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The influence of the organic aerosol component on CCN supersaturation spectra for different aerosol types 总被引：5，自引：0，他引：5
MIHAELA MIRCEA MARIA CRISTINA FACCHINI STEFANO DECESARI SANDRO FUZZI ROBERT J. CHARLSON 《Tellus. Series B, Chemical and physical meteorology》2002,54(1):74-81
Abstract This paper describes the effect of the presence of water-soluble organic compounds (WSOC) in aerosol particles on the aerosol critical supersaturation as defined by the Köhler theory and on cloud condensation nuclei (CCN) number concentration. Taking into account both the soluble mass increase and the surface tension depression due to WSOC, we calculated a substantial decrease of the aerosol critical supersaturation, which results in a large increase in CCN number concentration. CCN supersaturation spectra were computed for three different aerosol types: marine, rural and urban. The increase of CCN number concentration in the presence of WSOC (with respect to the case when only the inorganic aerosol compounds are considered) varies with aerosol type, with an increase up to 13% in the marine case, up to 97% in the rural case, and up to 110% in the urban case, for the supersaturation range typical of atmospheric conditions. 相似文献
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A remote sensing based approach to determine forest fire cycle: case study of the Yenisei Ridge dark taiga 总被引：1，自引：0，他引：1
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Changes in aerosol size- and phase distributions due to physical and chemical processes in fog 总被引：4，自引：0，他引：4
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Phase-partitioning and chemical reactions of low molecular weight organic compounds in fog 总被引：3，自引：0，他引：3
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Intra-Grain Sr Isotope Evidence for Crystal Recycling and Multiple Magma Reservoirs in the Recent Activity of Stromboli Volcano, Southern Italy 总被引：3，自引：1，他引：3
FRANCALANCI LORELLA; DAVIES GARETH R.; LUSTENHOUWER WIM; TOMMASINI SIMONE; MASON PAUL R. D.; CONTICELLI SANDRO 《Journal of Petrology》2005,46(10):1997-2021
Over the last several hundred years, Stromboli has been characterizedby steady-state Strombolian activity. The volcanic productsare dominated by degassed and highly porphyritic (HP-magma)black scoria bombs, lapilli and lava flows of basaltic shoshoniticcomposition. Periodically (about one to three events per year),more energetic explosive eruptions also eject light colouredvolatile-rich pumices with low phenocryst content (LP-magma)that have more mafic compositions than the HP-magma. An in situmajor and trace element and Sr isotope microanalysis study ispresented on four samples chosen to characterize the differentmodes of activity at Stromboli: a lava flow (1985–1986effusive event), a scoria bomb from the ‘normal’present-day activity of Stromboli (April 1984), and a scoriaand coeval pumice sample from a recent more explosive eruption(September 1996). Plagioclase (An62–90) and clinopyroxene(Mg-number between 0·69 and 0·91) phenocrystsin all samples record marked major element variations. Largeand comparable Sr isotope variations have been detected in plagioclaseand clinopyroxene. HP-magma crystals have resorbed cores, witheither high 87Sr/86Sr (0·70635–0·70630)or low 87Sr/86Sr (0·70614–0·70608); thelatter values are similar to the values of the outer cores.Mineral rims and glassy groundmasses generally have intermediate87Sr/86Sr (0·70628–0·70613). Similarly,mineral growth zones with three groups of 87Sr/86Sr values characterizeminerals from the LP-pumice, with the lowest values presentin mineral rims and groundmass glass. These results define amixing process between HP- and LP-magmas, plus crystallizationof clinopyroxene, plagioclase and olivine, occurring in a shallowmagma reservoir that feeds the present-day magmatic activityof Stromboli. An important observation is the presence of athird component (high 87Sr/86Sr in mineral cores) consideredto represent a pre-AD 1900 cumulus crystal mush reservoir situatedjust below the shallow magma chamber. These cumulus phases areincorporated by the LP-magma arriving from depth and transportedinto the shallow reservoir. A rapid decrease of 87Sr/86Sr inthe replenishing LP-magma immediately prior to eruption of theAD 1985 lava flow is associated with an increased volume ofLP-magma in the shallow magma chamber. The HP-magma in the shallowreservoir is not fully degassed when it interacts with the LP-magma,making efficient mixing possible that ultimately produces awell overturned homogeneous magma. Further degassing and crystallizationoccur at shallower levels as the HP-magma moves through a conduitto the surface. KEY WORDS: isotopic microsampling; mineral recycling; mixing; Sr isotope disequilibria; Stromboli 相似文献
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Net CO2 exchange rates in three different successional stages of the "Dark Taiga" of central Siberia
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