CEAZA Jul 2006

Aerosol-cloud interactions offshore Central and Northern

Chile

Laura Gallardo KlennerCentro de Modelamiento Matemático, Universidad

de Chilelgallard@dim.uchile.cl

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