Seasonal variability of ozone dry deposition under southern European climate conditions, in Portugal

Pio, Casimiro; Feliciano, Manuel; Vermeulen, Alex; Sousa, E. E.

doi:10.1016/s1352-2310(99)00276-9

Cited by 44 publications

(25 citation statements)

References 43 publications

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“…Studies of NO 2 and O 3 uptake resistances over temperate grasslands are often limited to measurements during the day (e.g., for NO 2 on lawn: 333–769 s m −1 [ Delany and Davies , 1983] and pasture: 38–67 s m −1 [ Duyzer et al , 1983]). Rates of removal of O 3 by grasslands have been reported by Pio et al [2000] to be 500 s m −1 at night to 200 s m −1 during the day, and Massman et al [1993] reported 100 s m −1 over a semiarid grassland.…”

Section: Resultsmentioning

confidence: 99%

Surface exchange of nitric oxide, nitrogen dioxide, and ozone at a cattle pasture in Rondônia, Brazil

et al. 2002

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[1] Measurements of NO-NO 2 -O 3 trace gas exchange were performed for two transition season periods during the La Niña year 1999 (30 April to 17 May, ''wet-dry,'' and 24 September to 27 October, ''dry-wet'') over a cattle pasture in Rondônia. A dynamic chamber system (applied during the dry-wet season) was used to directly measure emission fluxes of nitric oxide (NO) and surface resistances for nitrogen dioxide (NO 2 ) and ozone (O 3 ) deposition. A companion study was simultaneously performed in an oldgrowth forest. In order to determine ecosystem-representative NO 2 and O 3 deposition fluxes for both measurement periods, an inferential method (multiresistance model) was applied to measure ambient NO 2 and O 3 concentrations using observed quantities of turbulent transport. Supplementary measurements included soil NO diffusivity and soil nutrient analysis. The observed NO soil emission fluxes were nine times lower than oldgrowth rain forest emissions under similar soil moisture and temperature conditions and were attributed to the combination of a reduced soil N cycle and lower effective soil NO diffusion at the pasture. Canopy resistances (R c ) of both gases controlled the deposition processes during the day for both measurement periods. Day and night NO 2 canopy resistances were significantly similar (a = 0.05) during the dry-wet period. Ozone canopy resistances revealed significantly higher daytime resistances of 106 s m À1 versus 65 s m À1at night because of plant, soil, and wet skin uptake processes, enhanced by stomatal activity at night and aqueous phase chemistry on vegetative and soil surfaces. The surface of the pasture was a net NO x sink during 1999, removing seven times more NO 2 from the atmosphere than was emitted as NO.

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Section: Resultsmentioning

confidence: 99%

Surface exchange of nitric oxide, nitrogen dioxide, and ozone at a cattle pasture in Rondônia, Brazil

et al. 2002

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“…This distribution of higher O 3 around Arvin was not observed on every day, but was more common on ozone exceedance days. Because we only measured the NO 2 distribution once, it is more difficult to generalize, but the local maximum of NO 2 near Bakersfield has been reported elsewhere and is evident in seasonal satellite averages reported in Russell et al (2010) and Pusede and Cohen (2012). The colored circles in Fig.…”

Section: Other Budget Residualsmentioning

confidence: 97%

Observing entrainment mixing, photochemical ozone production, and regional methane emissions by aircraft using a simple mixed-layer framework

et al. 2016

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In situ flight data from two distinct campaigns during winter and summer seasons in the San Joaquin Valley (SJV) of California are used to calculate boundary-layer entrainment rates, ozone photochemical production rates, and regional methane emissions. Flights near Fresno, California, in January and February 2013 were conducted in concert with the NASA DISCOVER-AQ project. The second campaign (ArvinO3), consisting of 11 days of flights spanning June through September 2013 and 2014, focused on the southern end of the SJV between Bakersfield and the small town of Arvin, California -a region notorious for frequent violations of ozone air quality standards. Entrainment velocities, the parameterized rates at which free tropospheric air is incorporated into the atmospheric boundary layer (ABL), are estimated from a detailed budget of the inversion base height. During the winter campaign near Fresno, we find an average midday entrainment velocity of 1.5 cm s −1 , and a maximum of 2.4 cm s −1 . The entrainment velocities derived during the summer months near Bakersfield averaged 3 cm s −1 (ranging from 0.9 to 6.5 cm s −1 ), consistent with stronger surface heating in the summer months. Using published data on boundary-layer heights we find that entrainment rates across the Central Valley of California have a bimodal annual distribution peaking in spring and fall when the lower tropospheric stability (LTS) is changing most rapidly.Applying the entrainment velocities to a simple mixedlayer model of three other scalars (O 3 , CH 4 , and H 2 O), we solve for ozone photochemical production rates and find wintertime ozone production (2.8 ± 0.7 ppb h −1 ) to be about one-third as large as in the summer months (8.2 ± 3.1 ppb h −1 ). Moreover, the summertime ozone production rates observed above Bakersfield-Arvin exhibit an inverse relationship to a proxy for the volatile organic compound (VOC) : NO x ratio (aircraft [CH 4 ] divided by surface [NO 2 ]), consistent with a NO x -limited photochemical environment. A similar budget closure approach is used to derive the regional emissions of methane, yielding 100 (±100) Gg yr −1 for the winter near Fresno and 170 (±125) Gg yr −1 in the summer around Bakersfield. These estimates are 3.6 and 2.4 times larger, respectively, than current state inventories suggest. Finally, by performing a boundarylayer budget for water vapor, surface evapotranspiration rates appear to be consistently ∼ 55 % of the reference values reported by the California Irrigation Management Information System (CIMIS) for nearby weather stations.Published by Copernicus Publications on behalf of the European Geosciences Union.

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“…Stomatal fluxes generally differ from total ozone surface fluxes since only a part of the ozone 'deposited' (i.e., removed from the atmosphere) enters the leaf tissues through the stomata. So stomatal ozone fluxes are smaller than total ozone fluxes, and the ratio of these two quantities has formed the subject of a great deal of work (Galbally & Roy, 1980;Gerosa, Cieslik, & Ballarin-Denti, 2003;Hargreaves, Fowler, Storeton-West, & Duyzer, 1992;Labatut & Cieslik, 1997;Massman, 1993;Pio, Feliciano, Vermeulen, & Sousa, 2000;Wesely, Eastman, Stedman, & Yalvac, 1982). Stomata are physiologically active, as they show an opening/ closing daily cycle which acts as a regulation process for evapotranspiration.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Different Algorithms for Stomatal Ozone Flux Determination from Micrometeorological Measurements

Gerosa

Derghi

Cieslik

2006

Water Air Soil Pollut

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The determination of stomatal ozone fluxes is essential to assess the potential damage to plants due to ozone uptake. This parameter is not accessible directly with measurements, but can be deduced through algorithms using observational data. Total ozone fluxes and water vapour fluxes are generally used. Water vapour fluxes give an indication on stomatal aperture, which is the controlling factor of ozone uptake by vegetation. In this work, a series of observations made during the growing season over an onion field are used to show the equivalence of two algorithms found in the literature to derive ozone stomatal fluxes and both based on the similarity between ozone stomatal fluxes and water vapour stomatal fluxes. One of these algorithms uses the Penman-Monteith approach, where the water vapour pressure deficit is calculated using air temperatures; the second calculates, with another formulation, the water vapour deficit from the leaf temperature. The two approaches lead to the same results if applied properly, as shown in this work, both theoretically and numerically.

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Seasonal variability of ozone dry deposition under southern European climate conditions, in Portugal

Cited by 44 publications

References 43 publications

Surface exchange of nitric oxide, nitrogen dioxide, and ozone at a cattle pasture in Rondônia, Brazil

Surface exchange of nitric oxide, nitrogen dioxide, and ozone at a cattle pasture in Rondônia, Brazil

Observing entrainment mixing, photochemical ozone production, and regional methane emissions by aircraft using a simple mixed-layer framework

Comparison of Different Algorithms for Stomatal Ozone Flux Determination from Micrometeorological Measurements

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