scholarly journals Variations in Nocturnal Residual Layer Height and Its Effects on Surface PM2.5 over Wuhan, China

2021 ◽  
Vol 13 (22) ◽  
pp. 4717
Author(s):  
Xin Ma ◽  
Weicheng Jiang ◽  
Hui Li ◽  
Yingying Ma ◽  
Shikuan Jin ◽  
...  

Large amounts of aerosols remain in the residual layer (RL) after sunset, which may be the source of the next day’s pollutants. However, the characteristics of the nocturnal residual layer height (RLH) and its effect on urban environment pollution are unknown. In this study, the characteristics of the RLH and its effect on fine particles with diameters <2.5 μm (PM2.5) were investigated using lidar data from January 2017 to December 2019. The results show that the RLH is highest in summer (1.55 ± 0.55 km), followed by spring (1.40 ± 0.58 km) and autumn (1.26 ± 0.47 km), and is lowest in winter (1.11 ± 0.44 km). The effect of surface meteorological factors on the RLH were also studied. The correlation coefficients (R) between the RLH and the temperature, relative humidity, wind speed, and pressure were 0.38, −0.18, 0.15, and −0.36, respectively. The results indicate that the surface meteorological parameters exhibit a slight correlation with the RLH, but the high relative humidity was accompanied by a low RLH and high PM2.5 concentrations. Finally, the influence of the RLH on PM2.5 was discussed under different aerosol-loading periods. The aerosol optical depth (AOD) was employed to represent the total amount of pollutants. The results show that the RLH has an effect on PM2.5 when the AOD is small but has almost no effect on PM2.5 when the AOD is high. In addition, the R between the nighttime mean RLH and the following daytime PM2.5 at low AOD is −0.49, suggesting that the RLH may affect the following daytime surface PM2.5. The results of this study have a guiding significance for understanding the interaction between aerosols and the boundary layer.

2021 ◽  
Vol 8 (1) ◽  
pp. 17-22
Author(s):  
Duc Thang Duong ◽  
Thu Bac Vuong ◽  
Quang Long Nguyen ◽  
Thu Ha Nguyen Thi ◽  
Ngoc Quynh Nguyen ◽  
...  

In this study, aerosol samples at Hanoi, Vietnam from February 2017 to January 2018collected on the glass fiber filter were analyzed for 210Pb by using HPGe spectrometry. 210Pb weekly activity concentrations were in the range of 0.12 mBq.m-3 to 2.87 mBq.m-3 with an average value of 0.92 mBq.m-3 and 210Pb monthly activity concentrations were in the range of 0.99 mBq.m-3 to 9.24 mBq.m-3 with an average value of 4.01 mBq.m-3. The analysis of monthly averaged 210Pb activity concentrations revealed a dominant seasonal variability: high activity concentrations of 210Pb in winter and lower values in summer. The correlation between the activity concentrations of 210Pb in aerosoland the meteorological parameters (average temperature, precipitation and relative humidity) were observed and the obtained correlation coefficients are -0.95, -0.58 and -0.71, respectively.


2020 ◽  
Vol 27 (3) ◽  
pp. 373-385
Author(s):  
Predrag Ilić ◽  
Zoran Popović ◽  
Dragana Nešković Markić

AbstractThe paper presents results of the measurements of the tropospheric ozone (O3) concentration and meteorological parameters: temperature, air pressure, relative humidity, speed and wind direction. The data were collected from January 2016 to December 2016 at station located in locality Centre (Banja Luka), Republic of Srpska, Bosnia and Herzegovina. Ozone is one of the most harmful pollutants to plants and health and highly reactive secondary pollutant. The present study covers investigation of the relationship between the concentration of ozone and meteorological parameters as well as time variations of ozone concentration (by hours, months, seasons). This topic has not been studied up to now in this region, although the recent research data indicates that there is a correlation between them and previously obtained from the world’s relevant scientific centres, as already cited above. Statistical analysis confirms string of rolls, which shows directional connection between tropospheric ozone and meteorological parameters, specially temperature (r = 0.148), air pressure (r = –0.292) and relative humidity (r = –0.292). These parameters are the most important meteorological factors influencing the variation in ozone levels during the research. The correlation ozone concentrations with speed and direction of wind is not significant, like other parameters.


2020 ◽  
Author(s):  
Supari ◽  
Danang Eko Nuryanto ◽  
Amsari Muzakir Setiawan ◽  
Ardhasena Sopaheluwakan ◽  
Furqon AlFahmi ◽  
...  

Abstract On March 2, 2020, the first Coronavirus Disease (COVID-19) case was reported in Jakarta, Indonesia. One and half month later (15/05/2020), the cumulative number of infection cases was 16496 with a total of 1076 mortalities. This study is aimed to investigate the possible role of weather in the early cases of COVID-19 incidence in six selected cities in Indonesia. Daily data of temperature and relative humidity from weather stations nearby each city were collected during the period 3 March - 30 April 2020, together with data of COVID-19 cases. Correlation tests and regression analysis were performed to examine the association of those two data series. In addition, we analysed the distribution of COVID-19 with respect to weather data to estimate the effective range of weather data supporting COVID-19 incidence. Our results reveal that weather data is generally associated with COVID-19 incidence. The daily average temperature (T-ave) and relative humidity (RH) presents significant positive and negative correlation with COVID-19 data, respectively. However, the correlation coefficients are weak with the strongest correlations found at 5 day lag time i.e. 0.37 (-0.41) for T-ave (RH). The regression analysis consistently confirmed this relation. The distribution analysis reveals that the majority of COVID-19 cases in Indonesia occurred in the daily temperature range of 25-31oC and relative humidity of 74-92%. Our findings suggest that COVID-19 incidence in Indonesia has a weak association with weather conditions. Therefore, non-meteorological factors seem to play a larger role and should be given greater consideration in preventing the spread of COVID-19.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 187
Author(s):  
Olympia E. Anastasiou ◽  
Anika Hüsing ◽  
Johannes Korth ◽  
Fotis Theodoropoulos ◽  
Christian Taube ◽  
...  

Background: Seasonality is a characteristic of some respiratory viruses. The aim of our study was to evaluate the seasonality and the potential effects of different meteorological factors on the detection rate of the non-SARS coronavirus detection by PCR. Methods: We performed a retrospective analysis of 12,763 respiratory tract sample results (288 positive and 12,475 negative) for non-SARS, non-MERS coronaviruses (NL63, 229E, OC43, HKU1). The effect of seven single weather factors on the coronavirus detection rate was fitted in a logistic regression model with and without adjusting for other weather factors. Results: Coronavirus infections followed a seasonal pattern peaking from December to March and plunged from July to September. The seasonal effect was less pronounced in immunosuppressed patients compared to immunocompetent patients. Different automatic variable selection processes agreed on selecting the predictors temperature, relative humidity, cloud cover and precipitation as remaining predictors in the multivariable logistic regression model, including all weather factors, with low ambient temperature, low relative humidity, high cloud cover and high precipitation being linked to increased coronavirus detection rates. Conclusions: Coronavirus infections followed a seasonal pattern, which was more pronounced in immunocompetent patients compared to immunosuppressed patients. Several meteorological factors were associated with the coronavirus detection rate. However, when mutually adjusting for all weather factors, only temperature, relative humidity, precipitation and cloud cover contributed independently to predicting the coronavirus detection rate.


2021 ◽  
pp. 014556132110091
Author(s):  
Ying-Fang Jiang ◽  
Wen-Wei Luo ◽  
Xin Zhang ◽  
Dong-Dong Ren ◽  
Yi-Bo Huang

Objective: The associations between climate variables and diseases such as respiratory infections, influenza, pediatric seizure, and gastroenteritis have been long appreciated. Infection is the main reason for acute otitis media (AOM) incidence. However, few previous studies explored the correlation between climatic parameters and AOM infections. The most important meteorological factors, temperature, relative humidity, and fine particulate matter (PM2.5), were included in this study. We studied the relationship between these meteorological factors and the AOM visits. Materials and Methods: It was a retrospective cross-sectional study. A linear correlation and a linear regression model were used to explore the AOM visits and meteorological factors. Results: A total of 7075 emergency department visits for AOM were identified. Relative humidity was found an independent risk factor for the AOM visits in preschool children (regression coefficient = −10.841<0, P = .039 < .05), but not in infants and school-age children. Average temperature and PM2.5 were not correlated with AOM visits. Conclusion: Humidity may have a significant inverse impact on the incidence of AOM in preschool-age children.


2017 ◽  
Vol 17 (3) ◽  
pp. 1847-1863 ◽  
Author(s):  
Jiming Li ◽  
Qiaoyi Lv ◽  
Min Zhang ◽  
Tianhe Wang ◽  
Kazuaki Kawamoto ◽  
...  

Abstract. Based on 8 years of (January 2008–December 2015) cloud phase information from the GCM-Oriented Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) Cloud Product (GOCCP), aerosol products from CALIPSO and meteorological parameters from the ERA-Interim products, the present study investigates the effects of atmospheric dynamics on the supercooled liquid cloud fraction (SCF) during nighttime under different aerosol loadings at global scale to better understand the conditions of supercooled liquid water gradually transforming to ice phase. Statistical results indicate that aerosols' effect on nucleation cannot fully explain all SCF changes, especially in those regions where aerosols' effect on nucleation is not a first-order influence (e.g., due to low ice nuclei aerosol frequency). By performing the temporal and spatial correlations between SCFs and different meteorological factors, this study presents specifically the relationship between SCF and different meteorological parameters under different aerosol loadings on a global scale. We find that the SCFs almost decrease with increasing of aerosol loading, and the SCF variation is closely related to the meteorological parameters but their temporal relationship is not stable and varies with the different regions, seasons and isotherm levels. Obviously negative temporal correlations between SCFs versus vertical velocity and relative humidity indicate that the higher vertical velocity and relative humidity the smaller SCFs. However, the patterns of temporal correlation for lower-tropospheric static stability, skin temperature and horizontal wind are relatively more complex than those of vertical velocity and humidity. For example, their close correlations are predominantly located in middle and high latitudes and vary with latitude or surface type. Although these statistical correlations have not been used to establish a certain causal relationship, our results may provide a unique point of view on the phase change of mixed-phase cloud and have potential implications for further improving the parameterization of the cloud phase and determining the climate feedbacks.


2011 ◽  
Vol 189-193 ◽  
pp. 1538-1542
Author(s):  
Li Xiao Jia ◽  
Yong Zhen Zhang ◽  
Yong Ping Niu ◽  
San Ming Du ◽  
Jian Li

In order to decrease accidents of slips and falls, COFs of rubber samples with different surface roughness were measured by Brungraber Mark II. And the correlation coefficients between roughness parameters and COF were calculated. The rusults have shown that the COF increases with surface roughness and the correlation coefficient between Sq and COF is highest. In general, almost all the roughness parameters used in the study have high correlation with COF. Parameters had the highest correlation with COF depends on the materials used and test conditions.


2015 ◽  
Vol 10 (2) ◽  
Author(s):  
Radina P. Soebiyanto ◽  
Wilfrido A. Clara ◽  
Jorge Jara ◽  
Angel Balmaseda ◽  
Jenny Lara ◽  
...  

Seasonal influenza affects a considerable proportion of the global population each year. We assessed the association between subnational influenza activity and temperature, specific humidity and rainfall in three Central America countries, <em>i.e.</em> Costa Rica, Honduras and Nicaragua. Using virologic data from each country’s national influenza centre, rainfall from the Tropical Rainfall Measuring Mission and air temperature and specific humidity data from the Global Land Data Assimilation System, we applied logistic regression methods for each of the five sub-national locations studied. Influenza activity was represented by the weekly proportion of respiratory specimens that tested positive for influenza. The models were adjusted for the potentially confounding co-circulating respiratory viruses, seasonality and previous weeks’ influenza activity. We found that influenza activity was proportionally associated (P&lt;0.05) with specific humidity in all locations [odds ratio (OR) 1.21-1.56 per g/kg], while associations with temperature (OR 0.69-0.81 per °C) and rainfall (OR 1.01-1.06 per mm/day) were location-dependent. Among the meteorological parameters, specific humidity had the highest contribution (~3-15%) to the model in all but one location. As model validation, we estimated influenza activity for periods, in which the data was not used in training the models. The correlation coefficients between the estimates and the observed were ≤0.1 in 2 locations and between 0.6-0.86 in three others. In conclusion, our study revealed a proportional association between influenza activity and specific humidity in selected areas from the three Central America countries.


2018 ◽  
Vol 147 ◽  
Author(s):  
Chunxiao Duan ◽  
Xuefeng Zhang ◽  
Hui Jin ◽  
Xiaoqing Cheng ◽  
Donglei Wang ◽  
...  

AbstractSince the late 1990s, hand, foot and mouth disease (HFMD) has become a common health problem that mostly affects children and infants in Southeast and East Asia. Global climate change is considered to be one of the major risk factors for HFMD. This study aimed to assess the correlation between meteorological factors and HFMD in the Asia-Pacific region. PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang Data and Weipu Database were searched to identify relevant articles published before May 2018. Data were collected and analysed using R software. We searched 2397 articles and identified 51 eligible papers in this study. The present study included eight meteorological factors; mean temperature, mean highest temperature, mean lowest temperature, rainfall, relative humidity and hours of sunshine were positively correlated with HFMD, with correlation coefficients (CORs) of 0.52 (95% confidence interval (CI) 0.42–0.60), 0.43 (95% CI 0.23–0.59), 0.43 (95% CI 0.23–0.60), 0.27 (95% CI 0.19–0.35), 0.19 (95% CI 0.02–0.35) and 0.19 (95% CI 0.11–0.27), respectively. There were sufficient data to support a negative correlation between mean pressure and HFMD (COR = −0.51, 95% CI −0.63 to −0.36). There was no notable correlation with wind speed (COR = 0.10, 95% CI −0.03 to 0.23). Our findings suggest that meteorological factors affect the incidence of HFMD to a certain extent.


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