Analysis of number size distributions of tropical free tropospheric = rosol particles observed at Pico Espejo (4765 m a.s.l.), Venezuela
2011 (English)In: Atmospheric Chemistry And Physics, ISSN 1680-7316, Vol. 11, no 7, 3319-3332 p.Article in journal (Refereed) Published
The first long-term measurements of aerosol number and size distributions in South-American tropical free troposphere (FT) were performed from March 2007 until March 2009. The measurements took place at the high altitude Atmospheric Research Station Alexander von Humboldt. The station is located on top of the Sierra Nevada mountain ridge at 4765 m a.s.l. nearby the city of Merida, Venezuela. Aerosol size distribution and number concentration data was obtained with a custom-built Differential Mobility Particle Sizer (DMPS) system and a Condensational Particle Counter (CPC). The analysis of the annual and diurnal variability of the tropical FT aerosol focused mainly on possible links to the atmospheric general circulation in the tropics. Considerable annual and diurnal cycles of the particle number concentration were observed. Highest total particle number concentrations were measured during the dry season (January-March, 519+/-613 cm(-3)), lowest during the wet season (July September, 318+/-194 cm(-3)). The more humid FT (relative humidity (RH) range 50-95 %) contained generally higher aerosol particle number concentrations (573+/-768 cm(-3) during dry season, 320+/-195 cm(-3) during wet season) than the dry FT (RH <50 %, 454+/-332 cm(-3) during dry season, 275+/-172 cm(-3) during wet season), indicating the importance of convection for aerosol distributions in the tropical FT. The diurnal cycle in the variability of the particle number concentration was mainly driven by local orography.
Place, publisher, year, edition, pages
2011. Vol. 11, no 7, 3319-3332 p.
BOUNDARY-LAYER EXPERIMENT, HIGH-ALPINE SITE, RAIN-FOREST, LBA-CLAIRE-98 EXPERIMENT, WET SEASON, AIR MASSES, BIOMASS, AIRCRAFT, AMAZONIA
Meteorology and Atmospheric Sciences
IdentifiersURN: urn:nbn:se:su:diva-66656DOI: 10.5194/acp-11-3319-2011ISI: 000289548200019OAI: oai:DiVA.org:su-66656DiVA: diva2:468113
authorCount :92011-12-202011-12-202011-12-20Bibliographically approved