Max-Planck-Institute for Meteorology, Hamburg, Ger

AeroCom

… in the context of GEMS

S. Kinne

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Overview

what is AeroCom ? Goals

what does AeroCom do ? Activites

how does GEMS benefit from AeroCom? Initialization Evaluation

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what is AeroCom ?

AeroCom “Comparisons of Aerosol simulations to DATA”

co-organized by LSCE and MPI-Met• not officially funded (major problem)• supported by global aerosol modeling worldwide

AeroCom Goals document module differences investigate sub-step and sub-processes assemble useful (quality!) data-sets intensify links between groups (model, data)

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AeroCom - Activities (1)

organize regular workshops Paris 6/03, Ispra 3/04, N.York 12/04, Oslo 6/05

maintain a websitehttp://nansen.ipsl.jussieu.fr/AEROCOM

Information• conference summaries / papers

Protocol• data-format / data-request (Experiments) / input

Interactive diagnosis tool• Evaluations (Model vs Data)• Diversity / Outliers (Model vs Model)

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http://nansen.ipsl.jussieu.fr/AEROCOM/DATA/surfobs.html

aot

SO4

time-series

local networkcomparisons

distribution-plots

scatter-plots

selectionmenu

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AeroCom - Activities (2)

define common ‘Experiments’ A: ‘best as you can’ – simulation B: year 2000 with prescribed 2000 emissions* C: year 2000 with prescribed 1750 emissions*

B minus C: address anthropogenic ‘forcing’

INDI: sensitivity studies for indirect effects

* ftp://ftp.ei.jrc.it/pub/Aerocom/

prepare useful data-sets (for data-base) Evaluate – beyond downloading (satellite combo) Combine/ Process – for added value (AERONET)

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aot – sat. retrievals vs. AERONET

…but canlocal data expandedin regionsas here ?

sat - AnetR = -------------- Anet

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AeroCom - Questions

MODELING are component modules consistent ?

where is model diversity largest ? what do prescribed scenarios reveal?

DATA are there data to determine skill ?

are (operational, global) data available ? are data (sufficiently) accurate? can data correlations provide clues? are data applicable to scales in modeling?

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AeroCom - Participants

LO LOA 3.8/2.5 yr 2000 Reddy / BoucherLS LSCE 3.8/2.5 yr 2000 Schulz / Balkanski UL ULAQ 22.5/10 yr 2000 Pitari / Montenaro SP SPRINTARS 1.1/1.1 yr 2000 TakemuraCT CANADA 2.8/2.8 yr 2000 Gong MI MIRAGE 2.5/2.0 1yr avg Ghan / EasterEH ECHAM5 HAM 1.8/1.8 3yr avg Stier / FeichterNF NCAR MATCH 1.9/1.9 yr 2000 Fillmore / CollinsOC OSLO-CTM 2.8/2.8 yr 1996 Myhre / Isaksen OG OSLO-GCM 2.8/2.8 3yr avg Iversen et al.IM IMPACT 2.5/2.0 yr 2000 Liu / PennerGM GFDL MOZART 2.5/2.0 yr 2000 Ginoux / HorowitzGO GOCART 2.0/2.5 yr 2000 Chin / DiehlGI GISS 4.0/5.0 yr 2000 Koch / BauerTM TM5 4.0/6.0 yr 2000 Krol / DentenerEM ECHAM4 MADE 3.8/3.8 10yr avg Lauer / HendricksGR GRANTOUR 5.0/5.0 1yr avg Herzog / PennerNM NCAR MOZART 1.9/1.9 1yr avg Tie / BrasseurNC NCAR CAM 2.8/2.8 1yr avg MahonwaldEL ECHAM4 3.8/3.8 3yr avg Lohmann / Feichter

all models separate by aerosol species (SU,BC,OC,DU,SS)

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first results – model diversity

differences in mass-fields are dominated by differences in aerosol processing

year-to year variations are much smaller impact of ‘streamlined’ emissions is minor

differences among individual components (SU,BC,OC,DU,SS) are larger than for their sum

data constraint usually only for (sum-) totals comp-mix diversity means absorption diversity

large differences in aerosol water module (humidification) or GCM (envir) related?

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model diversity of emission and massmodel diversity of emission and mass

Exp B

Exp A

Exp B

Exp A

emission

mass

emission

mass

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diversity – in aot simulations

total aot diversity < aot sub-component diversity !

totalaot

SUaot

BCaot

DUaot

SSaot

OCaot

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first results - data

BAD data: an assimilator’s / evaluator’s nightmare

do not trust given error estimates compare with quality references

data of global data-sets are not globally of equal accuracy

focus on regional strength, establish composites a local samples can differ from its regional value

correlation can provide clues with the immediate need for absolute accuracy

aerosol and other atmospheric properties

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a case for S* (the retrieval composite)

composite

still noglobalcover!

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AeroCom – and GEMS

INITIALIZATION

provide datasets on aerosol data from ground-based networks

• AERONET, EARLINET, EMEP, IMPROVE data derived from space sensors

• satellite data and retrieval composites

provide reference from modeling global and complete data-sets from the

AeroCom model median collaborate on aerosol emissions

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climatology - aot / 0 / Angstrom

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AeroCom – and GEMS

EVALUATION

build on AeroCom evaluation web tools diganostics and scores (e.g Taylor plots)

provide a reference from global modeling statistics on simulated fields (average, diversity)

provide (independent) data for evaluation quality data not used in assimilations

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AeroCom and GEMS

both activities are complementary !

AeroCom dignostic tools will provide immediate feedback on simulation performance (score ?)

GEMS can build on AeroCom efforts to establish global quality data on aerosol

GEMS can build on the AeroCom effort to harmonize and update aerosol emissions

GEMS is expected to accelerate access to new quality data-sets for AeroCom model evalutions

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AeroCom - current ‘data’ base

Remote sensing – space satellites (Modis, Misr, Toms, Avhrr, Polder …)

• aot (individual + composite best), Angstrom

• aot associated atmos properties (clouds)

Remote sensing – ground AERONET (sun/sky-photometers)

• aot, size-dist., (ssa), Angstrom EARLINET (lidar)

• vertical profile, extinction

In-situ ground data IMPROVE

• SU, OC, BC, extinction EMEP

• SU, PM (?)

data priorityfor year 2000

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General Questions to GEMS

what are the priorities / GEMS needs ?…relating to AeroCom activities I can think of

data aquization data assessment data integration comparisons to other modeling efforts evaluating and scoring

who is going to do it / what ? extra techn. (wo)man-power for AeroCom? many GEMS participants are ready to contribute

with little pieces of the puzzles. Who integrates?

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extras

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up-scaling - of local ‘aot’

50% larger than the regional value level

50% smaller than the regional value level

at GSFC:local aots are ca. 20% aboveregional mean

with satellite data !

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data

correlations

aerosol - cloud

do higher cloud tops offset solar albedo losses?

what process: aerosol cloud? or cloud aerosol?

keya – aotA – aot (<1m)

t – cld top T L – lwc (T> 260K)

x(y) – x function of y

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model-diversity

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

total aot [at 550nm]

ECHAMGOCARTMIRAGEGISSSprintarsGrantourULAQNCAR

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

total (component combined) aot [at 550nm]

ECHAMGOCARTMIRAGEGISSSprintarsGrantourULAQNCARLOALSCECanadaNCAR-mozOSLO-ctmOSLO-gcmIMPACT

June 2004

June 2002

despite betteragreement forannual global aot …large diversity inmodeling remains

a- aot -S sulfate ab absorption aotm- dry mass -O part.o matter w0 ss-albedo r- mee (=a/m) -B black carbon cr bc/oc ratio -N seasalt -f frac of sizes <1 m -D dust An Angstrom param.

max / min factors of central 66% of aer.modules

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clima-tology

model satellite

aot

ssaaot

with medians

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AERONET Cape Verde aot 3/5/2004