scholarly journals Assessing and modeling particulate pollution in the city of Ouagadougou (Burkina Faso) 

2021 ◽  
Vol 2 (1b) ◽  
pp. C20A14-1-C20A14-6
Author(s):  
Issoufou Ouarma ◽  
◽  
Bernard Nana ◽  
Kayaba Haro ◽  
Jean Koulidiati ◽  
...  
Keyword(s):  
Rainy Season ◽  
Road Traffic ◽  
Threshold Value ◽  
Emission Factors ◽  
Dry Season ◽  
In Situ Measurements ◽  
Industrial Plant ◽  
Pm2.5 And Pm10 ◽  
The City

In the present work, the pollution levels of airborne particles in the city of Ouagadougou have been assessed through two campaigns of in situ measurements of PM2.5 and PM10 concentrations. These measures were performed using a portable device (AEROCET 531S) on roadside sites and on sites located in administrative services, secondary schools and outlying districts. Since in situ measurements don’t give any indication of the pollution that could be due to a new source (industrial plant, road, etc.) and how it is dispersed spatially and temporally, thus pollutant emissions from road traffic and the dispersion of these pollutants are obtained by a modelling chain that couples COPERT IV emission model under Pollemission code with MUNICH dispersion model. As results, the average 24-hour concentrations are 87±16 and 951±266 μg/m3 for the PM2.5 and PM10, respectively, in 2018 dry season. They are 29±5 and 158±43 μg/m3, respectively, in 2018 rainy season and, 22±9 and 187±67 μg/m3 in 2019 rainy season, respectively. These results show that independently of the season (dry or rainy), the PM10 concentrations are high and exceed the World Health Organization Air Quality Guidelines (WHO AQG) and European 24-hour threshold value of 50 μg/m3. Concerning the PM2.5 concentrations in dry season, they are high and exceed the WHO AQG and European 24-hour threshold value of 25 μg/m3. The results obtained concerning the modeling of the dispersion of PM air pollution due to road traffic in the city of Ouagadougou are partially satisfactory. The modeled maximum values of the exhaust emission factors are very high while the modeled concentrations are underestimated compared to the measured concentrations The estimated emission factors range between 0 and 400 g/km/h and between 0 and 303 g/km/h for exhaust PM2.5 and resuspension PM2.5, respectively. They vary between 0 and 2 997 g/km/h for resuspension PM10. Concerning the modelled concentrations, they are between 0 and 238 μg/m3 for PM2.5 and between 0 and 2 072 μg/m3 for PM10. These results can be improved with updated traffic and road characterization data.

scholarly journals Aerosol measurements at the Gual Pahari EUCAARI station: preliminary results from in-situ measurements

2010 ◽  
Vol 10 (15) ◽  
pp. 7241-7252 ◽  
Author(s):  
A.-P. Hyvärinen ◽  
H. Lihavainen ◽  
M. Komppula ◽  
T. S. Panwar ◽  
V. P. Sharma ◽  
...  
Keyword(s):  
Rainy Season ◽  
In Situ Measurements ◽  
Aerosol Size Distribution ◽  
Finnish Meteorological Institute ◽  
Convective Mixing ◽  
Average Fraction ◽  
Mode Size ◽  
First Time ◽  
Pm10 Mass

Abstract. The Finnish Meteorological Institute (FMI), together with The Energy and Resources Institute of India (TERI), contributed to the European Integrated project on Aerosol Cloud Climate and Air Quality Interactions, EUCAARI, by conducting aerosol measurements in Gual Pahari, India, from December 2007 to January 2010. This paper describes the station setup in detail for the first time and provides results from the aerosol in-situ measurements, which include PM and BCe masses, aerosol size distribution from 4 nm to 10 μm, and the scattering and absorption coefficients. The seasonal variation of the aerosol characteristics was very distinct in Gual Pahari. The highest concentrations were observed during the winter and the lowest during the rainy season. The average PM10 concentration (at STP conditions) was 216 μgm−3 and the average PM2.5 concentration was 126 μgm−3. A high percentage (4–9%) of the PM10 mass consisted of BCe which indicates anthropogenic influence. The percentage of BCe was higher during the winter; and according to the diurnal pattern of the BCe fraction, the peak occurred during active traffic hours. Another important source of aerosol particles in the area was new particle formation. The nucleated particles grew rapidly reaching the Aitken and accumulation mode size, thus contributing considerably to the aerosol load. The rainy season decreased the average fraction of particle mass in the PM2.5 size range, i.e. of secondary origin. The other mechanism decreasing the surface concentrations was based on convective mixing and boundary layer evolution. This diluted the aerosol when sun radiation and the temperature was high, i.e. especially during the pre-monsoon day time. The lighter and smaller particles were more effectively diluted.

scholarly journals Diurnal, Seasonal and Annual Variation of Microwave Radio Refractivity Gradient over Akure, South West Nigeria

2019 ◽  
pp. 1-11
Author(s):  
Adekunle Titus Adediji ◽  
Joseph Babatunde Dada ◽  
Moses Oludare Ajewole
Keyword(s):  
Rainy Season ◽  
Annual Variation ◽  
Ground Surface ◽  
Local Effect ◽  
Dry Season ◽  
Radio Link ◽  
Wet Season ◽  
Annual Variations ◽  
Microwave Radio

In this study, four years in-situ measurements of atmospheric parameters (pressure, temperature and relative humidity) were carried out. The measurement was by placing an automatic weather station at five different heights: ground surface, 50, 100, 150 and 200 m respectively on a 220 m Nigeria Television Authority TV tower in Akure, South Western Nigeria. The four years Data collected (January 2007 to December 2009 and January to December 2011) were used to compute radio refractivity and its gradient. The local effect of a location/ region cannot but looked into when designing effective radio link, hence the diurnal, seasonal and annual variations of the radio refractivity gradient were studied. Results showed that refractivity gradient steadily increases inthe hour of 8:30 and 9:30 to 18:00 during dry season throughout the years investigated, and decreases two hours in the rainy season than the dry season. The record shows that at 50 m altitude, the maximum and minimum values are 158 N-unit/km around 14:30 and - 286 N-unit/km around 13:30 to 14:00 hrs, LT during the dry and rainy season respectively. Seasonally, refractivity gradient is steeper with greater variability in the dry season months than in the wet season months.

scholarly journals The invertebrate colonization during decomposition of Eichhornia azurea kunth in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir (São Paulo, Brazil)

2002 ◽  
Vol 62 (2) ◽  
pp. 293-310 ◽  
Author(s):  
N. de L. STRIPARI ◽  
R. HENRY
Keyword(s):  
Decomposition Rate ◽  
Rainy Season ◽  
Dry Season ◽  
Material Loss ◽  
Litter Bags ◽  
Eichhornia Azurea ◽  
Mouth Zone ◽  
Dry Seasons ◽  
Invertebrate Colonization

The invertebrate colonization during decomposition of Eichhornia azurea was observed in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir in two periods of the year. The litter bags method was used for measuring the decomposition rate as well as to evaluate the invertebrates colonization. Forty-two litter bags, measuring 15 × 20 cm in size and 2 mm mesh net, were incubated "in situ". Six litter bags (three for colonization and three for decomposition measurements) were removed after the 1st, 3rd, 7th, 14th, 28th, 56th and 72nd days of incubation. After each day, the material was carefully cleaned for detritus removal and invertebrate sampling. The biological material was fixed with 4% formaline and then sorted and identified. The remaining plant material was dried in an oven (at 60ºC) and weighed. A fast material loss occurred during the first 24 hours and the decomposition rate was higher during the rainy season than in the dry season. A peak on invertebrate density (110 ind.g.DW--1) on the remaining detritus of Eichhornia azurea was recorded in the 56th day of dry season, when the polyphenol concentration of plant detritus was 0.57 UDO.g.DW--1. In the rainy season, higher density was found in the 28th day of incubation, when the polyphenol concentration was 4.36 UDO.g.DW--1. Apparently, the reduction in the polyphenol concentration was followed by an increase in invertebrate densities. The majority of the species observed in the detritus belongs to the collector group that was dominant after the 7th and 14th days in the rainy and dry seasons, respectively.

scholarly journals Co-located column and in situ measurements of CO<sub>2</sub> in the tropics compared with model simulations

2010 ◽  
Vol 10 (2) ◽  
pp. 3173-3187
Author(s):  
T. Warneke ◽  
A. K. Petersen ◽  
C. Gerbig ◽  
A. Jordan ◽  
C. Rödenbeck ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Southern Hemisphere ◽  
Dry Season ◽  
In Situ Measurements ◽  
Local Source ◽  
Air Samples ◽  
Model Simulations ◽  
Mixing Ratios ◽  
Source Component

Abstract. The first ground-based remote sensing measurements of the column averaged volume mixing ratio of CO2 (XCO2) for the inner tropics have been obtained at Paramaribo, Suriname (5.8° N, 55.2° W). The remote sensing observations are complemented by surface air-samples collected at the site, analyzed for CO2 and 13CO2. The surface in-situ measurements are strongly influenced by local sources. From the isotopic composition of the air samples the local source component is suggested to be dominated by the terrestrial biosphere. Using δ13C from the NOAA/ESRL stations Ascension Is. (ASC), 7.9° S, 14.4° W, and Ragged Point (RPB), 7.9° S, 14.4° W, the data has been corrected for the local source component. Due to the migration of the ITCZ over the measurement site the probed air masses belong to the Northern or Southern Hemisphere depending on the time of the year. Comparison to analyzed CO2 fields based on TM3 model simulations using optimized fluxes indicate agreement for XCO2 as well as for the corrected CO2 mixing ratios at the surface for the long dry season, when Paramaribo belongs to the Southern Hemisphere. A slightly worse agreement during the short dry season is attributed to a larger representation error during this time of the year. Overall the comparison demonstrates that the TM3 model is capable to simulate surface concentrations as well as column densities of CO2 correctly at the same location.

scholarly journals Seasonal morphological variability in an in situ Cyanobacteria monoculture: example from a persistent Cylindrospermopsis bloom in Lake Catemaco, Veracruz, Mexico

2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Owen Lind ◽  
Laura Dávalos-Lind ◽  
Carlos López ◽  
Martin López ◽  
Juli Dyble Bressie
Keyword(s):  
Rainy Season ◽  
Morphological Variability ◽  
Morphological Diversity ◽  
Dry Season ◽  
Transient Condition ◽  
Dry Seasons ◽  
Trichome Morphology ◽  
Determining Factor

<p>The phrase <em>cyanobacteria bloom</em> implies a transient condition in which one to few species dominates communities. In this paper we describe a condition in which the <em>bloom</em> is of multi-year duration consisting of different morphologies of a single cyanobacteria species. Lake Catemaco, Veracruz, México maintained a year-round massive (10<sup>8</sup> trichomes L<sup>-1</sup>) population of potentially toxin-producing cyanobacteria, <em>Cylindrospermopsis spp.</em> The trichomes are present as straight and coiled morphotypes.  The relative trichome morphology abundance varied with rainy (June – October) and dry seasons (November – May), but total trichome abundance did not vary.  Coiled trichomes and heterocytes (occurring only on coiled trichomes) were significantly more abundant, both absolutely and relatively, during the dry season. Both coiled trichome and heterocyte mean volumes were significantly smaller during the rainy season than during the dry season.  Biovolumes were largest in January when water temperature was 5º C cooler suggesting buoyancy as a morphology-determining factor. However, with a more than three-fold lower TIN concentration during the dry season, we hypothesized that the coiled morphotype became abundant primarily because it formed heterocytes, which the straight morphotype did not. Spatial trichome and heterocyte abundance differences were small among the 15 lake sites (average CV for all dates = 20%). However, there was a pattern of increased heterocyte and coiled trichome abundance from lake inflow, as a nitrogen source, to outflow during the rainy season. The total volume of heterocytes per litre of lake water increased progressively four-fold from a minimum early in the rainy season to a maximum at the end of the dry season. Morphological diversity, as seen in Lake Catemaco, can partially compensate for the lack of species diversity in determination of community structure.</p>

scholarly journals Relationship between respiratory diseases and environmental conditions: a time-series analysis in Eastern Amazon

2021 ◽  
Vol 56 (3) ◽  
pp. 398-412
Author(s):  
Mauricio Do Nascimento Moura ◽  
Maria Isabel Vitorino ◽  
Glauber Guimarães Cirino da Silva ◽  
Valdir Soares de Andrade Filho
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Rainy Season ◽  
Respiratory Diseases ◽  
Hospital Admissions ◽  
Dry Season ◽  
Climate Indices ◽  
Series Analysis ◽  
Decadal Scale ◽  
The City

This study examines the relationship between the time-series analysis of climate, deforestation, wildfire, Aerosol Optical Depth (AOD), and hospital admissions for respiratory diseases in the Eastern Amazon. Through a descriptive study with an ecological approach of an 18-year time-series analysis, we made a statistical analysis of two pre-established periods, namely, the rainy season and the dry season. On a decadal scale, analyzing the signals of climate indices [i.e., the Southern Oscillation Index (SOI) and the Atlantic Meridional Mode (AMM)], the city of Marabá presents correlations between hospital admissions, wildfire, and AOD. This is not observed with the same accuracy in Santarém. On a seasonal scale, our analysis demonstrated how both cities in this research presented an increase in the number of hospital admissions during the dry season: Marabá, 3%; Santarém, 5%. The same season also presented a higher number of fire outbreaks, AOD, and higher temperatures. The AOD monthly analysis showed that the atmosphere of Marabá may be under the influence of other types of aerosols, such as those from mining activities. There is a time lag of approximately 2 months in the records of wildfire in the city. Such lag is not found in Santarém. The linear regression analysis shows that there is a correlation above 64% (Marabá) and 50% (Santarém), which is statistically significant because it proves that the number of hospital admissions for respiratory diseases is dependable on the AOD value. From the cities in the study, Marabá presents the highest incidence of wildfire, with an average of 188.5— the average in Santarém is 68.7—, and therefore the highest AOD value, with an average of 0.66 (Santarém, 0.47), both during the dry season. It is evident that the climate component has a relevant contribution to the increase in the number of hospital admissions, especially during the rainy season, where there are few or no records of wildfires.

scholarly journals Aerosol measurements at the Gual Pahari EUCAARI station: preliminary results from first year in-situ measurements

2010 ◽  
Vol 10 (4) ◽  
pp. 9015-9044
Author(s):  
A.-P. Hyvärinen ◽  
H. Lihavainen ◽  
M. Komppula ◽  
T. S. Panwar ◽  
V. P. Sharma ◽  
...  
Keyword(s):  
Rainy Season ◽  
In Situ Measurements ◽  
Aerosol Size Distribution ◽  
Anthropogenic Activity ◽  
First Year ◽  
Preliminary Results ◽  
Convective Mixing ◽  
Average Fraction ◽  
Mode Size

Abstract. The Finnish Meteorogical Institute (FMI), together with The Energy and Resources Institute of India (TERI), contributed to the The European Integrated project on Aerosol Cloud Climate and Air Quality Interactions, EUCAARI, by conducting aerosol measurements in Gual Pahari, India, from December 2007 to January 2010. This paper describes the station setup in detail for the first time and provides 1st year preliminary results from the aerosol in-situ measurements, which include PM and BC masses, aerosol size distribution from 4 nm to 10 μm, and the scattering and absorption coefficients. The seasonal variation of the aerosol characteristics was very distinct in Gual Pahari. The highest concentrations were observed during the winter and the lowest during the rainy season. The average PM10 concentration (at STP conditions) was 177 μg m−3 and the average PM2.5 concentration was 120 μg m−3. A high percentage (4–9%) of the PM10 mass consisted of BC which indicates anthropogenic influence. The percentage of BC was higher during the winter; and according to the diurnal pattern of the BC fraction, the peak occurred during anthropogenic activity times. Another important source of aerosol particles in the area was new particle formation. The nucleated particles grew rapidly reaching the Aitken and accumulation mode size, thus contributing considerably to the aerosol load. The rainy season decreased the average fraction of particle mass in the PM2.5 size range, i.e. of secondary origin. The other removal, or in this case, dilution mechanism was based on convective mixing and boundary layer evolution. This diluted the aerosol when sun radiation and the temperature was high, i.e. especially during the pre-monsoon day time. The lighter and smaller particles were more effectively diluted.

Kondisi Gradien Temperatur terhadap Proses Pengenceran Smog Fotokimia di Cekungan Bandung

2020 ◽  
Vol 21 (2) ◽  
pp. 219-226
Author(s):  
Sumaryati Sumaryati ◽  
Asri Indrawati ◽  
Dyah Aries Tanti
Keyword(s):  
Air Pollution ◽  
Rainy Season ◽  
Inversion Layer ◽  
Dry Season ◽  
Photochemical Smog ◽  
Temperature Changes ◽  
Basin Topography ◽  
Using Data ◽  
Dry And Rainy Seasons

ABSTRACTBig cities with valley or basin topography such as Bandung, generally have problems with air pollution due to the inversion layer and photochemical smog formations. The inversion conditions cause photochemical smog settling so that the air looks dark on the surface. This study was conducted to analyze the character of inversion events in Bandung due to vertical temperature changes. The inversion layer is obtained from the TAPM (The Air Pollution Model) model and in situ measurement of vertical temperatures by flying a temperature sensor to get the temperature profile. The TAPM running model is carried out in July and December following the dry and rainy seasons. In situ temperature observations are carried out in September 2018 using a drone according to the dry season and data corresponding to the rainy season using data from previous research with a radiosonde balloon. The running model results show that the inversion layer in the rainy season is stronger and more persistent than in the dry season. The inversion layer at night until morning occurs at the surface level, then the inversion layer rises, and finally, the inversion layer breaks up around 10:00 in July and around 12:00 in December. Validation with in situ measurements shows similarity in the pattern. The inversion event correlates with the subsidence and dilution of smog and photochemical smog pollutants from the edge of the Bandung Basin area.Keywords: basin, urban, photochemical smog, inversionABSTRAKKota besar dengan topografi berbentuk lembah atau cekungan seperti Bandung, umumnya memiliki masalah dengan polusi udara karena adanya pembentukkan lapisan inversi dan smog fotokimia. Kondisi inversi menyebabkan terjadinya pengendapan smog fotokimia, sehingga udara terlihat gelap pada permukaan. Penelitian ini dilakukan untuk menganalisis karakter kejadian inversi di Cekungan Bandung akibat dari perubahan temperatur vertikal. Lapisan inversi diperoleh dari model TAPM (Model Polusi Udara) dan pengukuran in situ temperatur vertikal dengan menerbangkan sensor suhu untuk mendapatkan profil suhu. Running model TAPM dilakukan pada bulan Juli dan bulan Desember berkesesuaian dengan musim kemarau dan hujan, sedangkan pengamatan temperatur in situ dilakukan pada bulan September 2018 dengan menggunakan wahana drone yang berkesesuaian dengan musim kemarau, serta untuk data yang berkesesuaian dengan musim hujan menggunakan data hasil penelitian sebelumnya dengan wahana balon radiosonde. Hasil running model menunjukkan, lapisan inversi pada musim hujan lebih kuat dan lebih persisten dari pada musim kemarau. Lapisan inversi pada malam sampai pagi hari terjadi pada level permukaan, kemudian lapisan inversi ini naik dan akhirnya lapisan inversi pecah sekitar pukul 10:00 pada bulan Juli dan sekitar pukul 12:00 pada bulan Desember. Validasi dengan pengukuran in situ menunjukkan kemiripan pola. Kejadian inversi berkorelasi dengan pengendapan dan pengenceran polutan smog dan smog fotokimia dari pinggir Cekungan Bandung. Kata kunci: cekungan, urban, smog fotokimia, inversi

scholarly journals Co-located column and in situ measurements of CO<sub>2</sub> in the tropics compared with model simulations

2010 ◽  
Vol 10 (12) ◽  
pp. 5593-5599 ◽  
Author(s):  
T. Warneke ◽  
A. K. Petersen ◽  
C. Gerbig ◽  
A. Jordan ◽  
C. Rödenbeck ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Southern Hemisphere ◽  
Dry Season ◽  
In Situ Measurements ◽  
Local Source ◽  
Air Samples ◽  
Model Simulations ◽  
Mixing Ratios ◽  
Source Component

Abstract. The first ground-based remote sensing measurements of the column averaged volume mixing ratio of CO2 (XCO2) in tropical South America have been obtained at Paramaribo, Suriname (5.8° N, 55.2° W). The remote sensing observations are complemented by surface air-samples collected at the site, analyzed for CO2 and 13CO2. The surface in-situ measurements are strongly influenced by local sources. From the isotopic composition of the air samples the local source component is suggested to be dominated by the terrestrial biosphere. Using δ13C from the NOAA/ESRL stations Ascension Is. (ASC), 7.9° S, 14.4° W, and Ragged Point (RPB), 13.2° N, 59.4° W, the data has been corrected for the local source component. Due to the migration of the Intertropical Convergence Zone (ITCZ) over the measurement site the sampled air masses belong to the Northern or Southern Hemisphere depending on the time of the year. Comparison to analyzed CO2 fields based on TM3 model simulations using optimized fluxes indicate agreement for the seasonality in XCO2 as well as for the corrected CO2 mixing ratios at the surface for the long dry season, when Paramaribo belongs to the Southern Hemisphere. A slightly worse agreement during the short dry season is attributed to a larger representation error during this time of the year. Overall the comparison indicates that the TM3 model is capable to simulate the seasonal variation of surface concentrations as well as column densities of CO2 correctly at Paramaribo. It has been also shown that the column measurements currently performed at Paramaribo have a limited precision and lack the link to the in situ measurements. Solutions for future improvements have been suggested.

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