scholarly journals The Influence of Air Temperature on the Dew Point Temperature in Benin City, Nigeria

2017 ◽  
Vol 21 (4) ◽  
pp. 657 ◽  
Author(s):  
KE Ukhurebor ◽  
TB Batubo ◽  
IC Abiodun ◽  
E Enoyoze
Keyword(s):  
Air Temperature ◽  
Dew Point ◽  
Point Temperature ◽  
Dew Point Temperature ◽  
Benin City

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 Kernel Extreme Learning Machine: An Efficient Model for Estimating Daily Dew Point Temperature Using Weather Data

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2600
Author(s):  
Meysam Alizamir ◽  
Sungwon Kim ◽  
Mohammad Zounemat-Kermani ◽  
Salim Heddam ◽  
Nam Won Kim ◽  
...  
Keyword(s):  
Neural Network ◽  
Relative Humidity ◽  
Extreme Learning Machine ◽  
Air Temperature ◽  
Dew Point ◽  
Point Temperature ◽  
Dew Point Temperature ◽  
Input Parameters ◽  
Kernel Extreme Learning Machine ◽  
Learning Machine

Accurate estimation of dew point temperature (Tdew) has a crucial role in sustainable water resource management. This study investigates kernel extreme learning machine (KELM), boosted regression tree (BRT), radial basis function neural network (RBFNN), multilayer perceptron neural network (MLPNN), and multivariate adaptive regression spline (MARS) models for daily dew point temperature estimation at Durham and UC Riverside stations in the United States. Daily time scale measured hydrometeorological data, including wind speed (WS), maximum air temperature (TMAX), minimum air temperature (TMIN), maximum relative humidity (RHMAX), minimum relative humidity (RHMIN), vapor pressure (VP), soil temperature (ST), solar radiation (SR), and dew point temperature (Tdew) were utilized to investigate the applied predictive models. Results of the KELM model were compared with other models using eight different input combinations with respect to root mean square error (RMSE), coefficient of determination (R2), and Nash–Sutcliffe efficiency (NSE) statistical indices. Results showed that the KELM models, using three input parameters, VP, TMAX, and RHMIN, with RMSE = 0.419 °C, NSE = 0.995, and R2 = 0.995 at Durham station, and seven input parameters, VP, ST, RHMAX, TMIN, RHMIN, TMAX, and WS, with RMSE = 0.485 °C, NSE = 0.994, and R2 = 0.994 at UC Riverside station, exhibited better performance in the modeling of daily Tdew. Finally, it was concluded from a comparison of the results that out of the five models applied, the KELM model was found to be the most robust by improving the performance of BRT, RBFNN, MLPNN, and MARS models in the testing phase at both stations.

scholarly journals Selection of parameters to predict dew point temperature in arid lands using Grey theory: a case study of Iran

2019 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Mojtaba Qolipour ◽  
Ali Mostafaeipour ◽  
Mostafa Rezaei ◽  
Elham Behnam ◽  
Hossein Goudarzi ◽  
...  
Keyword(s):  
Water Vapor ◽  
Air Temperature ◽  
Sunshine Duration ◽  
Water Vapor Pressure ◽  
Arid Lands ◽  
Dew Point ◽  
Grey Theory ◽  
Effective Parameters ◽  
Point Temperature ◽  
Dew Point Temperature

Dew point is the temperature at which water vapor in the air condenses into liquid with the same rate it evaporates. Dew point study is important in arid lands with low rainfall, also in other regions with various hydrological and climatological conditions. In this study, the Grey theory is applied for the first time to propose a framework approach to identify the important parameters affecting the prediction of dew point temperature. The ability of Grey theory to estimate and rank the parameters of a problem with missing data and uncertain conditions means that it has a good potential for mentioned application. For this research, 8 parameters are selected using literature review including: global solar radiation on a horizontal surface (H), water vapor pressure (VP), atmospheric pressure (P), sunshine duration (n), minimum air temperature (Tmin), maximum air temperature (Tmax), average air temperature (Tavg), and Relative Humidity (RH). The study is conducted for the city of Abadeh in Iran by using the data pertaining to a 10 year period between 2005 and 2015. The findings show that RH, Tavg, P, Tmax, Tmin, H, n and Vp with the grey possibility degrees of, respectively, 0.534, 0.551, 0.608, 0.622, 0.635, 0.695, 0.697 and 0.712, are the most important and effective parameters in prediction of dew point temperature. The proposed method also prioritizes the studied parameters in the order of their effectiveness on predicted dew point temperature.

Further Study in Relationship Between Fruit and Air Temperatures

1942 ◽  
Vol 23 (1) ◽  
pp. 16-21
Author(s):  
Philip J. Powell
Keyword(s):  
Air Temperature ◽  
Low Temperatures ◽  
Fruit Juice ◽  
Dew Point ◽  
Petroleum Jelly ◽  
Temperature Index ◽  
Point Temperature ◽  
Dew Point Temperature ◽  
Air Temperatures ◽  
Rate Of Cooling

Summary Summarizing, the following points are emphasized as being important considerations in the proper heating of orange groves in Florida to protect the fruit against low temperatures:1.) With a fast drop of the air temperature, the fruit temperature tends to parallel it closely. With slowly falling or stationary air temperature, the fruit temperature invariably drops lower than the air temperature, except occasionally when freezing of the fruit has already begun. On dry nights, exposed oranges tend to maintain a temperature as much as 3° or more lower than a stationary or slowly falling air temperature. On nights when dew and frost form on the fruit, this temperature difference is usually reduced to from 1° to 2°. The factors believed responsible for this radically different characteristic of Florida oranges, as compared with California oranges, are the thinner rind and the greater amount of moisture in the rind of the Florida orange. Both these properties cause a faster rate of cooling by allowing more rapid conduction of heat from within the orange to the surface than does the thicker, drier skin of the California orange.2.) The proper use of fruit thermometers provides the best temperature index in scientific grove heating. On nights of dry cold, unshielded fruit thermometer records are representative of true grove conditions. From experimental data, however, it appears that to obtain reliable records on nights when the dew point temperature is high and frost forms, the puncture in the fruit made by the thermometer must be sealed with petroleum jelly, or some other suitable substance, to prevent the frost particles from coming in contact with the fruit juice at this point; otherwise, premature crystallization in the fruit will occur.

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