A simple cloud-based energy balance model to estimate dew

Madeira, Ana Carla; Kim, K. S.; Taylor, S. Elwynn; Gleason, Mark L.

doi:10.1016/s0168-1923(02)00004-7

Cited by 63 publications

(51 citation statements)

References 14 publications

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“…The distribution was done in accordance with the prevailing wind direction, with two collectors on the east side and two in the middle of the experiment. The leaf wetness duration (LWD) was measured by the "Electronic tree" (MOREIRA et al, 2011;GUEDES et al, 2013), with 12 electronic wetness sensors distributed at three heights (0.3; 0.6, and 0.9 m) representing the crop canopy, and the temperature and relative humidity of the air were measured in the same equipment at a height of 1.70 m. Eight Electronic trees were used in the experiment, one in each plot, to provide better representation and reliability of LWD, since this is a complex measure and depends not only on the weather conditions but also on their interaction with the structure, composition, and physiology of the crop canopy (MAGAREY, 1999;MADEIRA et al, 2002;SENTELHAS et al, 2005;MARTA et al, 2007).…”

Section: Methodsmentioning

confidence: 99%

Application of prediction models of asian soybean rust in two crop seasons, in Londrina, Pr

Igarashi

França

Silva

et al. 2016

SCA

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Predictive models of Asian soybean rust have been described by researchers to estimate favorable responses to epidemics. The prediction strategies are based on weather data obtained during period when initial symptoms of the disease are observed. Therefore, this study will evaluate the application of two prediction models of Asian soybean rust, and compare the results from two harvest seasons. The experiments were carried out during the 2011/2012 and 2012/2013 seasons in Londrina, PR. "SIGA spore traps" were installed to monitor the presence of Phakopsora pachyrhizi uredospores, and "Electronic trees," to collect data on weather variables. Following the detection of the first urediniospores, incidence and disease severity were assessed and compared with the predictions made by the models ResumoModelos de previsão da ferrugem asiática da soja foram descritos por pesquisadores para estimar a favorabilidade climática para a ocorrência de epidemias. As estratégias de previsão estão fundamentadas em dados meteorológicos, a partir dos sintomas iniciais da doença. Portanto, objetivou-se aplicar dois modelos de previsão da ferrugem asiática da soja, e comparar com os resultados de duas safras agrícolas. A condução dos experimentos ocorreu nas safras 2011/2012 e 2012/2013 no município de Londrina, PR. Foram instalados "Coletores de esporos SIGA" para monitorar a presença de uredósporos de P. pachyrhizi, e "Árvores Eletrônicas de Molhamento" para coletar dados das variáveis meteorológicas. A partir da detecção dos primeiros uredósporos foram realizadas avaliações da incidência e da severidade da ferrugem, para comparar com as previsões feitas pelos modelos. O modelo de Reis et al. (2004) não indicou condições para o desenvolvimento das primeiras lesões da ferrugem após a chegada dos primeiros uredósporos na safra 2011/2012. Os primeiros sintomas da ferrugem na primeira e na segunda safra foram constatados apenas quando o modelo de Reis et al. (2004) indicou SVDPI próximo a 15

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Section: Methodsmentioning

confidence: 99%

Application of prediction models of asian soybean rust in two crop seasons, in Londrina, Pr

Igarashi

França

Silva

et al. 2016

SCA

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“…The zero plane displacement and roughness length depend on plant density [35,41] and leaf area index [42,43] and can therefore differ by ±20% or more from the values we computed. Probably because of these dependencies, a wide range of coefficients is suggested in the literature for the calculation of the zero plane displacement and roughness length as a function of plant height [23,[44][45][46].…”

Section: ∆T ( • C)mentioning

confidence: 99%

Agreement of Four Equations for Computing Dewfall in Northern Germany

Xiao

Meißner

Borg

et al. 2017

Water

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Abstract:The energy balance (EB), turbulent vapour transport (TVT), Penman-Monteith (PM) and Bowen ratio energy balance (BREB) equation were used to estimate dewfall based on meteorological data. Initially there were big disagreements between the estimates from these four equations. However, after multiplying the heat and vapour conductance terms by 0.33 the agreement was much better. This implies that the disagreements derived from improper conductance values. Initially we did not consider the effect of atmospheric stability on the conductances. With stability correction the conductances were on average 0.5 times the values without stability correction. To arrive at the aforementioned 0.33, the conductances with stability correction still need to be lower by a factor of 0.66. The value of the von Karman constant and the relationships for the zero plane displacement and the roughness length we used in our conductance computations are widely used, but not the only possible ones. With different values and relationships also suggested in the literature one can reach this factor. However, it is also possible that our wind speed data contributed to the fact that the conductances we computed were too high. Their computation for a given canopy-atmosphere system requires wind speeds from a wind profile in equilibrium with the vegetation. This in turn requires an adequate fetch around the investigated surface. The highly varied vegetation in and around the site where the study was conducted makes adequate fetch rather doubtful. To obtain valid conductance values the atmospheric stability conditions must be considered, the appropriate values for the von Karman constant, the zero plane displacement and roughness length must be used, and there must be adequate fetch. The BREB equation does not contain a conductance term and therefore does not suffer from the problems just stated. The other three equations do. However, the BREB, like the EB and TVT equations, need the surface temperature which is not routinely measured. This then leaves the PM equation from which this temperature has been eliminated as the only option. Hence, in a future study dewfall estimates from the PM equation should be compared with direct measurements with a high precision weighing lysimeter.

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“…Our approach is based on an energy balance model similar to those in e.g. Nilsson (1996), Madeira et al (2002), Beysens et al (2005), Jacobs et al (2008), Richards (2009) and Maestre-Valero et al (2011), who have demonstrated that their models are able to predict the measured dew yields within reasonable accuracy.…”

Section: Introductionmentioning

confidence: 99%

Estimates of global dew collection potential on artificial surfaces

Vuollekoski

Vogt

Sinclair

et al. 2015

Hydrol. Earth Syst. Sci.

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Abstract. The global potential for collecting usable water from dew on an artificial collector sheet was investigated by utilizing 34 years of meteorological reanalysis data as input to a dew formation model. Continental dew formation was found to be frequent and common, but daily yields were mostly below 0.1 mm. Nevertheless, some water-stressed areas such as parts of the coastal regions of northern Africa and the Arabian Peninsula show potential for large-scale dew harvesting, as the yearly yield may reach up to 100 L m −2 for a commonly used polyethylene foil. Statistically significant trends were found in the data, indicating overall changes in dew yields of between ±10 % over the investigated time period.

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A simple cloud-based energy balance model to estimate dew

Cited by 63 publications

References 14 publications

Application of prediction models of asian soybean rust in two crop seasons, in Londrina, Pr

Application of prediction models of asian soybean rust in two crop seasons, in Londrina, Pr

Agreement of Four Equations for Computing Dewfall in Northern Germany

Estimates of global dew collection potential on artificial surfaces

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