View
217
Download
2
Tags:
Embed Size (px)
Citation preview
CEAZA Jul 2006
Aerosol-cloud interactions offshore Central and Northern
Chile
Laura Gallardo KlennerCentro de Modelamiento Matemático, Universidad
CEAZA Jul 2006
Outline
• VOCALS REx: a few highlights
• Anthropogenic S perturbation of Sc?
– Emissions– Coastal lows– Simulations– Observations
• Summary and next steps“Camanchaca”
CEAZA Jul 2006Biotic and Abiotic Sulfur Impacts on
Stratocumulus (BASIS) Nov 2002
To take over the world!...PERSIS-
TENCE
CEAZA Jul 2006
Mechoso Bretherton
Huebert Weller
Wood
SOLAS/IGAC?http://www.joss.ucar.edu/vocals/
CEAZA Jul 2006
SST CC%
CF
Why focusing over the South East Pacific (SEP)? Subtropical high
(subsidence)Andes Cordillera induces LLJUpwelling cold water and nutrients (fishery)CCN productionPersistent ScEffective coolingImportant for regional and global climate…but models don’t get the Sc right +Substantial anthropogenic perturbations
CEAZA Jul 2006
CGCM Problems
•There is a meridional shift in ITCZ •a warm SST bias
•and insufficient stratocumulus cloud cover
Mechoso, 2006
CFS Errors
SST
Prec
CLD
CEAZA Jul 2006
South Eastern Pacific/Western South America…WOW!!!
• Active volcanoes (natural emissions)
• Atacama: dryest desert of the world between the open Pacific and the heigh Andes (dust and circulations)
• Intensive and long-term mining activities (anthropogenic emissions)
• Humboldt current, upwelling and fishery (biogenic emissions, air-sea exchange and circulations)
• Most persistent and extensive subtropical Sc deck of the SH (microphysics and energy balance)
CEAZA Jul 2006Garreaud, 2006
DMS, sea salt
CEAZA Jul 2006
Pockets of open cells (POCs)e.g.,
WOW
CEAZA Jul 2006
In the remote marine atmosphere the supply of DMS and its oxidation mechanisms limit the rates of new particle nucleation and growth.
These processes probably control the re-filling of POCs with clouds.
Iodine, ammonia, and organics may also play a role.
Huebert, 2006
e.g., WOW
CEAZA Jul 2006
Weller, 2006
Surface forcing from buoy driving a one-dimensional ocean model (PWP) produces a surface layer that is too warm and too salty.
Additional cooling and freshening is needed…..Eddies?)
e.g., WOW
CEAZA Jul 2006
Wood, 2006
CEAZA Jul 2006
NB. Optimi$m•NASA/NOAA/NSF proposals under review•Chilean projects (FONDECYT?, Millenium?)
1 month intensive campaign in October 2007 8
CEAZA Jul 2006
Swedish connection…CCN characterization
~ 250 kUSD
Chilean Air Force
CEAZA Jul 2006
IMARPE fishery research cruise:
Oct-Nov 2007
Study region
Main goals (main instruments):
1. Characterize the near-coastal 3D wind structure (ship-borne wind profiling radar).
2. Assess the relation between the wind and mesoscale ocean processes (upwelling and eddies) (wind profiler, CTDs and ADCP)
3. Determine the dynamical and thermodynamical structure associated with the coastal clearing (ship-borne radiosoundings).
Field experiment: October-November 2007
Cost ~ $70K (Peru)
International Partners - Peru
CEAZA Jul 2006
Chile is world’s largest Cu producer… Peru is also a Cu producer
Lefhon et al, 1999
CONAMA, 2001
CEAZA Jul 2006
Could the man made S emissions affect the cloud radiative properties? Under which conditions are anthropogenic emissions transported offshore?
CEAZA Jul 2006
MODIS-Cloud droplet number concentration
Wood 2005
CEAZA Jul 2006
Garreaud et al, 2002
COASTAL LOWS once a week
CEAZA Jul 2006
Coupled circulations/summer
Mechoso, 2006
CEAZA Jul 2006
Cerro Moreno
Chuquicamata
Strong easterly wind events downwind from the largest smelter…CL like?
Huneeus, 2003
•Evalution of Antofagasta soundings 1989-2002•Focus on extreme events: v700hPa >5 m/s
82 events Composite
CL like
CEAZA Jul 2006
S-SO2 S-SO4
Em
issi
on
s (9
5%)
Em
issi
on
s (5
%)
Dry
dep
osi
tio
n
Dry
/ w
et
dep
osi
tio
n
OH
Swedish MATCH+HIRLAM fields (ca. 0.1°)
Dynamical Interpolation
CEAZA Jul 2006
Model Outputs
CEAZA Jul 2006
We should expect changes in cloud droplet radii …CDNC.. …or????
Average Jul20-Aug20 Event July 26
CEAZA Jul 2006
Observations?Average Jul20-Aug20 July 26
][
4
3
3
3
cm
kHr
LWPCDNC
effw
Suggestive, isn’t it?
CEAZA Jul 2006
Furthermore…one can relate CDNC and (sulfate)aerosols
Penner et al, 2001Thanks to an anonymous reviewer!
CEAZA Jul 2006
21.095.1)4log(*)052.0257.0()log( SOCDNC
Connecting CDNC and sulfate mass(Leaitch et al, 1992)
More than suggestive, uh?
CEAZA Jul 2006
…But still non-conclusive• What about
– DMS?
– Sea-salt
– Other aerosols
• Are CLs the only relevant weather conditions?
• Shouldn´t one see a trend change since the 90’s?
• What are the expected changes in terms of W/m2?
CEAZA Jul 2006
•Aerosol characterizations•DMS fluxes and evolution•Radiative measurements•Aerosol-cloud-interactions
CEAZA Jul 2006
FO
ND
EC
YT
2007-2010
Ana María Córdova (CEAZA)Manuel Leiva (CENMA)Laura Gallardo (CMM)
• …emission strengths/distribution …– Anthropogenic and volcanic: compile, order, check, extrapolate…– Biogenic:…parameterize…ROUGH estimate
• …regional distribution and relative contributions..– Dispersion modeling using re-analysis and downscaling– Compare with available observations
• …which aerosols become CCN…– Intensive campaign (2008):
• activated aerosols at a camanchaca station (CVI+on-line analysis)
• PM10/PM2.5 at the same site & PIXE analyses & ionchromatograph
• SO2 continuosly• Sunphotometer(s)
– Deploy passive samplers for N-S transect and seasonal changes• ..changes in reff, CDNC…
– Regional climate model simulations– Trend analyses for satellite data
CEAZA Jul 2006
Millennium Science Nucleus on Coastal Climate Dynamics (2007-2010) ?
• Understanding of the dynamics of the coastal low-level jet system and its relationship with low-cloud cover variability and coastal upwelling
• Assessing the relative contributions of local and remote forcings in the effectiveness (nutrient availability) of upwelling in north-central Chile
• Increasing our understanding of how anthropogenic and natural aerosols, mainly sulfate aerosols, interact with the persistent stratocumulus deck in the coastal areas of Central and Northern Chile.
• Define adequate assimilation strategies for improving radiative transfer simulations in regional atmospheric models
CEAZA Jul 2006
Summary• The SEP region is a fantastic research area!!..with a large
potential for scientific growth• VOCALS offers a unique opportunity to improve our
(quantitative) understanding of aerosol-cloud-climate and land-sea-atmosphere interactions
• There is “evidence” of an impact of anthropogenic sulfate aerosols on the subtropical Sc deck (Huneeus et al, 2006)
• CEAZA can play a central role…hydrological cycle!
Laguna Chaxa, Atacama, Chile