Modelling of indoor radon activity concentration dynamics and its validation through in-situ measurements on regional scale

Abstract. Ammonia (NH3) is a major source of nitrates in the atmosphere and a major source of fine particulate matter. As such, there have been increasing efforts to measure the atmospheric abundance of NH3 and its spatial and temporal variability. In this study, long-term measurements of NH3 derived from multiscale datasets are examined. These NH3 datasets include 16 years of total column measurements using Fourier transform infrared (FTIR) spectroscopy, 3 years of surface in situ measurements, and 10 years of total column measurements from the Infrared Atmospheric Sounding Interferometer (IASI). The datasets were used to quantify NH3 temporal variability over Toronto, Canada. The multiscale datasets were also compared to assess the representativeness of the FTIR measurements. All three time series showed positive trends in NH3 over Toronto: 3.34 ± 0.89 %/yr from 2002 to 2018 in the FTIR columns, 8.88 ± 5.08 %/yr from 2013 to 2017 in the surface in situ data, and 8.38 ± 1.54 %/yr from 2008 to 2018 in the IASI columns. To assess the representative scale of the FTIR NH3 columns, correlations between the datasets were examined. The best correlation between FTIR and IASI was obtained with coincidence criteria of ≤25 km and ≤20 min, with r=0.73 and a slope of 1.14 ± 0.06. Additionally, FTIR column and in situ measurements were standardized and correlated. Comparison of 24 d averages and monthly averages resulted in correlation coefficients of r=0.72 and r=0.75, respectively, although correlation without averaging to reduce high-frequency variability led to a poorer correlation, with r=0.39. The GEOS-Chem model, run at 2∘ × 2.5∘ resolution, was compared to FTIR and IASI to assess model performance and investigate the correlation of observational data and model output, both with local column measurements (FTIR) and measurements on a regional scale (IASI). Comparisons on a regional scale (a domain spanning 35 to 53∘ N and 93.75 to 63.75∘ W) resulted in r=0.57 and thus a coefficient of determination, which is indicative of the predictive capacity of the model, of r2=0.33, but comparing a single model grid point against the FTIR resulted in a poorer correlation, with r2=0.13, indicating that a finer spatial resolution is needed for modeling NH3.

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Simulating Secondary Inorganic Aerosols using the chemistry transport model MOCAGE version R2.15.0

Geoscientific Model Development Discussions ◽

10.5194/gmdd-8-3593-2015 ◽

2015 ◽

Vol 8 (4) ◽

pp. 3593-3651 ◽

Cited By ~ 1

Author(s):

J. Guth ◽

B. Josse ◽

V. Marécal ◽

M. Joly

Keyword(s):

North America ◽

Transport Model ◽

Regional Scale ◽

In Situ Measurements ◽

Aerosol Composition ◽

Chemistry Transport Model ◽

Inorganic Aerosols ◽

Modis Aod ◽

Inorganic Aerosol

Abstract. In this study we develop a Secondary Inorganic Aerosol (SIA) module for the chemistry transport model MOCAGE developed at CNRM. Based on the thermodynamic equilibrium module ISORROPIA II, the new version of the model is evaluated both at the global scale and at the regional scale. The results show high concentrations of secondary inorganic aerosols in the most polluted regions being Europe, Asia and the eastern part of North America. Asia shows higher sulfate concentrations than other regions thanks to emissions reduction in Europe and North America. Using two simulations, one with and the other without secondary inorganic aerosol formation, the model global outputs are compared to previous studies, to MODIS AOD retrievals, and also to in situ measurements from the HTAP database. The model shows a better agreement in all geographical regions with MODIS AOD retrievals when introducing SIA. It also provides a good statistical agreement with in situ measurements of secondary inorganic aerosol composition: sulfate, nitrate and ammonium. In addition, the simulation with SIA gives generally a better agreement for secondary inorganic aerosols precursors (nitric acid, sulfur dioxide, ammonia) in particular with a reduction of the Modified Normalised Mean Bias (MNMB). At the regional scale, over Europe, the model simulation with SIA are compared to the in situ measurements from the EMEP database and shows a good agreement with secondary inorganic aerosol composition. The results at the regional scale are consistent with those obtained with the global simulations. The AIRBASE database was used to compare the model to regulated air quality pollutants being particulate matter, ozone and nitrogen dioxide concentrations. The introduction of the SIA in MOCAGE provides a reduction of the PM2.5 MNMB of 0.44 on a yearly basis and even 0.52 on a three spring months period (March, April, May) when SIA are maximum.

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Multiscale observations of NH3 around Toronto, Canada

10.5194/egusphere-egu2020-10486 ◽

2020 ◽

Author(s):

Shoma Yamanouchi ◽

Camille Viatte ◽

Kimberly Strong ◽

Dylan B. A. Jones ◽

Cathy Clerbaux ◽

...

Keyword(s):

Case Studies ◽

Biomass Burning ◽

Grid Point ◽

Fine Particulate Matter ◽

Regional Scale ◽

Model Performance ◽

In Situ Measurements ◽

Coefficient Of Determination ◽

Predictive Capacity

<div> <div> <div> <p>Ammonia (NH<sub>3</sub>) is a major source of nitrates in the atmosphere, and a major source of fine particulate matter. As such, there have been increasing efforts to monitor NH<sub>3</sub>. This study examines long-term measurements of NH<sub>3</sub> around Toronto, Canada, derived from three multiscale datasets: 16 years of total column measurements using ground-based Fourier transform infrared (FTIR) spectroscopy, three years of surface in-situ measurements, and ten years of total columns from the Infrared Atmospheric Sounding Interferometer (IASI) sensor onboard the Metop satellites. These datasets were used to quantify NH<sub>3</sub> temporal variabilities (trends, inter-annual, seasonal) over Toronto to assess the observational footprint of the FTIR measurements, and two case studies of pollution events due to transport of biomass burning plumes.</p> <p>All three timeseries showed increasing trends in NH<sub>3</sub> over Toronto: 3.34 &#177; 0.44 %/year from 2002 to 2018 in the FTIR columns, 8.88 &#177; 2.49 %/year from 2013 to 2017 in the surface in-situ data, and 8.78 &#177; 0.84 %/year from 2008 to 2018 in the IASI columns. To assess the observational footprint of the FTIR NH<sub>3</sub> columns, correlations between the datasets were examined. The best correlation between FTIR and IASI was found for coincidence criterion of &#8804; 50 km and &#8804; 20 minutes, with r = 0.66 and a slope of 0.988 &#177; 0.058. The FTIR column and in-situ measurements were standardized and correlated, with 24-day averages and monthly averages yielding correlation coefficients of r = 0.72 and r = 0.75, respectively.<br>FTIR and IASI were also compared against the GEOS-Chem model, run at 2&#176; by 2.5&#176; resolution, to assess model performance and investigate correlation of the model output with local column measurements (FTIR) and measurements on a regional scale (IASI). Comparisons on a regional scale (domain spanning from 35&#176;N to 53&#176;N, and 93.75&#176;W to 63.75&#176;W) resulted in r = 0.62, and thus a coefficient of determination, which is indicative of the predictive capacity of the model, of r<sup>2</sup> = 0.38, but comparing a single model grid point against the FTIR resulted in a poorer correlation, with r<sup>2</sup> = 0.26, indicating that a finer spatial resolution is needed to adequately model the variability of NH<sub>3</sub>. This study also examines two case studies of NH<sub>3</sub> enhancements due to biomass burning plumes, in August 2014 and May 2016. In these events, enhancements in both the total columns and surface NH3, were observed.</p> </div> </div> </div>

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Indoor radon monitoring in selected fault zones, Slovakia – preliminary results from the summer monitoring period

Contributions to Geophysics and Geodesy ◽

10.2478/congeo-2019-0020 ◽

2019 ◽

Vol 49 (4) ◽

pp. 391-402

Author(s):

Iveta Smetanová ◽

Andrej Mojzeš ◽

František Marko ◽

Kamil Fekete ◽

Kristián Csicsay

Keyword(s):

Direct Contact ◽

Activity Concentration ◽

Structural Parameters ◽

Indoor Radon ◽

Fault Zones ◽

Multidisciplinary Research ◽

Monitoring Period ◽

Radon Activity ◽

Radon Survey ◽

Radon Monitoring

Abstract Indoor radon survey in Sološnica, Vydrník and Zázrivá villages has been performed within the framework of the project “Multidisciplinary research of geophysical and structural parameters, and environmental impacts of faults of the Western Carpathians”. Integration measurement of 222Rn activity concentration has been carried out using RamaRn detectors in houses, offices, schools and kindergartens. Indoor radon activity in the summer monitoring period (June–August 2018) varied from values under the detection limit of 55 Bq/m3 to 480 Bq/m3. In 94% of rooms the radon activity below 200 Bq/m3 was found. The results have been examined in respect of the most used building material and presence or absence of a cellar underneath the room. Indoor radon higher than 300 Bq/m3 was measured only in rooms in direct contact with the subsoil.

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MEASUREMENT OF RADON ACTIVITY CONCENTRATION IN BUILDING MATERIALS USED IN BOSNIA AND HERCEGOVINA

Contemporary Materials ◽

10.7251/comen2001051a ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Ema Sinanović ◽

Feriz Adrović ◽

Amira Kasumović ◽

Amela Kasić

Keyword(s):

Ionizing Radiation ◽

Bosnia And Herzegovina ◽

Building Materials ◽

Activity Concentration ◽

Indoor Radon ◽

Natural Radionuclides ◽

Mean Values ◽

Indoor Exposure ◽

Radon Activity ◽

Materials Used

Man is continuously exposed to ionizing radiation because of the presence of naturally occurring radioactive materials (NORM) in the environment. Various technological processes of processing and using of materials that contain natural radionuclides generate materials of enhanced natural radioactivity (TENORM). The largest contribution to irradiance with natural sources of ionizing radiation is the exposure of the population to indoor radon. This gas originates from the radioactive decay of 226Ra and 224Ra that are present in the soil under houses and building materials. Depending on the type of building materials, indoor exposure to radon at dwellings and workplaces can be over a thousand times greater than in outdoor space. In Bosnia and Herzegovina, no valid and comprehensive radiological studies on the building materials have been performed that would guarantee for their dosimetric safety use for installation in residential and industrial buildings, highways, as well as their application for other purposes. The quantification of the radon levels that comes from building materials is a necessary and very important part of the global protection of the population from ionizing radiation. This paper presents the first results of a study on the radon activity concentrations in building materials used in Bosnia and Herzegovina. Measurements were performedwith a professional Alpha GUARD system. The mean values of the activity concentration of the exhaled radon of investigated building materials varied from 10 Bqm-3 to 101 Bqm-3, radon exhalation rate values ranged from 77.0 mBqm-2h-1 to 777.7 mBqm-2h-1. Gamma dose rate was in the range 57–112 nSv h−1.

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Indoor radon levels in Hungarian kindergartens

Journal of Radioanalytical and Nuclear Chemistry ◽

10.1007/s10967-020-07501-1 ◽

2021 ◽

Author(s):

Anita Csordás ◽

Katalin Zsuzsanna Szabó ◽

Zoltán Sas ◽

Erika Kocsis ◽

Tibor Kovács

Keyword(s):

Seasonal Variation ◽

Activity Concentration ◽

Indoor Radon ◽

Annual Average ◽

Radon Activity ◽

Closed Period

AbstractAnnual average indoor radon activity concentration was studied in 88 Hungarian kindergartens in 76 towns of 10 different counties. Annual average indoor radon activity concentration in the kindergartens was 61 Bq m− 3, maximum was 160 Bq m− 3. In the kindergartens the seasonal variation of radon is not so strong like in dwellings, because of the permanent ventilation and the closed period during the summer break.

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Effectiveness of passive ventilation on radon indoor level in Puglia Region according to European Directive 2013/59/EURATOM

Indoor and Built Environment ◽

10.1177/1420326x20940364 ◽

2020 ◽

pp. 1420326X2094036

Author(s):

Vittoria D'Avino ◽

Mariagabriella Pugliese ◽

Giuseppe La Verde

Keyword(s):

Activity Concentration ◽

Southern Italy ◽

Residential Buildings ◽

Indoor Radon ◽

Remedial Action ◽

Previous Survey ◽

Radon Activity ◽

Average Value ◽

Local Characteristics ◽

High Concentrations

The effectiveness of the increase in passive ventilation was studied as remedial action for high concentrations of indoor radon gas activity. The rationale has been to apply the provisions of Directive 2013/59/EURATOM, partially implemented by a regional law of Puglia Region (Southern Italy). Residential buildings were selected based on characteristics common to those of commercial premises, which are the recipients of legislative obligations. The final goal of this study was to evaluate the feasibility of carrying out the same remediation activity for both types of buildings. From a previous survey in Puglia in 2013–2014, 18 houses were selected and passive ventilation strategy was applied in order to evaluate its effect on the radon activity concentration. A specially designed protocol defined frequency and time of windows operation. The average value of the annual measurement revealed a significant reduction of the internal radon activity concentration: mitigation ranged from 21 ± 5% to 58 ± 2% with an average value of 33 ± 3%. The results of the study showed that passive ventilation is an effective method of mitigation of the internal radon concentration if correctly designed according to the local characteristics of the buildings and habits of the occupants.

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Status of the Tibetan Plateau observatory (Tibet-Obs) and a 10-year (2009–2019) surface soil moisture dataset

10.5194/essd-2020-209 ◽

2020 ◽

Author(s):

Pei Zhang ◽

Donghai Zheng ◽

Rogier van der Velde ◽

Jun Wen ◽

Yijian Zeng ◽

...

Keyword(s):

Soil Moisture ◽

Tibetan Plateau ◽

Current Model ◽

Regional Scale ◽

In Situ Measurements ◽

The Tibetan Plateau ◽

Model Based ◽

Network Area

Abstract. The Tibetan Plateau observatory of plateau scale soil moisture and soil temperature (Tibet-Obs) was established ten years ago, which has been widely used to calibrate/validate satellite- and model-based soil moisture (SM) products for their applications to the Tibetan Plateau (TP). This paper reports on the status of the Tibet-Obs and presents a 10-year (2009–2019) surface SM dataset produced based on in situ measurements taken at a depth of 5 cm collected from the Tibet-Obs that consists of three regional-scale SM monitoring networks, i.e. the Maqu, Naqu, and Ngari (including Ali and Shiquanhe) networks. This surface SM dataset includes the original 15-min in situ measurements collected by multiple SM monitoring sites of the three networks, and the spatially upscaled SM records produced for the Maqu and Shiquanhe networks. Comparisons between four spatial upscaling methods, i.e. arithmetic averaging, Voronoi diagram, time stability and apparent thermal inertia, show that the arithmetic average of the monitoring sites with long-term (i.e. ≥ six years) continuous measurements are found to be most suitable to produce the upscaled SM records. Trend analysis of the 10-year upscaled SM records using the Mann-Kendall method shows that the Maqu network area in the eastern part of the TP is drying while the Shiquanhe network area in the west is getting wet that generally follow the change of precipitation. To further demonstrate the uniqueness of the upscaled SM records in validating existing SM products for long term period (~ 10 years), comparisons are conducted to evaluate the reliability of three reanalysis datasets for the Maqu and Shiquanhe network areas. It is found that current model-based SM products still show deficiencies in representing the trend and variation of measured SM dynamics in the Tibetan grassland (i.e. Maqu) and desert ecosystems (i.e. Shiquanhe) that dominate the landscape of the TP. The dataset would be also valuable for calibrating/validating long-term satellite-based SM products, evaluation of SM upscaling methods, development of data fusion methods, and quantifying the coupling strength between precipitation and SM at 10-year scale. The dataset is available in the 4TU.ResearchData repository at https://doi.org/10.4121/uuid:21220b23-ff36-4ca9-a08f-ccd53782e834 (Zhang et al., 2020).

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Detection of irrigation events on maize plots using sentinel-1 soil moisture products

10.5194/egusphere-egu2020-8588 ◽

2020 ◽

Author(s):

Michel Le Page ◽

Lionel Jarlan ◽

Aaron Boone ◽

Mohammad El Hajj ◽

Nicolas Baghdadi ◽

...

Keyword(s):

Soil Moisture ◽

Water Balance ◽

Surface Soil ◽

Regional Scale ◽

Absolute Error ◽

In Situ Measurements ◽

Irrigation Event ◽

Balance Model ◽

Surface Soil Moisture

<p>An accurate knowledge of irrigation timing and rate is essential to compute the water balance of irrigated plots. However, at the plot scale irrigation is a data essentially known by the irrigator. These data do not go up to higher management scales, thus limiting both the management of water resources on a regional scale and the development of irrigation decision support tools at the farm scale. The study focuses on 6 experimental plots in the south-west of France. The new method consists in assessing surface soil moisture (SSM) change between observations and a water balance model. The approach was tested using both in situ measurements and surface soil moisture (SSM) maps derived from Sentinel-1 radar data. The score is obtained by assessing if the irrigation event is detected within +/- three days. The use of in situ SSM showed that: (1) the best revisit time between two SSM observations is 3 days; short gaps is subject to uncertainties while longer gap miss possible SSM variations; (2) in general, higher rates (>20mm) of irrigation are well identified while it is very difficult to identify irrigation event when it is raining or when irrigation rates are small (<10mm). When using the SSM microwave product, the performances are degraded but are still acceptable given the discontinuity of irrigation events: 34% of absolute error and a bias of 5% for the whole season. Although high vegetation cover degrades the SSM absolute estimates, the dynamic appeared to be in accordance with in-situ measurements.</p>

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Status of the Tibetan Plateau observatory (Tibet-Obs) and a 10-year (2009–2019) surface soil moisture dataset

Earth System Science Data ◽

10.5194/essd-13-3075-2021 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3075-3102

Author(s):

Pei Zhang ◽

Donghai Zheng ◽

Rogier van der Velde ◽

Jun Wen ◽

Yijian Zeng ◽

...

Keyword(s):

Soil Moisture ◽

Tibetan Plateau ◽

Current Model ◽

Regional Scale ◽

In Situ Measurements ◽

The Tibetan Plateau ◽

Monitoring Networks ◽

Model Based

Abstract. The Tibetan Plateau observatory (Tibet-Obs) of plateau scale soil moisture and soil temperature was established 10 years ago and has been widely used to calibrate/validate satellite- and model-based soil moisture (SM) products for their applications to the Tibetan Plateau (TP). This paper reports on the status of the Tibet-Obs and presents a 10-year (2009–2019) surface SM dataset produced based on in situ measurements taken at a depth of 5 cm collected from the Tibet-Obs that consists of three regional-scale SM monitoring networks, i.e. the Maqu, Naqu, and Ngari (including Ali and Shiquanhe) networks. This surface SM dataset includes the original 15 min in situ measurements collected by multiple SM monitoring sites of the three networks and the spatially upscaled SM records produced for the Maqu and Shiquanhe networks. Comparisons between four spatial upscaling methods – i.e. arithmetic averaging, Voronoi diagrams, time stability, and apparent thermal inertia – show that the arithmetic average of the monitoring sites with long-term (i.e. ≥ 6-year) continuous measurements is found to be most suitable to produce the upscaled SM records. Trend analysis of the 10-year upscaled SM records indicates that the Shiquanhe network in the western part of the TP is getting wet, while there is no significant trend found for the Maqu network in the east. To further demonstrate the uniqueness of the upscaled SM records in validating existing SM products for a long-term period (∼10 years), the reliability of three reanalysis datasets is evaluated for the Maqu and Shiquanhe networks. It is found that current model-based SM products still show deficiencies in representing the measured SM dynamics in the Tibetan grassland (i.e. Maqu) and desert ecosystems (i.e. Shiquanhe). The dataset would also be valuable for calibrating/validating long-term satellite-based SM products, evaluation of SM upscaling methods, development of data fusion methods, and quantifying the coupling of SM and precipitation at a 10-year scale. The dataset is available in the 4TU.ResearchData repository at https://doi.org/10.4121/12763700.v7 (Zhang et al., 2020).

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