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 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 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 Secular Variation in Rainfall Intensity and Temperature in Eastern Australia

2013 ◽  
Vol 14 (4) ◽  
pp. 1356-1363 ◽  
Author(s):  
Yi-Ru Chen ◽  
Bofu Yu ◽  
Graham Jenkins
Keyword(s):  
Minimum Temperature ◽  
Rainfall Intensity ◽  
Annual Rainfall ◽  
Maximum Temperature ◽  
Trend Test ◽  
Long Duration ◽  
Eastern Australia ◽  
Long Term Trends ◽  
The Mean

Abstract It is generally assumed that rainfall intensity will increase with temperature increase, irrespective of the underlying changes to the average rainfall. This study documents and investigates long-term trends in rainfall intensities, annual rainfall, and mean maximum and minimum temperatures using the Mann–Kendall trend test for nine sites in eastern Australia. Relationships between rainfall intensities at various durations and 1) annual rainfall and 2) the mean maximum and minimum temperatures were investigated. The results showed that the mean minimum temperature has increased significantly at eight out of the nine sites in eastern Australia. Changes in annual rainfall are likely to be associated with changes in rainfall intensity at the long duration of 48 h. Overall, changes in rainfall intensity at short durations (&lt;1 h) positively correlate with changes in the mean maximum temperature, but there is no significant correlation with the mean minimum temperature and annual rainfall. Additionally, changes in rainfall intensity at longer durations (≥1 h) positively correlate with changes in the mean annual rainfall, but not with either mean maximum or minimum temperatures for the nine sites investigated.

A model of vegetative flush development and its potential use managing macadamia (Macadamia integrifolia) tree canopies

2009 ◽  
Vol 60 (5) ◽  
pp. 420 ◽  
Author(s):  
J. D. Wilkie ◽  
M. Sedgley ◽  
T. Olesen
Keyword(s):  
Solar Radiation ◽  
Stem Elongation ◽  
Stem Length ◽  
Weather Data ◽  
Macadamia Integrifolia ◽  
Mean Temperature ◽  
Tree Canopies ◽  
The Mean ◽  
The Relationship

We examined the relationship between shoot growth and temperature and solar radiation in macadamia (Macadamia integrifolia Maiden and Betche, M. integrifolia × tetraphylla Johnson) as an aid to developing pruning strategies for this crop. Trees growing at Alstonville (28.9°S) in northern NSW, Australia, were pruned at various times to promote vegetative flushing under a range of environmental conditions. Flush development in macadamia is cyclic: bud release and stem elongation followed by a period of dormancy, before bud release of the subsequent flush. The rate of bud release after pruning was best correlated with the product of the mean temperature and solar radiation (r2 = 0.75, P < 0.0001), whereas the rate of flush development was best correlated with the mean temperature (r2 = 0.76, P < 0.0001). The number of buds released per pruned stem was greater under higher temperatures and solar radiation (r2 = 0.37, P < 0.001), but the length of the flush after pruning decreased with increasing temperatures (r2 = 0.32, P < 0.01). The descriptive models were combined with long-term weather data to predict the duration and characteristics of flushes following pruning at various times of the year along Australia’s eastern seaboard, from Mareeba (17.0°S) to Coffs Harbour (30.3°S). Flush duration and stem length following June pruning were predicted to be greater than following early autumn or September pruning and to vary from year to year, and with location (latitude). We discuss the implications of the model predictions for productivity and propose pruning times intended to optimise flowering and yield. Further research is required to test these proposed pruning strategies.

scholarly journals Trends and periodicities in sub-divisional rainfall

MAUSAM ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 77-86
Author(s):  
S. K. SUBRAMANIAN ◽  
S. V. PALANDE ◽  
B.N. DEWAN ◽  
S. K. DIKSHIT ◽  
LAWRENCE JOSEPH
Keyword(s):  
Monsoon Rainfall ◽  
Statistical Tests ◽  
Power Spectrum Analysis ◽  
Rainfall Series ◽  
Annual Rainfall ◽  
Frequency Range ◽  
The Mean ◽  
Long Term Trend ◽  
Normal Rainfall

The monthly and annual rainfall data for 35 meteorological sub-divisions for the 87-year period (1901-1987) have been used to study the trends and periodicities of monsoon and annual rainfall series. A number of distribution-free statistical tests have been applied to the rainfall series for testing non-randomness. Comparison of the decadewise means with the mean of the whole period showed that, for the country as a whole, the annual rainfall indicated four different climatic periods -two periods of above normal rainfall from 1960-1965 and from 1975 onwards and two periods of below normal rainfall from 1901-1915 and 1965-1975 whereas the monsoon rainfall showed two different climatic periods-a period of below normal rainfall from 1901-1920 and a period of above normal rainfall from 1920 onwards. The series were also subjected to low-passfilters which showed the presence of significant long term trend for a few sub-divisions. The power spectrum analysis for the annual and monthly rainfall series for a large number of sub-divisions showed significant periodicities of 2. 1-3.6 years, which correspond to the frequency range of the QBO. In addition, periodicities of 5.1 to 10.0 years and 19.3 years or more were also significant for a number of sub-divisions.  

scholarly journals Impacts of solar intermittency on future photovoltaic reliability

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jun Yin ◽  
Annalisa Molini ◽  
Amilcare Porporato
Keyword(s):  
Climate Change ◽  
Solar Radiation ◽  
Power Supply ◽  
Arid Regions ◽  
Climate Model ◽  
Climate Scenarios ◽  
Photovoltaic Power ◽  
The Mean ◽  
Impacts Of Climate Change

Abstract As photovoltaic power is expanding rapidly worldwide, it is imperative to assess its promise under future climate scenarios. While a great deal of research has been devoted to trends in mean solar radiation, less attention has been paid to its intermittent character, a key challenge when compounded with uncertainties related to climate variability. Using both satellite data and climate model outputs, we characterize solar radiation intermittency to assess future photovoltaic reliability. We find that the relation between the future power supply and long-term mean solar radiation trends is spatially heterogeneous, showing power reliability is more sensitive to the fluctuations of mean solar radiation in hot arid regions. Our results highlight how reliability analysis must account simultaneously for the mean and intermittency of solar inputs when assessing the impacts of climate change on photovoltaics.

scholarly journals An Extended Version of the Richardson Model for Simulating Daily Weather Variables

2000 ◽  
Vol 39 (5) ◽  
pp. 610-622 ◽  
Author(s):  
Marc B. Parlange ◽  
Richard W. Katz
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Precipitation Amount ◽  
Statistical Properties ◽  
Skewed Distribution ◽  
Weather Data ◽  
Extended Model ◽  
Weather Variables ◽  
Stochastic Weather Generator ◽  
Daily Weather

Abstract The Richardson model is a popular technique for stochastic simulation of daily weather variables, including precipitation amount, maximum and minimum temperature, and solar radiation. This model is extended to include two additional variables, daily mean wind speed and dewpoint, because these variables (or related quantities such as relative humidity) are required as inputs for certain ecological/vegetation response and agricultural management models. To allow for the positively skewed distribution of wind speed, a power transformation is applied. Solar radiation also is transformed to make the shape of its modeled distribution more realistic. A model identification criterion is used as an aid in determining whether the distributions of these two variables depend on precipitation occurrence. The approach can be viewed as an integration of what is known about the statistical properties of individual weather variables into a single multivariate model. As an application, this extended model is fitted to weather data in the Pacific Northwest. To aid in understanding how such a stochastic weather generator works, considerable attention is devoted to its statistical properties. In particular, marginal and conditional distributions of wind speed and solar radiation are examined, with the model being capable of representing relationships between variables in which the variance is not constant, as well as certain forms of nonlinearity.

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

2008 ◽  
Vol 8 (2) ◽  
pp. 5761-5812 ◽  
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. A long-term measurement of precipitation chemistry has been carried-out in a rural area of Banizoumbou, in the Sahel (Niger), representative of the african semi-arid savanna ecosystem. A total of 305 rainfall samples, representing 90% of the total annual rainfall, were collected with an automatic wet-only rain sampler from June 1994 to September 2005. Using ionic chromatography, pH major inorganic and organic ions were analyzed. Rainwater chemistry at the site is controlled by soil dust emissions associated to a strong terrigeneous contribution represented by SO42–, Ca2+, Carbonates, K+ and Mg2+. Calcium and carbonates represent about 40% of the total ionic charge of precipitation. The second highest contribution is nitrogenous, with annual Volume Weighed Mean (VWM) NO3– and NH4+, concentrations of 11.6 and 18.1 μeq.l−1, respectively. This is thesignature of ammonia sources related to animals and NOx emissions from savannas soils rain-induced, at the beginning of the rainy season. 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 and reflects the marine signature from the monsoon humid air masses coming from the ocean. The mean pH value, calculated from the VWM of H+, is 5.64. Acidity is neutralized by mineral dust, mainly carbonates, and/or dissolved gases such NH3. High level of organic acidity with 8 μeq.l−1 and 5.2 μeq.l−1 of formate and acetate were found, respectively. The analysis of monthly Black Carbon emissions and FAPAR values show that both biogenic emission from vegetation and biomass burning sources could explain the organic acidity content of the precipitation. The interannual variability of the VWM concentrations around the mean (1994–2005) presents fluctuations between ±5% and ±30% mainly attributed to the variations of sources strength associated with rainfall spatio-temporal distribution. From 1994 to 2005, the total mean wet deposition flux in the Sahelian region is 60.1 mmol.m−2.yr−1 and fluctuates around ±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 loadings presents a strong negative gradient from the dry savanna to the forest (143.7, 100.2 to 86.6 μeq.l–1), associated with the gradient of terrigeneous compounds sources. The wet deposition fluxes present an opposite gradient, 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 the rainfall gradient along the ecosystems transect.

Acute and Chronic Changes in Platelet Volume and Count After Cardiopulmonary Bypass Induced Thrombocytopenia in Man

1987 ◽  
Vol 57 (01) ◽  
pp. 55-58 ◽  
Author(s):  
J F Martin ◽  
T D Daniel ◽  
E A Trowbridge
Keyword(s):  
Platelet Count ◽  
Mean Platelet Volume ◽  
Artery Bypass ◽  
Bypass Graft ◽  
Control Group ◽  
Artery Bypass Graft ◽  
Platelet Volume ◽  
Young Males ◽  
The Mean

SummaryPatients undergoing surgery for coronary artery bypass graft or heart valve replacement had their platelet count and mean volume measured pre-operatively, immediately post-operatively and serially for up to 48 days after the surgical procedure. The mean pre-operative platelet count of 1.95 ± 0.11 × 1011/1 (n = 26) fell significantly to 1.35 ± 0.09 × 1011/1 immediately post-operatively (p <0.001) (n = 22), without a significant alteration in the mean platelet volume. The average platelet count rose to a maximum of 5.07 ± 0.66 × 1011/1 between days 14 and 17 after surgery while the average mean platelet volume fell from preparative and post-operative values of 7.25 ± 0.14 and 7.20 ± 0.14 fl respectively to a minimum of 6.16 ± 0.16 fl by day 20. Seven patients were followed for 32 days or longer after the operation. By this time they had achieved steady state thrombopoiesis and their average platelet count was 2.44 ± 0.33 × 1011/1, significantly higher than the pre-operative value (p <0.05), while their average mean platelet volume was 6.63 ± 0.21 fl, significantly lower than before surgery (p <0.001). The pre-operative values for the platelet volume and counts of these patients were significantly different from a control group of 32 young males, while the chronic post-operative values were not. These long term changes in platelet volume and count may reflect changes in the thrombopoietic control system secondary to the corrective surgery.

Sign in / Sign up

Export Citation Format

Share Document