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Ministerio de Ciencia e Innovación (Espanya)
Ministerio de EconomÃa y Competitividad (Espanya) |
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Sánchez Romero, Alejandro
González Gutiérrez, Josep Abel Calbó Angrill, Josep Sánchez Lorenzo, Arturo Michalsky, J. |
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2016 June 15 | |
Column aerosol optical properties were derived from multifilter rotating shadowing radiometer (MFRSR) observations carried out at Girona (northeast Spain) from June 2012 to June 2014. We used a technique that allows estimating simultaneously aerosol optical depth (AOD) and Ångström exponent (AE) at high time-resolution. For the period studied, mean AOD at 500 nm was 0.14, with a noticeable seasonal pattern, i.e. maximum in summer and minimum in winter. Mean AE from 500 to 870 nm was 1.2 with a strong day-to-day variation and slightly higher values in summer. So, the summer increase in AOD seems to be linked with an enhancement in the number of fine particles. A radiative closure experiment, using the SMARTS2 model, was performed to confirm that the MFRSR-retrieved aerosol optical properties appropriately represent the continuously varying atmospheric conditions in Girona. Thus, the calculated broadband values of the direct flux show a mean absolute difference of less than 5.9 W m-2 (0.77%) and R = 0.99 when compared to the observed fluxes. The sensitivity of the achieved closure to uncertainties in AOD and AE was also examined. We use this MFRSR-based dataset as a reference for other ground-based and satellite measurements that might be used to assess the aerosol properties at this site. First, we used observations obtained from a 100 km away AERONET station; despite a general similar behavior when compared with the in-situ MFRSR observations, certain discrepancies for AOD estimates in the different channels (R < 0.84 and slope < 1) appear. Second, AOD products from MISR and MODIS satellite observations were compared with our ground-based retrievals. Reasonable agreements are found for the MISR product (R = 0.92), with somewhat poorer agreement for the MODIS product (R = 0.70). Finally, we apply all these methods to study in detail the aerosol properties during two singular aerosol events related to a forest fire and a desert dust intrusion This research was supported by the Spanish Ministry of Economy and Competitiveness projects NUCLIERSOL (CGL2010-18546) and NUBESOL (CGL2014-55976-R). The first author enjoys a grant by the FPU program (FPU AP2010-0917) of the SpanishMinistry of Education. The fourth author enjoys a grant fromthe SpanishMinistry of Economy and Competitiveness (JCI-2012-12508) |
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application/pdf | |
http://hdl.handle.net/10256/13133 | |
eng | |
Elsevier | |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.atmosres.2016.02.002 info:eu-repo/semantics/altIdentifier/issn/0169-8095 info:eu-repo/grantAgreement/MICINN//CGL2010-18546/ES/LAS NUBES Y SUS EFECTOS SOBRE LA RADIACION: DEL ESTUDIO DE SITUACIONES A ESCALA LOCAL AL ANALISIS CLIMATOLOGICO DE ALCANCE GLOBAL. INTERACCIONES CON EL AEROSOL ATMOSFERICO/ info:eu-repo/grantAgreement/MINECO//CGL2014-55976-R/ES/EXPLORANDO LA FRONTERA ENTRE NUBE Y AEROSOL MEDIANTE OBSERVACIONES DESDE SUPERFICIE Y MODELIZACION DE LA TRANSFERENCIA RADIATIVA/ |
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Tots els drets reservats | |
Radiació solar
Solar radiation Aerosols |
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Aerosol optical depth in a western Mediterranean site: An assessment of different methods | |
info:eu-repo/semantics/article | |
DUGiDocs |