Embed Size (px)
Citation preview
7th International Workshop on Sand/Duststorms and Associated Dustfall Frascati, Italy, 2-4 December 2013
Sara Basart a), Carla Gama b), Oriol Jorba a), Michele Spada a), Carlos Pérez c), José María Baldasano a,d), Oxana Tchepel b) and Casimiro Pio b)
Desert dust and sea-salt evaluation of the NMMB/BSC-CTM model for
Cape Verde (North Africa)
a) Earth Sciences Department, Barcelona Supercomputing Center, Spain b) Centre for Environmental and Marine Studies , University of Aveiro, Portugal
c) Earth Institute at Columbia University, NASA Goddard Institute for Space Studies and International Research Institute for Climate and Society, New York, USA
d) Environmental Modelling Laboratory, Technical University of Catalonia, Barcelona, Spain
The NMMB/BSC-Chemical Transport Model
2
NMMB/BSC-CTM
NMMB
BSC-CTM
DUST
Pérez et al., ACP, 2011
CHEM
Jorba et al., JGR, 2012
SEA-SALT
Spada et al, ACP, 2013
The main system is build on the meteorological driver NMMB, under development at NCEP Unified model for a broad range of spatial and temporal scales
Multiscale: global to regional scales allowed
Fully on-line access coupling: feedback processes allowed
Nonhydrostatic Multiscale Meteorological Model
on the B grid OBJECTIVE: Full year evaluation of the sea salt and desert dust components for NMMB/BSC-CTM
http://www.bsc.es/earth-sciences/nmmbbsc-project
3
NMMB/BSC-Dust (Pérez et al. 2011)
)1)·(1·(· SnowCoverVEGFRACPREFUSGS
Image from Carlos Pérez
EMISSION SCHEME
Source function: includes update land databases (vegetation fraction, land textures, soil types and albedo) and a preferential “topographic” source mask
Physically-based emission scheme which includes saltation and sandblasting
http://www.bsc.es/earth-sciences/mineral-dust/nmmbbsc-dust-forecast/
DAILY OPERATIONAL DUST FORECAST AT BSC
4
NMMB/BSC-Salt (Spada et al. 2013)
Emission of maritime aerosol depends on surface wind speed and SST
Combined Monahan et al. (1986) and Smith et al. (1993)
Aerosol module extended to wet aerosol
RESULTS FOR 2006
EMISSION SCHEME
5
Methods
NMMB/BSC-CTM configuration: − Year 2011
− North Africa, Middle East and Europe domain
− Horizontal spatial resolution: 0.25º x 0.25º
− Vertical resolution: 40 vertical layers
− Fundamental time step of 40s
− Cold start without data assimilation
− Initial conditions from NCEP/FNL meteorological analysis 1ºx1º at 0UTC and meteorology fields updated boundary conditions every 6 h
− Model outputs time resolution: 3-hourly
OBJECTIVE: Full year evaluation of the sea salt and desert dust components for NMMB/BSC-CTM
Observations:
−Satellite aerosol products (MODIS, MISR, Aura OMI)
Seasonal averages
−Aerosol optical properties from AERONET Level 2.0
15-minutes data
−Surface concentration measured in Praia, Cape Verde (from CV-DUST Project)
Hourly data
6
www.cesam.ua.pt/cv_dust
Sampling site and sampling period
outskirts of Praia, Santiago Island, Cape Verde
from January 2011 to January 2012
range of measurement: 0.25 mm to >32 mm (31 size channels)
data presentation: 6 s (measurement); 5 min (storage)
particle concentration: number of particles/volume
1. Monitoring and sampling atmospheric dust during one year
2. Chemical and structural characterization of collected samples
3. Source Identification; Transport and Deposition Modeling
4. Quantify African dust input to Cape Verde Air Quality
5. Explain processes governing dust production, transport, and removal from atmosphere over the Atlantic
GRIMM EDM164 optical dust monitor
Seasonal satellite comparison: AOD at 550nm
7
• Underestimations in summer in the Sahara
• North Atlantic sea salt contributions in wintertime
Model results: AOD at 550nm in Winter
8
du
st
se
a s
alt
High sea salt contributions in North Atlantic associated to deep depressions (strong surface winds U10 > 9m/s)
Model results: AOD at 550nm in Summer
9
du
st
se
a s
alt
Maximum dust emissions at ~20ºN
Minimum salt emission in North Atlantic
AERONET comparison: year 2011
Annual correlation coeficient Annual MB
48 stations in 8 regions
• 48 stations distributed in 8 regions • Filter applied to the AERONET observations
• AE < 0.75 is considered in the calculations • AE >= 0.75 and of the rest of cases we assign AOD observe = 0
• Overestimations in Sahel during winter
→ low-level instrusions
• Underestimations in Sahara during summer
→ Convective phenomena → Missing sources → Wet deposition scheme
AERONET comparison: Capo Verde 2011
11
• Underestimations in summer
• The coarse fraction is well reproduced by the model meanwhile fine fractions are slightly overestimated.
Vertical profile from M’Bour (Senegal)
See A.Mortier et al., poster Session
Cape Verde comparison: surface level
12
statistical parameters: Sea-salt & dust: r = 0.62 IOA = 0.77 RMSE = 42.0 µg.m-3 bias = - 9.3 µg.m-3 (27.3 – 36.6)
Only dust: r = 0.62 IOA = 0.75 RMSE = 43.4 µg.m-3 bias = - 17.5 µg.m-3 (19.1 – 36.6)
Cape Verde comparison: surface level
13
statistical parameters: Sea-salt & dust: r = 0.63 IOA = 0.75 RMSE = 21.3 µg.m-3 bias = - 1.3 µg.m-3 (15.7 – 17.0)
Only dust: r = 0.63 IOA = 0.74 RMSE = 20.9 µg.m-3 bias = - 5.5 µg.m-3 (11.5 – 17.0)
By comparison to satellite derived data, the NMMB/BSC-CTM model shows its ability to reproduce the aerosol spatial distribution in North Africa and Southern Europe;
The comparison with AERONET observations shows annual correlations between 0.6 and 0.8.
NMMB/BSC-CTM is capable to reproduce the desert dust long-range transport to the Mediterranean.
For the model comparison in Cape Verde, the annual correlation of the NMMB/BSC-CTM for PM10, PM2.5 and AOD is around 0.6. The inclusion of marine aerosol plays an important role in the ability of the model to reproduce the background levels this site.
The coarse fraction is well reproduced by the model meanwhile fine fractions are slightly overestimated.
Summer underestimations in the Sahel • Convective phenomena • Missing sources • Wet deposition scheme
North Atlantic overestimations • Emissions u10 > 9m/s enhance the salt emission in the coarser bins, this is
linked to Smith et al. (1993) parameterizations
By comparison to satellite derived data, the NMMB/BSC-CTM model shows its ability to reproduce the aerosol spatial distribution in North Africa and Southern Europe;
The comparison with AERONET observations shows annual correlations between 0.6 and 0.8.
NMMB/BSC-CTM is capable to reproduce the desert dust long-range transport to the Mediterranean.
For the model comparison in Cape Verde, the annual correlation of the NMMB/BSC-CTM for PM10, PM2.5 and AOD is around 0.6. The inclusion of marine aerosol plays an important role in the ability of the model to reproduce the background levels this site.
The coarse fraction is well reproduced by the model meanwhile fine fractions are slightly overestimated.
Summer underestimations in the Sahel • Convective phenomena • Missing sources • Wet deposition scheme
North Atlantic overestimations • Emissions u10 > 9m/s enhance the salt emission in the coarser bins, this is
linked to Smith et al. (1993) parameterizations
Conclusions
14
CONTACT: [email protected]| [email protected]
15
A C K N O W L E G M E N T S :
K. Haustein, N. Huneeus, M. Schulz, Z. Janjic, A. Badia, T. Black, D. Dabdub, K. Haustein, M. Carreras, K. Serradell, A. Mortier, P. Gouloub, T. Nunes, M. Cerqueira and J. Cardoso
We thank the AERONET, EARLINET and MODIS community for their valuable data.
This work is funded by the projects CGL2006-11879, CGL2008-02818, CGL2010-19652 of the Spanish Ministry of Science and Innovation.
Simulations have been performed in the Marenostrum supercomputer. The CV-DUST Project was supported by the Portuguese FCT (PTDC/AAC-CLI/100331/2008 Project).
FCT is also acknowledged for the PhD grant of C. Gama (SFRH/BD/87468/2012).
