Transcript IGAC 2004 Report - Atmospheric Physics

The International Global
Atmospheric Chemistry Project
A Core Project of the
International GeosphereBiosphere Programme (IGBP)
Phil
Rasch
IGBP Steering Committee
4-7 March 2006, Pune, India
In Cooperation with the
IAMAS Commission on
Atmospheric Chemistry and
Global Pollution (CACGP)
What is IGAC?
•
Focused on understanding the changing chemical composition
of the earth’s atmosphere, particularly the troposphere.
Implementation:
•
1. Endorsement & support of TASKS:




•

2. Co-sponsorship of WORKSHOPS:
Review/assess current state of knowledge on an issue

Define a framework for resolving open questions

Produce a white paper or similar with workshop results
3. Top-down INITIATIVES:

Atmospheric Chemistry & Climate

Mega-cites Integration

Aerosols, Clouds & Precipitation

•
Focused scientific question
3-4 year timetable
QA/QC & public data access
Educational & capacity building efforts.
End-point: peer-reviewed manuscript(s).
Task: AICI (Air-Ice Chemical
Interactions)
• Campaigns at South Pole and
Halley Bay (Antarctica) in
2004-2005 to study:
 tropospheric ozone
depletion
 ice photochemistry
 halogen cycles
• In data analysis/paperwriting stage
• New: AICI-IPY
(International Polar Year)
South Pole
NO > 200 pptv (model expectation 1-5 pptv)
OH ~2 x 106 molecules cm-3
Polar Study using Aircraft, Remote Sensing,
Surface Measurements and Models, of
Climate, Chemistry, Aerosols, and Transport
(POLARCAT)
• International Polar Year project
• Specific foci are:




pollution transport to the Arctic
aerosol radiative effect in the Arctic
boreal forest fires (with SPARC)
chemistry of Arctic (with AICI)
• Activities ongoing to secure funding
for the experiments and aircraft and
ship time
Task: Mega-cities Asia
• Integrated approach air to
quality & climate
• Japan, China, South Korea
and China-Taipei
• Focus on:
 Consistency in
measurements across the
region (instrument
intercomparison)
 Communication
 Data sharing
IMPACT: Integrated Measurement Program
for Aerosol and Oxidant Chemistry in Tokyo
Task: Intercontinental Transport
and Chemical Transformation
(ITCT-Lagrangian 2k4)
• Focus: transformation and
removal processes of aerosols,
oxidants and precursors during
intercontinental transport
• “-2k4” based on Summer 2004
field campaign:
 Trans-Atlantic transport
 Pseudo-Lagrangian with
platforms on both sides of the
Atlantic
• In the data analysis / paperwriting stage
2004 field campaign
Four aircrafts used to track pollutant
plumes in combination with modelling,
satellite, surface data
Task: African Monsoon
Multidisciplinary Analysis (AMMA)
• Atmospheric chemistry
component of the larger
AMMA project
• Larger AMMA project focus:
 Integrated study of land
surface, emissions,
monsoon, human dimensions
• Focus of the IGAC/iLEAPS
AMMA Task will be the
Enhanced Operation Period,
2005-2007
Task: Deposition of Biologically
Important Trace Species
(DEBITS II)
•
Builds on a project of the IGAC
first phase
•
Study of wet and dry deposition
of chemical species
•
Second phase emphasis:
 data synthesis
 Long-term, uniform
measurements
 inclusion of new parameters
•
Three study regions
•
Coordinated with WMO-GAW
Precipitation Chemistry Activity
Large Scale
Biosphere
Atmosphere
Experiment
In Amazonia
(LBA)
IGAC
DEBITS
Africa
(IDAF)
Composition &
Acidity of Asian
Precipitation
(CAAP)
Task: Global HO Systematic Tests
(GHOST)
• Addressing the problem of
quantifying the global
distribution of the hydroxyl
radical OH through alternative
tracers
• In the very early stages of
development…
Workshops organized
• Aerosol Indirect Effect Workshop
 5-7 January 2005, Manchester, England (Co-sponsored by
IGAC, NOAA and NASA)
• Processes Controlling the Chemical Composition of the Midlatitude UTLS
 May 18-20, 2005, Mainz, Germany (Co-sponsored by IGAC &
SPARC
• Aerosol Formation Workshop
 August 15-17, 2005; Hyytiälä, Finland (Co-sponsored by iLEAPS,
IGAC, SOLAS, ACCENT, BACCI)
• The routes for organics oxidation in the atmosphere and its
implications to the atmosphere
 January 7-11, 2006, Alpe D’Huez, France (Co-sponsored by
SPARC, IGAC, ACCENT)
IGAC International Conferences
Capetown, SA, 17th – 23rd September 2006
Joint CACGP / IGAC / WMO Symposium
•
•
•
•
•
•
•
•
•
•
•
Atmospheric chemistry observations and
their integration and synthesis
Chemical weather on regional to global
scales: simulations, analysis and impacts
Long-range transport and chemical
transformations
Aerosol-cloud interactions and climate
implications
Aerosol chemistry and the interactions
between aerosols and gas phase chemistry
Reactive chemistry and exchanges
between the MBL and the ocean mixed
layer.
Land-atmosphere biogeochemical cycles
Biomass burning emissions and impacts on
atmospheric chemistry
Metro-Agro-Plexes
Chemistry of the UT/LS region (A Joint
IGAC-SPARC Session)
Interface processes between the Ocean,
Atmosphere, Sea Ice, and Snow in Polar
Regions
Beijing, China
9-12th November 2006
Earth System Science Partnership
•
•
Chemistry and Climate in the Upper
Troposphere/Lower Stratosphere
(UT/LS) Region (SPARC-IGAC)
Too many to list….
Connections IGAC / this workshop
• WCRP/IGBP Atmospheric Chemistry & Climate
Initiative (driven from the SPARC/IGAC level)
• Aerosols, Clouds & Precipitation Initiative (iLEAPS,
IGAC, GEWEX)
• Specific science issues (a few thoughts):




The small crystal puzzle
Potentials for mixing line analysis in the troposphere
Ozone
…
Atmospheric Chemistry and Climate
Initiative: Rationale
•Two objectives of the project:
• Understanding the role of emissions via atmosphere
chemistry on atmospheric composition
• relating the concentrations to radiative
forcings/climate change
Understanding Climate:
Understanding and quantifying Processes!
Sources
Precursors
Processes
Abundance
composition
Properties/
Processes
Radiative
Forcing/
Health effects
Chemistry
Chemistry, other factors (including policy)
Climate
•Modeling these processes in Climate and Earth System Models are
needed.
 Providing the ability to do it, with respect to chemistry, is the
aim of AC&C.
Choice of First Problem to be tackled by
Task Force
• Define an important, tractable problem:
 Modeling Project
 CCM-Val extension to the troposphere
• Emphasis will be on:
 Aerosol (formation, transformations, cloud interaction,
photolysis, reactivity)
 Ozone
 Deposition processes
 forcings & feedbacks
• Problems relevant to many aspects of climate change AND will yield
short-term needed info
• Common to all advanced next generation models for Climate Change
Studies.
Products
• Statements about component processes that contribute most to
uncertainty in radiative forcing and climate change (e.g.,
emissions, formation mechanisms, removal processes, interaction with
other components [e.g. land, ocean, society])
• Identification of metrics that provide insight into model
behavior w.r.t. chemistry/climate interactions
• Pointers to more promising (less desirable) formulations for
process representation
• Identify opportunities for programs and projects to contribute
to improving models
Use of mixing lines to diagnose convection
Paluch (1997),
conserved quantities
under nonprecipitation, phase
change
Fischer et al 2000,
tracer/tracer
correlations as
diagnositics of
strat/trop mixing
The small ice crystal puzzle
(observations)
David Mitchell, Phil Rasch, Paul Lawson
• amplitude of small mode
 Brighter in solar
 Fall much more slowly
• Rate of supply of mass
of water substance to TTL
differs dramatically!
• Along with the water goes
tracers!
Sedimentation velocity
Small Ice Crystal (Implications)
Ice Water Content
Mitchell et al class
Heymsfield et al class
Summary
• Role of TTL is an important topic for climate and
chemistry
• IGAC is interested in participating
~THE END ~
The Phase 1 task: Modeling Study
• Many modeling centers have already built or are building higher
resolution global models with interactive chemistry
• Help the centers to systematically:

Define gaps in current representations

Assist in filling those gaps

Define simulations relevant to an inter-comparison activity


Emissions, boundary condition

Verification/validation datasets
compare model behavior

Define metrics

identify deficiencies

Archive simulation outputs
A path to Nirvana
A HIGHLY UNDERSAMPLED ATMOSPHERE.
Gas phase chemistry processes in models OK
Inadequate representation of aerosol production, removal,
transformation, and properties.
Poorly understood & characterized emissions.
Poorly understood and characterized removal processes.
Need:
Fully characterized and predictable (modeled) emission.
Complete
chemistry in a
fully coupled
Earth System
model
Complete
representation of the
all critical species
and their interactionincluding formation,
transformation, and
properties of
aerosols
Understanding of processes that predict formation and transformations of gas phase and
aerosol species, and properties of aerosols species.
Improvements in other components- e.g., transport, convection, exchange with biosphere and
oceans, ….
A path to Nirvana, continued
Complete
chemistry in a
fully coupled
Earth System
model
Where other WCRP/IGBP programs provide needed information:
SPARC- stratosphere and UT/LS chemistry
IGAC- Lower tropospheric chemistry
SOLAS- exchanges
Emission- AIMES, ILeAPS, CLiC?….
Dynamics and transport- WCRP projects
Others…
Other modulations and changes: IHDP, DIVERSITAS….
Chemistry & Climate change predictions
•Most anthropogenic forcing agents are controlled by chemical processes.
•Understanding, quantifying, and accurately representing them in models is
essential for assessing human influence on climate.
•Many forcing agents are also pollutants! (“win-win” options? “win-lose”
consequence?)
•Lifetimes determine policy decision information.