scholarly journals Comparação de Modelos de Estimativa da Radiação de Onda Curta a partir de dados MODIS/Terra (Comparision Models for estimating the Shortwave Radiation from MODIS / Terra data)

2013 ◽  
Vol 6 (5) ◽  
pp. 1037 ◽  
Author(s):  
Francineide Amorim Santos ◽  
Bernardo Barbosa da Silva ◽  
Argemiro Lucena Araújo ◽  
Madson Tavares Silva ◽  
Alexandra Chaves Braga
Keyword(s):  
Relative Humidity ◽  
Key Words ◽  
Relative Error ◽  
Air Temperature ◽  
Cane Sugar ◽  
Dew Point ◽  
Shortwave Radiation ◽  
Weather Station ◽  
Error Percentage ◽  
Relative Humidity Data

O objetivo do presente estudo é analisar a precisão de diferentes metodologias na estimativa da radiação de onda curta incidente a partir de dados MODIS/TERRA em diferentes ecossistemas (cerrado e cana-de-açúcar). Foram utilizados três métodos que se convencionou denominar SEBAL (S), METRIC (M) e Bisht (B). Para aplicação do método SEBAL são necessários apenas dados de temperatura do ar e para o METRIC, de temperatura do ar e umidade relativa, dados que são facilmente obtidos em estações meteorológicas. A metodologia Bisht, porém, processou-se de forma totalmente autônoma, pois a temperatura do ar, assim como a temperatura do ponto do orvalho, foram obtidas de dados MODIS. O método que demonstrou maior precisão foi Bisht, com erro relativo percentual (ERP) de 3,94% no Cerrado e de 7,6% na cana-de-açúcar, seguido do METRIC e do SEBAL. No entanto, o METRIC foi o que proporcionou melhor correlação entre observações versus estimativas para a área do cerrado (R2 = 0,897) contra R2 = 0,847 do Bisht. Já para a área de cana-de-açúcar, o Bisht apresentou melhor correlação (R2 = 0,772), enquanto a correlação obtida com o METRIC foi de 0,744. A B S T R A C T The objective of this study is to analyze the accuracy of different methodologies to estimate the incident shortwave radiation from MODIS / TERRA in different ecosystems (savanna and cane sugar). Were used three methods that been conventionally called SEBAL (S), METRIC (M) and Bisht (B). To apply the method SEBAL requires only data of air temperature and for the METRIC, air temperature and relative humidity, data that are easily obtained from weather station. The methodology Bisht, however, was processed in a totally autonomous because the air temperature as well as the temperature of the dew point, were obtained from MODIS data. The method Bisht demonstrated greater accuracy, with relative error percentage (REP) of 3.94% in the Cerrado and 7.6% in cane sugar, followed by METRIC and SEBAL. However, METRIC was what provided the best correlation between observations versus estimates for the area of cerrado (R2 = 0.897) against R2 = 0.847 the Bisht. Already for the area of cane sugar, Bisht showed better correlation (R2 = 0.772), whereas the correlation with the METRIC obtained was 0.744. Key-Words: ecosystem, methodologies, accuracy, autonomous

scholarly journals Solar Radiation, Air Temperature, Relative Humidity, and Dew Point Study: Damak, Jhapa, Nepal

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Arun Kumar Shrestha ◽  
Arati Thapa ◽  
Hima Gautam
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Air Temperature ◽  
Gaussian Function ◽  
Great Influence ◽  
Dew Point ◽  
Upward Trend ◽  
Summer Maximum ◽  
Online Calculator ◽  
Climatic Phenomenon

Monitoring and prediction of the climatic phenomenon are of keen interest in recent years because it has great influence in the lives of people and their environments. This paper is aimed at reporting the variation of daily and monthly solar radiation, air temperature, relative humidity (RH), and dew point over the year of 2013 based on the data obtained from the weather station situated in Damak, Nepal. The result shows that on a clear day, the variation of solar radiation and RH follows the Gaussian function in which the first one has an upward trend and the second one has a downward trend. However, the change in air temperature satisfies the sine function. The dew point temperature shows somewhat complex behavior. Monthly variation of solar radiation, air temperature, and dew point shows a similar pattern, lower at winter and higher in summer. Maximum solar radiation (331 Wm-2) was observed in May and minimum (170 Wm-2) in December. Air temperature and dew point had the highest value from June to September nearly at 29°C and 25°C, respectively. The lowest value of the relative humidity (55.4%) in April indicates the driest month of the year. Dew point was also calculated from the actual readings of air temperature and relative humidity using the online calculator, and the calculated value showed the exact linear relationship with the observed value. The diurnal and nocturnal temperature of each month showed that temperature difference was relatively lower (less than 10°C) at summer rather than in winter.

scholarly journals Human Thermal Comfort Situation in the Goller (Lakes) District of Turkey

2016 ◽  
pp. 137-144
Author(s):  
Yuksel Guclu
Keyword(s):  
Relative Humidity ◽  
Thermal Comfort ◽  
Human Health ◽  
Air Temperature ◽  
Mediterranean Region ◽  
Human Thermal Comfort ◽  
Almost All ◽  
Relative Humidity Data ◽  
Recreation Activities

Abstract In this study, the determination of the human thermal comfort situation in the Goller District (in the Mediterranean Region) of Turkey has been aimed. In the direction of the aim, the air temperature and relative humidity data of total 11 meteorology stations have been examined according to The Thermo-hygrometric Index (THI) and the New Summer Simmer Index (SSI). According to this, it has been determined that the thermal comfort conditions are not appropriate in the period of October-May on average monthly. The months of June and September are the most appropriate to almost all kinds of tourism and recreation activities in the outdoor in terms of thermal comfort. When THI and SSI indices’ values are evaluated together, the periods between 5th – 25th June and 29th August-16th September are the most appropriate periods in the study area on average in terms of the thermal comfort for the tourism and recreation activities in the outdoor. Keywords: Thermal comfort, human health, The Thermo-Hygrometric Index, The Summer Simmer Index, Goller District, Turkey.

scholarly journals 31 years of hourly spatially distributed air temperature, humidity, and precipitation amount and phase from Reynolds Critical Zone Observatory

2018 ◽  
Vol 10 (2) ◽  
pp. 1197-1205 ◽  
Author(s):  
Patrick R. Kormos ◽  
Danny G. Marks ◽  
Mark S. Seyfried ◽  
Scott C. Havens ◽  
Andrew Hedrick ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Precipitation Amount ◽  
Critical Zone ◽  
Dew Point ◽  
Elevation Gradients ◽  
Wide Range ◽  
Critical Zone Observatory ◽  
Reynolds Creek ◽  
Spatially Distributed

Abstract. Thirty-one years of spatially distributed air temperature, relative humidity, dew point temperature, precipitation amount, and precipitation phase data are presented for the Reynolds Creek Experimental Watershed, which is part of the Critical Zone Observatory network. The air temperature, relative humidity, and precipitation amount data are spatially distributed over a 10 m lidar-derived digital elevation model at an hourly time step using a detrended kriging algorithm. This 21 TB dataset covers a wide range of weather extremes in a mesoscale basin (238 km2) that encompasses the rain–snow transition zone and should find widespread application in earth science modeling communities. Spatial data allow for a more holistic analysis of basin means and elevation gradients, compared to weather station data measured at specific locations. Files are stored in the NetCDF file format, which allows for easy spatiotemporal averaging and/or subsetting. Data are made publicly available through an OPeNDAP-enabled THREDDS server hosted by Boise State University Libraries in support of the Reynolds Creek Critical Zone Observatory (https://doi.org/10.18122/B2B59V).

scholarly journals Study of winter fog over Indian subcontinent : Climatological perspectives

MAUSAM ◽  
2021 ◽  
Vol 65 (1) ◽  
pp. 19-28
Author(s):  
G.K. SAWAISARJE ◽  
P Khare ◽  
C.Y. SHIRKE ◽  
S. DEEPAKUMAR ◽  
N.M. NARKHEDE
Keyword(s):  
Relative Humidity ◽  
Spatial Variability ◽  
Air Temperature ◽  
West Bengal ◽  
Indian Subcontinent ◽  
Winter Season ◽  
Dew Point ◽  
North India ◽  
Gangetic Plains ◽  
Long Period

Fog is localized phenomenon where horizontal visibility is reduced to less than 1000 m due to suspension of very small water droplets in the air. In fact Fog is cloud at surface level. This phenomenon matters to us in our daily activities due to its effect on life, public health, road safety, and economic prosperity.  Its knowledge is essential to meet critical societal needs. In India, radiation and advection fog are most common which occur mostly over north India in winter. This study presents results of spatial variability of average number of days having visibility less than 1000 m at 0300 UTC during winter season over Indian subcontinent (0° N-35° N and 60° E-100° E) using synoptic hour daily surface data. Analysis of Fog events based on half hourly METAR observations for winter months             (December 2010-February 2011) at selected ICAO stations of India is also presented.    The monthly spatial variability of average number of days with fog having visibility less than 1000 m indicates presence of fog over Indo-Gangetic plains on an average of 7 to 10 days during December and more than 8 days during January. South Gangetic West Bengal is susceptible to fog during February. Seasonal variation of fog shows that there is prominence of fog over Indo-Gangetic plains on an average of more than 6.5 days. Significant incidences of foggy days occur over South Interior Karnataka and Coastal Karnataka has incidence of foggy days on an average of 6.5 days. North India is susceptible to dense fog on average of 2.5 days during the season while Gangetic West Bengal, West Rajasthan and adjoining parts of east Rajasthan and East Uttar Pradesh have occurrence of fog on an average of 3.5 days. Thick fog occurs on an average of 3 days over northern India during the winter season. Analysis of time series of air temperature, dew point temperature, dew point depression, visibility, zonal and meridional components of wind and its magnitude at selected ICAO stations indicate that visibility reduces to below 1000 m while light winds are southeasterly at Ahmedabad, northerly to northwesterly at Amritsar, northerly to northeasterly at New Delhi, westerly to southwesterly at Kolkata, Guwahati and dew point depression is below 3 °C during such conditions. Long period 1971-2010 analysis of visibility conditions less than 1000 m over Indian subcontinent shows Indo-Gangetic plains region to have average wind speed to be 0.6 m/s, air temperature in the range 9 °C to 15 °C during December-February at 0300 UTC. Long period 1971- 2010 analysis of relative humidity shows Indo-Genetic plains region to have relative humidity in the range 72% to 84% at 0300 UTC during December-February.

scholarly journals Development and validation of a data logger for thermal characterization in laying hen facilities

2019 ◽  
Vol 23 (10) ◽  
pp. 787-793 ◽  
Author(s):  
Letícia C. da S. R. Freitas ◽  
Ilda de F. F. Tinôco ◽  
Richard S. Gates ◽  
Matteo Barbari ◽  
Márcia G. L. Cândido ◽  
...  
Keyword(s):  
Experimental Data ◽  
Relative Humidity ◽  
Data Storage ◽  
Relative Error ◽  
Air Temperature ◽  
Low Cost ◽  
Linear Regression Analysis ◽  
Field Performance ◽  
Data Logger ◽  
Calibration Equations

ABSTRACT The environmental monitoring in animal facilities that includes collected data storage in a robust, practical and feasible way is a constant challenge. The aim of this study was to develop a reliable data logger for monitoring the air temperature and air relative humidity of aviaries and to assess the adequacy of the design using commercially available reference standard instruments. The experimental data logger was installed together with a commercial data logger, a mercury thermometer and a calibrated Vaisala HMP110 air relative humidity probe in a meteorological shelter. Linear regression analysis was performed with the collected air temperature and air relative humidity to develop calibration equations. The Nash-Sutcliffe Index and the relative error were calculated to validate the experimental data logger. The air temperature and the air relative humidity calibration equations presented Nash-Sutcliffe of 0.993 and -0.281 for the commercial data logger, and 0.913 and 0.932 for the experimental data. The mean relative error of the air temperature readings was 3 and 1% and for air relative humidity 5 and 20%, for the experimental and commercial logger, respectively. The experimental data logger reliably stored all collected data without error to the micro-SD card. The experimental data logger can be considered low-cost and sufficiently accurate for monitoring air temperature and air relative humidity in aviaries, presenting field performance very close to the commercial data logger for air temperature measurement, and better performance than the commercial data logger for the measurement of air relative humidity.

scholarly journals Estimate of The Dynamical Change of Air TemperAture, Relative Humidity and Dew Point TemperaTure for Some Selected Station in Iraq

2021 ◽  
Vol 910 (1) ◽  
pp. 012010
Author(s):  
Wedyan G. Nassif ◽  
Sundus H. Jaber ◽  
Salwa S. Naif ◽  
Osama T. Al-Taai
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Meteorological Factors ◽  
Geographical Area ◽  
Dew Point ◽  
Point Temperature ◽  
Dew Point Temperature ◽  
Relative Value ◽  
Low Humidity ◽  
Dynamical Change

Abstract Relative humidity can be inferred from the dew point values. When the air temperature and dew point temperatures are very close, the air has high relative humidity. The converse is true when there is a large difference between the air temperature and the dew point temperature, indicating the presence of low humidity air. To understand the expected changes in the climatic elements in the atmosphere, changes in temperature behavior, dew point, and relative humidity have been studied This study used data obtained from the European Center (ECMWF), which includes monthly and annual mean temperatures, dew, and relative humidity during the period (1988-2018) for selected stations in Iraq. The highest values of temperature and dew were recorded in July and August, and they were accompanied by a decrease in relative humidity. The highest value of relative humidity was recorded in December and January, accompanied by a decrease in temperature and dew, as we note through the results that there is an inverse relationship between relative humidity, temperature, and dew point Relative humidity changes when the temperature rises or falls, and the relative humidity may be higher in the morning when the temperature drops. The lowest amount of relative humidity during the day is when the temperature rises, the highest temperature value was recorded on 21July 2017 (12:00 PM) for Basra Station, while the highest relative value is humidity in Basra Governorate. Mosul station on January 21, 2014 (12:00 AM), and the reason is due to meteorological factors and the nature of the geographical area.

scholarly journals ANÁLISE BIOCLIMÁTICA E INVESTIGAÇÃO DO CONFORTO TÉRMICO EM AMBIENTE EXTERNO NA REGIÃO CENTRAL DO RS

2019 ◽  
Vol 34 (3) ◽  
pp. 377-388
Author(s):  
Zanandra Boff Oliveira ◽  
Alberto Eduardo Knies
Keyword(s):  
Heat Stress ◽  
Thermal Stress ◽  
Relative Humidity ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Central Region ◽  
External Environment ◽  
Dew Point ◽  
Santa Maria ◽  
E Mail

ANÁLISE BIOCLIMÁTICA E INVESTIGAÇÃO DO CONFORTO TÉRMICO EM AMBIENTE EXTERNO NA REGIÃO CENTRAL DO RS   ZANANDRA BOFF DE OLIVEIRA1, ALBERTO EDUARDO KNIES2   Professora adjunta, Coordenadoria Acadêmica, Universidade Federal de Santa Maria Campus em Cachoeira do Sul, Rua Ernesto Barros, nº 1345, Bairro Santo Antônio, cep: 96506-322, Cachoeira do Sul – RS, Brasil. E-mail: [email protected] Professor adjunto, Universidade Estadual do Rio Grande do Sul Unidade em Cachoeira do Sul, Rua Sete de Setembro, nº 1040, Bairro Santo Centro, cep: 96508-010, Cachoeira do Sul – RS, Brasil. E-mail: [email protected]   RESUMO: o presente trabalho teve como objetivo realizar a análise bioclimática e a investigação do conforto térmico em ambiente externo na região central do RS. Para isso, utilizaram-se os seguintes índices de conforto térmico: índice de temperatura e umidade (ITU) e índice de desconforto humano (IDH). Os dados meteorológicos de temperatura do ar máxima (Tmax) e mínima (Tmin) e umidade relativa do ar máxima (URmax) e mínima (URmin) foram obtidos de uma série de 10 anos (2005-2015) de dados de uma estação meteorológica automática instalada em Santa Maria (RS). A temperatura do ponto de orvalho foi estimada a partir da Tmax e Tmin e da URmin e URmax, respectivamente. Os índices de conforto térmico foram calculados a partir das médias diárias do período (10 anos) para a situação de máximo desconforto térmico que ocorre nos extremos: 1) quando a temperatura do ar é máxima e a umidade relativa do ar é mínima - denominados de ITUmax e IDHmax; 2) quando a temperatura do ar é mínima e a umidade relativa do ar é máxima - denominados de ITUmin e IDHmin. Em função da elevada amplitude térmica mensal (>10ºC<18ºC) e diária (>5ºC<10ºC), os valores dos índices de conforto térmico (ITU e IDH) variam entre 51,5 e 80,4, indicando que a situação de conforto térmico do ambiente externo na região central do RS vai nos extremos de estresse térmico devido ao frio (julho) a estresse térmico devido ao calor (janeiro). No período de maio a outubro o conforto térmico ocorre na Tmax, mas na Tmin a situação é de desconforto a estresse por frio. No período de novembro a fevereiro, o conforto térmico ocorre na Tmin, mas na Tmax ocorre desconforto a estresse térmico por calor. Nos meses de março e abril, o desconforto ocorre tanto por frio quanto por calor. Dessa forma, para a produção zootécnica e para o conforto térmico humano na região central do RS, são necessárias práticas de acondicionamento ambiental que visem a minimização do estresse térmico.   Palavra-chaves: índices de conforto térmico; análise bioclimática; amplitude térmica.   BIOCLIMATIC ANALYSIS AND RESEARCH OF THERMAL COMFORT IN EXTERNAL ENVIRONMENT IN THE CENTRAL REGION OF RS   ABSTRACT: The present work had the aim of performing the bioclimatic analysis and the investigation of the thermal comfort in an external environment in the Central region of RS. For this, the following thermal comfort indexes were used: temperature and humidity index (THI) and human discomfort index (HDI). The maximum air temperature (Tmax) and minimum air temperature (Tmin) and maximum relative humidity (URmax) and minimum air humidity (URmin) were obtained from a series of 10 years (2005 to 2015) of data of an automatic meteorological station installed in Santa Maria - RS. The temperature of the dew point was estimated from the Tmax and Tmin and the URmin and URmax, respectively. The thermal comfort indexes were calculated from the daily average of the period (10 years) for the situation of maximum thermal discomfort that occurs in the extremes: (i) when the air temperature is maximum and the relative humidity of the air is minimal - denominated of THImax and HDImax; (ii) when the air temperature is minimal and the relative humidity of the air is maximum - denominated THImin and HDImin. In function to the high temperature amplitude, monthly (> 10ºC <18ºC) and daily (> 5ºC <10ºC), the values of thermal comfort indexes (THI and HDI) vary from 51.5 to 80.4, indicating that thermal comfort of the external environment in the Central region of RS goes in the extremes of thermal stress due to the cold (July) to the heat stress due to the heat (January). In the period from May to October the thermal comfort occurs in Tmax, but in Tmin the situation is of cold stress discomfort. In the period from November to February, thermal comfort occurs in Tmin, but in Tmax, heat stress discomfort occurs. In the months of March and April the discomfort occurs as much by cold as by heat. Thus, for a zootechnical production and human thermal comfort in the central region of RS, it is necessary to practice environmental conditioning to minimize thermal stress.   Keywords: thermal comfort index; bioclimatic analysis; thermal amplitude.  

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