scholarly journals Effective terrestrial radiant energy at the ground at Pune

MAUSAM ◽  
2021 ◽  
Vol 49 (2) ◽  
pp. 203-210
Author(s):  
V. DESIKAN ◽  
V. R. CHIVATE
Keyword(s):  
Meteorological Parameters ◽  
Radiant Energy ◽  
Ground Surface ◽  
Daily Maximum ◽  
Rainfall Distribution ◽  
Direct Measurements

The effective outgoing terrestrial radiant energy controls the variations in other meteorological parameters near the ground surface. In the absence of direct measurements of this energy, the values are derived from other radiation parameters that are being measured at Pune.        On an average day the loss of this terrestrial energy is of the order of 8.5 MJm-2. The maximum of        12.53 MJm-2 is reached in April and the minimum of 3.87 MJm-2 during August. The daily maximum occurs at noon or just after that. Year-to-year variations however depend on the rainfall distribution and the moisture in the air.

scholarly journals El polen de Poaceae en la atmósfera de Lugo y su relación con los parámetros meteorológicos (1999-2001).

2002 ◽  
Vol 27 ◽  
pp. 49-63 ◽  
Author(s):  
F. Javier Rodríguez-Rajo ◽  
M. Victoria Jato ◽  
M. Jesús Aira
Keyword(s):  
Pollen Season ◽  
Meteorological Parameters ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
Main Pollen Season ◽  
Pollen Concentrations ◽  
Poaceae Pollen ◽  
Annual Total ◽  
Maximum Temperatures ◽  
The City

RESUMEN. El polen de Poaceae en la atmósfera de Lugo y su relación con los parámetros meteorológicos (1999-2001). Se han estudiado las concentraciones de polen de Poaceae presente en la atmósfera de la ciudad de Lugo durante 3 años (1999-2001). Para ello se ha utilizado un captador volumétrico tipo Hirst, modelo Lanzoni VPPS-2000. El polen de Poaceae es el más abundante y su porcentaje frente al total de polen anual es de un 38-40%. La cantidad total de polen anual es de 8.400 granos como resultado de la media de los tres años de estudio, con un período de polinización durante los meses de Junio y Julio. A lo largo del día los máximos de concentración tienen lugar durante la tarde. Se ha realizado un análisis de correlación con los principales parámetros meteorológicos, siendo la temperatura máxima la variable que presentó el coeficiente más elevado. La suma acumulada de la temperatura máxima y la regresión múltiple integrando la temperatura máxima y las concentraciones de polen del día anterior como estimadores, resultaron métodos válidos y complementarios para realizar la predicción del inicio del periodo de polinización y de las concentraciones medias diarias que se alcanzan durante el periodo de polinización principal respectivamente.Palabras clave. Polen, Lugo, Meteorología, Predicción, lntradiario, Poaceae.ABSTRACT. The Poaceae pollen in the atmosphere of Lugo and its relationship with meteorological parameters ( 1999-2001). The pollen concentrations of Poaceae in the atmosphere of the city of Lugo has been studied during 3 years (1999-2001). A volumetric sampler type Hirst, model Lanzoni VPPS-2000 has been used. The Poaceae pollen is the most abundant and its percentage with respect to the total annual pollen ranged from 38-40 %. The annual total quantity of pollen of Poaceae were 8.400 grains as average of the three years studied, with a period of pollination during the months of June and July. The daily maximum concentrations take place during the evening. An analysis of correlation has been carried out between pollen concentrations and the main meteorological parameters, the maximum temperature being the variable that presented the highest coefficient value. The sum of maximum temperatures and the multiple regression integrating maximum temperature and pollen concentrations of the previous day as predictors, were successful and complementary methods in order to predict the beginning of the pollination period and the daily mean concentrations reached during the main pollen season respectively.Key words. Pollen, Lugo, Meteorology, Prediction, Intradiurnal, Poaceae.

scholarly journals Determining the Daytime Earth Radiative Flux from National Institute of Standards and Technology Advanced Radiometer (NISTAR) Measurements

2019 ◽  
Author(s):  
Wenying Su ◽  
Patrick Minnis ◽  
Lusheng Liang ◽  
David P. Duda ◽  
Konstantin Khlopenkov ◽  
...  
Keyword(s):  
Near Infrared ◽  
Radiant Energy ◽  
Correlation Coefficients ◽  
Energy System ◽  
Low Earth Orbit ◽  
Spectral Radiance ◽  
Daily Maximum ◽  
Distribution Models ◽  
The Earth ◽  
Highly Correlated

Abstract. The National Institute of Standards and Technology Advanced Radiometer (NISTAR) onboard Deep Space Climate Observatory (DSCOVR) provides continuous full disc global broadband irradiance measurements over most of the sunlit side of the Earth. The three active cavity radiometers measures the total radiant energy from the sun-lit side of the Earth in shortwave (SW, 0.2–4 µm), total (0.4–100 µm), and near-infrared (NIR, 0.7–4 µm) channels. The Level 1 NISTAR dataset provides the filtered radiances (the ratio between irradiance and solid angle). To determine the daytime top-of-atmosphere (TOA) shortwave and longwave radiative fluxes, the NISTAR measured shortwave radiances must be unfiltered first. An unfiltering algorithm was developed for the NISTAR SW and NIR channels using a spectral radiance data base calculated for typical Earth scenes. The resulting unfiltered NISTAR radiances are then converted to full disk daytime SW and LW flux, by accounting for the anisotropic characteristics of the Earth-reflected and emitted radiances. The anisotropy factors are determined using scene identifications determined from multiple low Earth orbit and geostationary satellites and the angular distribution models (ADMs) developed using data collected by the Clouds and the Earth's Radiant Energy System (CERES). Global annual daytime mean SW fluxes from NISTAR are about 6 % greater than those from CERES, and both show strong diurnal variations with daily maximum-minimum differences as great as 20 Wm−2 depending on the conditions of the sunlit portion of the Earth. They are also highly correlated, having correlation coefficients of 0.89, indicating that they both capture the diurnal variation. Global annual daytime mean LW fluxes from NISTAR are about 3 % greater than those from CERES, but the correlation between them is only about 0.38.

scholarly journals Surface Radio Refractivity of Akure and Ondo town, Southwest Nigeria

2021 ◽  
Vol 4 (1) ◽  
pp. 212-219
Author(s):  
IP Onujagbe ◽  
F Ahmed-Ade ◽  
M Mopah ◽  
AJ David
Keyword(s):  
Meteorological Parameters ◽  
Ground Surface ◽  
Mean Value ◽  
Strongly Correlated ◽  
K Value ◽  
Earth Radius ◽  
A Value ◽  
Daily Data ◽  
Southwest Nigeria ◽  
The Mean

The surface radio refractivity, refractivity gradient at 1km above ground surface and the effective earth radius factor, K over Akure and Ondo town of South west Nigeria has been investigated using Ten (10) years daily data of the meteorological parameters of Pressure, air temperature and humidity. The result showed that the mean monthly value of the surface refractivity at the Ondo station is generally slightly higher than that of Akure. The monthly mean value of refractivity at the two stations was found to be strongly correlated with a value of 0.915. The most negative refractive gradient value observed at Ondo and Akure are of -46.48N-units/km and -45.64N-units/km respectively and the least effective earth radius factor, k value of 1.421 and 1.410 were observed at the station respectively. These results showed that the Ondo and Akure station were generally super-refractive. The Ondo station was however found to be slightly more super-refractive than the Akure station.

scholarly journals Determining the daytime Earth radiative flux from National Institute of Standards and Technology Advanced Radiometer (NISTAR) measurements

2020 ◽  
Vol 13 (2) ◽  
pp. 429-443 ◽  
Author(s):  
Wenying Su ◽  
Patrick Minnis ◽  
Lusheng Liang ◽  
David P. Duda ◽  
Konstantin Khlopenkov ◽  
...  
Keyword(s):  
Near Infrared ◽  
Radiant Energy ◽  
Correlation Coefficients ◽  
Energy System ◽  
Low Earth Orbit ◽  
Spectral Radiance ◽  
Daily Maximum ◽  
Distribution Models ◽  
The Earth ◽  
Full Disk

Abstract. The National Institute of Standards and Technology Advanced Radiometer (NISTAR) onboard the Deep Space Climate Observatory (DSCOVR) provides continuous full-disk global broadband irradiance measurements over most of the sunlit side of the Earth. The three active cavity radiometers measure the total radiant energy from the sunlit side of the Earth in shortwave (SW; 0.2–4 µm), total (0.4–100 µm), and near-infrared (NIR; 0.7–4 µm) channels. The Level 1 NISTAR dataset provides the filtered radiances (the ratio between irradiance and solid angle). To determine the daytime top-of-atmosphere (TOA) shortwave and longwave radiative fluxes, the NISTAR-measured shortwave radiances must be unfiltered first. An unfiltering algorithm was developed for the NISTAR SW and NIR channels using a spectral radiance database calculated for typical Earth scenes. The resulting unfiltered NISTAR radiances are then converted to full-disk daytime SW and LW flux by accounting for the anisotropic characteristics of the Earth-reflected and emitted radiances. The anisotropy factors are determined using scene identifications determined from multiple low-Earth orbit and geostationary satellites as well as the angular distribution models (ADMs) developed using data collected by the Clouds and the Earth's Radiant Energy System (CERES). Global annual daytime mean SW fluxes from NISTAR are about 6 % greater than those from CERES, and both show strong diurnal variations with daily maximum–minimum differences as great as 20 Wm−2 depending on the conditions of the sunlit portion of the Earth. They are also highly correlated, having correlation coefficients of 0.89, indicating that they both capture the diurnal variation. Global annual daytime mean LW fluxes from NISTAR are 3 % greater than those from CERES, but the correlation between them is only about 0.38.

Measurements of radiant emissive power and temperatures in crown fires

2004 ◽  
Vol 34 (8) ◽  
pp. 1577-1587 ◽  
Author(s):  
B W Butler ◽  
J Cohen ◽  
D J Latham ◽  
R D Schuette ◽  
P Sopko ◽  
...  
Keyword(s):  
Forest Canopy ◽  
Radiant Energy ◽  
Ground Surface ◽  
Forest Stand ◽  
Radiative Energy ◽  
Fire Intensity ◽  
Energy Fluxes ◽  
Emissive Power ◽  
Radiant Intensity ◽  
Air Temperatures

This study presents spatially and temporally resolved measurements of air temperatures and radiant energy fluxes in a boreal forest crown fire. Measurements were collected 3.1, 6.2, 9.2, 12.3, and 13.8 m above the ground surface. Peak air temperatures exceeded 1330 °C, and maximum radiant energy fluxes occurred in the upper third of the forest stand and reached 290 kW·m–2. Average radiant flux from the flames across all experiments was found to be approximately 200 kW·m–2. Measured temperatures showed some variation with vertical height in the canopy. Equivalent radiometric temperatures calculated from radiant heat flux measurements exceeded thermocouple-based temperatures for all but the 10-m height, indicating that fire intensity estimates based on thermocouple measurements alone may result in underestimation of actual radiant intensity. The data indicate that the radiative energy penetration distance is significantly longer in the forest canopy than in the lower levels of the forest stand.

scholarly journals Sensitivity analysis of the surface ozone and fine particulate matter to meteorological parameters in China

2020 ◽  
Vol 20 (21) ◽  
pp. 13455-13466
Author(s):  
Zhihao Shi ◽  
Lin Huang ◽  
Jingyi Li ◽  
Qi Ying ◽  
Hongliang Zhang ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Meteorological Parameters ◽  
Surface Ozone ◽  
Fine Particulate Matter ◽  
Great Influence ◽  
Meteorological Conditions ◽  
Daily Maximum ◽  
Fine Particulate ◽  
Surface O3

Abstract. Meteorological conditions play important roles in the formation of ozone (O3) and fine particulate matter (PM2.5). China has been suffering from serious regional air pollution problems, characterized by high concentrations of surface O3 and PM2.5. In this study, the Community Multiscale Air Quality (CMAQ) model was used to quantify the sensitivity of surface O3 and PM2.5 to key meteorological parameters in different regions of China. Six meteorological parameters were perturbed to create different meteorological conditions, including temperature (T), wind speed (WS), absolute humidity (AH), planetary boundary layer height (PBLH), cloud liquid water content (CLW) and precipitation (PCP). Air quality simulations under the perturbed meteorological conditions were conducted in China in January and July of 2013. The changes in O3 and PM2.5 concentrations due to individual meteorological parameters were then quantified. T has a great influence on the daily maximum 8 h average O3 (O3-8 h) concentrations, which leads to O3-8 h increases by 1.7 in January in Chongqing and 1.1 ppb K−1 in July in Beijing. WS, AH, and PBLH have a smaller but notable influence on O3-8 h with maximum change rates of 0.3 ppb %−1, −0.15 ppb %−1, and 0.14 ppb %−1, respectively. T, WS, AH, and PBLH have important effects on PM2.5 formation of both in January and July. In general, PM2.5 sensitivities are negative to T, WS, and PBLH and positive to AH in most regions of China. The sensitivities in January are much larger than in July. PM2.5 sensitivity to T, WS, PBLH, and AH in January can be up to −5 µg m−3 K−1, −3 µg m−3 %−1, −1 µg m−3 %−1, and +0.6 µg m−3 %−1, respectively, and in July it can be up to −2 µg m−3 K−1, −0.4 µg m−3 %−1, −0.14 µg m−3 %−1, and +0.3 µg m−3 %−1, respectively. Other meteorological factors (CLW and PCP) have negligible effects on O3-8 h (less than 0.01 ppb %−1) and PM2.5 (less than 0.01 µg m−3 %−1). The results suggest that surface O3 and PM2.5 concentrations can change significantly due to changes in meteorological parameters, and it is necessary to consider these effects when developing emission control strategies in different regions of China.

scholarly journals The Study of Terrestrial Solar Radiation in Awka Using Measured Meteorological Data

2019 ◽  
pp. 1-6
Author(s):  
Chinelo U. Ikeh ◽  
Chukwunwike C. Okeke
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Meteorological Parameters ◽  
Meteorological Data ◽  
Ground Surface ◽  
Weather Station ◽  
Wet Season ◽  
Integrated Sensor ◽  
Useful Knowledge ◽  
Energy Conversion Systems

This work investigated the terrestrial solar radiation over Awka, South Eastern Nigeria using meteorological parameters of terrestrial temperature and relative humidity collected during 2013- 2014 respectively, using Davis weather station vantage pros2 (with Integrated Sensor Suite, ISS) positioned close to the ground surface. The data were logged at 30 minutes interval continuously for each day during the period. Hourly, daily and monthly averages of terrestrial radiation during dry and wet seasons were calculated from the data obtained. The result indicated that the terrestrial radiation during dry season is generally higher than during the wet season. The month of March has the highest value of terrestrial solar radiation of 410 Wm-2 , while the least terrestrial radiation of about 381 Wm-2 occurred in August. The result also showed that terrestrial solar radiation correlates positively with water vapour and more positively with temperature at 0.57 and 0.81 coefficients respectively. The results obtained from this work provide useful knowledge that is necessary to enhance the deployment of solar energy conversion systems.

scholarly journals Amplified role of potential HONO sources in O<sub>3</sub> formation in North China Plain during autumn haze aggravating processes

2021 ◽  
Author(s):  
Jingwei Zhang ◽  
Chaofan Lian ◽  
Weigang Wang ◽  
Maofa Ge ◽  
Yitian Guo ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Heterogeneous Reaction ◽  
Ground Surface ◽  
Field Studies ◽  
Daily Maximum ◽  
Pollution Levels ◽  
The North ◽  
Order Of Magnitude ◽  
High Concentrations

Abstract. Co-occurrences of high concentrations of PM2.5 and ozone (O3) have been frequently observed in haze aggravating processes in the North China Plain (NCP) over the past few years, and higher O3 concentrations during hazy days were supposed to be related to nitrous acid (HONO), but the key sources of HONO enhancing O3 during haze aggravating processes remain unclear, and will be explored in this study by using the WRF-Chem model, which is improved to include ground-based (traffic, soil, and indoor emissions, and the NO2 heterogeneous reaction on ground surface (Hetground)) and aerosol-related (the NO2 heterogeneous reaction on aerosol surfaces (Hetaerosol) and nitrate photolysis (Photnitrate)) potential HONO sources. The results indicate that ground-based HONO sources producing HONO enhancements showed a rapid decrease with height, while the NO+OH reaction and aerosol-related HONO sources decreased slowly with height. Photnitrate contributions to HONO concentrations enhanced with aggravated pollution levels, the enhanced HONO due to Photnitrate in hazy days was about one order of magnitude larger than in clean days and Photnitrate dominated HONO sources (~30–70 % when the ratio of the photolysis frequency of nitrate (Jnitrate) to gas nitric acid (JHNO3) equals 30) at higher layers (> 800 m). Compared with that in clean days, the Photnitrate contribution to the enhanced daily maximum 8-h averaged O3 was increased by over one magnitude during the haze aggravating process. Photnitrate contributed only ~5 % of the surface HONO in daytime with a Jnitrate/JHNO3 ratio of 30 but contributed ~30–50 % of the enhanced O3 near the surface in NCP in hazy days. Surface O3 was dominated by volatile organic compounds-sensitive chemistry, while O3 at higher altitude (> 800 m) was dominated by NOx-sensitive chemistry. Photnitrate had a limited impact on nitrate concentrations (< 15 %) even with a Jnitrate/JHNO3 ratio of 120. The above results suggest that more field studies of Jnitrate in the atmosphere are still needed.

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