Regional Weather Stations Research Articles

노지재배 감자의 생육시기별 물 요구량 구명

Water is the most important resource for the potato cultivation, especially to get the maximum water use efficiency and yield of potato, Water has to be applied moderately based on the water requirement of the potato. Crop water requirement (WR) is a function of the Potential evapo-transpiration(PET) and Crop coefficient (Kc). PET can be estimated by the climate data measured at the weather station in the production region. Kc was measured by the NIAST (RDA) through Lysimeter experiments. In this study, the growth stage of potato was divided as four (G-1 : Apr. 1~Apr. 15, G-2 : Apr. 16~May. 10, G-3 : May. 11~May. 31, G4 : Jun. 1~Jun. 15). The average PET during potato growing season of the 45 areas was . The most water requirement was the G-3 stage among the potato growth stage. The MWR (Mean water requirement) according to growth stage was 1.0~1.2 (average 1.1), 1.5~1.8 (average 1.6), 1.9~2.2 (average 2.0) and 1.7~2.1 (average 1.8) mm , in the G-1, G-2, G-3 and G-4 stage, respectively. The TWR (Total water requirement) according to growth stage was 18.0~22.1 (average 19.3), 50.6~66.6 (average 56.3), 63.5~88.2 (average 72.4) and 38.3~54.5 (average 44) mm, in the G-1, G-2, G-3 and G-4 stage, respectively.

Fruit transpiration in kiwifruit: environmental drivers and predictive model

In most fruit crops, storage quality varies greatly between regions and seasons, causing significant commercial loss. Understanding the sources of this variability will contribute to the knowledge of fruit developmental physiology and may also benefit commercial fruit production via altered managements that reduce it or forecasts that predict it. A causal-chain relationship is proposed to help elucidate the sources of variability in fruit storage quality: the weather →(i)→ fruit transpiration →(ii)→ fruit calcium →(iii)→ fruit storage quality. This paper explores the first link of this hypothesis, →(i)→, for Hayward kiwifruit using field measurements of fruit transpiration rate and concurrent meteorological recordings. The aims are to identify the key environmental variables driving fruit transpiration and develop a predictive fruit transpiration model. Fruit transpiration was determined hourly over several 24-h periods by recording weight loss of detached fruit, on Days 23, 35, 49, 65, 94 and 140 after full bloom. Meteorological records were made every 15 min throughout the season at an adjacent regional weather station. A model of fruit transpiration was developed in which the usual meteorological variables (radiation, temperature, windspeed and relative humidity) were incorporated in a Fick's Law transpiration flux equation. Fruit transpiration rate (i.e. the molar flux density, mmol cm(-2) h(-1)) varied diurnally and decreased during the season. The dominant fruit variable governing transpiration rate was skin conductance and the dominant environmental variables were relative humidity and temperature. Radiation and windspeed were not significantly influential. The model provides a good fit to the fruit transpiration rate measurements regardless of the time of day/night or the stage of fruit development. The model allows reasonably accurate and continuous predictions of fruit transpiration rate throughout fruit development based on standard meteorological recordings. It also allows estimates of cumulative fruit transpiration throughout the season.

Temporal and spatial analyses of temperature in a French wine‐producing area: the Loire Valley

AbstractGlobal warming is causing earlier phenological dates for vines and changes in the quality of wines all around the world. To understand how vines are liable to react to future climate evolution, the climate of viticultural areas needs to be known as accurately as possible. In this article, temporal evolution and spatial variability of temperature in the wine producing area of the Loire Valley were analysed with a multi‐scalar approach. First, the regional evolution of temperature and bioclimatic indices were studied over the past 60 years in the wine‐producing area of the Loire Valley and showed a general warming at all locations in the regional weather station network (Météo‐France). Secondly, temperature data from weather stations located within the vineyards between Angers and Saumur were studied for the year 2010 and underlined spatial variability of temperature between the different plots according to the different topoclimates. Finally, particular attention was paid to theCoteaux du Layonvineyards (sweet wine producing appellation) where 21 temperature data loggers were set up in the vine rows to study climate at local scale. The study showed, in particular, that the spatial variability of temperature and bioclimatic indices in these vineyards was greater than those observed at larger scales. Copyright © 2012 Royal Meteorological Society

The risk of pine wilt disease in Poland

The pine wood nematode (PWN) Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle (Aphelenchida, Parasitaphelenchidae), causing the pine wilt disease (PWD), is a quarantine species of Europe that was found in Portugal in 1999. High ambient temperature (above 20° C) is considered to be one of the main factors enhancing the development of PWD in pine stands. In the early 90s of the last century, Poland was considered a country of low risk of PWN establishment. The aim of our study was to verify whether this status has changed due to the effects of climate change. We analysed changes in monthly mean ambient temperatures in June, July and August from 75 weather stations in various regions of Poland from 2005– 2010. Additional analyses of changes in monthly mean temperatures in July and August in the period 1991– 2010 were performed for the weather station where the highest temperatures were recorded. Multi-year (2005– 2010) average of mean temperatures in June did not exceed 20° C at any of the meteorological stations. However, in July it was higher than the threshold temperature at 26 meteorological stations located in the central part of Poland. The highest multi-year average temperatures were recorded at the station in Kolo (52° 12’ N, 18° 38’ E). A detailed analysis of July and August temperature changes at this station during the period 1991– 2010 revealed increasing trends that were described by polynomial functions. The most substantial increase has been observed since 2001. The mean temperature in July and August over the last decade (2001– 2010) has increased by 2.4 and 1.5° C respectively when compared to the previous decade. It is our conclusion that, although the PWN has not yet been found in Poland, the country should no longer be regarded as an area of low risk due to the effects of summer temperature increase. Other factors favourable for the pine wilt disease development and spread were discussed.

Heat waves in Central Europe (1991-2006)

The extreme weather phenomenon of heat waves poses a serious threat to humans and has been shown to contribute to increased sickness rates and even deaths, mostly in large cities. The paper concerns the occurrence of heat waves in Central Europe. Data was collected from five regional weather stations in Budapest, Krakow, Lvov, Prague and Vienna and included records of the average, maximum and minimum daily air temperatures during the period 1991–2006. The authors defined a heat wave as an unbroken period of at least three days with a maximum temperature of more than 30ºC. The study demonstrates that the greatest intensity of heat stress is observed during short heat waves that lasted typically for three to four days and whose timing did not coincide at the different stations involved. Indeed, even longer heat waves, characterised by lower temperature values, were not always recorded at all the stations. This was due to the division of the region by mountain ranges, which impeded the flow of hot tropical air into southern Poland and western Ukraine.

Why Analyze Mental Models of Local Climate Change? A Case from Southern Mozambique

AbstractPeople construct mental models of local climate change based on their observations and experiences of past climate events and changes. These mental models offer critical insight into locally important factors that trigger responses to new climate conditions and can be used to ground-truth regional climate models. In this paper, the authors explore mental models of changes to local climate patterns and climate-associated environmental changes over the past 45 years (1963–2008) in two rural communities in Matutúine District, Mozambique. Interview results are compared to data from a regional weather station. Residents discuss temperature increases, short-term and long-term precipitation changes, and altered seasonal timing. Measurable climate change in this region includes increasing temperatures and more erratic rainfall leading to drought and altered season timing. The climate-associated environmental changes residents observed draw attention to links between local livelihood practices and climate, as well as emphasize changes that would not necessarily appear in regional climate models. Such changes include reduced crop and wild fruit production, fewer cattle, variable forest size, increased wildfires and elephant conflict, drying up of water sources, poor health, and cultural change. Differences between adjacent communities highlight the potential interaction of landscape and vegetation variability, gender, and livelihoods in observations and experiences of climate change and demonstrate how mental models can provide insight into local ecological patterns and processes.

The significance of chemical, isotopic, and detrital components in three coeval stalagmites from the superhumid southernmost Andes (53°S) as high-resolution palaeo-climate proxies

Stalagmites are important palaeo-climatic archives since their chemical and isotopic signatures have the potential to record high-resolution changes in temperature and precipitation over thousands of years. We present three U/Th-dated records of stalagmites (MA1–MA3) in the superhumid southern Andes, Chile (53°S). They grew simultaneously during the last five thousand years (ka BP) in a cave that developed in schist and granodiorite. Major and trace elements as well as the C and O isotope compositions of the stalagmites were analysed at high spatial and temporal resolution as proxies for palaeo-temperature and palaeo-precipitation. Calibrations are based on data from five years of monitoring the climate and hydrology inside and outside the cave and on data from 100 years of regional weather station records. Water-insoluble elements such as Y and HREE in the stalagmites indicate the amount of incorporated siliciclastic detritus. Monitoring shows that the quantity of detritus is controlled by the drip water rate once a threshold level has been exceeded. In general, drip rate variations of the stalagmites depend on the amount of rainfall. However, different drip-water pathways above each drip location gave rise to individual drip rate levels. Only one of the three stalagmites (MA1) had sufficiently high drip rates to record detrital proxies over its complete length. Carbonate-compatible element contents (e.g. U, Sr, Mg), which were measured up to sub-annual resolution, document changes in meteoric precipitation and related drip-water dilution. In addition, these soluble elements are controlled by leaching during weathering of the host rock and soils depending on the pH of acidic pore waters in the peaty soils of the cave’s catchment area. In general, higher rainfall resulted in a lower concentration of these elements and vice versa. The Mg/Ca record of stalagmite MA1 was calibrated against meteoric precipitation records for the last 100 years from two regional weather stations. Carbonate-compatible soluble elements show similar patterns in the three stalagmites with generally high values when drip rates and detrital tracers were low and vice versa. δ 13C and δ 18O values are highly correlated in each stalagmite suggesting a predominantly drip rate dependent kinetic control by evaporation and/or outgassing. Only C and O isotopes from stalagmite MA1 that received the highest drip rates show a good correlation between detrital proxy elements and carbonate-compatible elements. A temperature-related change in rainwater isotope values modified the MA1 record during the Little Ice Age (∼0.7–0.1 ka BP) that was ∼1.5 °C colder than today. The isotopic composition of the stalagmites MA2 and MA3 that formed at lower drip rates shows a poor correlation with stalagmite MA1 and all other chemical proxies of MA1. ‘Hendy tests’ indicate that the degassing-controlled isotope fractionation of MA2 and MA3 had already started at the cave roof, especially when drip rates were low. Changing pathways and residence times of the seepage water caused a non-climatically controlled isotope fractionation, which may be generally important in ventilated caves during phases of low drip rates. Our proxies indicate that the Neoglacial cold phases from ∼3.5 to 2.5 and from ∼0.7 to 0.1 ka BP were characterised by 30% lower precipitation compared with the Medieval Warm Period from 1.2 to 0.8 ka BP, which was extremely humid in this region.

Prediction of spatially distributed regional‐scale fields of air temperature and vapor pressure over mountain glaciers

Physically based models of glacier melt require fields of near‐surface air temperature (Tg) and vapor pressure (eg) for estimating turbulent heat exchanges. However, katabatic boundary layer (KBL) processes limit the effectiveness of standard interpolation or extrapolation routines for estimating Tg and eg from regional weather station networks. Climate data collected from nine automatic weather stations operated over three ablation seasons at three glaciers in the southern Coast Mountains of British Columbia are analyzed in this study. On‐glacier observations were compared to ambient values (Ta and ea) estimated from a regional network of off‐glacier weather stations. Piecewise regressions of Tg versus Ta at each AWS site reveal (1) a critical threshold temperature (T*) that denotes the onset of katabatic boundary layer (KBL) development and (2) a temperature damping that is consistent at each site, but variable between sites. Variations in near‐surface vapor pressure are related to processes of condensation or evaporation/sublimation at the glacier surface, which are controlled by the vapor pressure gradient between the surface and the ambient air. Statistical relations with flow path lengths calculated from glacier digital elevation models are used to predict the strength of KBL effects on Tg and eg, and examples of the approach for generating distributed fields of Tg and eg are given.

A Test of Temperature Estimation From Solar Irradiation and a Simple Statistical Method to Integrate Elevation Into Prediction Models

Temperature drives ecosystem function and can be estimated from potential solar irradiation (the surface angle of the Earth in relationship to the sun). However, indirect topographical proxies (i.e., aspect) are often used in lieu of direct temperature estimates; and temperature models based on potential solar irradiation typically omit elevation, a key parameter in temperature estimation. Using temperature data (2002–04) from regional weather stations and field sites in the southern Appalachian region of North Carolina and north Georgia, I test the efficacy of temperature estimations based on potential solar irradiation and present a simple method to improve such estimations by incorporating elevational temperature gradients. The heat load index, which weighs afternoon sun as more integral to heat generation than morning sun, fits actual weather station and field site temperatures better than solar angle alone. However, in all years and data sets, adjusting the heat load index for elevational substantially improves its fit with actual temperatures. Further, by calibrating the adjusted heat load estimation with annual weather station temperature data, actual field site temperature for individual years can be accurately predicted. This paper presents a relatively simple method for generating temperature data that requires only spreadsheet or statistical software. This is useful for estimating temperatures from data sets where only topographical or GPS data were collected. It also can be used to derive missing data when sampling sites outnumber temperature loggers.

Monte Carlo Simulations of Wind Speed Data

A new Monte Carlo simulation procedure and nearby regional weather station data are used to predict wind speed and turbine energy. The evaluation of the predication values used cumulative distribution function (CDF) graphs. The predication process employed Weibull shape and scale values developed from 1, 12, 20 and 24 years of record for each weather station. Simulation using one year of wind speed data of a weather station located downwind of the wind turbine site resulted in the greatest match of simulation results to the measured values[ED1]. Most simulations of energy values were a closer match to the measured values than those of wind speed. A closer match was defined as simulated values in the CDF central range of 10 to 75 percent which is also a 25 to 75 percent probability factor.

Glacier retreat and climatic variability in the eastern Terskey–Alatoo, inner Tien Shan between the middle of the 19th century and beginning of the 21st century

Changes in the extent of glaciers and rates of glacier termini retreat in the eastern Terskey–Alatoo Range, the Tien Shan Mountains, Central Asia have been evaluated using the remote sensing techniques. Changes in the extent of 335 glaciers between the end of the Little Ice Age (LIA; mid-19th century), 1990 and 2003 have been estimated through the delineation of glacier outlines and the LIA moraine positions on the Landsat TM and ASTER imagery for 1990 and 2003 respectively. By 2003, the glacier surface area had decreased by 19% of the LIA value, which constitutes a 76 km 2 reduction in glacier surface area. Mapping of 109 glaciers using the 1965 1:25,000 maps revealed that glacier surface area decreased by 12.6% of the 1965 value between 1965 and 2003. Detailed mapping of 10 glaciers using historical maps and aerial photographs from the 1943–1977 period, has enabled glacier extent variations over the 20th century to be identified with a higher temporal resolution. Glacial retreat was slow in the early 20th century but increased considerably between 1943 and 1956 and then again after 1977. The post-1990 period has been marked by the most rapid glacier retreat since the end of the LIA. The observed changes in the extent of glaciers are in line with the observed climatic warming. The regional weather stations have revealed a strong climatic warming during the ablation season since the 1950s at a rate of 0.02–0.03 °C a − 1 . At the higher elevations in the study area represented by the Tien Shan meteorological station, the summer warming was accompanied by negative anomalies in annual precipitation in the 1990s enhancing glacier retreat. However, trends in precipitation in the post-1997 period cannot be evaluated due to the change in observational practices at this station. Neither station in the study area exhibits significant long-term trends in precipitation.

Downscaling Climate over Complex Terrain: High Finescale (<1000 m) Spatial Variation of Near-Ground Temperatures in a Montane Forested Landscape (Great Smoky Mountains)*

AbstractLandscape-driven microclimates in mountainous terrain pose significant obstacles to predicting the response of organisms to atmospheric warming, but few if any studies have documented the extent of such finescale variation over large regions. This paper demonstrates that ground-level temperature regimes in Great Smoky Mountains National Park (Tennessee and North Carolina) vary considerably over fine spatial scales and are only partially linked to synoptic weather patterns and environmental lapse rates. A 120-sensor network deployed across two watersheds in 2005–06 exhibited finescale (<1000-m extent) temperature differences of over 2°C for daily minima and over 4°C for daily maxima. Landscape controls over minimum temperatures were associated with finescale patterns of soil moisture content, and maximum temperatures were associated with finescale insolation differences caused by topographic exposure and vegetation cover. By linking the sensor array data to 10 regional weather stations and topographic variables describing site radiation load and moisture content, multilevel spatial models of 30-m resolution were constructed to map daily temperatures across the 2090-km2 park, validated with an independent 50-sensor network. Maps reveal that different landscape positions do not maintain relative differences in temperature regimes across seasons. Near-stream locations are warmer in the winter and cooler in the summer, and sites of low elevation more closely track synoptic weather patterns than do wetter high-elevation sites. This study suggests a strong interplay between near-ground heat and water balances and indicates that the influence of past and future shifts in regional temperatures on the park’s biota may be buffered by soil moisture surfeits from high regional rainfall.

Combining the standardized precipitation index and climatic water deficit in characterizing droughts: a case study in Romania

This paper characterizes droughts in Romania using the approach of both the standardized precipitation index (SPI) and climatic water deficit (WD). The values of the main climatic factors (rainfall, temperature, reference evapotranspiration, etc.) were obtained from 192 weather stations in various regions of Romania. Penman–Monteith reference evapotranspiration (ETo-PM) was used to calculate WD as the difference between precipitation (P) and ETo-PM. SPI was calculated from precipitation values. There is a clear difference between drought and aridity. Drought occurrence determines higher WD values for plains and plateaus and lower climatic excess water (EW) values for high mountains in Romania, depending on the aridity of the specific region considered and drought severity. WD calculated as mean values for both normal conditions and, for all locations studied, various types of drought was correlated with mean annual precipitation and temperature, respectively. The combined approach of WD and SPI was mainly carried out for periods of 1 year, but such studies could also be done for shorter periods like months, quarters, or growing season. The most arid regions did not necessarily coincide with areas of the most severe drought, as there were no correlations between WD and SPI and no altitude-based SPI zones around the Carpathian Mountains, as is the case for other climate characteristics, soils and vegetation. Water resource problems arise where both SPI values characterize extremely droughty periods and WD values are greatly below −200 mm/year. This combined use of SPI and WD characterizes the dryness of a region better than one factor alone and should be used for better management of water in agriculture in Romania and also other countries with similar climate characteristics.

Above ground biomass changes in the mountain birch forests and mountain heaths of Finnmarksvidda, northern Norway, in the period 1957–2006

Birch forests cover large areas of the northern Fennoscandia and the mountain birch ( Betula pubescens ssp. czerepanovii) often forming the altitudinal and Arctic forest and tree lines. Interpreting the factors leading to landscape changes in mountain birch forest involves disturbance from anthropogenic use and climate as important factors. Using vegetation maps based on aerial photographs and satellite images from 7 years in combination with statistical data and ground estimation data of biomass in the period 1957–2006, we were able to assess the transitions among mountain heaths and different types of forest, the displacement of the altitudinal forest line and hence the change in biomass. The tree biomass as well as the growing stock for birch in Finnmarksvidda doubled in the period 1957–2006. Only lichen biomass has been significantly reduced in the period 1957 to 2000, with a subsequent slight increase of lichen biomass in the period 2000 to 2006. The results presented in this paper show significant and positive relationships between measured tree biomass and the increase in reindeer population in the period 1957–2006 in the study area. The hypothesis concerning the removal of the “lichen barrier effect” by heavy reindeer grazing which leads to increased success for birch seeds to germinate and sprout is therefore considered to be valid. However, also, climate change effects like increased precipitation, moth attacks, freezing and thawing events during winter and long-transported air pollution (e.g. nitrogen) may also have reinforced the changes in biomass. Climatic variables from regional weather stations for the period 1955–2006 did not, however, reveal any consistent change except for that the increased snow depth had a negative impact on the reindeer population while increase in snow depth hindering the reindeer in grazing seemed to have a positive impact on the lichen biomass. The ongoing development of increased forest cover and hence elevated forest line will lead to reduction of open habitats, and hence decreased grazing accessibility for the reindeer. The effects on forestry and carbon sequestration are also discussed, and here one of the suggestions is to let the northern birch forests act as carbon sinks contributing to the reduction of total net emission of CO 2 in the Nordic countries. Land use like reindeer husbandry has shown to strongly affect relationships between ecological processes like tree-growth and climate. Moreover, reindeer husbandry is such a widespread human activity in the arctic and boreal region that it might affect the global carbon budget.

Extinction vulnerability of tropical montane endemism from warming and upslope displacement: a preliminary appraisal for the highest massif in Madagascar

One of the predicted biological responses to climate warming is the upslope displacement of species distributions. In the tropics, because montane assemblages frequently include local endemics that are distributed close to summits, these species may be especially vulnerable to experiencing complete habitat loss from warming. However, there is currently a dearth of information available for tropical regions. Here, we present a preliminary appraisal of this extinction threat using the herpetological assemblage of the Tsaratanana Massif in northern Madagascar (the island's highest massif), which is rich with montane endemism. We present meteorological evidence (individual and combined regional weather station data and reanalysis forecast data) for recent warming in Madagascar, and show that this trend is consistent with recent climate model simulations. Using standard moist adiabatic lapse rates, these observed meteorological warming trends in northern Madagascar predict upslope species displacement of 17–74 m per decade between 1993 and 2003. Over this same period, we also report preliminary data supporting a trend for upslope distribution movements, based on two surveys we completed at Tsaratanana. For 30 species, representing five families of reptiles and amphibians, we found overall mean shifts in elevational midpoint of 19–51 m upslope (mean lower elevation limit 29–114 m; mean upper elevation limit −8 to 53 m). We also found upslope trends in mean and median elevational observations in seven and six of nine species analysed. Phenological differences between these surveys do not appear to be substantial, but these upslope shifts are consistent with the predictions based on meteorological warming. An elevational range displacement analysis projects complete habitat loss for three species below the 2 °C ‘dangerous’ warming threshold. One of these species is not contracting its distribution, but the other two were not resampled in 2003. A preliminary review of the other massifs in Madagascar indicates potential similar vulnerability to habitat loss and upslope extinction. Consequently, we urgently recommend additional elevational surveys for these and other tropical montane assemblages, which should also include, when possible, the monitoring of local meteorological conditions and habitat change.

Radioactive pollution of the Baikal area as a result of nuclear ground tests

Results of analyses for 137Cs in soils sampled in more than 800 localities have shown that the Baikal area pollution is much contributed by local radioactive fallout from the Semipalatinsk nuclear ground tests. We studied the effect of the amount of atmospheric precipitation and the types of landscapes and soils on the content of 137Cs in regional soils. Local radioactive fallout is confirmed by the total beta activity of daily atmospheric precipitation measured at regional weather stations.

A web-based interactive system for risk management of potato late blight in Michigan

A web-based expert system was developed to help potato growers in Michigan make important decisions on optimal use and timing of fungicide applications to mitigate the risk of potato late blight (PLB) disease development. The system was developed around a relational database which stores information on PLB risk which is generated using a PLB prediction model implemented in Perl. The model uses data on relative humidity and temperature from a network of automated weather stations in Michigan to estimate if environmental conditions are favorable for PLB epidemic development. Management recommendations are then produced based on the level of risk. Information stored in the database is presented to users through a series of interactive web pages which are dynamically generated through a combination of Perl and PHP scripts which interface between the website and relational database. This system differs from traditional systems in two major ways. Firstly, the system is web-based and interactive, allowing growers to access site specific, weather-based recommendations through their personal computer without the purchase or installation of additional equipment and/or software. Secondly, the system incorporates geographic proximity of known PLB occurrences and data from a network of regional weather stations into daily risk estimates and management recommendations for 48 locations in Michigan. Recommendations include application timing and spray rates for common fungicides. The interactive website is accessible over the web at URL: http://www.lateblight.org.

Temporal Variation of Ixodes ricinus Intensity on the Rodent Host Apodemus flavicollis in Relation to Local Climate and Host Dynamics

The risk to humans of contracting tick-borne zoonotic diseases depends on the risk of a bite from an infected tick, which can be broken down into its component parts as the number of host-seeking ticks in the environment, in particular nymphs, and the prevalence of tick-borne pathogens they are carrying. In turn, the prevalence of tick-borne pathogens is dependent upon tick biting intensity on hosts that support transmission between ticks; namely rodents. These ticks once fed moult into the next life stage and search for the next blood meal, thus posing a zoonotic risk. Here, we analyse tick biting intensity on rodents in a known tick-borne encephalitis (TBE) focus in Trentino (northern Italy). We examine patterns of tick demography and the influence of host densities and climate on ticks' generation time, development rates, tick density and intensity. During the period 2000-2004, a population of the yellow-necked mouse, Apodemus flavicollis, the most important TBE transmission host, was intensively monitored. Ticks feeding on individual rodents were counted, distinguishing between the larval and nymph life-stages. Local temperature and relative humidity was calculated using both data-loggers in the field site and regional weather stations. We investigated which factors had a predictive value both on feeding tick intensity and on the overall density of larvae or nymphs feeding on rodents in a year. We observed a negative effect of rodent density on tick intensity, while temperature influenced positively both larvae and nymph intensity. Overall larval density was higher in the years and trapping grids where rodent density was higher, while for nymphs no such effect was observed. The best explanatory variable for nymph density was the larval density in the previous year, confirming the discrete nature of tick demography. This provides important information in terms of monitoring the risk to humans of acquiring pathogen-infected ticks.

Comparison between solar radiation models based on cloud information

Simple radiation estimation models using few input parameters are often used in the applications requiring rough estimations of solar horizontal radiation. Cloud cover information is widely available for multiple regional and national weather stations. Kasten and Czeplak (1980) as well as Lam and Li (1998) have proposed cloud-based models for the estimation of global and diffuse horizontal irradiation. Muneer and Gul (2000) have analyzed solar radiation estimation models based on meteorological data and modified the Kasten–Czeplak's models to allow for local coefficients to be used. In this study, the Lam–Li model has been modified to allow for local coefficients, and three new models, which are primarily based on modifications to the Kasten–Czeplak model, have been proposed. To compare the validity of the above models, statistical indicators have been presently developed for assessing the accuracy of estimation of both global and diffuse irradiation. The slope of the best-fit line and the coefficient of determination between I G, measured; and I G, calculated; and I D, measured; and I D, calculated;, the percentage error, mean bias error and root mean square error for both global and diffuse horizontal irradiation were calculated. In addition, the kurtosis and skewness of error histograms were also obtained. These parameters were used to obtain the statistical indicators for the models under validation. It was concluded that although the proposed models outperformed the original Kasten–Czeplak and Lam–Li models, they performed on a par with the simpler Kasten–Czeplak model with modified local coefficients.

Vibrio parahaemolyticusO3:K6 Epidemic Diarrhea, Chile, 2005

<i>Vibrio parahaemolyticus</i>O3:K6 Epidemic Diarrhea, Chile, 2005