scholarly journals CLIGEN Parameter Regionalization for Mainland China

2021 ◽  
Author(s):  
Wenting Wang ◽  
Shuiqing Yin ◽  
Bofu Yu ◽  
Shaodong Wang
Keyword(s):  
Standard Deviation ◽  
Solar Radiation ◽  
Mainland China ◽  
Cumulative Distribution ◽  
Annual Rainfall ◽  
Stochastic Weather Generator ◽  
Critical Set ◽  
The Mean ◽  
Parameter Values

Abstract. Stochastic weather generator CLIGEN can simulate long-term weather sequences as input to WEPP for erosion predictions. Its use, however, has been somewhat restricted by limited observations at high spatial-temporal resolutions. Long-term daily temperature, daily and hourly precipitation data from 2405 stations and daily solar radiation from 130 stations distributed across mainland China were collected to develop the most critical set of site-specific parameter values for CLIGEN. Universal Kriging (UK) with auxiliary covariables, longitude, latitude, elevation, and the mean annual rainfall was used to interpolate parameter values into a 10 km × 10 km grid and parameter accuracy was evaluated based on leave-one-out cross-validation. The results demonstrated that Nash-Sutcliffe efficiency coefficients (NSEs) between UK interpolated and observed parameters were greater than 0.85 for all parameters apart from the standard deviation of solar radiation, skewness coefficient of daily precipitation, and cumulative distribution of relative time to peak intensity, with relatively lower interpolation accuracy (NSE > 0.66). In addition, CLIGEN simulated daily weather sequences using UK-interpolated and observed inputs showed consistent statistics and frequency distributions. The mean absolute discrepancy between the two sequences in the average and standard deviation of the temperature was less than 0.51 °C. The mean absolute relative discrepancy for the same statistics for solar radiation, precipitation amount, duration and maximum intensity in 30-min were less than 5 %. CLIGEN parameters at the 10 km resolution would meet the minimum WEPP climate requirements throughout in mainland China. The dataset is availability at http://clicia.bnu.edu.cn/data/cligen.html and http://doi.org/10.12275/bnu.clicia.CLIGEN.CN.gridinput.001 (Wang et al., 2020).

scholarly journals CLIGEN parameter regionalization for mainland China

2021 ◽  
Vol 13 (6) ◽  
pp. 2945-2962
Author(s):  
Wenting Wang ◽  
Shuiqing Yin ◽  
Bofu Yu ◽  
Shaodong Wang
Keyword(s):  
Solar Radiation ◽  
Precipitation Amount ◽  
Mainland China ◽  
Annual Rainfall ◽  
Efficiency Coefficient ◽  
Stochastic Weather Generator ◽  
Critical Set ◽  
The Mean ◽  
Parameter Values

Abstract. The stochastic weather generator CLIGEN can simulate long-term weather sequences as input to WEPP for erosion predictions. Its use, however, has been somewhat restricted by limited observations at high spatial–temporal resolutions. Long-term daily temperature, daily, and hourly precipitation data from 2405 stations and daily solar radiation from 130 stations distributed across mainland China were collected to develop the most critical set of site-specific parameter values for CLIGEN. Ordinary kriging (OK) and universal kriging (UK) with auxiliary covariables, i.e., longitude, latitude, elevation, and the mean annual rainfall, were used to interpolate parameter values into a 10 km×10 km grid, and the interpolation accuracy was evaluated based on the leave-one-out cross-validation. Results showed that UK generally outperformed OK. The root mean square error between UK-interpolated and observed temperature-related parameters was ≤0.88 ∘C (1.58 ∘F). The Nash–Sutcliffe efficiency coefficient for precipitation- and solar-radiation-related parameters was ≥0.87, except for the skewness coefficient of daily precipitation, which was 0.78. In addition, CLIGEN-simulated daily weather sequences using UK-interpolated and observed parameters showed consistent statistics and frequency distributions. The mean absolute discrepancy between the two sequences for temperature was <0.51 ∘C, and the mean absolute relative discrepancy for solar radiation, precipitation amount, duration, and maximum 30 min intensity was <5 % in terms of the mean and standard deviation. These CLIGEN parameter values at 10 km resolution would meet the minimum data requirements for WEPP application throughout mainland China. The dataset is available at http://clicia.bnu.edu.cn/data/cligen.html (last access: 20 May 2021) and https://doi.org/10.12275/bnu.clicia.CLIGEN.CN.gridinput.001 (Wang et al., 2020).

scholarly journals Long term precipitation chemistry and wet deposition in a remote dry savanna site in Africa (Niger)

2009 ◽  
Vol 9 (5) ◽  
pp. 1579-1595 ◽  
Author(s):  
C. Galy-Lacaux ◽  
D. Laouali ◽  
L. Descroix ◽  
N. Gobron ◽  
C. Liousse
Keyword(s):  
Wet Deposition ◽  
Ph Value ◽  
Precipitation Chemistry ◽  
Annual Rainfall ◽  
Deposition Flux ◽  
Air Concentration ◽  
Ionic Charge ◽  
Rainfall Gradient ◽  
The Mean

Abstract. Long-term precipitation chemistry have been recorded in the rural area of Banizoumbou (Niger), representative of a semi-arid savanna ecosystem. A total of 305 rainfall samples ~90% of the total annual rainfall) were collected from June 1994 to September 2005. From ionic chromatography, pH major inorganic and organic ions were detected. Rainwater chemistry is controlled by soil/dust emissions associated with terrigeneous elements represented by SO42−, Ca2+, Carbonates, K+ and Mg2+. It is found that calcium and carbonates represent ~40% of the total ionic charge. The second highest contribution is nitrogenous, with annual Volume Weighed Mean (VWM) for NO3− and NH4+ concentrations of 11.6 and 18.1 μeq.l−1, respectively. This is the signature of ammonia sources from animals and NOx emissions from savannas soil-particles rain-induced. The mean annual NH3 and NO2 air concentration are of 6 ppbv and 2.6 ppbv, respectively. The annual VWM precipitation concentration of sodium and chloride are both of 8.7 μeq.l−1 which reflects the marine signature of monsoonal and humid air masses. The median pH value is of 6.05. Acidity is neutralized by mineral dust, mainly carbonates, and/or dissolved gases such NH3. High level of organic acidity with 8μeq.l−1 and 5.2 μeq.l−1 of formate and acetate were also found. The analysis of monthly Black Carbon emissions and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) values show that both biogenic emission from vegetation and biomass burning could explain the rainfall organic acidity content. The interannual variability of the VWM concentrations around the mean (1994–2005) is between ±5% and ±30% and mainly due to variations of sources strength and rainfall spatio-temporal distribution. From 1994 to 2005, the total mean wet deposition flux in the Sahelian region is of 60.1 mmol.m−2.yr−1 ±25%. Finally, Banizoumbou measurements are compared to other long-term measurements of precipitation chemistry in the wet savanna of Lamto (Côte d'Ivoire) and in the forested zone of Zoétélé (Cameroon). The total chemical loading presents a maximum in the dry savanna and a minimum in the forest (from 143.7, 100.2 to 86.6 μeq.l−1), associated with the gradient of terrigeneous sources. The wet deposition fluxes present an opposite trend, with 60.0 mmol.m−2.yr−1 in Banizoumbou, 108.6 mmol.m−2.yr−1 in Lamto and 162.9 mmol.m−2.yr−1 in Zoétélé, controlled by rainfall gradient along the ecosystems transect.

VARIATIONS IN THE KARA SEA LEVEL, THEIR STERIC FACTORS, AND SOLAR RADIATION DURING 1993-2018

2021 ◽  
pp. 38-52
Author(s):  
A.V. KHOLOPTSEV ◽  
◽  
S.A. PODPORIN ◽  
V.A. SAFONOV ◽  
◽  
...  
Keyword(s):  
Solar Radiation ◽  
Sea Level ◽  
Water Layer ◽  
Kara Sea ◽  
Mean Values ◽  
Mean Intensity ◽  
Steric Factors ◽  
The Mean ◽  
Long Term Variations

The GLORYS12v.1 and ERA5 reanalyses for different months are used to study a relationship between long-term variations in the monthly mean values of sea level in different areas of the Kara Sea and their steric factors during 1993-2018. The areas of the sea were identified where the relationships between these changes and variations in the mean temperature and salinity of the upper quasihomogeneous water layer, as well as the variations in the monthly mean intensity of their insolation, are statistically significant.

scholarly journals Internal consistency of the Regional Brewer Calibration Centre for Europe triad during the period 2005–2016

2018 ◽  
Vol 11 (7) ◽  
pp. 4059-4072 ◽  
Author(s):  
Sergio Fabián León-Luis ◽  
Alberto Redondas ◽  
Virgilio Carreño ◽  
Javier López-Solano ◽  
Alberto Berjón ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Data Sets ◽  
Individual Values ◽  
Relative Standard ◽  
The World ◽  
The Mean ◽  
The Individual ◽  
Ozone Column

Abstract. Total ozone column measurements can be made using Brewer spectrophotometers, which are calibrated periodically in intercomparison campaigns with respect to a reference instrument. In 2003, the Regional Brewer Calibration Centre for Europe (RBCC-E) was established at the Izaña Atmospheric Research Center (Canary Islands, Spain), and since 2011 the RBCC-E has transferred its calibration based on the Langley method using travelling standard(s) that are wholly and independently calibrated at Izaña. This work is focused on reporting the consistency of the measurements of the RBCC-E triad (Brewer instruments #157, #183 and #185) made at the Izaña Atmospheric Observatory during the period 2005–2016. In order to study the long-term precision of the RBCC-E triad, it must be taken into account that each Brewer takes a large number of measurements every day and, hence, it becomes necessary to calculate a representative value of all of them. This value was calculated from two different methods previously used to study the long-term behaviour of the world reference triad (Toronto triad) and Arosa triad. Applying their procedures to the data from the RBCC-E triad allows the comparison of the three instruments. In daily averages, applying the procedure used for the world reference triad, the RBCC-E triad presents a relative standard deviation equal to σ = 0.41 %, which is calculated as the mean of the individual values for each Brewer (σ157 = 0.362 %, σ183 = 0.453 % and σ185 = 0.428 %). Alternatively, using the procedure used to analyse the Arosa triad, the RBCC-E presents a relative standard deviation of about σ = 0.5 %. In monthly averages, the method used for the data from the world reference triad gives a relative standard deviation mean equal to σ = 0.3 % (σ157 = 0.33 %, σ183 = 0.34 % and σ185 = 0.23 %). However, the procedure of the Arosa triad gives monthly values of σ = 0.5 %. In this work, two ozone data sets are analysed: the first includes all the ozone measurements available, while the second only includes the simultaneous measurements of all three instruments. Furthermore, this paper also describes the Langley method used to determine the extraterrestrial constant (ETC) for the RBCC-E triad, the necessary first step toward accurate ozone calculation. Finally, the short-term or intraday consistency is also studied to identify the effect of the solar zenith angle on the precision of the RBCC-E triad.

scholarly journals EVALUATION OF GRADATION VARIATION OF THE GRANITE AGGREGATES USED IN ASPHALT MIXTURES AT THEIR MANUFACTURING PLACE

2020 ◽  
Author(s):  
Mantas Makulavičius ◽  
Henrikas Sivilevičius
Keyword(s):  
Standard Deviation ◽  
Asphalt Mixture ◽  
Quality Parameters ◽  
Key Factors ◽  
Manufacturing Plants ◽  
Road Pavement ◽  
Research Findings ◽  
The Mean ◽  
Mixture Homogeneity

Asphalt mixture gradation homogeneity is one of the key factors for proper laying and compaction during road pavement and its long-term maintenance afterwards. To achieve the good quality asphalt mixture homogeneity of aggregates used in road pavement must be kept in mind. Regarding to this, gradation variation of five different granite aggregates fractions (0/2, 2/5, 5/8, 8/11 and 11/16) from one of the largest manufacturing plants in Lithuania were determined in this paper. Total of 244 samples were taken from conveyer belt at the manufacturing place and all the data was evaluated by statistical methods providing histograms with theoretical curves of normal distribution. After that, the results were compared to each other and the requirements issued by Lithuanian road administration authority. Regression analysis was used to determine the dependence of standard deviation of percent passing and the mean percent passing through the sieves. The obtained research findings revealed that the maximum value of standard deviation of this dependence was equal to mean of 50% percent passing. Further investigations should include other aggregates quality parameters variation and its homogeneity throughout different stages of technological and transportation processes.

scholarly journals Merging ground-based sunshine duration observations with satellite cloud and aerosol retrievals to produce high-resolution long-term surface solar radiation over China

2021 ◽  
Vol 13 (3) ◽  
pp. 907-922
Author(s):  
Fei Feng ◽  
Kaicun Wang
Keyword(s):  
Standard Deviation ◽  
High Resolution ◽  
Solar Radiation ◽  
Spatial Resolution ◽  
Sunshine Duration ◽  
Ordinary Least Squares ◽  
Cloud Fraction ◽  
Surface Solar Radiation ◽  
The Impact

Abstract. Although great progress has been made in estimating surface solar radiation (Rs) from meteorological observations, satellite retrieval, and reanalysis, getting best-estimated long-term variations in Rs are sorely needed for climate studies. It has been shown that Rs data derived from sunshine duration (SunDu) can provide reliable long-term variability, but such data are available at sparsely distributed weather stations. Here, we merge SunDu-derived Rs with satellite-derived cloud fraction and aerosol optical depth (AOD) to generate high-spatial-resolution (0.1∘) Rs over China from 2000 to 2017. The geographically weighted regression (GWR) and ordinary least-squares regression (OLS) merging methods are compared, and GWR is found to perform better. Based on the SunDu-derived Rs from 97 meteorological observation stations, which are co-located with those that direct Rs measurement sites, the GWR incorporated with satellite cloud fraction and AOD data produces monthly Rs with R2=0.97 and standard deviation =11.14 W m−2, while GWR driven by only cloud fraction produces similar results with R2=0.97 and standard deviation =11.41 W m−2. This similarity is because SunDu-derived Rs has included the impact of aerosols. This finding can help to build long-term Rs variations based on cloud data, such as Advanced Very High Resolution Radiometer (AVHRR) cloud retrievals, especially before 2000, when satellite AOD retrievals are not unavailable. The merged Rs product at a spatial resolution of 0.1∘ in this study can be downloaded at https://doi.org/10.1594/PANGAEA.921847 (Feng and Wang, 2020).

Dihedral angles between alveolar septa

1988 ◽  
Vol 64 (1) ◽  
pp. 299-307 ◽  
Author(s):  
E. H. Oldmixon ◽  
J. P. Butler ◽  
F. G. Hoppin
Keyword(s):  
Standard Deviation ◽  
Lung Parenchyma ◽  
Cumulative Distribution ◽  
Connective Tissues ◽  
Lower Lung ◽  
Angle Alpha ◽  
Alveolar Duct ◽  
The Mean ◽  
Locally Homogeneous ◽  
Theoretical Considerations

To determine the dihedral angle, alpha, at the characteristic three-way septal junctions of lung parenchyma, we examined photomicrographs of sections. The three angles, A, formed where three septal traces meet on section, were measured and found to range between approximately 50 and 170 degrees. Theoretical considerations predicted that the dispersion of alpha is much narrower than that of A. The mean of A and alpha is identically 120 degrees. The standard deviation of alpha was inferred from the cumulative distribution function of A. In lungs inflated to 30 cmH2O (VL30), the standard deviation of alpha was very small (approximately 2 degrees) and increased to approximately 6 degrees in lungs inflated to 0.4 VL30. These findings imply that at VL30 tensions exerted by septa are locally homogeneous (2% variation) and at lower lung volumes become less so (6% variation). At high distending pressures, tissue forces are thought to dominate interfacial forces, and therefore the local uniformity of tensions suggests a stress-responsive mechanism for forming or remodeling the connective tissues. The source of the local nonuniformity at lower volumes is unclear but could relate to differences in mechanical properties of alveolar duct and alveoli. Finally, local uniformity does not imply global uniformity.

Speed of ultrasound in Hereford bulls and its correlation with carcass composition

1991 ◽  
Vol 52 (2) ◽  
pp. 263-269 ◽  
Author(s):  
G. A. J. Fursey ◽  
C. A. Miles ◽  
S. J. Page ◽  
A. V. Fisher
Keyword(s):  
Standard Deviation ◽  
Carcass Composition ◽  
Lipid Concentration ◽  
Residual Standard Deviation ◽  
Hind Limbs ◽  
The Mean ◽  
Speed Of Ultrasound ◽  
Total Fat ◽  
Animal Interaction

ABSTRACTMeasurements were made of the speed of ultrasound transmission through sites in the hind limbs of 125 pedigree Hereford bulls. Twenty-five of these were measured twice at weekly intervals on three occasions prior to slaughter to assess the short-term repeatability of the measurement and the magnitude of long-term changes. Analyses of variance of the means of the measurements at two sites showed that the residual standard deviation (within animal and occasion), was 0·01 (μs/cm. There was a decrease of 0·01 (μs/cm in the group mean over the 2-week period and a significant time × animal interaction. This showed that lipid concentration at the measurement sites decreased as the bulls adjusted to their new surroundings following delivery to the Institute's farm. When a separate group of 64 bulls was measured at the farm at which they were being reared an increase in the group mean of 0·006 iμs/cm was recorded over a 30·day period, indicating an increase in lipid concentration. The residual standard deviation for that group was 0·007 μs/cm, similar to that recorded above.The mean of the reciprocal speeds at the two sites, when used in a multiple regression with live mass, yielded a residual standard deviation in predicted proportion of lean in the side of 20·0 g/kg and in total fat proportion of 22·1 g/kg. These corresponded to population standard deviations, adjusted for live mass, of 29·7 and 34·1 g/kg respectively. It was concluded that the measurement of ultrasound speed in the hind limbs of Hereford bulls could be used to predict lean proportion in the carcass. The method does not require subjective interpretation and responds equally to subcutaneous and interand intra-muscular fat.

scholarly journals Have You Seen the Standard Deviation?

2019 ◽  
Vol 3 ◽  
pp. 1-10
Author(s):  
Jyotirmoy Sarkar ◽  
Mamunur Rashid
Keyword(s):  
Standard Deviation ◽  
Cumulative Distribution Function ◽  
Geometric Method ◽  
Cumulative Distribution ◽  
Mean Deviation ◽  
Similar Data ◽  
Tabular Data ◽  
Empirical Cumulative Distribution Function ◽  
Quadratic Transformation ◽  
The Mean

Background: Sarkar and Rashid (2016a) introduced a geometric way to visualize the mean based on either the empirical cumulative distribution function of raw data, or the cumulative histogram of tabular data. Objective: Here, we extend the geometric method to visualize measures of spread such as the mean deviation, the root mean squared deviation and the standard deviation of similar data. Materials and Methods: We utilized elementary high school geometric method and the graph of a quadratic transformation. Results: We obtain concrete depictions of various measures of spread. Conclusion: We anticipate such visualizations will help readers understand, distinguish and remember these concepts.

scholarly journals Performance of CAMS Radiation Service and HelioClim-3 databases of solar radiation at surface: evaluating the spatial variation in Germany

2020 ◽  
Vol 17 ◽  
pp. 143-152
Author(s):  
Mathilde Marchand ◽  
Yves-Marie Saint-Drenan ◽  
Laurent Saboret ◽  
Etienne Wey ◽  
Lucien Wald
Keyword(s):  
Standard Deviation ◽  
Solar Radiation ◽  
Correlation Coefficient ◽  
Satellite Images ◽  
Ground Level ◽  
Spatial Trend ◽  
The North ◽  
Spatial Consistency ◽  
The Mean ◽  
Sky Conditions

Abstract. The present work deals with the spatial consistency of two well-known databases of solar radiation received at ground level: the CAMS Radiation Service database version 3.2, abbreviated as CAMS-Rad and the HelioClim-3 database version 5, abbreviated as HC3v5. Both databases are derived from satellite images. They are validated against 10 min means of irradiance for the period 2010–2018 recorded in a network of 26 ground stations in Germany operated by the Deutscher Wetterdienst (DWD). For the CAMS-Rad database, the correlation coefficient between ground measurements and estimates ranges between 0.83 and 0.92 for all sky conditions. The bias ranges from −41 and 32 W m−2 (−11 % and 10 % of the mean irradiance). The standard deviation ranges between 89 and 129 W m−2 (25 % and 39 %). For the HC3v5 database, the correlation coefficient ranges between 0.90 and 0.95. The bias and the standard deviation are comprised between −22 and 16 W m−2 (−6 % and 5 %), and between respectively 70 and 104 W m−2 (20 % and 31 %). For the CAMS Rad database, overestimation is observed in the South, and underestimation in the North with a faint tendency of the bias to increase from East to West. For the HC3v5 database, the bias is fairly homogeneous across Germany. For both databases, there is no noticeable spatial trend in the standard deviation.

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