfall and rainfall distributions and the occurrence frequencies of each weather pattern for the period 1810/1811 to 1858/1859 were analysed. It was found that the occurrence frequencies of winter monsoon weather patterns were high from the late 1820s to the early 1840s. This period almost coincided with a summer cold period in the 19th century. The result implies that strengthening of a cold air mass around Japan occurred in the late 1820s, not only in summer but also in winter. The frequencies of the typical winter monsoon patterns correspond with the freezing dates of Lake Suwa, which have been used as an indicator of winter coldness in previous studies. On the basis of the frequencies of the winter monsoon weather patterns, mean January temperatures for western Japan were estimated. In the time series of estimated temperatures, a cooling period from the late 1820s to the early 1830s was revealed. Copyright © 2007 Royal Meteorological Society [source] Conservation action in a changing climateCONSERVATION LETTERS, Issue 2 2008T.R. McClanahan Abstract Climate change will pose new challenges to conserving Earth's natural ecosystems, due to incremental changes in temperature and weather patterns, and to increased frequency and intensity of extreme climate events. Addressing these challenges will require pragmatic conservation actions informed by site-specific understanding of susceptibility to climate change and capacity of societies to cope with and adapt to change. Depending on a location's environmental susceptibility and social adaptive capacity, appropriate conservation actions will require some combination of: (1) large-scale protection of ecosystems; (2) actively transforming and adapting social-ecological systems; (3) building the capacity of communities to cope with change; and (4) government assistance focused on de-coupling communities from dependence on natural resources. We apply a novel analytical framework to examine conservation actions in five western Indian Ocean countries, where climate-mediated disturbance has impacted coral reefs and where adaptive capacity differs markedly. We find that current conservation strategies do not reflect adaptive capacity and are, therefore, ill prepared for climate change. We provide a vision for conservation policies that considers social adaptive capacity that copes with complexities of climate change better than the singular emphasis on government control and the creation of no-take areas. [source] Application of carbon isotope analysis to ancient maize agriculture in the Petexbatún region of GuatemalaGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 3 2007Kristofer D. Johnson The ancient Maya subsisted in an environment limited by shallow soils and unpredictable weather patterns until their collapse ,A.D. 800,900. Ancient subsistence can be a difficult subject, with little physical evidence of agricultural artifacts and structures. This study characterized soil profiles and utilized changes in stable carbon isotope ratios of soil organic matter (SOM) to locate and interpret areas of ancient C4 plant growth and maize (Zea mays) cultivation among the Maya. The investigation indicated some of the challenges the Maya faced, including shallow and sloped soils in some areas. The C4 plant signature was found in seasonal wetland soils on the opposite side of the Laguneta Aguateca from the ruins of Aguateca, but not in the perennial wetlands on the immediate side. No C4 plant signature was detected in the shoulder and backslope soils. Based on these findings, the ancient Maya of Aguateca probably adapted to their environment by farming rich toeslope soils. It is possible that maize was also grown in the seasonal wetlands adjacent to the site. If the steep backslope soils around Aguateca were used in ancient agriculture, the evidence has probably eroded away. © 2007 Wiley Periodicals, Inc. [source] Stress synergy between drought and a common environmental contaminant: studies with the collembolan Folsomia candidaGLOBAL CHANGE BIOLOGY, Issue 4 2001Rikke Højer Summary The term global change is used predominantly in connection with the global temperature increase and associated changes in weather patterns over the next century. In a broader sense it also covers other anthropogenic impacts on the environment such as habitat fragmentation and pollution. The individual effects of each of these stress types have been extensively studied in the biota. However, organisms will frequently encounter these stress types in combination rather than alone and there is little information available on the effects of stress combinations. Here an examination is made of the interaction between realistic levels of summer drought and a common contaminant of agricultural soil (4-nonylphenol, NP), on a widespread soil invertebrate, the collembolan Folsomia candida. These stress factors were tested individually and in combination using a full factorial design. This approach revealed the existence of highly significant Bliss type synergistic interaction between the two stress types. Thus, exposure to NP significantly reduced the drought tolerance of this organism and, reciprocally, the toxicity of NP (LC50) during realistic summer drought was more than doubled in comparison to the value obtained under optimal soil moisture conditions. Furthermore, it is shown that NP has a detrimental effect on the physiological mechanisms underlying this animal's drought tolerance, thus providing some explanation for the mechanisms involved in the synergy. It is argued that this type of synergy is unlikely to be confined to this particular combination of stresses and thus there is a need to study the interactions between dominant natural stresses and pollution. The most important implication of these results is that some of the effects of global climate changes can be predicted to be most severe in polluted areas. [source] The challenges of conservation for declining migrants: are reserve-based initiatives during the breeding season appropriate for the Pied Flycatcher Ficedula hypoleuca?IBIS, Issue 3 2009ANNE E. GOODENOUGH Creating conservation policies for declining migrant species in response to global change presents a considerable challenge. Migrant species are affected by factors at breeding grounds, overwintering areas and during migration. Accordingly, reserve-based management during the breeding season is not always a suitable conservation strategy. Recent Pied Flycatcher population decline typifies the pattern for many migrants. The UK population has declined by 43% in the past decade, but explanations, and possible solutions, remain elusive. We use 15 years of data (1990,2004) from a declining British population to establish possible reasons for decline, considering: (1) breeding performance (including the influences of competition and predation); (2) weather patterns caused by the winter phase (December,March) of the North Atlantic Oscillation (NAO), which modify conditions experienced at wintering grounds and on migration; and (3) possible impacts of climate change on spring temperatures. We conclude that decreasing breeding performance is contributing to decline, but that non-breeding factors are more important. Winter NAO index is a strong predictor of breeding population, probably because it influences food abundance in Africa and at migratory stopover points. Importantly, however, year itself enhances the predictive model, indicating that influences on population remain unaccounted for by current research. Management strategies based on increasing breeding productivity cannot fully address population decline because non-breeding factors appear important. However, as breeding performance is declining, breeding-based strategies remain useful conservation tools. To this end, our research indicates that optimal placement of nestboxes as regards orientation and habitat management to increase larval food supplies could increase productivity significantly. [source] Reconstruction of winter climate variations during the 19th century in JapanINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 11 2008Junpei Hirano Abstract An attempt was made to reconstruct winter climate conditions in Japan for the period 1810/1811 to 1858/1859 on the basis of daily weather records documented in old diaries. Daily weather maps for each winter were drawn using 19th century weather records collected by our research group. Maps were divided into five types by classifying daily snowfall and rainfall distributions and the occurrence frequencies of each weather pattern for the period 1810/1811 to 1858/1859 were analysed. It was found that the occurrence frequencies of winter monsoon weather patterns were high from the late 1820s to the early 1840s. This period almost coincided with a summer cold period in the 19th century. The result implies that strengthening of a cold air mass around Japan occurred in the late 1820s, not only in summer but also in winter. The frequencies of the typical winter monsoon patterns correspond with the freezing dates of Lake Suwa, which have been used as an indicator of winter coldness in previous studies. On the basis of the frequencies of the winter monsoon weather patterns, mean January temperatures for western Japan were estimated. In the time series of estimated temperatures, a cooling period from the late 1820s to the early 1830s was revealed. Copyright © 2007 Royal Meteorological Society [source] The influence of large-scale atmospheric circulation on the surface energy balance of the King George Island ice capINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 1 2001Matthias Braun Abstract During the austral summer 1997,1998 three automatic weather stations were operated at different altitudes on the sub-Antarctic ice cap of King George Island (South Shetland Islands). Snowmelt was derived from energy balance computations. Turbulent heat fluxes were calculated from meteorological measurements using the bulk aerodynamic approach, with net radiation being measured directly. Modelled ablation rates were compared with readings at ablation stakes and continuously measured snow height at a reference site. Snow depletion and daily snowmelt cycles could be well reproduced by the model. Generally, radiation balance provided the major energy input for snowmelt at all altitudes, whereas sensible heat flux was a second heat source only in lower elevations. The average latent heat flux was negligible over the entire measuring period. A strong altitudinal gradient of available energy for snowmelt was observed. Sensible heat flux as well as latent heat flux decreased with altitude. The measurements showed a strong dependence of surface energy fluxes and ablation rates on large-scale atmospheric conditions. Synoptic weather situations were analysed based on AVH RR infrared quicklook composite images and surface pressure charts. Maximum melt rates of up to 20 mm per day were recorded during a northwesterly advection event with meridional air mass transport. During this northwesterly advection, the contribution of turbulent heat fluxes to the energy available for snowmelt exceeded that of the radiation balance. For easterly and southerly flows, continentally toned, cold dry air masses dominated surface energy balance terms and did not significantly contribute to ablation. The link between synoptic situations and ablation is especially valuable, as observed climatic changes along the Antarctic Peninsula are attributed to changes in the atmospheric circulation. Therefore, the combination of energy balance calculations and the analysis of synoptic-scale weather patterns could improve the prediction of ablation rates for climate change scenarios. Copyright © 2001 Royal Meteorological Society [source] Influence of climate and reproductive timing on demography of little brown myotis Myotis lucifugusJOURNAL OF ANIMAL ECOLOGY, Issue 1 2010Winifred F. Frick Summary 1. Estimating variation in demographic rates, such as survival and fecundity, is important for testing life-history theory and identifying conservation and management goals. 2. We used 16 years (1993,2008) of mark,recapture data to estimate age-specific survival and breeding probabilities of the little brown myotis Myotis lucifugus LeConte in southern New Hampshire, USA. Using Kendall & Nichols' (1995) full-likelihood approach of the robust design to account for temporary emigration, we tested whether survival and breeding propensity is influenced by regional weather patterns and timing of reproduction. 3. Our results demonstrate that adult female survival of M. lucifugus ranged from 0·63 (95% CL = 0·56, 0·68) to 0·90 (95% CL = 0·77, 0·94), and was highest in wet years with high cumulative summer precipitation. First-year survival [range: 0·23 (95% CL = 0·14, 0·35) to 0·46 (95% CL = 0·34, 0·57)] was considerably lower than adult survival and depended on pup date of birth, such that young born earlier in the summer (c. late May) had a significantly higher probability of surviving their first year than young born later in the summer (c. mid-July). Similarly, the probability of young females returning to the maternity colony to breed in the summer following their birth year was higher for individuals born earlier in the summer [range: 0·23 (95% CL = 0·08, 0·50) to 0·53 (95% CL = 0·30, 0·75)]. 4. The positive influence of early parturition on 1st-year survival and breeding propensity demonstrates significant fitness benefits to reproductive timing in this temperate insectivorous bat. 5. Climatic factors can have important consequences for population dynamics of temperate bats, which may be negatively affected by summer drying patterns associated with global climate change. 6. Understanding long-term demographic trends will be important in the face of a novel disease phenomenon (White-Nose Syndrome) that is associated with massive mortalities in hibernating bat species, including M. lucifugus, in the northeastern United States. [source] Quantification of effects of season and nitrogen supply on tree below-ground carbon transfer to ectomycorrhizal fungi and other soil organisms in a boreal pine forestNEW PHYTOLOGIST, Issue 2 2010Mona N. Högberg Summary ,The flux of carbon from tree photosynthesis through roots to ectomycorrhizal (ECM) fungi and other soil organisms is assumed to vary with season and with edaphic factors such as nitrogen availability, but these effects have not been quantified directly in the field. ,To address this deficiency, we conducted high temporal-resolution tracing of 13C from canopy photosynthesis to different groups of soil organisms in a young boreal Pinus sylvestris forest. ,There was a 500% higher below-ground allocation of plant C in the late (August) season compared with the early season (June). Labelled C was primarily found in fungal fatty acid biomarkers (and rarely in bacterial biomarkers), and in Collembola, but not in Acari and Enchytraeidae. The production of sporocarps of ECM fungi was totally dependent on allocation of recent photosynthate in the late season. There was no short-term (2 wk) effect of additions of N to the soil, but after 1 yr, there was a 60% reduction of below-ground C allocation to soil biota. ,Thus, organisms in forest soils, and their roles in ecosystem functions, appear highly sensitive to plant physiological responses to two major aspects of global change: changes in seasonal weather patterns and N eutrophication. [source] Behavioral adaptations to heat stress and water scarcity in white-faced capuchins (Cebus capucinus) in Santa Rosa National Park, Costa RicaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2009Fernando A. Campos Abstract We examined thermoregulatory behaviors in a wild population of white-faced capuchins (Cebus capucinus) inhabiting a highly seasonal dry forest in Santa Rosa National Park (SRNP), Costa Rica. The dry season in SRNP lasts ,5 months and is characterized by high ambient temperatures regularly exceeding 37°C, low relative humidity, and the near absence of precipitation. This study demonstrates that capuchins rest more and travel shorter distances during the hottest and driest hours of the day, and suggests that they extend their tongues to lower body temperature via evaporative cooling. Seasonal weather patterns and group movement data reported here are based on 940 h of observations on three social groups of capuchins (wet season: 370 h, dry season: 570 h). In the dry season, the proportion of time spent resting increased at higher temperatures whereas the proportion of time spent traveling decreased. Distance traveled between location points taken at half-hour intervals decreased significantly as temperature increased, although the correlation was not strong. Capuchins exposed their tongues during hot, dry, windy conditions, and this behavior was much more frequent in the dry season. Temperature was significantly higher and humidity significantly lower for "tongue-out" events than expected for a random event in the dry season. Finally, as surface water became scarce, home-range areas of heavy use became increasingly centered on the remaining permanent water sources. These results suggest that heat stress and water scarcity are significant influences on the behavior of capuchins in hot, dry conditions. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Modelling Spikes in Electricity Prices,THE ECONOMIC RECORD, Issue 263 2007RALF BECKER During periods of market stress, electricity prices can rise dramatically. Electricity retailers cannot pass these extreme prices on to customers because of retail price regulation. Improved prediction of these price spikes therefore is important for risk management. This paper builds a time-varying-probability Markov-switching model of Queensland electricity prices, aimed particularly at forecasting price spikes. Variables capturing demand and weather patterns are used to drive the transition probabilities. Unlike traditional Markov-switching models that assume normality of the prices in each state, the model presented here uses a generalised beta distribution to allow for the skewness in the distribution of electricity prices during high-price episodes. [source] Changes of State: Slow-Motion Trauma in the Gangetic Plains of IndiaARCHITECTURAL DESIGN, Issue 5 2010Anthony Acciavatti Abstract In recent years, the vicissitudes wrought by harsh weather patterns and natural disasters have resulted in hurricanes and earthquakes and had a catastrophic impact on people's lives. The Ganges River Corridor in northern India is a region that perennially undergoes extreme changes in weather and climate with the onslaught of the monsoon season. AnthonyAcciavatti, in his Dynamic Atlas series of drawings, has measured the effects of rainfall and agrarian processes in relation to the fast-paced modes of urbanisation in the area. Copyright © 2010 John Wiley & Sons, Ltd. [source] Relative impacts of cattle grazing and feral animals on an Australian arid zone reptile and small mammal assemblageAUSTRAL ECOLOGY, Issue 3 2010JOHN L. READ Abstract The effect of different levels of cattle grazing on an arid Australian small terrestrial mammal and lizard assemblage was assessed in a long-tem series of cross-fence comparisons. Cross-fenced sites were closely matched for edaphic and vegetation characteristics and experienced near identical weather patterns, to ensure that cattle grazing pressure was the principal determinant of any differences in fauna assemblages. In addition, the effects of removal of cattle, cats, foxes and rabbits from three of these long-term monitoring sites were assessed to determine the relative impacts of cattle grazing and feral animals. Small mammal captures, with the exception of Mus musculus, revealed a significant negative response to cattle grazing pressure but this response was of a considerably lower magnitude than the dramatic increase in rodent captures and species richness within the feral animal-proof Arid Recovery Reserve. Higher kangaroo numbers in ungrazed controls, compared with treatments grazed by cattle, possibly negated the benefits to small mammals of removing cattle grazing. No reptile species responded significantly to the grazing treatments although reptile richness and captures of geckos and skinks were the lowest and agamid captures were the highest at heavily grazed sites. Nephrurus levis was the only reptile species to increase significantly, while captures of some smaller geckoes declined, within the feral-proof treatment. Feral predation exerted a more significant effect on most small mammal species than the levels of cattle grazing assessed in this study, yet reptile responses to grazing or feral animals were less apparent and were likely primarily driven by changes in vegetation cover or secondary trophic impacts. [source] | |||||||||||||