Showing papers on "Weather station published in 2003"

Review of users' needs in operational fire danger estimation: The Oklahoma example

Abstract: This paper reviews users' needs in operational fire danger systems, that is, those systems which provide routine (e.g. daily) assessments of fire danger over broad geographical areas. We begin by discussing those elements comprising the fire environment: topography, fuels and weather. With respect to wildland fuels, we consider fuel models, live and dead fuels, and the role of remote sensing in this arena. Weather, both current and forecast, is seen to be crucial and the one element common to all operational systems. We then consider fire models, which utilize the environmental input and produce fire danger output related to either fire potential or behaviour. We end the review with a look at fire detection systems and the need for near-real-time accessibility of fire danger information. The paper then concludes with a specific example of an operational fire danger system from the state of Oklahoma (USA). Use of a mesoscale automated weather station network, the Oklahoma Mesonet, allows for a suite of nea...

Weather, ice, and snow conditions at Deception Island, Antarctica: long time-series photographic monitoring

Abstract: An autonomous weather station (Terrestrial station) was developed and deployed at Deception Island, Antarctica, an active volcanic island, to monitor the daily weather conditions as part of a long time-series marine ecosystem study of the sunken caldera, Port Foster. The principal components of the Terrestrial station were a time-lapse digital camera, ultrasonic wind sensor, controller, wind turbine generators, and batteries. The Terrestrial station was installed on a ridge at 200 m altitude overlooking Port Foster and the surrounding terrain from 9 March 1999 until 20 November 2000. Ice cover on Port Foster began in late July 2000 and was intermittently visible through early November. Daily averaged wind speeds ranged from 0.2 m s−1 in October to 47.4 m s−1 in June, with the prevailing direction from the southwest and less frequently from the northeast. Daily averaged air temperatures fluctuated from a low of −12.6°C in August 2000 to 2.7°C in March 1999. Weather conditions measured at Deception Island were generally consistent with those concurrently measured in the region of the South Shetland Islands. Ice cover in Port Foster was less pronounced in 1999 and 2000 than reported in previous years, suggesting regional warming.

The Georgia Automated Environmental Monitoring Network: Ten Years of Weather Information for Water Resources Management

Abstract: With the continuing drought that started in 1998, access to accurate rainfall information for remote locations in Georgia remains very important. One of the main goals of the Automated Environmental Monitoring Network (AMEN) is the collection of weather data across the state of Georgia. The AEMN was established in 1991 with the installation of four automated weather stations in Griffin, Tifton, Watkinsville and Midville. A major milestone was reached at the end of 2001 with the completion of 10 years of continuous records for these first stations. A second milestone was reached in September 2002 with the installation of the 50th weather station in Homerville in south Georgia. The weather data are disseminated in near real-time mode via the world wide web (www.Georgiaweather.net). The main goal of this paper is to present an overview of the network and examples of the application of this information for water resources management.

Development of a Livestock Safety Monitor for Cattle

Abstract: Summer heat can result in stressful conditions for Bos taurus feeder cattle, and in extreme instances these conditions can be fatal. A study was conducted during the summer of 2001 at RLHUSMARC to determine physiological responses of cattle under shade or no-shade conditions. The study involved eight steers assigned to individual pens with four pens fitted with shade structures and the remainder had no shade available. Respiration rate (RR), feed intake, and body temperature were measured as response variables to the shade treatments. Environmental conditions were monitored for the experimental period. The resulting RR data demonstrated a 25°C threshold for the treatment of shade/no-shade. A linear regression was developed for RR that included effects of temperature, humidity, air speed, and solar radiation. Thresholds were developed from that linear relationship to relate RR to THI (temperaturehumidity index) to estimate thermal status of livestock. The equations and the corresponding thresholds have been implemented in a monitoring device for use at livestock production facilities. The monitoring device, referred to as a Livestock Safety Monitor (LSM), consists of a commercial weather station (Vantage PRO by Davis Instruments, Hayward, CA) coupled to a microcomputer (TFX-11, by Onset Computer, Pocasset, MA). The weather station collects current weather data including temperature, humidity, wind speed, and solar radiation. The weather information is transferred to the micro-computer where values alert the operator of current conditions that include: 1) normal, 2) alert, 3) danger, and 4) emergency. This report will summarize operating experience using the LSM.

Weather station on a chip

Abstract: This paper proposes a concept about Weather Station On a Chip (WSOC). WSOC is defined as a system which includes sensors, a microcontroller, interface circuits for linking the microcontroller and sensors, and ASIC for power management. WSOC is used to monitor environmental weather parameters including temperature, humidity, barometric pressure, anemometer, and wind direction. Research and development of WSOC in our laboratory is briefly introduced.

Mapping Pre‐Fire Forest Conditions with NOAA‐AVHRR Images in Northern Boreal Forests

Abstract: In Canada, fire danger maps, predicted by the Canadian Fire Weather Index system, produced from weather station records, are limited spatially. Thus, remote sensing as a potential fire danger mapping tool was investigated. NOAA‐AVHRR images were used to map pre‐fire conditions over Canadian northern boreal forests. Daily mean surface and air temperature, normalized difference vegetation index and fire weather index values were analysed for burned and unburned areas. Prior to fire ignitions, it was hypothesized that mean surface temperature will: (i) increase with approaching ignition dates; (ii) be greater in burned than unburned areas; and (iii) be positively related to the fire weather index. Despite cloud contaminated images, a positive trend in mean burned area surface temperature was observed as ignition dates approached. This was not the case for mean air temperature. Similar trends were observed over unburned areas. A good relationship was found between surface temperature and the fire wea...

Chemical application and flight guidance control system and method

Abstract: A chemical distribution such as a mosquito control guidance system is operable for controlling the distribution of airborne product via an aircraft passing over a target field. The system includes a weather station carried by a helium balloon positioned at aircraft altitude which communicates with a ground weather station positioned at or near the target field for transmitting weather data in real time to a central communications station and the aircraft for providing guidance in accurately, safely and effectively distributing chemicals onto the target field.

Wind data for natural ventilation design in Hong Kong

Abstract: The paper discusses what kind of wind data are required for natural ventilation design for residential buildings and the results of a statistical analysis on the wind data records measured from 1984 to 1998 at a weather station within an urban area in Hong Kong In addition to the general patterns of wind speeds and directions, the study analysed the durations of stagnant periods It was found that most stagnant periods lasted for only 1–2 h; the total duration of stagnant periods accounted only for 014% of the time in the 15 years; the durations between two consecutive stagnant periods were predominantly over 24 h; and the most frequent time of occurrence of stagnant periods was before dawn in the winter months

Estimation of Potential Evapotranspiration from NOAA-AVHRR Satellite

Abstract: Potential evapotranspiration is widely used by farmers and hydrologists as a measure for determining actual evapotranspiration for irrigation scheduling, drought monitoring, hydrologic modeling and regional water balance studies. In the present study a comprehensive methodology has been developed for estimating reference crop (Grass) ET using Penman–Monteith combination equation from Advanced Very High Resolution Radiometer (AVHRR) for Texas at a spatial resolution of 1 km2. As part of this study 282 NOAA–14, AVHRR satellite images acquired between May 1999 to August 2000 and weather data measured at several weather stations across Texas were analyzed. Regression relationships were developed to calculate the weather parameters maximum air temperature and vapor pressure deficit from satellite’s infrared surface temperature. The regression relationships were validated using independent weather station observations. The root mean square error (RMSE) of daily ET calculated using these weather parameter estimates was within .1.1 mm day–1 when compared to ET derived from ground–based weather station measurements of climatic variables.

Validating the use of an atmometer as an irrigation management tool

Abstract: Evapotranspiration (ET) data obtained using commercially available atmometers with three types of fabric covers were compared to evapotranspiration estimated using weather data from an automated weather station. Atmometers were established in a replicated random design within the compound of an automated weather station. Three years average data show that evaporation from an atmometer with canvas 54 cover is within 5 percent of evapotranspiration calculated from weather data using modified Penman equation for alfalfa as a reference crop. The ET gage with canvas 54 cover gave under-estimation. Similarly, three years average from atmometer with canvas 30 cover was within 4 percent of ETo estimated for grass as a reference crop. The ETgage with canvas 30 cover however gave an overestimation. Gore-Tex® covered atmometer established at 1m fixed height overestimated ETr more than 15 percent, some year as high as 30 percent. Individual ETgage units showed some variation, which may be attributed to manufacturing or data reading errors. Further analysis of data is waiting to establish the significance of the variation.

Evaluating the reliability of point estimates of wetland reference evaporation

Abstract: . The Penman-Monteith formulation of evaporation has been criticised for its reliance upon point estimates so that areal estimates of wetland evaporation based upon single weather stations may be misleading. Typically, wetlands comprise a complex mosaic of land cover types from each of which evaporative rates may differ. The need to account for wetland patches when monitoring hydrological fluxes has been noted. This paper presents work carried out over a wet grassland in Southern England. The significance of fetch on actual evaporation was examined using the approach adopted by Gash (1986) based upon surface roughness to estimate the fraction of evaporation sensed from a specified distance upwind of the monitoring station. This theoretical analysis (assuming near-neutral conditions) reveals that the fraction of evaporation contributed by the surrounding area increases steadily to a value of 77% at a distance of 224 m and thereafter declines rapidly. Thus, point climate observations may not reflect surface conditions at greater distances. This result was tested through the deployment of four weather stations on the wetland. The resultant data suggested that homogeneous conditions prevailed so that the central weather station provided reliable areal estimates of reference evaporation during the observation period March–April 1999. This may be a result of not accounting for high wind speeds and roughness found in wetlands that lead to widespread atmospheric mixing. It should be noted this analysis was based upon data collected during the period March-April when wind direction was constant (westerly) and the land surface was moist. There could be more variation at other times of the year that would lead to greater heterogeneity in actual evaporation. Keywords: evaporation, Penman-Monteith, automatic weather station, fetch, wetland

Variability at Ocean Weather Station M in the Norwegian Sea

Abstract: Time series of temperature and salinity from Ocean Weather Station M are analysed for periodic cycles of interannual to decadal scale. Time evolutions of the spectra show various spectral peaks at all depths, but none of these cycles show persistence throughout the 50 years. In addition isopycnal surfaces and temperature and salinity values on these surfaces, are estimated and studied in terms of the relative influence of horizontal advection and vertical movement on the observed changes of water properties.

Weather Station Siting

Abstract: Temperature is the driving factor in most phenological models, and proper measurement is critical for both development and use of the models In addition to selecting accurate sensors, they should be mounted at an appropriate height and properly shielded from short-wave radiation (double shielding is best) Choosing small sensors that respond rapidly, protecting electronic leads, and ventilation (in areas with little wind) can improve accuracy of the temperature measurements Data should be collected at a height that is typical of other weather stations in the area where the model will be used Generally, agricultural weather stations collect temperature data at 15 to 20 m height and weather services tend to measure at 100 m height For phenological models of natural vegetation, it is best to site the weather station in a similar environment without irrigation However, when the models are used for irrigated crops, the stations should be sited over an irrigated grass surface to avoid temperature fluctuations due to intermittent rainfall at the measurement site Strong temperature gradients can occur near large water bodies (eg, the ocean or large lakes) and in hilly or mountainous regions where sunlight is blocked during part of the day In such regions, more weather stations are needed to better characterize microclimate differences However, even when the temperature data are accurately determined, inaccuracies in model predictions can occur because it is plant temperature rather than air temperature that truly drives the phenological development Although little or no literature on the topic exists, perhaps using vapor pressure deficits to estimate plant from air temperature could improve models and make them more universally applicable

Using Artificial Neural Networks to Predict Local Disease Risk Indicators with Multi-Scale Weather, Land and Crop Data

Abstract: The risk of fungal and bacterial crop disease can be predicted using risk models with specific environmental parameters such as temperature, relative humidity, solar radiation, wind speed, and leaf wetness duration (LWD). LWD has long been recognized as key in the management of crop disease. Air temperature and wetness influence the majority of fungal plant diseases. Wetness also impacts insect populations, as well as pollution deposits. Many parameters are well understood, readily defined, and easily measured. Unfortunately, LWD is a complex phenomenon, due to its spatial and temporal variability within a crop canopy. The inconvenience and uncertainty associated with monitoring LWD at the local leaf scale and the complexity of upscaling to the crop level prevent existing disease risk models from being used with reliability. In spite of their imprecision, LW projections are already included in a number of online weather products. One non- parametric statistical approach receiving scant attention for the modeling of LWD is that of artificial neural networks (ANNs). In this work, two previously untried ANNs estimate this key environmental variable at local crop scales, using local and regional weather station data and site-specific sensing data. The first ANN combines two statistical methods to accomplish this spatial mapping (a K-nearest means classifier and a Bayesian classifier), while the recurrent nature of the second ANN provides a means of leveraging the temporal property of the data. The ultimate goal is to embed the ANN into a highly-portable tool, designed to predict leaf wetness duration as an SOC (system on a chip) in conjunction with local weather stations, and as input to real-time decision support systems.

Floating weather station

Abstract: The present invention relates to a floating weather station, particularly a floating weather station which is able to evaluate the meteorological quantities in shallow basins. More particularly, the present invention relates to a floating weather station (1) for the measurement of meteorological variables in a water basin, which is able to float in a few centimeters of water, comprising a supporting structure (100), floating means (3a, 3b) and meteorological surveying means (A1-A5) connected to said supporting structure, characterized in that said supporting structure comprises a base consisting of at least three legs (2) which are placed radially and symetrically, and a shaft (4) extending upwards from the conjunction point of the legs (2).

Data Collection and Analysis of Moisture and Soil Strength Information for Validation of New State-of-the-Ground Models (CD-ROM)

Abstract: : ELECTRONIC FILE CHARACTERISTICS: 11 files; Adobe Acrobat (PDF) and MS Excel (XLS) PHYSICAL DESCRIPTION: 1 computer laser optical disc (CD-ROM); 4 3/4 in; 182 MB SYSTEMS DETAIL NOTE: IBM-clone PC-compatible ABSTRACT: This report provides data from a weather station near Mound, LA, on a fluvial plain at a site entitled Mud Lake Mud Lake is located across the Mississippi River, 10 miles from Vicksburg, MS The weather station data were collected over a 1-year period These data are reported real-time through telemetry to the US Army Engineer Research and Development Center (ERDC), Vicksburg Data collection teams were sent to the site intermittently to collect soil moisture, soil strength, and other related soils data for calibration with the weather station probes and support of input requirements to FASSST-C

Quantifying Temporal Variance in High-Latitude Air–Sea Interactions

Abstract: A novel way of quantifying the variance of a time series is presented. The method first involves filtering the time series using filters with different temporal characteristics, and then using a moving window to calculate the variances in each filtered time series. The use of a moving window allows the original temporal resolution to be retained, as well as allowing one to study how the variance changes with time. Air–sea interaction time series from Ocean Weather Station (OWS) Bravo in the Labrador Sea are analyzed as an example. High-pass, bandpass, and low-pass filters are used to isolate the diurnal signal, the storm/cyclone signature, and the weather regime transition signal, respectively. The variance during the winter months is found to be strongly influenced by weather systems in the bandpass and the low-pass frequency range. The variance during the summer months, on the other hand, is dominated by the shortwave radiation in the high-pass frequency range.

Variability at Ocean Weather Station M in the

Abstract: Time series of temperature and salinity from Ocean Weather Station M are analysed for periodic cycles of interannual to decadal scale. Time evolutions of the spectra show various spectral peaks at all depths, but none of these cycles show persistence throughout the 50 years. In addition isopycnal surfaces and temperature and salinity values on these surfaces, are estimated and studied in terms of the relative influence of horizontal advection and vertical movement on the observed changes of water properties.