scholarly journals Characteristics and Meteorological Factors of Severe Haze Pollution in China

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Chao He ◽  
Song Hong ◽  
Hang Mu ◽  
Peiyue Tu ◽  
Lu Yang ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Meteorological Data ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Weather Conditions ◽  
Large Contribution ◽  
Low Wind Speed ◽  
Haze Pollution ◽  
Secondary Aerosols ◽  
Pm2.5 Concentration

A severe haze pollution incident caused by unfavorable weather conditions and a northern air mass occurred in eastern, northern, northwestern, and southwestern China from January 15 to January 22, 2018. To comparatively analyze variations in PM2.5 pollution, hourly monitoring data and 24 h meteorological data were collected. Air quality observations revealed large spatiotemporal variation in PM2.5 concentrations in Handan, Zhengzhou, Xi’an, Yuncheng, Chengdu, Xiangyang, and Jinan. The daily mean PM2.5 concentrations ranged from 111.35 to 227.23 μg·m−³, with concentration being highest in Zhengzhou. Hourly mean PM2.5 concentration presented multiple U-shaped curves, with higher values at night and lower values during the day. The ratios of PM2.5 to PM10 were large in target cities and the results of multiscale geographic weighted regression model (MGWR) and Pearson correlation coefficients showed that PM2.5 had a significant positive or negative correlation with PM10, CO, NO2, and SO2. The concentration of PM2.5 was closely related to the combustion of fossil fuels and other organic compounds, indicating the large contribution of secondary aerosols to PM2.5 concentrations. The analysis of meteorological conditions showed that low temperature, low wind speed, and high relative humidity could aggravate the accumulation of regional pollutants in winter. Northwestern trajectory clusters were predominant contributions except in Jinan, and the highest PM2.5 concentrations in target cities were associated with short trajectory clusters in winter. The potential sources calculated by Weight Potential Source Contribution Function (WPSCF) and Weight Concentration-Weighted Trajectory (WCWT) models were similar and the highest values of the WPSCF (>0.5) and the WCWT (>100 μg·m−³) were mainly distributed in densely populated, industrial, arid, and semiarid regions.

scholarly journals The effect of air temperature on forest fire risk in the municipality of Negotin

2015 ◽  
Vol 95 (4) ◽  
pp. 67-76
Author(s):  
Stanimir Zivanovic ◽  
Milena Gocic ◽  
Radomir Ivanovic ◽  
Natasa Martic-Bursac
Keyword(s):  
Air Temperature ◽  
Forest Fires ◽  
Meteorological Data ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Fire Risk ◽  
Annual Number ◽  
Absolute Maximum ◽  
Maximum Air Temperature ◽  
Forest Fire Risk

Fires in nature are caused by moisture content in the burning material, which is dependent on the values of the climatic elements. The occurrence of these fires in Serbia is becoming more common, depending on the intensity and duration have a major impact on the state of vegetation. The aim of this study was to determine the association between changes in air temperature and the dynamics of the appearance of forest fires. To study the association of these properties were used Pearson correlation coefficients. The analysis is based on meteorological data obtained from meteorological station in Negotin for the period 1991-2010. Research has found that the annual number of fires, correlating with an average annual air temperature (p = 0.317, ? = 0.21). Also, it was found that the annual number of fires positive, medium intensity, correlate with the absolute maximum air temperature (p = 0.578, ? = 0.26), but not statistically significant (p> 0.05).

Regional analysis of winter wheat yields under different ecological conditions in Hungary and Croatia

2011 ◽  
Vol 59 (1) ◽  
pp. 23-33 ◽  
Author(s):  
P. Pepó ◽  
V. Kovačević
Keyword(s):  
Winter Wheat ◽  
Meteorological Data ◽  
Pearson Correlation ◽  
Regional Analysis ◽  
Crop Protection ◽  
Weather Conditions ◽  
Water Shortage ◽  
Spring Temperature ◽  
Temperature Regimes ◽  
The Impact

Wheat is the second most important field crop on arable lands in Hungary and Croatia. Yield variations between years are high in both countries. In the short term these variations are mainly the result of the weather parameters specific to individual growing seasons. The aim of this study was to compare variations in winter wheat yields over years in four counties in Hungary and five in Croatia, with the emphasis on the impact of rainfall and mean air temperature regimes. The results showed that rainfall in spring was most decisive for winter wheat yields. The highest winter wheat yields were obtained when the rainfall in the winter half-year ranged from 230–260 mm and the spring rainfall from 180–230 mm. The precipitation in the growing season is much higher in eastern Croatia than in eastern Hungary, so water shortage is a more pronounced environmental problem for wheat in Hungary. This is probably why wheat yields were lower in eastern Hungary than in eastern Croatia in the period tested. Pearson correlation analysis on the yields and meteorological data between 1990 and 2009 revealed a positive correlation between spring rainfall and the yield, and a negative correlation between spring temperature and the yield. The results proved that yields were determined not only by weather conditions, but by many other factors (crop rotation, tillage, fertilization, variety, crop protection, etc.).

scholarly journals Measuring the Impact of Statistical Techniques for Computation of Weighting Factors in Avalanche Forecasting Model

2019 ◽  
Vol 8 (4) ◽  
pp. 886-891
Keyword(s):  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Weather Conditions ◽  
Skill Score ◽  
Forecasting Model ◽  
Avalanche Forecasting ◽  
Weighting Factors ◽  
The Impact

Avalanche forecasting is an important measure required for the safety of the people residing in hilly regions. Snow avalanches are caused due to the changes that occur in the snow and weather conditions. The prominent changes, that cause the variations which further culminate into an avalanche, can be given higher significance in the forecasting model by application of appropriate weights. These weights are decided based on the relation of each weather parameter to snow avalanche occurrence by the forecaster with the help of historical data. A method is proposed in the current work that can help in removing this subjectivity by using correlation coefficients. Present work explores the use of Pearson correlation coefficient, Spearman rank correlation coefficient and Kendall Tau correlation coefficient to obtain the weighting factors for each parameter used for avalanche forecasting. These parameters are further used in the cosine similarity based nearest neighbour model for avalanche forecasting. Bias and Peirce’s Skill Score are performance measures used to evaluate the outcome of the experimental work.

scholarly journals Retrieval of aerosol optical properties over Beijing: a comparison between SKYNET and AERONET

2019 ◽  
Author(s):  
Xianyi Yang ◽  
Huizheng Che ◽  
Hitoshi Irie ◽  
Quanliang Chen ◽  
Ke Gui ◽  
...  
Keyword(s):  
Optical Properties ◽  
Meteorological Data ◽  
Aerosol Particles ◽  
Fine Particulate Matter ◽  
Correlation Coefficients ◽  
Weather Conditions ◽  
Distribution Patterns ◽  
Single Scattering ◽  
Aerosol Optical Properties ◽  
Pollution Event

Abstract. This study assesses the performance of SKYNET in comparison to AERONET (Aerosol Robotic Network) for retrieving aerosol optical properties (AOPs) in Beijing, China. The results obtained from simultaneous measurements show high correlation coefficients (> 0.994) for aerosol optical depth (AOD) at each wavelength. The highest correlation coefficient for Ångström exponent is 0.825, at 500–870 nm. The single scattering albedo (SSA) of SKYNET is systematically larger than that of AERONET at each wavelength, and adjusting the SVA (solid view angle) and SA (surface albedo) input values can easily affect the value of SKYNET SSA. The volume size distribution patterns derived from the two networks’ instruments are both bimodal, which is typical, while the coarse-mode volume of SKYNET is larger than that of AERONET on average. According to the frequency distribution of aerosol particles, coarser aerosol particles often present in autumn and finer particles usually exist in winter, and there are more absorbent aerosol particles in winter. SKYNET data, combined with meteorological data, CALIPSO (Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations) data, backward trajectories, and WPSCF (weighted potential source contribution function) and WCWT (weighted concentrated weighted trajectory) analyses are used to analyze a serious pollution event in winter over Beijing. The results suggest that it was not only affected by local emissions but also by regional transport. The AOPs under three weather conditions (clean, dusty, haze) in Beijing are discussed. The values of AOD on haze days are about 10.3, 10.0, 8.7, 6.3 and 6.2 times larger than those on clean days at 400, 500, 670, 870 and 1020 nm, respectively; and under haze conditions, the PM2.5 (fine particulate matter) is about 7.6 times larger than that under clean conditions. The values of AOD on dusty days are about 7.1, 7.4, 7.0, 5.3 and 5.2 times larger than those on clean days at 400, 500, 670, 870 and 1020 nm, respectively; and under haze conditions, the PM2.5 is about 5.2 times larger than that under clean conditions.

Impact of weather conditions on variability in sunflower yield over years in eastern parts of Croatia and Hungary

2012 ◽  
Vol 60 (4) ◽  
pp. 397-405 ◽  
Author(s):  
A. Mijić ◽  
I. Liović ◽  
V. Kovačević ◽  
P. Pepó
Keyword(s):  
Meteorological Data ◽  
Correlation Coefficients ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Soil Conditions ◽  
Field Crops ◽  
Oil Crops ◽  
Air Temperatures ◽  
Important Field ◽  
The Impact

Oil crops constitute the second most important field crops worldwide and are important both in Hungary and Croatia. Among the oil crops, sunflower has a significant role in Hungary (∼550,000 ha) and Croatia (∼30,000 ha). The main aim of this study was to compare sunflower yields and their variation over years (2000–2007) in the eastern parts of Hungary and Croatia, with the emphasis on the impact of rainfall and temperature regime, and using a rain factor (RFm) calculated monthly as the quotient of precipitation (mm) and mean air temperatures (°C). The results showed that the year had a different effect on the yield of sunflower in the different counties of eastern Hungary and Croatia, because of their different soil conditions. The results proved that the highest yields of sunflower (2140–2710 kg ha−1) were obtained in years when the rainfall before and during the vegetation period was 110–130 mm and 350–420 mm, which was very similar to the 30-year mean data (82–108 mm and 305–346 mm, respectively). The strongest correlations (positive and negative r values) between meteorological data and sunflower yields were found in counties with unfavourable soil conditions. In counties with better soil fertility the correlation coefficients were smaller, indicating that better soil conditions can compensate for unfavourable year effects (especially temporary shortage of rainfall or unfavourable rainfall distribution).

scholarly journals 209Novel indicator of air pollution control efficacy: analysis of 196 countries from 2000 to 2016

2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Chunlei Han
Keyword(s):  
Air Pollution ◽  
Pollution Control ◽  
Co2 Emission ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Gdp Per Capita ◽  
Air Pollution Control ◽  
Control Efficacy ◽  
Per Capita ◽  
Pm2.5 Concentration

Abstract Background PM2.5 concentration is different with the same CO2 emission across countries, which might because of different air pollution control efficacy. But there is no indicator to reflect the level of air pollution control efficacy in previous studies. We aimed to develop such an indicator, and to evaluate its global and temporal distribution and its association with country-level health metrics. Methods A novel indicator, PM2.5 concentration per unit per capita CO2 emission (PC), was developed to show the air pollution control efficacy. We estimated and mapped the global average distribution of PC and PC changes during 2000-2016 of 196 countries for the first time. Gini coefficient was used to show the inequity of PC among different countries. Pearson correlation coefficients and Generalized Additive Mixed Model (GAMM) were used to evaluate the relationship between PC and health metrics. Results PC varied by country with an inverse association with GDP per capita. PC showed a declining trend globally from 2000 to 2016. The most remarkable decreases were observed for countries in Central Africa like Chad, Democratic Republic of Congo and Niger, then China and India. The international inequality of PC has also decreased. The Pearson correlation coefficients between PC and life expectancy at birth (LE), Infant-mortality rate (IMR), Under-five mortality rate (U5MR) and logarithm of GDP per capita(LPGDP) were -0.566, 0.646, 0.659,-0.585 respectively(all P-values <0.05). Compared with PM2.5 and CO2, PC could explain more variation of LE, IMR and U5MR. Conclusions PC might be a good indicator of air pollution control efficacy and was related to important health indicators. Our findings provide a new way to interpret health equity across the globe from the point of air pollution control efficacy. Key messages air pollution, climate change, health equity, air pollution control efficacy our study developed a novel air pollution control efficacy indicator named PM2.5 concentration per unit per capita CO2 emission (PC). In the context of global climate change, PC is a good indicator to deal with air pollution for policymakers.

scholarly journals Cranberry Stomatal Conductivity

HortScience ◽  
1993 ◽  
Vol 28 (11) ◽  
pp. 1114-1116 ◽  
Author(s):  
Paul J. Croft ◽  
Mark D. Shulman ◽  
Roni Avissar
Keyword(s):  
Current Knowledge ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Weather Conditions ◽  
Physical Structure ◽  
Time Of Day ◽  
Vaccinium Macrocarpon ◽  
Fruit Maturation ◽  
Stomatal Conductivity ◽  
Scatter Plots

Cranberry (Vaccinium macrocarpon Ericaceae Ait.) stomatal conductivity (SC) was investigated in the field to examine plant response as a function of weather conditions. Measurements were made during fruit maturation on 14 days between 0540 and 1710 h r, as weather conditions permitted. SC ranged from 0.02 to 0.08 cm·s-1 and was much lower than for most other crops. Scatter plots of SC vs. leaf temperature by day indicated only a weak linear relationship. When the data were stratified by time of day and by clear and overcast skies, several significant Pearson correlation coefficients suggested a stomatal response. The findings, when combined with current knowledge of the physical structure of cranberry stomata, suggest that cranberries behave as xeromorphic plants.

Reliability of the Minimum Masking Level as Outcome Variable in Tinnitus Clinical Research

2020 ◽  
Vol 29 (3) ◽  
pp. 429-435
Author(s):  
Patricia C. Mancini ◽  
Richard S. Tyler ◽  
Hyung Jin Jun ◽  
Tang-Chuan Wang ◽  
Helena Ji ◽  
...  
Keyword(s):  
Standard Deviation ◽  
High Frequency ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Outcome Variable ◽  
Reliable Estimate ◽  
Moderate Correlation ◽  
Trained Subjects ◽  
The Relationship ◽  
Minimum Intensity

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.

A tes

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
IJE Manager
Keyword(s):  
Energy Supply ◽  
Fossil Fuels ◽  
Geographical Location ◽  
Weather Conditions ◽  
Past Century ◽  
Solar Pv ◽  
Pv Systems ◽  
Trade Offs ◽  
A Site ◽  
Selection Methodology

In the past century, fossil fuels have dominated energy supply in Indonesia. However, concerns over emissions are likely to change the future energy supply. As people become more conscious of environmental issues, alternatives for energy are sought to reduce the environmental impacts. These include renewable energy (RE) sources such as solar photovoltaic (PV) systems. However, most RE sources like solar PV are not available continuously since they depend on weather conditions, in addition to geographical location. Bali has a stable and long sunny day with 12 hours of daylight throughout the year and an average insolation of 5.3 kWh/m2 per day. This study looks at the potential for on-grid solar PV to decarbonize energy in Bali. A site selection methodology using GIS is applied to measure solar PV potential. Firstly, the study investigates the boundaries related to environmental acceptability and economic objectives for land use in Bali. Secondly, the potential of solar energy is estimated by defining the suitable areas, given the technical assumptions of solar PV. Finally, the study extends the analysis to calculate the reduction in emissions when the calculated potential is installed. Some technical factors, such as tilting solar, and intermittency throughout the day, are outside the scope of this study. Based on this model, Bali has an annual electricity potential for 32-53 TWh from solar PV using amorphous thin-film silicon as the cheapest option. This potential amount to three times the electricity supply for the island in 2024 which is estimated at 10 TWh. Bali has an excessive potential to support its own electricity demand with renewables, however, some limitations exist with some trade-offs to realize the idea. These results aim to build a developmental vision of solar PV systems in Bali based on available land and the region’s irradiation.

Comparative Responses to Squats Completed with Free Weights and an Exoskeleton

2020 ◽  
Vol 4 (1) ◽  
pp. 51-63
Author(s):  
Peter Neuhaus ◽  
Chris Jumonville ◽  
Rachel A. Perry ◽  
Roman Edwards ◽  
Jake L. Martin ◽  
...  
Keyword(s):  
Data Collection ◽  
Female Athletes ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Actual Data ◽  
Limited Data ◽  
Comparative Similarity ◽  
Insufficient Amount ◽  
Force Data ◽  
Familiarization Session

AbstractTo assess the comparative similarity of squat data collected as they wore a robotic exoskeleton, female athletes (n=14) did two exercise bouts spaced 14 days apart. Data from their exoskeleton workout was compared to a session they did with free weights. Each squat workout entailed a four-set, four-repetition paradigm with 60-second rest periods. Sets for each workout involved progressively heavier (22.5, 34, 45.5, 57 kg) loads. The same physiological, perceptual, and exercise performance dependent variables were measured and collected from both workouts. Per dependent variable, Pearson correlation coefficients, t-tests, and Cohen's d effect size compared the degree of similarity between values obtained from the exoskeleton and free weight workouts. Results show peak O2, heart rate, and peak force data produced the least variability. In contrast, far more inter-workout variability was noted for peak velocity, peak power, and electromyography (EMG) values. Overall, an insufficient amount of comparative similarity exists for data collected from both workouts. Due to the limited data similarity, the exoskeleton does not exhibit an acceptable degree of validity. Likely the cause for the limited similarity was due to the brief amount of familiarization subjects had to the exoskeleton prior to actual data collection. A familiarization session that accustomed subjects to squats done with the exoskeleton prior to actual data collection may have considerably improved the validity of data obtained from that device.

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