The CACIQUE campaign: understanding the role of sugarcane .../Session2... · The CACIQUE campaign:...
Transcript of The CACIQUE campaign: understanding the role of sugarcane .../Session2... · The CACIQUE campaign:...
The CACIQUE campaign: understanding the role of
sugarcane agriculture on air pollution in the
Cauca River Valley, ColombiaRodrigo Jimenez 1, Lady Mateus 1, Néstor Y. Rojas 1,
Germán Rueda 2, John H. Reina 3, Germán Restrepo 4, Crystal Weagle 5, Brent N. Holben 6
(1) Universidad Nacional de Colombia – Bogota, Department of Chemical and Environmental Engineering, Air Quality Research Group; [email protected]
(2) Universidad Nacional de Colombia – Palmira(3) Universidad del Valle – Cali; (4) CVC, Cali(5) Dalhousie University, Halifax, NS, Canada
(6) NASA Goddard Space Flight Center, Greenbelt, MD, USA
WorkshopBlack carbon concentrations and emissions in Colombian cities
Cali, November 28-30, 2018
Collaborations and other investigators❑ Universidad Nacional de Colombia –
Palmira: Jennifer Marin, Angela C. Vargas, Svenja Weber
❑ Universidad del Valle: John H. Reina, Carlos A. Melo, Jonnathan Cespedes
❑ Leibniz Institute for Tropospheric Research (TROPOS) – Leipzig, Germany:Alfred Wiedensohler, Dominik van Pinxteren, Hartmut Herrmann
❑ Max Planck Institute forBiogeochemistry – Jena, Germany:Carlos A. Sierra
❑ DAGMA – Cali: Gisella Arizabaleta
Colombia: complex meteorology → AQ❑ Equatorial (moist convection) + very complex topography
(mesoscale thermal circulation) → complex meteorology →mild winds but high turbulence intensity
❑ Several airsheds with different boundary conditions →starting to understand they modulate AQ in Colombia
15-day HYSPLIT back trajectories from UNC sites (receptors at 1 km AGL) during the strong El Niño of January 1992
Bogota
MedellinArauca
Leticia
Palmira
San Andres
V. de Leyva
The Cauca River Valley (CARV)
sugarcane (SC) agro-industry
❑ Added value chain
→ multiple
emission sources
❑ Focus on pre-
harvest burning
economic /
social constraints
❑ High air pollution
toxicity (higher
than from road
traffic)CARV 300 kha
❑ 226 kha sowed
❑ 22 Mton sugarcane/year
❑ 265k employees
❑ 1.5% Colombia’s GDP
❑ 5% Colombia’s
industrial GDP
AQ impact of SC pre-harvest burning
~2.5 g PM2.5 / kg burned DM
~7103 kg DM / ha (leaves)
226 103 ha
fraction of area burned (~20%)
800 ton PM2.5 / year
Significant for
chronic effects
(AQ baseline, public health)
(Unburned HC)
NOx + VOC → O3 / SOA
CACIQUE: CAuca river valley sugarCane pre-
harvest burning aIr QUality Effects
CACIQUE
Scientific questions
▪ What is impact and share of sugarcane pre-harvest
/ prescribed burning on air quality in the Cauca
River Valley (CARV)? (relative contributions to number
and mass of primary and secondary aerosols)
▪ How emitted aerosols physically and chemically
transform along the CARV region? What are the size
distributions of primary and secondary aerosols in
CARV?
▪ Do sugarcane agriculture emissions enhance
photochemical pollution and SOA production?
Sun photometer
max-DOAS
Meteorology
Aerosol sampling
Nephelometer
PM10 beta
Trace gases
U. Nacional – Palmira
IOP 1: 23.7-24.9.2018
IOP 2 pending
Measurement campaign
CVC
mobile
unit
Preliminary results – Cascade impactor
❑ Bimodal
distribution: ~0.9
m, ~5.2 m
❑ Stage-collected
mass will be
chemically
analyzed → size
resolved
composition!
Preliminary results – Nephelometer
AERONET sun photometer
❑ 8 dichroic filters (1020, 940, 870, 675, 500, 440, 380, 340 nm)
❑ Scenarios: Direct, Almucantar, Principal plane
Cimel CE 318N (VBS8, Ver. 5)
Measurements are possible only
under near cloud-free sky conditions
along the optical path
AERONET sun photometer
AERONET sun photometer
AERONET sun photometer
AERONET sun photometer
AERONET sun photometer
AERONET sun photometer
AERONET sun photometer
Conclusions❑ Sugarcane pre-harvest burning emissions in
CARV deserve detailed calculations. First order
calculations suggest PMx emissions are sufficiently
elevated to cause at least chronic atmospheric effects
(baseline augmentation; photochemical pollution,
secondary aerosols?) and derived health effects.
❑ This an ongoing investigation. Regarding PMx, we
expect to report the 1st particle size resolved
chemical characterization in Colombia.
Composition will include EC and OC (and
carbohydrates within).
Conclusions❑ The first results on gravimetric (cascade impactor) and
remote sensing (sun photometer) particle size
distributions show bimodal distributions with a
persistent coarse mode. Fine mode is typically less
important but also persistent.
❑ Ground based sun photometer measurements show a
high temporal variability of both aerosol load,
measured as AOT, and size, measured as
Angstrom exponent. A multiday column dust episode
is clearly seen on the time series.
Thanks for your attention! Questions?Air Quality Research Group
Universidad Nacional de Colombia –Bogota
Sun photometry
𝐼 𝜆 = 𝐼0 𝜆 ∙ 𝑒−𝑎 𝜆 ∙𝑚
𝑚 ≈ 1/ cos 𝑧
m >> 1m = 1
a: Total atmospheric optical thickness (attenuation)
light attenuation (extinction) = scattering (Rayleigh, Mie) + absorption (particle, gas)
I0
m: Air Mass Factor (AMF) radiative transfer
Sun photometry
𝑎 𝜆 = 𝐴𝑂𝑇 𝜆 + 𝑎𝑅 𝜆 +𝑗𝑎𝐺,𝑗 𝜆
𝐴𝑂𝑇 𝜆
𝐴𝑂𝑇 𝜆0=
𝜆
𝜆0
−𝛼
Almucantar Principal plane
(Torres et al, 2013)
Sun photometry – Phase functions Palmira