The Role of Planetary Boundary-Layer Parameterizations in the Air Quality of an Urban Area with Complex Topography   总被引：3，自引：1，他引：2  

Elizabeth Bossioli  Maria Tombrou  Aggeliki Dandou  Eleni Athanasopoulou  Kostas V. Varotsos 《Boundary-Layer Meteorology》2009,131(1):53-72

The effect of different planetary boundary-layer (PBL) parameterization schemes on the spatial distribution of atmospheric pollution over the complex topography of the greater Athens area is investigated. Four PBL schemes originally implemented in a numerical meteorological model and a fifth one simulating the urban effect are examined. Two different atmospheric conditions are analyzed; a typical summer and a typical winter pollution episode. The relative importance of chemical and physical processes of the pollution predictions is discussed using process analysis. It is revealed that, for primary pollutants, a local scheme seems more adequate to represent the maximum observed concentrations while, completely different in structure, a non-local scheme reproduces the mean observed values in the basin. Concerning secondary pollutants, peak concentration differences, due to the different PBL schemes, are smoothed out. Nevertheless, the PBL scheme selection shapes the horizontal and the vertical extension of maximum values. The non-local and semi non-local schemes are superior to the others, favouring strong vertical mixing and transport towards the surface. The stronger turbulence accommodated effectively by the semi non-local urban scheme enhances ozone production along the sea-breeze axis and preserves the high ozone concentrations during the nighttime hours in the urban core.  相似文献   

Women advancing research on hydrological processes: Preface     

Doerthe Tetzlaff  Elizabeth Boyer  Tanya Doody  Anne Jefferson  Annalisa Molini 《水文研究》2021,35(7):e14267

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High-frequency Faraday rotation observations of the solar corona     

Elizabeth A. Jensen 《Planetary and Space Science》2008,56(11):1562-1564

This thesis, presented on January 31, 2007 under the supervision of Professor Christopher T. Russell, discusses the solar coronal magnetic field observations that can be obtained using the phenomenon of Faraday rotation. It was defended in the Department of Earth and Space Sciences at the University of California, Los Angeles (595 Charles E. Young, Dr. East, Los Angeles, CA 90095). A resume can be found at http://acs-consulting.com/.  相似文献   

A limit on the number density of bright z≈ 7 galaxies     

Elizabeth R. Stanway  Malcolm N. Bremer  Valentina Squitieri  Laura S. Douglas  Matthew D. Lehnert 《Monthly notices of the Royal Astronomical Society》2008,386(1):370-376

We present a survey of bright optical dropout sources in two deep, multiwavelength surveys comprising 11 widely separated fields, aimed at constraining the galaxy luminosity function at   z ≈ 7  for sources at  5–10  L * ( z = 6)  . Our combined survey area is 225 arcmin² to a depth of   J _AB= 24.2  (3σ) and 135 arcmin² to   J = 25.3  (4σ). We find that infrared data longwards of 2 μm are essential for classifying optical dropout sources, and in particular for identifying cool Galactic star contaminants. Our limits on the number density of high-redshift sources are consistent with current estimates of the Lyman break galaxy luminosity function at   z = 6  .  相似文献   

Reanalysis of the Historic AFTAC Bolide Infrasound Database     

Douglas O. ReVelle  Elizabeth A. Sukara  Wayne N. Edwards  Peter G. Brown 《Earth, Moon, and Planets》2008,102(1-4):337-344

We have recently digitized and partially reanalyzed the historic bolide infrasonic database. These 10 events were originally detected by the U.S. Air Force Technical Applications Center (AFTAC) from ∼1960 to 1974. In this paper we present the first preliminary reanalysis results for two of the 10 bolide events, namely the Revelstoke bolide of 3/31/1965 as well as the Prince Edward Islands (P.E.I). S. African bolide of 8/03/1963, which were among the largest bolides detected during this time period. These bolides have been investigated initially since they are most likely to have had a significant effect on the computed global influx rate of ReVelle (Global Infrasonic Monitoring of Large Bolides, pp 483–490, 2001) as indicated in Brown et al. (Nature, 420:314–316, 2002). We are in the process of recomputing all relevant infrasonic propagation quantities such as plane wave back azimuth, signal velocities, power spectra, spectrograms, as well as energy estimates using multiple techniques. In a future paper we will present a complete digital reanalysis of the AFTAC bolide infrasonic data and its final resulting global bolide influx implications.  相似文献   

Hydrogen fluence in Genesis collectors: Implications for acceleration of solar wind and for solar metallicity     

Gary R. Huss  Elizabeth Koeman‐Shields  Amy J. G. Jurewicz  Donald S. Burnett  Kazuhide Nagashima  Ryan Ogliore  Chad T. Olinger 《Meteoritics & planetary science》2020,55(2):326-351

NASA's Genesis mission was flown to capture samples of the solar wind and return them to the Earth for measurement. The purpose of the mission was to determine the chemical and isotopic composition of the Sun with significantly better precision than known before. Abundance data are now available for noble gases, magnesium, sodium, calcium, potassium, aluminum, chromium, iron, and other elements. Here, we report abundance data for hydrogen in four solar wind regimes collected by the Genesis mission (bulk solar wind, interstream low‐energy wind, coronal hole high‐energy wind, and coronal mass ejections). The mission was not designed to collect hydrogen, and in order to measure it, we had to overcome a variety of technical problems, as described herein. The relative hydrogen fluences among the four regimes should be accurate to better than ±5–6%, and the absolute fluences should be accurate to ±10%. We use the data to investigate elemental fractionations due to the first ionization potential during acceleration of the solar wind. We also use our data, combined with regime data for neon and argon, to estimate the solar neon and argon abundances, elements that cannot be measured spectroscopically in the solar photosphere.  相似文献   

Geographic Dimensions of Relocation Activity: A Comparative Analysis of Intrametropolitan and Out-of-State Relocation Activity     

Elizabeth A. Mack  Ran Wei 《The Professional geographer》2018,70(1):103-113

Over the years, research on relocation activity has provided insights about the characteristics of firms and regions that drive relocation. The spatial dimensions of these relocation decisions, however, particularly within states or metropolitan areas, remain an understudied aspect of the relocation literature. There is also little work comparing the destinations of relocations originating from within metropolitan areas compared to relocation activity from other states. Given the theoretical and practical importance of higher resolution, comparative research on relocation activity within metropolitan areas, this article uses both areal and point-based spatial statistics to test hypotheses about similarities and differences in the relocation behavior of locally oriented and out-of-state businesses within the Phoenix, Arizona, metropolitan area. Analytical results highlight distinct differences in the destinations of relocation activity originating from within the metropolitan area compared to out-of-state relocation activity. Intrametropolitan relocations tend to locate in less expensive and racially and ethnically diverse neighborhoods, whereas out-of-state relocations locate in wealthier, well-known locations of the metropolitan area. Out-of-state relocations are also less likely to locate in the downtown core. This suggests that expensive smokestack-chasing efforts directed at attracting businesses from out of state are unlikely to help revitalize the downtown core.  相似文献   

A complete sample of radio sources in the North Ecliptic Cap, selected at 38 MHz – III. Further imaging observations and the photometric properties of the sample     

Mark Lacy  Mary Elizabeth Kaiser  Gary J. Hill  Steve Rawlings  Gareth Leyshon 《Monthly notices of the Royal Astronomical Society》1999,308(4):1087-1095

Further imaging observations of a sample of radio sources in the North Ecliptic Cap are presented and a number of new identifications are made. Using redshifts from spectroscopic data presented in a companion paper by Lacy et al., the photometric properties of the galaxies in the sample are discussed. It is shown that: (1) out to at least z ≈0.6 radio galaxies are good standard candles irrespective of radio luminosity; (2) for 0.6≲ z ≲1 a large fraction of the sample has magnitudes and colours consistent with a non-evolving giant elliptical, and (3) at higher redshifts, where the R -band samples the rest-frame UV flux, most objects have less UV luminosity than expected if they form their stellar populations at a constant rate from a high redshift to z ∼1 in unobscured star-forming regions (assuming an Einstein–de Sitter cosmology). The consequences of these observations are briefly discussed.  相似文献   

Fijian villagers adapt to changes in local fisheries     

Elizabeth Matthews  Joeli Veitayaki  Vina Ram Bidesi 《Ocean & Coastal Management》1998,38(3):207-224

This paper analyzes some of the problems encountered by a village-run fishing cooperative in rural Fiji. Concern about the limited success of this fishing cooperative led the villagers of Kaba Point, Fiji to ask for biological and socioeconomic studies to determine the roots of the cooperative’s problems. The villagers also required an assessment of their proposal to revitalize the cooperative through a development scheme that would enable them to increase their catch. The surveys, undertaken by researchers from the University of the South Pacific and the Fiji Fisheries Division, indicate that the area has been overfished, primarily through the widespread local and commercial use of gillnets and the reliance on fishing as a sole source of village income, and further expansion of the current resource exploitation patterns would be very damaging. In addition, although the cooperative provides an important sense of communalism in the village, only a few people regularly provide fish to the coop. The semi-subsistence lifestyle of rural Fiji is one factor limiting villagers participation in full-time fishing activities. The traditional social and management structures inherent in this village (especially, marine tenure, chiefly responsibility for the community, and a demonstrated history of communal projects) can form a strong basis for a modern community-based marine management program. However, if not carefully watched, resources can also be locally mismanaged because of the increasing demands of the modern market-driven economy.  相似文献   

It all comes out in the wash: Actualistic petrofacies modeling of temper provenance,Tonto Basin,Arizona, USA     

Elizabeth J. Miksa  James M. Heidke 《Geoarchaeology》2001,16(2):177-222

Prehistoric potters frequently tempered their pottery with sand, the provenance of which can be established petrographically. In the Tonto Basin of central Arizona, the bedrock geology is highly variable, giving rise to geographically unique sands. Zones of sands with similar compositions can be modeled at an archaeologically relevant scale. Here we use the actualistic petrofacies concept, the Gazzi–Dickinson point‐counting technique, and multivariate statistics to create a petrofacies model, then apply it to sand‐tempered utilitarian pottery recovered from three Tonto Basin project areas. Data analysis reveals strong temporal and spatial ceramic production and consumption patterns. Production of pottery for exchange was established in at least one petrofacies ca. A.D. 600–950, with increasing specialization through time. By ca. A.D. 1150, corrugated wares had been added, and specialized production by ware was established in two petrofacies. Provenance evidence suggests different regional affiliations for groups in different parts of the basin. © 2001 John Wiley & Sons, Inc.  相似文献