scholarly journals SURFACE OZONE CONCENTRATIONS AND THE METEOROLOGICAL CONDITIONS AT AN URBAN TROPICAL SITE IN THE SOUTHERN HEMISPHERE

2014 ◽  
Vol 32 (3) ◽  
pp. 383
Author(s):  
Abel Antônio Silva
Keyword(s):  
Cloud Cover ◽  
Surface Ozone ◽  
Meteorological Condition ◽  
Meteorological Conditions ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Late Winter ◽  
Daily Maximum ◽  
Anthropogenic Pollutants ◽  
The One

ABSTRACT. Surface ozone plays a key role in the photochemistry of the low troposphere being associated with health and environmental problems. It is formed froma pool of reactions involving natural and anthropogenic pollutants, solar radiation, and the meteorological condition. In this study, 12-months of recent measurementsof surface ozone concentration (SOC) are presented for an urban tropical site (19.92◦S, 43.94◦W, 858 m asl, 331 km2) in Brazil. An analysis of the SOC dependenceon the meteorological conditions (cloud cover, wind direction and speed, number of rainy days, precipitation, humidity, and daily maximum temperature) is introduced.The daily maxima of the one-hour averaged data of SOC (1-h SOC) ranged from 8.7 to 96.1 parts-per-billion by volume (ppbv) and averaged 38.1 ± 13.7 ppbv (1σ),while the maxima of the monthly averages of the 1-h SOC varied from 24.5 ±8.8 ppbv in early fall to 46.7± 9.3 ppbv in late winter. Monthly averages of 1-h SOC andhumidity showed fair linearity among the meteorological parameters investigated. In addition, the cloud cover in summer seems to affect SOC the most.Keywords: ozone, clouds, meteorology.RESUMO. O ozônio de superfície desempenha um importante papel na fotoquímica da baixa troposfera, estando associado a questões ambientais e de saúde. Ele é formado a partir de um grupo de reações envolvendo fontes naturais e antropogênicas de poluentes, radiação solar e condições meteorológicas. Neste trabalho, 12 meses de medidas recentes da concentração de ozônio de superfície (COS) são apresentadas para uma localidade urbana tropical (19,92◦S, 43,94◦O, 858 m anm, 331 km2) no Brasil. Uma análise da dependência da COS com as condições meteorológicas (cobertura de nuvens, direção e velocidade dos ventos, número de dias chuvosos, precipitação, umidade e temperatura máxima diária) é introduzida. As máximas diárias da média horária de COS (1-h COS) variaram de 8,7 a 96,1 partes por bilhão em volume (ppbv) com média de 38,1±13,7 ppbv (1σ), enquanto as máximas das médias mensais de 1-h COS variaram de 24,5±8,8 ppbv no início do outono a 46,7±9,3 ppbv no final da primavera. As médias mensais de 1-h COS e umidade apresentaram uma linearidade razoável dentre os parâmetros meteorológicos investigados. Além disso, a cobertura de nuvens no verão parece ter afetado de forma mais intensa a COS.Palavras-chave: ozônio, nuvens, meteorologia.

scholarly journals Sensitivity of Surface Ozone Simulation to Cumulus Parameterization

2008 ◽  
Vol 47 (5) ◽  
pp. 1456-1466 ◽  
Author(s):  
Zhining Tao ◽  
Allen Williams ◽  
Ho-Chun Huang ◽  
Michael Caughey ◽  
Xin-Zhong Liang
Keyword(s):  
Cloud Cover ◽  
Surface Ozone ◽  
Meteorological Conditions ◽  
Cumulus Parameterization ◽  
Daily Maximum ◽  
Boundary Layer Height ◽  
Ozone Concentrations ◽  
Simulated Precipitation ◽  
Cumulus Schemes ◽  
The Impact

Abstract Different cumulus schemes cause significant discrepancies in simulated precipitation, cloud cover, and temperature, which in turn lead to remarkable differences in simulated biogenic volatile organic compound (BVOC) emissions and surface ozone concentrations. As part of an effort to investigate the impact (and its uncertainty) of climate changes on U.S. air quality, this study evaluates the sensitivity of BVOC emissions and surface ozone concentrations to the Grell (GR) and Kain–Fritsch (KF) cumulus parameterizations. Overall, using the KF scheme yields less cloud cover, larger incident solar radiation, warmer surface temperature, and higher boundary layer height and hence generates more BVOC emissions than those using the GR scheme. As a result, the KF (versus GR) scheme produces more than 10 ppb of summer mean daily maximum 8-h ozone concentration over broad regions, resulting in a doubling of the number of high-ozone occurrences. The contributions of meteorological conditions versus BVOC emissions on regional ozone sensitivities to the choice of the cumulus scheme largely offset each other in the California and Texas regions, but the contrast in BVOC emissions dominates over that in the meteorological conditions for ozone differences in the Midwest and Northeast regions. The result demonstrates the necessity of considering the uncertainty of future ozone projections that are identified with alternative model physics configurations.

The differing impact of air stagnation on near-surface ozone across Europe

2020 ◽  
Author(s):  
José M. Garrido-Pérez ◽  
Carlos Ordóñez ◽  
Ricardo García-Herrera ◽  
Jordan L. Schnell
Keyword(s):  
Climate Model ◽  
Surface Ozone ◽  
Weather Conditions ◽  
Ozone Production ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Southern Europe ◽  
Near Surface ◽  
Photochemical Production

<p>Daily maximum temperature is known to be the meteorological variable that mostly controls the afternoon near-surface ozone concentrations during summer. Air stagnation situations, characterised by stable weather conditions and poor ventilation, also lead to the accumulation of pollutants and regional ozone production close to the surface. This work evaluates the joint effect of daily maximum temperature and a simplified air stagnation index on surface ozone observations in eight regions of Europe during summer 1998-2015.</p><p>As expected, the correlations of MDA8 O<sub>3</sub> (maximum daily 8-h running average ozone) with temperature are higher than with stagnation for most regions. Nevertheless, stagnation can also be considered as a good predictor of ozone, especially in the regions of central/southern Europe, where the correlation coefficients between MDA8 O<sub>3</sub> and the percentage of stagnant area are within the range 0.50–0.70. MDA8 O<sub>3</sub> consistently increases over central/southern Europe under stagnant conditions, but this is not always the case in the north. Under non-stagnant conditions and daily maximum temperatures within 20-25 ºC (typical temperatures of fair weather conditions that allow photochemical production), northern Europe is affected by southerly advection that often brings aged air masses from more polluted areas, increasing the MDA8 O<sub>3</sub> mixing ratios.</p><p>We have also found that the ozone diurnal cycles in the central/southern regions exhibit large amplitudes, with above-average daytime and below-average night-time concentrations, when stagnation occurs. Stagnant nights are often associated with stable shallow planetary boundary layer and, presumably, enhanced dry deposition and chemical destruction of ozone. After sunrise, mixing with air from air from the residual layer, accumulation of ozone and precursors, and photochemical production seem to be the main mechanisms involved in the build-up of daytime ozone.</p><p>According to previous studies, some of the central/southern European regions where stagnation has a clear impact on ozone have undergone significant upward trends in air stagnation in the past and are also likely to experience increases in the future. However, our study has identified other regions with unclear responses of summer ozone to the occurrence of stagnation. This indicates that climate model projections of increases in stagnation should not directly be translated into enhanced summer ozone pollution if the sensitivity of this pollutant to stagnation has not been proved for a particular region.</p>

scholarly journals Population Exposure to Compound Droughts and Heatwaves in the Observations and ERA5 Reanalysis Data in the Gan River Basin, China

Land ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1021
Author(s):  
Yuqing Zhang ◽  
Guangxiong Mao ◽  
Changchun Chen ◽  
Liucheng Shen ◽  
Binyu Xiao
Keyword(s):  
River Basin ◽  
Population Change ◽  
Reanalysis Data ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Circulation System ◽  
Population Exposure ◽  
Daily Maximum ◽  
The One ◽  
Background Fields

The frequency, duration, and magnitude of heatwaves and droughts are expected to increase in a warming climate, which can have profound impacts on the environment, society, and public health, and these may be severely affected specifically by compound droughts and heatwaves (CDHWs). On the basis of daily maximum temperature data and the one-month standardized precipitation evapotranspiration index (SPEI) from 1961 to 2018, the Gan River Basin (GRB) was taken as a case here to construct CDHW identification indicators and quantify the population exposure to CDHWs. We found that ERA5 reanalysis data performed well in overall simulating temperature, precipitation, one-month SPEI, heatwaves, and CDHWs in the GRB from 1961 to 2018. CDHWs during the period from 1997 to 2018 were slightly higher than that in 1961–1997. CDHWs were more likely to occur in the southern parts of the basin due to the relatively high values of drought–heatwave dependence indices. Atmospheric circulation analysis of the 2003 CDHW in the GRB showed a relatively long-lasting anomalous high pressure and anticyclonic circulation system, accompanied by the positive convective inhibition and surface net solar radiation anomalies. These circulating background fields eventually led to the exceptional 2003 CDHW occurrence in the GRB. The population exposure to CDHWs basically increased, especially for the moderate CDHWs in ERA5. The change in total exposure was mainly due to climate change. Compared with the period from 1989 to 1998, the contributions of the population change effect in 2009–2018 gradually increased with the increase in the CDHW magnitude both in the observations and ERA5 reanalysis data.

scholarly journals Attributing trends in extremely hot days to changes in atmospheric dynamics

2015 ◽  
Vol 3 (5) ◽  
pp. 3323-3367
Author(s):  
J. A. García-Valero ◽  
J. P. Montávez ◽  
J. J. Gómez-Navarro ◽  
P. Jiménez-Guerrero
Keyword(s):  
Large Scale ◽  
Atmospheric Dynamics ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Sea Level Pressure ◽  
Circulation Types ◽  
Hot Days ◽  
The One ◽  
Atmospheric Variables

Abstract. This paper proposes a method that allows the detection of trends in the frequency of extreme events and its attribution to changes in atmospheric dynamics characterized through Circulation Types (CTs). The method is applied to summer Extremely Hot Days (EHD) in Spain during the period 1958–2008. For carrying out this exercise, regional series of daily maximum temperature are derived from the regional dataset Spain02. Eight regions with different daily maximum temperature variability are identified. All of them exhibit important trends in the occurrence of EHDs, especially in inner regions. Links between the probability of EHD occurrence in the regions and CTs have been calculated. Furthermore, the consistency of the results to the atmospheric variables used in defining the CTs is analyzed. Sea Level Pressure (SLP), Temperature at 850 hPa Level (T850) and Geopotential Height at 500 hPa Level (Z500) from the ERA40 dataset have been used for the six CT classifications obtained using the variables separately and in different combinations of pairs. The optimum choice of large scale variables depends on the region under consideration, being the combination SLP-T850 the one giving the most suitable characterization for most of them. Finally, an attribution exercise of the regional EHD trends to the dynamics is proposed. Results show that the maximum of attributable EHD trends to changes in dynamics in every region is always below 5 %, being even lower than 20% in those regions with the largest EHD trends, mainly located in the center of the Iberian Peninsula (IP).

scholarly journals Analysis of the Relationship between Changes in Meteorological Conditions and the Variation in Summer Ozone Levels over the Central Kanto Area

2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
Mai Khiem ◽  
Ryozo Ooka ◽  
Hong Huang ◽  
Hiroshi Hayami ◽  
Hiroshi Yoshikado ◽  
...  
Keyword(s):  
Wind Speed ◽  
Ground Level ◽  
Meteorological Conditions ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Ground Level Ozone ◽  
Ozone Concentrations ◽  
Term Variation ◽  
The Relationship

An increasing trend in ground-level ozone () concentrations has recently been recognized in Japan, although concentrations of ozone precursors, nitrogen oxides (NOx), volatile organic compounds (VOCs) and nonmethane hydrocarbons (NMHCs) have decreased. In this paper, the relationship between meteorological factors (temperature and wind speed) and ground-level ozone concentrations in the summer over the central Kanto area of Japan was examined using both statistical analyses and numerical models. The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) and the Community Multiscale Air Quality (CMAQ) model were employed in this study. It was found that there is a close relationship between meteorological conditions and ground-level ozone concentrations over the central Kanto area. In summer, up to 84% of the long-term variation in peak ozone concentrations may be accounted for by changes in the seasonally averaged daily maximum temperature and seasonally averaged wind speed, while about 70% of the recent short-term variation in peak ozone depends on the daily maximum temperature and the daily averaged wind speed. The results of numerical simulations also indicate that urban heat island (UHI) phenomena can play an important role in the formation of high ozone concentrations in this area.

scholarly journals Changes in Cloud Cover, Precipitation, and Summer Temperature in North America from 1982 to 2009

2013 ◽  
Vol 26 (5) ◽  
pp. 1733-1744 ◽  
Author(s):  
Qiuhong Tang ◽  
Guoyong Leng
Keyword(s):  
North America ◽  
Land Surface ◽  
Cloud Cover ◽  
Dominant Factor ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Local Factor ◽  
Middle Latitudes ◽  
Temperature Trends

Abstract In North America (NA), trends in summer surface air temperatures vary on decadal time scales, and some regions have temperature trends that exhibit a lack of warming in 1982–2009. From a surface energy balance perspective, the summer mean daily maximum temperature change can be affected by changes in solar heating that are associated with cloud cover change and changes in surface evaporative cooling caused by different precipitation and land surface wetness, but little is known about regional cloud cover and precipitation feedbacks to decadal temperature trends. Changes in cloudiness and precipitation and their connections with summer mean daily maximum temperature variations in NA were investigated using observation-based products of temperature and precipitation and satellite-derived cloud cover and radiation products. Results show that summer mean daily maximum temperature variance is largely explained by changes in cloud cover and precipitation. Cloud cover effect dominates at the high and middle latitudes of NA, and precipitation is a more dominant factor in the southern United States. The results indicate that cloud cover is either the major indicator of the summer mean daily maximum temperature changes (the effect) or the important local factor influencing the changes (the cause). Cloud cover is negatively correlated with mean daily maximum temperature variation in spring and autumn at the middle latitudes of NA but not at the high latitudes.

scholarly journals Social media reveal ecoregional variation in how weather influences visitor behavior in U.S. National Park Service units

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily J. Wilkins ◽  
Peter D. Howe ◽  
Jordan W. Smith
Keyword(s):  
National Park ◽  
National Park Service ◽  
Spatial Behavior ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Daily Weather ◽  
Visitor Behavior ◽  
Park Service ◽  
The Impact

AbstractDaily weather affects total visitation to parks and protected areas, as well as visitors’ experiences. However, it is unknown if and how visitors change their spatial behavior within a park due to daily weather conditions. We investigated the impact of daily maximum temperature and precipitation on summer visitation patterns within 110 U.S. National Park Service units. We connected 489,061 geotagged Flickr photos to daily weather, as well as visitors’ elevation and distance to amenities (i.e., roads, waterbodies, parking areas, and buildings). We compared visitor behavior on cold, average, and hot days, and on days with precipitation compared to days without precipitation, across fourteen ecoregions within the continental U.S. Our results suggest daily weather impacts where visitors go within parks, and the effect of weather differs substantially by ecoregion. In most ecoregions, visitors stayed closer to infrastructure on rainy days. Temperature also affects visitors’ spatial behavior within parks, but there was not a consistent trend across ecoregions. Importantly, parks in some ecoregions contain more microclimates than others, which may allow visitors to adapt to unfavorable conditions. These findings suggest visitors’ spatial behavior in parks may change in the future due to the increasing frequency of hot summer days.

scholarly journals Joint Occurrence of Daily Temperature and Precipitation Extreme Events over Canada

2014 ◽  
Vol 53 (9) ◽  
pp. 2148-2162 ◽  
Author(s):  
Bárbara Tencer ◽  
Andrew Weaver ◽  
Francis Zwiers
Keyword(s):  
Climate Models ◽  
Regional Climate ◽  
Heavy Precipitation ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Negative Consequences ◽  
Temperature And Precipitation ◽  
Joint Occurrence

AbstractThe occurrence of individual extremes such as temperature and precipitation extremes can have a great impact on the environment. Agriculture, energy demands, and human health, among other activities, can be affected by extremely high or low temperatures and by extremely dry or wet conditions. The simultaneous or proximate occurrence of both types of extremes could lead to even more profound consequences, however. For example, a dry period can have more negative consequences on agriculture if it is concomitant with or followed by a period of extremely high temperatures. This study analyzes the joint occurrence of very wet conditions and high/low temperature events at stations in Canada. More than one-half of the stations showed a significant positive relationship at the daily time scale between warm nights (daily minimum temperature greater than the 90th percentile) or warm days (daily maximum temperature above the 90th percentile) and heavy-precipitation events (daily precipitation exceeding the 75th percentile), with the greater frequencies found for the east and southwest coasts during autumn and winter. Cold days (daily maximum temperature below the 10th percentile) occur together with intense precipitation more frequently during spring and summer. Simulations by regional climate models show good agreement with observations in the seasonal and spatial variability of the joint distribution, especially when an ensemble of simulations was used.

scholarly journals Observed Trends in Indices of Daily Temperature Extremes in South America 1960–2000

2005 ◽  
Vol 18 (23) ◽  
pp. 5011-5023 ◽  
Author(s):  
L. A. Vincent ◽  
T. C. Peterson ◽  
V. R. Barros ◽  
M. B. Marino ◽  
M. Rusticucci ◽  
...  
Keyword(s):  
Climate Change ◽  
South America ◽  
Climate Extremes ◽  
Daily Temperature ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Temperature Extremes ◽  
Increasing Trends

Abstract A workshop on enhancing climate change indices in South America was held in Maceió, Brazil, in August 2004. Scientists from eight southern countries brought daily climatological data from their region for a meticulous assessment of data quality and homogeneity, and for the preparation of climate change indices that can be used for analyses of changes in climate extremes. This study presents an examination of the trends over 1960–2000 in the indices of daily temperature extremes. The results indicate no consistent changes in the indices based on daily maximum temperature while significant trends were found in the indices based on daily minimum temperature. Significant increasing trends in the percentage of warm nights and decreasing trends in the percentage of cold nights were observed at many stations. It seems that this warming is mostly due to more warm nights and fewer cold nights during the summer (December–February) and fall (March–May). The stations with significant trends appear to be located closer to the west and east coasts of South America.

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