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Evaluation of urban surface parameterizations in the WRF model using measurements during the Texas Air Quality Study 2006 field campaign
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. Lee S.-H.; Kim S.-W.; Angevine W.M.; et al. - Copernicus GmbH, 2011The performance of different urban surface parameterizations in the WRF (Weather Research and Forecasting) in simulating urban boundary layer (UBL) was investigated using extensive measurements during the Texas Air Quality Study 2006 field campaign. The extensive field measurements collected on surface (meteorological, wind profiler, energy balance flux) sites, a research aircraft, and a research vessel characterized 3-dimensional atmospheric boundary layer structures over the Houston-Galveston Bay area, providing a unique opportunity for the evaluation of the physical parameterizations. The m ...
[article]Evaluation of urban surface parameterizations in the WRF model using measurements during the Texas Air Quality Study 2006 field campaign
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Available online: http://www.atmos-chem-phys.net/11/2127/2011/
S.-H. Lee ; S.-W. Kim ; W.M. Angevine ; L. Bianco ; S.A. McKeen ; C.J. Senff ; M. Trainer ; S.C. Tucker ; R.J. Zamora
in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 5 [03/11/2011] . - p.2127-2143The performance of different urban surface parameterizations in the WRF (Weather Research and Forecasting) in simulating urban boundary layer (UBL) was investigated using extensive measurements during the Texas Air Quality Study 2006 field campaign. The extensive field measurements collected on surface (meteorological, wind profiler, energy balance flux) sites, a research aircraft, and a research vessel characterized 3-dimensional atmospheric boundary layer structures over the Houston-Galveston Bay area, providing a unique opportunity for the evaluation of the physical parameterizations. The model simulations were performed over the Houston metropolitan area for a summertime period (12–17 August) using a bulk urban parameterization in the Noah land surface model (original LSM), a modified LSM, and a single-layer urban canopy model (UCM). The UCM simulation compared quite well with the observations over the Houston urban areas, reducing the systematic model biases in the original LSM simulation by 1–2 °C in near-surface air temperature and by 200–400 m in UBL height, on average. A more realistic turbulent (sensible and latent heat) energy partitioning contributed to the improvements in the UCM simulation. The original LSM significantly overestimated the sensible heat flux (~200 W m−2) over the urban areas, resulting in warmer and higher UBL. The modified LSM slightly reduced warm and high biases in near-surface air temperature (0.5–1 °C) and UBL height (~100 m) as a result of the effects of urban vegetation. The relatively strong thermal contrast between the Houston area and the water bodies (Galveston Bay and the Gulf of Mexico) in the LSM simulations enhanced the sea/bay breezes, but the model performance in predicting local wind fields was similar among the simulations in terms of statistical evaluations. These results suggest that a proper surface representation (e.g. urban vegetation, surface morphology) and explicit parameterizations of urban physical processes are required for accurate urban atmospheric numerical modeling.
Language(s): English
Format: Digital (Free)Tags: Environment and landscape ; Measure ; Urban zone ; Air quality ; United States of America
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Transport analysis of ozone enhancement in Southern Ontario during BAQS-Met
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. He H.; Tarasick D.W.; Hocking W.K.; et al. - Copernicus GmbH, 2011Twice-daily ozonesondes were launched from Harrow, in southwestern Ontario, Canada, during the BAQS-Met (Border Air Quality and Meteorology Study) field campaign in June and July of 2007. A co-located radar windprofiler measured tropopause height continuously. These data, in combination with continuous surface ozone measurements and geo-statistical interpolation of satellite ozone observations, present a consistent picture and indicate that a number of significant ozone enhancements in the troposphere were observed that were the result of stratospheric intrusion events. The combined observatio ...
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Available online: http://dx.doi.org/10.5194/acp-11-2569-2011
H. He ; D.W. Tarasick ; W.K. Hocking ; T.K. Carey-Smith ; Y. Rochon ; J. Zhang ; P.A. Makar ; M. Osman ; J. Brook ; M.D. Moran ; D.B.A. Jones ; C. Mihele ; J.C. Wei ; G. Osterman ; P.S. Argall ; J. McConnell ; M.S. Bourqui
in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 3 [03/01/2011] . - p.2569-2583Twice-daily ozonesondes were launched from Harrow, in southwestern Ontario, Canada, during the BAQS-Met (Border Air Quality and Meteorology Study) field campaign in June and July of 2007. A co-located radar windprofiler measured tropopause height continuously. These data, in combination with continuous surface ozone measurements and geo-statistical interpolation of satellite ozone observations, present a consistent picture and indicate that a number of significant ozone enhancements in the troposphere were observed that were the result of stratospheric intrusion events. The combined observations have also been compared with results from two Environment Canada numerical models, the operational weather prediction model GEM (as input to FLEXPART), and a new version of the regional air quality model AURAMS, in order to examine the ability of these models to accurately represent sporadic cross-tropopause ozone transport events. The models appear to reproduce intrusion events with some skill, implying that GEM dynamics (which also drive AURAMS) are able to represent such events well. There are important differences in the quantitative comparison, however; in particular, the poor vertical resolution of AURAMS around the tropopause causes it to bring down too much ozone in individual intrusions.
Language(s): English
Format: Digital (Free)Tags: Canada ; Measure ; Observations ; Ozone ; Troposphere
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Measurements of volatile organic compounds at a suburban ground site (T1) in Mexico City during the MILAGRO 2006 campaign: measurement comparison, emission ratios, and source attribution
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Bon D.M.; Ulbrich I.M.; de Gouw J.A.; et al. - Copernicus GmbH, 2011Volatile organic compound (VOC) mixing ratios were measured with two different instruments at the T1 ground site in Mexico City during the Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign in March of 2006. A gas chromatograph with flame ionization detector (GC-FID) quantified 18 light alkanes, alkenes and acetylene while a proton-transfer-reaction ion-trap mass spectrometer (PIT-MS) quantified 12 VOC species including oxygenated VOCs (OVOCs) and aromatics. A GC separation system was used in conjunction with the PIT-MS (GC-PIT-MS) to evaluate PIT-MS measurements an ...
[article]Measurements of volatile organic compounds at a suburban ground site (T1) in Mexico City during the MILAGRO 2006 campaign: measurement comparison, emission ratios, and source attribution
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Available online: http://dx.doi.org/10.5194/acp-11-2399-2011
D.M. Bon ; I.M. Ulbrich ; J.A. de Gouw ; C. Warneke ; W.C. Kuster ; M.L. Alexander ; A. Baker ; A.J. Beyersdorf ; D. Blake ; R. Fall ; J.L. Jimenez ; S.C. Herndon ; L.G. Huey ; W.B. Knighton ; J. Ortega ; S. Springston ; O. Vargas
in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 3 [03/01/2011] . - p.2399-2421Volatile organic compound (VOC) mixing ratios were measured with two different instruments at the T1 ground site in Mexico City during the Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign in March of 2006. A gas chromatograph with flame ionization detector (GC-FID) quantified 18 light alkanes, alkenes and acetylene while a proton-transfer-reaction ion-trap mass spectrometer (PIT-MS) quantified 12 VOC species including oxygenated VOCs (OVOCs) and aromatics. A GC separation system was used in conjunction with the PIT-MS (GC-PIT-MS) to evaluate PIT-MS measurements and to aid in the identification of unknown VOCs. The VOC measurements are also compared to simultaneous canister samples and to two independent proton-transfer-reaction mass spectrometers (PTR-MS) deployed on a mobile and an airborne platform during MILAGRO. VOC diurnal cycles demonstrate the large influence of vehicle traffic and liquid propane gas (LPG) emissions during the night and photochemical processing during the afternoon. Emission ratios for VOCs and OVOCs relative to CO are derived from early-morning measurements. Average emission ratios for non-oxygenated species relative to CO are on average a factor of ~2 higher than measured for US cities. Emission ratios for OVOCs are estimated and compared to literature values the northeastern US and to tunnel studies in California. Positive matrix factorization analysis (PMF) is used to provide insight into VOC sources and processing. Three PMF factors were distinguished by the analysis including the emissions from vehicles, the use of liquid propane gas and the production of secondary VOCs + long-lived species. Emission ratios to CO calculated from the results of PMF analysis are compared to emission ratios calculated directly from measurements. The total PIT-MS signal is summed to estimate the fraction of identified versus unidentified VOC species.
Language(s): English
Format: Digital (Free)Tags: Atmosphere ; Volatile Organic Compounds (VOCs) ; Measure ; Urban zone ; Observations ; Mexico
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The effect of H2SO4 – amine clustering on chemical ionization mass spectrometry (CIMS) measurements of gas-phase sulfuric acid
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Kurtén T.; Petäjä T.; Smith J.; et al. - Copernicus GmbH, 2011The state-of-the art method for measuring atmospheric gas-phase sulfuric acid is chemical ionization mass spectrometry (CIMS) based on nitrate reagent ions. We have assessed the possible effect of the sulfuric acid molecules clustering with base molecules on CIMS measurements using computational chemistry. From the computational data, three conclusions can be drawn. First, a significant fraction of the gas-phase sulfuric acid molecules are very likely clustered with amines if the amine concentration is around or above a few ppt. Second, some fraction of these acid-amine clusters may not be cha ...
[article]The effect of H2SO4 – amine clustering on chemical ionization mass spectrometry (CIMS) measurements of gas-phase sulfuric acid
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Available online: http://dx.doi.org/10.5194/acp-11-3007-2011
T. Kurtén ; T. Petäjä ; J. Smith ; I.K. Ortega ; M. Sipilä ; H. Junninen ; M. Ehn ; H. Vehkamäki ; L. Mauldin ; D.R. Worsnop ; M. Kulmala
in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 3 [03/01/2011] . - p.3007-3019The state-of-the art method for measuring atmospheric gas-phase sulfuric acid is chemical ionization mass spectrometry (CIMS) based on nitrate reagent ions. We have assessed the possible effect of the sulfuric acid molecules clustering with base molecules on CIMS measurements using computational chemistry. From the computational data, three conclusions can be drawn. First, a significant fraction of the gas-phase sulfuric acid molecules are very likely clustered with amines if the amine concentration is around or above a few ppt. Second, some fraction of these acid-amine clusters may not be charged by the CIMS instrument, though the most reliable computational methods employed predict this fraction to be small; on the order of ten percent or less. Third, the amine molecules will evaporate practically immediately after charging, thus evading detection. These effects may need to be taken into account in the interpretation of atmospheric measurement data obtained using chemical ionization methods. The purpose of this study is not to criticize the CIMS method, but to help understand the implications of the measured results.
Language(s): English
Format: Digital (Free)Tags: Atmosphere ; Environment and landscape ; Measure ; Observations ; Air pollution ; Research
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GAW Report, 198. Data Quality Objectives (DQO) for Solar Ultraviolet Radiation Measurements - Part I: Scanning Spectral and Broadband Instruments. Addendum to WMO/GAW Report No. 146 - Quality Assurance in Monitoring Solar Ultraviolet Radiation, state of the Art
Data Quality Objectives (DQO) for Solar Ultraviolet Radiation Measurements - Part I: Scanning Spectral and Broadband Instruments. Addendum to WMO/GAW Report No. 146 - Quality Assurance in Monitoring Solar Ultraviolet Radiation, state of the Art
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World Meteorological Organization (WMO) ; Vitali Fioletov ; Serm Janjai ; Takashi Koide ; Richard McKenzie ; G. Seckmeyer ; Craig Sinclair ; A. Webb ; Liisa Jalkanen
Published by: WMO ; 2011Collection(s) and Series: GAW Report- No. 198
Language(s): English
Format: Digital (Free), Hard copyTags: Global Atmosphere Watch Programme (GAW) ; Solar radiation ; Measure ; Observations ; Meteorological instrument
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GAW Report, 200. WMO/GAW Standard Operating Procedures for In-situ Measurements of Aerosol Mass Concentration, Light Scattering and Light Absorption
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Extending atmospheric CO2 and tracer capabilities in ACCESS
Corbin Katherine D.; Law Rachel M. - Centre for Australian Weather and Climate Research, 2011 (CAWCR Technical Report-No. 035)The Australian Community Climate and Earth System Simulator (ACCESS) is a coupled landocean-atmosphere model being developed for a wide variety of applications. One key area of research with ACCESS is the carbon cycle, in particular atmospheric carbon dioxide (CO2) and methane (CH4) concentrations resulting from prescribed surface fluxes. ACCESS derives its atmospheric model from the UK Met Office Unified model (UM), which included both a specific atmospheric CO2 tracer (used for climate-carbon feedback studies) as well as other generic atmospheric tracers, developed for stratospheric transpor ...
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IOM Report, 106. WMO Field Intercomparison of Thermometer Screens/Shields and Humidity Measuring Instruments : Ghardaïa, Algeria, November 2008 – October 2009
The WMO Combined Intercomparison of Temperature Screens/Shields in Conjunction with Humidity Measuring Instruments was carried out in Ghardaïa, Algeria from November 2008 to October 2009, at the kind invitation of the Algerian Meteorological Service and under the leadership of CIMO. This intercomparison allowed testing the performance of the instruments in desert conditions, in a dry, hot and dusty environment. It was planned to carry out a follow-up intercomparison of similar instruments in an arctic environment at a later stage. The main objectives of this intercomparison were to gain knowle ...
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GAW Report, 195. WMO/GAW Expert Workshop on Global Long-term Measurements of Nitrogen Oxides and Recommendations for GAW Nitrogen Oxides Network
World Meteorological Organization (WMO) ; Gilge S.; Plass-Duelmer C.; et al. - WMO, 2011 (WMO/TD-No. 1570)Nitrogen oxides are a component of a group of reactive gases required to be measured in the GAW Programme. The reactive gases group focuses on gases known to be intimately involved in various aspects of the chemistry of the troposphere and includes surface ozone (O3), carbon monoxide (CO), volatile organic compounds (VOCs), and sulphur dioxide (SO2), as well as oxidized nitrogen species. The sum of nitric oxide (NO) and nitrogen dioxide (NO2) has traditionally been called NOx. The sum of oxidized nitrogen species with an oxidation number >1, both organic and inorganic, is referred to as ...
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Air pollution by ozone across Europe during summer 2010 : overview of exceedances of EC ozone threshold values for April–September 2010
EEA, 2011Despite efforts to mitigate ozone pollution, the number of exceedances of EU ground-level ozone concentration standards for protecting human health (Directive 2008/50/EC) remained at sustained levels during summer 2010 (1).
In 2010, the threshold of 120 μg/m3 maximum daily eight-hour mean was exceeded on more than 25 days in a significant part of Europe. This is the threshold that will be used to assess whether countries meet the target value for protecting human health (2). Exceedances of this threshold occurred in 17 EU Member States (Austria, Bulgaria, Cyprus, the Czech Republic, Fra ...
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GAW Report, 194. 15th WMO/IAEA Meeting of Experts on Carbon Dioxyide, other Greenhouse Gases and Related Tracers Measurement Techniques
The 15th WMO/IAEA Meeting of Experts on Carbon Dioxide, Other Greenhouse Gases and Related Tracers Measurement Techniques took place from 7 to 10 September 2009 at the MaxPlanck-Institute for Biogeochemistry in Jena, Germany. The meeting reviewed current WMO data quality objectives, covering such topics as carbon dioxide and other greenhouse gases, stable isotopes, radiocarbon in greenhouse gas measurements, calibration, quality control, data management and archiving. The experts also discussed new and emerging technologies, including measurements of greenhouse gases with high-precision spectr ...
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Guide to Hydrological Practices, Volume II : Management of Water Resources and Applications of Hydrological Practices
This comprehensive guide provides practicing hydrologists with handy access to state-of-the-art and reliable information on hydrological practices, from simple discharge measurement to modeling complex hydrological systems. It was first published in 1965 and has been regularly updated since to reflect the evolving needs of, and practices employed by, the National Hydrological Services and other professionals working in water related fields.
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GAW Report, 186. 14th WMO/IAEA Meeting of Experts on Carbon Dioxide, other Greenhouse Gases and Related Tracers Measurement Techniques
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GAW Report, 185. Guidelines for the Measurement of Methane and Nitrous Oxide and their Quality Assurance
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54 - March 2008 - Establishment of a cold charcoal trap-gas chromatography-gas counting system for 85Kr measurements in Japan and results from 1995 to 2006
is an issue of 気象研究所技術報告. Aoyama Michio; Fujii Kenji; Hirose Katsumi; et al. - Meteorological Research Institute, 2008
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