Universidade de Aveiro Seaso Seasonal nal varia variability bility of of atmosp tmospheric dust o heric dust over er Cape V Ca pe Ver erde islands de islands C. Pio 1 ; M.C. Freitas 2 ; J. Cardoso 1,3 ; T. Nunes 1 ; S.M. Almeida 2 ; M. Almeida 2 ; O. Tchepel 1 ; F. Rocha 1 ; M. Cerqueira 1 ; J. Ferreira 1 ; D. Terroso 1 ; ; P. Fialho 4 ; Ho Dung 2 ; Danilo Custódio 1 1 - Universidade de Aveiro; 2 - Instituto Tecnológico e Nuclear; 3 - Universidade de Cabo Verde; 4 - Universidade dos Açores ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Presentation based on CVDUST project: “CVDUST - Atmospheric aerosol in Cape Verde region: seasonal evaluation of composition, sources and transport” • Joint initiative of : University of Aveiro; Technological and Nuclear Institute; Cape Verde University . • Support of the Cape Verde Atmospheric Observatory (CVAO) . • Funding through Portuguese FCT . ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Why study atmospheric dust in Cape Verde? Estimated Global Emission rates of particles into the Atmosphere (Tg yr-1) Fine Particles Coarse Particles Sea Salt 82.1 2460 Dust 250 1000-4875 Carbon 81 Sulfate 150 Nitrate 11.3 Ammonium 33.6 ref: Raes et al., (2000) • Dust Sources: Natural Soil; • Agriculture (example “Dust Bowl” in USA); • Transports; • Industry (cement; mining) ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro TOMS satellite seasonally averaged values of Aerosol Index in the period 1980-92 NOVEMBER-JANUARY • Sahara emissions predominate • Higher AI values during summer MAY-JULY http://ozoneaq.gsfc.nasa.gov/TOMSAerosol.md (ref: Engelstaedter, 2006) ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Impacts of desert dust emissions • Atmospheric Heat Balance and Climate Control • Weakening of Atlantic Tropical Cyclones • Biogeochemical Cycles • Biogeochemical Cycles in Atlantic and Amazon Basin • Toxic Algae Blooms • Human Health • Spreading of meningitis in Sahel (Sultan et al., 2005) • Kawasaki disease in Japan and Western USA (Fraser, 2012) ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Objectives of Project CVDUST: 1. Monitoring and sampling atmospheric dust during one year 2. Chemical and structural characterization of collected samples • Water Soluble ions • Carbonate and Carbonaceous forms • Elemental Composition (NAA) • Mineralogical Composition (XRD; TEM; SEM) • Organic Species (GC/MS) • Microbial and fungi characterization 3. Source Identification; Transport and Deposition Modeling • Source Apportionment (PMF; PCA/MLRA) • Transport Modeling (Trajectory Analysis; DREAM Model) 4. Quantify African dust input to Cape Verde Air Quality 5. Explain processes governing dust production, transport, and removal from atmosphere over the Atlantic ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Monitoring and Sampling: Performed at Praia airport during one year (Jan2011-Jan2012) Equipment: 1 GRIMM Aerosol Spectromeeter (0.25->32µm) 31 channels 1 Aethalometer (7 wavelength channels) 2 PM10 LowVol filter samplers 1 PM10 HighVol filter Samplers 1 Berner LowVol impactor (0.063-16 µm) 8 stages 1 HighVol impactor (<0.49-10µm) 6 stages 1 Meteo Station ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Special Conditions of Cape Verde to perform Sahara Dust Studies : • Out of West Africa Coast (900 km) • Dust Season Period (Bruma Seca – Dry Fog) • Safety and Electricity Supply • Good relations and Low Cost CLEAN ATMOSPHERE BRUMA SECA – DRY FOG ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Dust Size Distribution Dust mass mainly in size range 1-10 µm Average dust size profile measured with the GRIMM Optical Spectrometer , for 18 Jan 2011, at Praia, Santiago Island AERONET Integrated Air Column Size Profile Dust Volume Concentration, for 18 Jan 2011, in Sal Island ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Hourly averaged dust size distribution variability along the day 18 Jan 2011 Local re-suspension processes probably responsible for dust particles above 10 µm ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Aerosol concentration variability at Praia during 2011 500 Daily Averaged 400 PM2.5 PM10 Daily Averaged 300 3 ) PTS Concentrations concentração ( g/m 200 Concentrations 100 50 25 0 WHO 01/01/11 01/02/11 01/03/11 01/04/11 01/05/11 01/06/11 01/07/11 01/08/11 01/09/11 01/10/11 01/11/11 01/12/11 01/01/12 01/02/12 Guide 300 values Monthly Averaged PM2.5 250 PM10 concentração ( g/m 3 ) Concentrations PTS Monthly Averaged 200 Concentrations 150 100 50 0 Jan 11 Feb 11 Mar 11 Apr 11 May 11 Jun 11 Jul 11 Aug 11 Sep 11 Oct 11 Nov 11 Dec 11 Jan 12 ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Particulate Pollution Levels and daily exceedences, at Praia Annual WHO Guide Parameter Average* Values (µg/m 3 ) (µg/m 3 ) Particulate pollution levels PM 2.5 17.5 10 clearly exceed PM 10 37.5 20 WHO Guides and TSP 66.0 - probably affect 14 Nº of daily exceedences local Human PM2.5 12 PM10 Health, principally nº de excedências 10 during “BRUMA 8 SECA” Season 6 4 2 0 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 n b r r y n l g p t v c n u a p c a o e a e u u e a J O M A J F M J A S N D J ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Major Chemical Class Composition of Praia Aerosol WSII- Water Soluble Inorganic Ions ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro 48 Hours backward trajectories for every day in Febr. 2011 First week Second week Third week Fourth week ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro 48 Hours backward trajectories for every day in August 2011 Second week First week Third week Fourth week ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Universidade de Aveiro Source apportionment: Composition relations -3 ) 5 Sm/Fe=0.00024 [Sm] (ng.m 4 3 2 Sm/Fe=0.00012 1 Cl/Mg=14.9 0 25000 0 5000 10000 15000 20000 25000 -3 ) 50 [Rb] (ng.m Rb/Fe=0.0056 40 30 20 Rb/Fe=0.0018 10 Na/Mg=8.3 0 25000 0 5000 10000 15000 20000 25000 [Fe] (ng.m -3 ) ) Green- Sea salt composition Red- Saharan soil composition (Reguigui et al., 2002); Blue- Global soil composition (Manson and Moore (1982) ICEH 2012 , Lisbon 29May-1June ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Emission, Transport and Deposition Modeling DREAM - Dust REgional Atmospheric Model | BSC-DREAM8b http://www.bsc.es/projects/earthscience/DREAM/ predicts the atmospheric life cycle of the eroded Saharan desert dust D UST P RODUCTION S CHEME : Type of soil Type of vegetation cover Soil moisture content Surface atmospheric turbulence ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro DR DREA EAM ad adapt ptation tion/a /app pplica ication tion to to CV CV-DU DUST ST Pr Project ect Outputs A EROSOL CONCENTRATION D UST LOAD C OLUMN D RY / WET DEPOSITION 24 vertical layers (km) 15 Resolution: 37 x 37 km 2 19N 10 AERONET 5 Sampling point 13N -26W -14E 0 ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro DREAM EAM Mo Model del ou output put exa xampl mple F OUR DAYS SURFACE AEROSOL CONCENTRATION , END FEBRUARY 2011 ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro DR DREA EAM - Inte tercomparis comparison on Model el / M / Mea easurements ements ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro PROVISIONAL CONCLUSIONS • A complete chemical e physical composition seasonal data set for atmospheric aerosol offshore of northwest Africa, gathered; • Clear existence of two seasons with different particulate pollution levels; • Particulate pollution levels clearly above WHO health guides, principally during the “Bruma Seca” dust season; • Chemical composition shows two predominant aerosol sources: sea salt spray and soil dust; • DREAM model can reproduce reasonably the transport of dust and the aerosol loading in Cape Verde region; • Continuation of analytical and modeling work in the near future are expected to permit further insight into source characterization and quantification and dust transport and deposition to the Atlantic. ICEH 2012 , Lisbon 29May-1June
Universidade de Aveiro Thanks for your attention! Casim simiro iro A. Pio io ═══════════════════════════ CESAM & Departamento de Ambiente Universidade de Aveiro 3810-193 Aveiro; Portugal Phone- +351-234370245 Email- casimiro@ua.pt http://www.cesam.ua.pt/cpio ═══════════════════════════ ICEH 2012 , Lisbon 29May-1June
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