scholarly journals Performance of different methods for reference evapotranspiration estimation in Jaíba, Brazil

2018 ◽  
Vol 22 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Gustavo H. da Silva ◽  
Santos H. B. Dias ◽  
Lucas B. Ferreira ◽  
Jannaylton É. O. Santos ◽  
Fernando F. da Cunha
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Standard Method ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Air Humidity ◽  
Method Performance ◽  
Relative Air Humidity ◽  
Evapotranspiration Estimation ◽  
Missing Variables

ABSTRACT FAO Penman-Monteith (FO-PM) is considered the standard method for the estimation of reference evapotranspiration (ET0) but requires various meteorological data, which are often not available. The objective of this work was to evaluate the performance of the FAO-PM method with limited meteorological data and other methods as alternatives to estimate ET0 in Jaíba-MG. The study used daily meteorological data from 2007 to 2016 of the National Institute of Meteorology’s station. Daily ET0 values were randomized, and 70% of these were used to determine the calibration parameters of the ET0 for the equations of each method under study. The remaining data were used to test the calibration against the standard method. Performance evaluation was based on Willmott’s index of agreement, confidence coefficient and root-mean-square error. When one meteorological variable was missing, either solar radiation, relative air humidity or wind speed, or in the simultaneous absence of wind speed and relative air humidity, the FAO-PM method showed the best performances and, therefore, was recommended for Jaíba. The FAO-PM method with two missing variables, one of them being solar radiation, showed intermediate performance. Methods that used only air temperature data are not recommended for the region.

scholarly journals Comparative Study of Evapotranspiration Variation and its Relationship with other Climatic Parameters in Asaba and Uyo

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Okwunna M Umego ◽  
Temitayo A Ewemoje ◽  
Oluwaseun A Ilesanmi
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Small Variation ◽  
Climatic Variables ◽  
Maximum Temperature ◽  
Climatic Parameters ◽  
Sunshine Hours

This study was carried out to assess the variations of Reference Evapotranspiration (ETO also denoted with RET) calculated using FAO-56 Penman Monteith model of two locations Asaba and Uyo and evaluate its relationships with the variations of other climatic parameters. Meteorological data of forty one years (1975-2015) and thirty five years (1981-2015) period for Asaba and Uyo, respectively gotten from Nigeria Meteorological Agency, Abuja were used. It was observed that the variations of Evapotranspiration (ET) in both locations were in line with two seasons (rainy and dry) normally experienced in Nigeria having its highest value in March (4.8 mm/day) for Asaba and for Uyo in February (4.5 mm/day); and its lowest value in August (3.1 mm/day) for Asaba and in July (2.9 mm/day) for Uyo. ET variation when compared with other climatic variables in both locations was observed to have the same trend with maximum temperature, solar radiation and sunshine hours. It also has the same variation with minimum temperature though with slight deviation. It was observed that ET variation is inversely proportional to the variation relative humidity. Wind speed displayed relatively small variation in its trend over the study period and is not in line with the variations of ET.Keywords— Evapotranspiration, Climatic Variables, FAO Penman-Monteith Model, Variations

scholarly journals Hourly reference evapotranspiration by Moretti-Jerszurki-Silva method using data from alternative station

2021 ◽  
Vol 25 (8) ◽  
pp. 505-513
Author(s):  
Jorge L. M. de Souza ◽  
Sísara R. de Oliveira ◽  
Stefanie L. K. Rosa ◽  
Daniela Jerszurki
Keyword(s):  
Air Temperature ◽  
Reference Evapotranspiration ◽  
Climate Variables ◽  
Air Humidity ◽  
Climate Type ◽  
Financial Conditions ◽  
Satisfactory Performance ◽  
Relative Air Humidity ◽  
Using Data ◽  
Evapotranspiration Estimation

ABSTRACT Reliable measures of climate variables and the availability of alternative and safe methods are fundamental in estimating reference evapotranspiration (ETo) under unfavorable technical and financial conditions. The objective of this study was to evaluate the performance of the reference evapotranspiration estimation, in hourly periodicity, using the Moretti-Jerszurki-Silva models (EToMJS(ψair); EToMJS(ψair;Ra)), which considers air temperature (T) and relative air humidity (RH) data measured in an alternative station. The calibration and validation of the alternative station measurements were performed using data from automatic meteorological stations in Curitiba in Paraná (climate type Cfb) and Santa Rita de Cássia in Bahia (climate type Aw), Brazil. The use of the alternative station for hourly measurements of air temperature and relative air humidity in the analyzed climate types and locations were promising. The Moretti-Jerszurki-Silva models were robust in the analyzed locations, indicating satisfactory performance for the hourly periodicity. The Moretti-Jerszurki-Silva method that uses atmospheric water potential and solar radiation (EToMJS(ψair;Ra)) provided better adjustments and estimates of the hourly reference evapotranspiration, as opposed to the standard Penman-Monteith model.

scholarly journals Analysis of the NASA-POWER system for estimating reference evapotranspiration in the Comarca Lagunera, Mexico

2021 ◽  
Vol 13 (2) ◽  
pp. 201-226
Author(s):  
Sergio Iván Jiménez-Jiménez ◽  
◽  
Waldo Ojeda-Bustamante ◽  
Marco Antonio Inzunza-Ibarra ◽  
Mariana de Jesús Marcial-Pablo ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Reanalysis Data ◽  
Measured Data ◽  
System Data ◽  
Data Source

Introduction: The FAO-56 Penman-Monteith (PM) is one of the most solid and commonly used methods for estimating reference evapotranspiration (ETo); however, it requires meteorological data that are not always available, so an alternative is the use of reanalysis data. Objective: To estimate the error that the NASA-POWER (NP) system data can generate in the ETo of the Comarca Lagunera, Mexico. Methodology: Daily and decadal average ETo were estimated in five different ways. In each case, a different method was used to estimate ETo (FAO-56 PM or Hargreaves and Samani [HS]) and a different meteorological data source (measured, NP data or combination of both). Results: NP data can be used to provide temperature, solar radiation and relative humidity variables, but not wind speed. The NP data overestimate the measured ETo, an RMSE of 1.15 and 0.89 mm∙d-1 was found for daily and decadal periods, respectively. Limitations of the study: A grid error analysis could not be carried out because the number of stations is limited. Originality: The use of reanalysis data to estimate ETo has not been analyzed locally. Conclusion: When measured data are not available, NP data and the HS equation can be used. When using the FAO-56 PM method and NP data, the in situ wind speed must be available.

scholarly journals Seasonal and Diurnal Variation of Air/Water Exchange of Gaseous Mercury in a Southern Reservoir Lake (Cane Creek Lake, Tennessee, USA)

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2102
Author(s):  
William C. Crocker ◽  
Hong Zhang
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Water Exchange ◽  
Meteorological Data ◽  
Global Solar Radiation ◽  
Primary Control ◽  
Seasonal Trends ◽  
Gaseous Mercury ◽  
Air Temperatures ◽  
Emission Fluxes

A year-long field study of mercury (Hg) air/water exchange was conducted at a southern reservoir lake, Cane Creek Lake (Cookeville, TN, USA). The Hg air/water exchange fluxes and meteorological data including solar radiation (global solar radiation, Rg and ultraviolent radiation, UVA), water and air temperatures, relative humidity, and wind speed were collected to study the daily and seasonal trends of the Hg air/water exchange at the lake in relation to solar radiation and wind speed. The Hg exchange fluxes generally exhibited diurnal patterns with a rise in the morning, a peak around noontime, and a fall in the afternoon through the evening, closely following the change of solar radiation. There were cases that deviated from this general daily trend. The Hg emission fluxes were all below 3 ng m−2 h−1 with the daily mean fluxes < 2 ng m−2 h−1. The fluxes in the summer (mean: 1.2 ng m−2 h−1) were higher than in the fall (mean: 0.6 ng m−2 h−1) and winter (mean: 0.7 ng m−2 h−1). The daily and seasonal trends of the Hg air/water exchange fluxes are similar to the trends of the changes of the dissolved gaseous mercury (DGM) concentrations in the lake observed in our previous study. Solar radiation was found to exert a primary control over the Hg air/water exchange, while wind speed appeared to have a secondary effect on the Hg exchange. The two-thin-film model was used to calculate Hg emission fluxes from the Cane Creek Lake water.

scholarly journals The relationship between flowering phenology and pollen seasons of Alnus Miller

2012 ◽  
Vol 65 (2) ◽  
pp. 57-66 ◽  
Author(s):  
Agnieszka Dąbrowska ◽  
Bogusław Michał Kaszewski
Keyword(s):  
Wind Speed ◽  
Pollen Season ◽  
Meteorological Factors ◽  
Airborne Pollen ◽  
Gravimetric Method ◽  
Air Humidity ◽  
Inflorescence Development ◽  
Relative Air Humidity ◽  
Pollen Seasons ◽  
The Relationship

The dynamics of flowering and pollen release in anemophilous plants and the length of the particular phases depend largely on the geobotanical features of a region, its climate, meteorological factors, biological characteristics of vegetation, and abundance of pollen resources. The aim of the study was to determine the relationship between the flowering phases in eight <i>Alnus</i> taxa and the dynamics of occurrence and abundance of airborne pollen grains as well as the meteorological factors (maximum and minimum temperature, relative air humidity, maximum wind speed, and precipitation). The flowering phenophases and pollen seasons were studied in 2008–2011. Phenological observations of flowering were conducted in the Maria Curie-Skłodowska University Botanical Garden in Lublin and they involved the following taxa: <i>Alnus crispa</i> var. <i>mollis</i>, <i>A. glutinosa</i>, <i>A. incana</i>, <i>A. incana</i> ‘Aurea’, <i>A. incana</i> ‘Pendula’, <i>A. maximowiczii</i>, <i>A. rubra</i> and <i>A. subcordata</i>. Spearman’s r correlation coefficients were calculated in order to determine the relationship between the dynamics of inflorescence development and meteorological conditions. Aerobiological monitoring using the gravimetric method was employed in the determination of <i>Alnus</i> pollen content in the air. The annual phenological cycles in 2008-2011 varied distinctly in terms of the time of onset of successive flowering phases in the <i>Alnus</i> taxa studied, which depended largely on the taxonomic rank and meteorological factors. The following flowering sequence was revealed in the 2008-2011 growing seasons: <i>A. subcordata</i> (December or January), <i>A. incana</i> ‘Pendula’, <i>A. incana</i>, <i>A. maximowiczii</i>, <i>A. rubra</i>, <i>A. glutinosa</i>, <i>A. incana</i> ‘Aurea’ (February or March), and <i>A. crispa</i> var. <i>mollis</i> (April). The study demonstrated that the pollen of the taxa persisted in the air, on average, from mid-December to early May. The mean length of the flowering period, which coincided with various phases of the pollen season, was 17 days. The <i>Alnus</i> pollen season in 2008 started at the end of January and lasted until mid-March. In 2009, 2010, and 2011, the beginning of the pollen season was recorded in the first week of March and the end in the first week of April. The maximum concentration of airborne <i>Alnus</i> pollen was found at the full bloom stage of mainly <i>A. glutinosa</i> and <i>A. rubra</i>. Inflorescence development was most closely related to temperature and relative air humidity; there was a weaker relationship with wind speed and precipitation.

Environmental Assessment of the Impact of Meteorological Parameters on Man-Made Pollution by Carcinogenicly Dangerous Chemicals in the Voronezh Air Basin

2021 ◽  
Vol 25 (2) ◽  
pp. 60-65
Author(s):  
S.A. Kurolap ◽  
V.S. Petrosyan ◽  
O.V. Klepikov ◽  
V.V. Kulnev ◽  
D.Yu. Martynov
Keyword(s):  
Wind Speed ◽  
Air Temperature ◽  
Meteorological Parameters ◽  
Carcinogenic Risk ◽  
Meteorological Conditions ◽  
Air Humidity ◽  
Maximum Permissible Level ◽  
Relative Air Humidity ◽  
The Impact ◽  
The City

Based on the analysis of official statistics from the Voronezh Hydrometeorological Service, the patterns of the dynamics of pollutants (formaldehyde and soot) are investigated depending on the combination of various meteorological parameters — air temperature, wind speed, relative air humidity. A positive relationship has been established between the increase in atmospheric pollution with formaldehyde and air temperature. With increasing wind speed and relative humidity, the concentration of formaldehyde and soot in the atmosphere of the city, as a rule, decrease. The maximum permissible level of carcinogenic risk to public health has been established, causing concern. The obtained patterns can be used to predict the level of technogenic pollution of the city’s atmosphere, depending on meteorological conditions.

Bioclimatic characteristics of the regions of the Russian region from the standpoint of assessing the health risk of the population by effective temperature

2021 ◽  
pp. 38-46
Author(s):  
Rofail Salykhovich Rakhmanov ◽  
Elena Sergeevna Bogomolova ◽  
Denis Alekseevich Narutdinov
Keyword(s):  
Heat Stress ◽  
Wind Speed ◽  
Air Humidity ◽  
Climatic Zones ◽  
Dry Air ◽  
Wind Speeds ◽  
Monthly Average ◽  
Relative Air Humidity ◽  
Russian Region ◽  
Effective Temperatures

We calculated the effective temperatures based on 10-year data for temperatures (monthly average and minimum), wind speeds (monthly average and maximum) and relative air humidity in the climatic zones of the Krasnoyarsk Territory (subarctic No. 1) and temperate continental (Krasnoyarsk (object No. 2) and Minusinsk (3) We assessed the health risk.In winter, in the subarctic zone, the temperature is –23.3 ± 1.5 0 C (minimum –30.2 ± 2.1 0 C), in object No. 2 — –17.3 ± 1.6 0 C (–19.3 ± 1.0 0 С) and object No. 3 — –19.9 ± 1.4 0 С (–25.5 ± 1.9 0 С). In spring at object No. 1 it varied from –16.5 ± 1.7 0 С to + 1.6 ± 1, 0 0 С, object No. 2 — from –3.9 ± 0.9 0 С to + 9.4 ± 0.5 0 С, object No. 3 — from –4.5 ± 0.9 to + 10.6 ± 0.4. Temperatures ranged from + 8.2 ± 0.9 0 C to –17.8 ± 1.2 0 C (object No. 1), from + 9.4 ± 0.5 0 C to –7.5 ± 0.9 0 C and from +10.4 ± 0.4 0 C to –6.4 ± 1.0 0 C. In summer, the temperature was 19.9 ± 0.9 0 C, 18.8 ± 0.3 0 C, and 19.8 ± 0.4 0 C, respectively. Wind speed at object No. 3.6 ± 0.05 m/s in July increased to 5.4 ± 0.2 m/s in December (maximum 16.2 m/s); No. 2 in July 1.4 ± 0.05 m/s, in October-May 1.8 ± 0.2–2.1 ± 0.07 (maximum in December 10.1 ± 0.1 m/s); No. 3 minimum wind in January and February (1.1 ± 0.1 m/s), maximum 10.7 ± 0.6 m/s in May. A moderately dry climate is recorded during 2, 4 and 5 months. In the conditions of Krasnoyarsk and Minusinsk in the spring, humidity drops to the limits of dry air. Average effective temperatures indicated a possible risk of frostbite in the subarctic zone after 20–30 minutes within 2 months; at minimum temperatures and maximum winds in March, frostbite in 20–30 minutes, in November, December and February in 10–25 minutes; in January — in 5 minutes. In the Krasnoyarsk region in January frostbite is possible within 20–30 minutes, in Minusinsk in February in 20–30 minutes, in January 10–15 minutes. Heat stress is undefined.

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