Project ABC Science Team Meeting
November 4-5, 2002 at the Scripps Institution of Oceanography
La Jolla, California
Chairs: J. Fein and A. P. Mitra
Rapporteur: E. Wilcox
The first session of the Project ABC meeting included a series of talks outlining the major scientific issues facing the Project and the status of
V. Ramanathan (SIO/UCSD)
Origins of Project ABC arose from results of INDOEX which indicated that there was much more work to be done on the pollution emanating from the region. The first document related to the Project is the concept paper by Ramanathan and Crutzen (May 2001). The first Project ABC meeting occurred in London (August 2002) and coincided with the release of the UNEP Climate Impact report.
Project ABC aims to address the emissions of air pollution (including smoke, haze, CO, NOx, CH4, hydrocarbons) and their impacts. Direct impacts are regional and global climate forcing as well as health effects. The Project will seek to address natural responses to climate forcing, paying particular attention to impacts on water resources. The Project will also seek to address the health impacts.
C4 and UNEP are the primary coordinators for the Project. The funding strategy for science involves grants from national agencies to the individual researchers, including contributions from several nations in Asia hosting potential observatory sites. The science consists of observations and impact studies, which will ideally guide policy decisions related to educational activities, sustainable development, etc…
Future research will rely upon observatories based on the Kaashidhoo Climate Observatory model. This INDOEX station monitored aerosol radiative forcing (documenting significant reductions in UV and photosynthetically active radiation at the surface) and chemical composition. Other key research results have included satellite observations of direct microphysical suppression of rainfall by aerosols, and model simulations of regional shifts in precipitation resulting from INDOEX observed radiative forcing.
Major topics for Project ABC discussions:
a) Priority topics of research for next 3 years, including:
- source characterization/upstream effects
- aerosol composition and contribution to radiative effects
- regional aerosol models
- observationally-based estimate of regional aerosol forcing for all of Asia
b) Selection of surface observatory sites
c) Regional and global assessment, including:
- water budget of the wet-season monsoon
- agriculture, such as rice productivity at regional scale
- health impacts
S. Shrestha (UNEP)
Support and resources for ABC have been expressed by: Asian Development Bank, Maldives, China, Japan and European partners. A goal for this meeting should be the development of a plan with cost estimates so that development for the observatories may continue in conjunction with the supporting nations.
G. Charmichael (U. of Iowa)
Key scientific issues related to aerosol emissions include:
- linking emissions to specific human activities,
- characterizing “total” emissions, in addition to the anthropogenic component (e.g., separating natural dust from resuspended dust and separating biofuels from biomass).
Variability in economic sectors across Asia contributes to tremendous regional variability in emissions.
Though emissions inventories are starting to be produced that are useful for climate impact studies, some issues remain:
- under-prediction of CO during high CO events – which has been linked to under-reporting of emissions from the domestic sector in central/east China (i.e., the use of low-quality coal for home heating/cooking),
- representing the latitudinal gradient in aerosol distribution,
- uncertainties (as high as hundreds of %) in OC/BC, as well as CO,
- representing the 10-50% variability in deposition/transport of aerosol simply resulting from interannual variability in meteorology.
K. Prather (UCSD/SIO)
Real-time measurements of single particle mass spectrometry allows:
- measurements of individual particle size and composition,
- chemical association (e.g., mixing state, source identification, aging),
- composition as a function of size,
- high temporal resolution,
- resolving spatial variability (both horizontal and vertical),
- relating to simultaneous gas phase and meteorological measurements.
Accomplished with Aerosol Time-of-Flight Mass Spectrometer (ATOFMS).
Determining the +/- ion spectra can distinguish the origin of dust or carbon by identifying the elements present in the particle. Markers (or fingerprints) have been developed to determine source characterization (e.g., detection of a biofuel signal) which are linked to a source region with airmass trajectories. The approach is also capable of detecting dramatically different source signatures over small distances.
A. P. Mitra (National Physical Lab, India)
Post-INDOEX activities in India have been directed at:
- developing observing stations,
- establishing international traceability, and
- determining upstream trajectories.
New observing stations have been developed at: Hante (at ~15,000 ft altitude), Delhi, Darjeeling (at ~8000 ft. altitude), Sundarbans, and Port Blair.
Emissions from slash/burn activities in Andrea Pradesh is now studied annually.
Institutional arrangements are being made to reduce the uncertainties in emissions factors.
Coal and diesel dominate black carbon emissions in India, however biofuel activity is highly uncertain; as is its contribution to Indian BC.
The CO emissions reported in the UNEP report have been revised to lower values.
India is pursuing new a new automobile policy to reduce emissions from diesel vehicles.
Additional modeling efforts are required:
- chemical modeling is available to some extent,
- climate modeling efforts need to be expanded,
- modeling of impacts needs much more attention.
M. Thiemens (UCSD)
Studies of sulfates and nitrates using measurements of mass-independent isotope fractionation:
- indicate a production of large sulfate particles in the ITCZ that cannot have been transported from India,
- indicate a 35S signal that can only be supplied from the upper troposphere,
- can distinguish nitrates resulting from gas-phase reactions from those of soil origin.
H. Akimoto (Inst. for Global Change Research, Japan)
Results from ground stations in Japan, China and Europe.
NOx emissions are growing in East Asia while declining in West. Asian emissions are now greater than Europe. In Europe during winter, low-level background ozone and photochemically aged ozone levels are equivalent and the trends are flat. In summertime, photochemical component is higher than background and increasing year-to-year.
In Japan, spring/summer photochemical ozone component is increasing, however wintertime airmasses originate over the continent and ozone levels are 2-3 times higher than summertime values (which are oceanic airmasses).
In Thailand, CO and O3 are low in the summer wet season and high in the wintertime owing to biomass burning. Wintertime CO levels peak at night, while O3 levels peak in daytime. Summertime diurnal variability is low.
W. Collins (NCAR)
The first operational aerosol assimilation model has been developed and is presently being updated to assimilate all modern NASA data (e.g., ICEsat, Calipso, MODIS, MISR).
Blending the aerosol assimilation with global models is used to compute climate forcing. Furthermore, model/assimilation differences are used to reveal model errors. Can be used as a “transport” GCM that can also be used in “climate” model in order to separate errors associated with aerosol parameterizations from errors associated with GCM meteorology.
Major sources of error in aerosol assimilation are:
- source characterization,
- production of secondary organics,
- importance of mixing assumptions (internal/external),
- processing during transport,
- cloud/precip./aerosol interactions.
The assimilation (and other models) provides profiles of aerosol, however the only global dataset available for validating aerosol profiles is SAGE. Though 80% of aerosols reside below 5km, SAGE only observes aerosols residing above 5km. That is, SAGE can only measure aerosols that are able to live longer than about 100 days.
Intersections between NCAR and other U.S. agencies will be pursued through Project ABC to provide improved aerosol assimilations. Many of these efforts will be geared to quantify errors in models, as much as to provide useful analyses.
November 4 Afternoon Session
“Status of Observations and ABC Observatories”
Chairs: P.J. Crutzen and H. Rodhe
Rapporteour: S.A. Guazzotti
Several presentations highlighting the state of current and planned observations in the Indo-Asia-Pacific region, together with descriptions of potential ABC observatories, were presented in the afternoon session of the Project ABC Meeting. A brief summary of the major points addressed by the different researchers is presented below.
Dr. Podgorny presented a general overview of available surface monitoring sites in the Indo-Asia-Pacific region making reference to the corresponding report prepared for this meeting. Additional information showing results of cluster analysis of 7-day back trajectories (500 mb and 700 mb) on each observatory location were introduced from an additional report. The information on the present state of the observatories was collected mostly from Internet web-sites and communications with interested parties. Dr. Podgorny mentioned that the report will be made public in the ABC web-site after the conclusion of the meeting and the revision of the present document. In the report, observatories are divided between Global and Regional Networks. Interrelation among networks was highlighted by Dr. Podgorny with examples from both global (e.g., overlap among the GAW network, BSRN, and AERONET) and regional networks (e.g., APEX, ADEC, and ACE-Asia/ TRACE-P). Dr. Ramanathan indicated that the report was requested in the London meeting to survey available observations before deciding on new observatories (which will need to be coordinated with existing ones).
A. Jayaraman (S. Asia)
Dr. Jayaraman’s presentation focused on existing and proposed sites in India. He indicated that during INDOEX most of the surface observations were made in peninsular India. Stations currently available and proposed in India were divided in four groups depending on the type of measurements being carried out: a) LIDAR measurements (Mount Abu, Ahmedabad, Pune, Gadanki, Trivandrum); b) AOD measurements (Delhi, Ahmedabad, Pune, Hyderabad, Vishakaptnam, Mysore, Trivandrum, Kanpur); c) Aerosol Chemistry measurements (Delhi, Ahmedabad, Bombay, Kolkata, Trivandrum); d) Trace Gases and Ozone measurements (Delhi, Ahmedabad, Pune, Trivandrum). Discussion on new proposed sites in Darjeeling (NPL), Ahmedabad / Mount Abu (PRL), Port Blair (ISRO, NPL), and Hanimaadho (C4), and the availability of ships of opportunities (e.g., R/V Sagar Kanya) was also presented.
H. Rodhe (S. Asia)
For this presentation stations were divided in three groups, namely GAW background stations (solar radiation and gas-phase measurements), GAW regional stations (rural sites), and RAPIDC rural stations (emphasis on precipitation and aerosol chemistry). Dr. Rodhe indicated that currently there are no aerosol chemistry measurements available for the background stations. Potential interesting rural site stations (e.g., KO, NA, JO, MC, MO, PB) were discussed. Other issues highlighted by Dr. Rodhe were: a) the importance of including precipitation chemistry in planned future observations; b) necessary research on soot cycle (lack of information on this issue); c) relevance of source regions studies (e.g., northern India, inland central China).
Z. Li (E. Asia)
Dr. Li described the status of current observation programs in China, indicating that they rely mostly on the Solar Radiation Network. Also, he highlighted the utility of the AERONET network on determining aerosol properties and the existing gap in the network in regions of East China. Discussion on the possibility of selecting a site near Beijing for the ABC Project was presented as well.
H. Akimoto (E. Asia)
Dr. Akimoto presented information on the ground stations for APEX and ACE-Asia and discussed relevant issues concerning criteria for observatory locations selection (e.g., possibility of selecting stations at high altitudes for clean background information, effect of local and regional influences on sites, etc.). He indicated that stations like the ones proposed near Beijing and Seoul can be affected by local sources, therefore making them ideal for health effects and source studies, but not suited for studies of the regional impact of anthropogenic pollution. The existence of un-manned stations for greenhouse gases and the logistic difficulties of carrying out aerosol chemistry measurements at these sites were also some of the issues raised in this presentation. Dr. Carmichael indicated that sites at high altitude (e.g., Rishiri) would be needed for studies focusing on the interaction of dust with anthropogenic pollution and dust transport.
K. Perry (E. Asia)
In this presentation results from the ACE-Asia Campaign were introduced. The potential for the Hefei site as an aerosol chemistry site for the ABC Project was discussed. The importance of sites at high elevations for the study of aerosol transport was also highlighted.
R. Weiss (AGAGE)
Dr. Weiss described the main features of the AGAGE network and the collaborations with NOAA-CMDL, NIES, and SOGE. He described the objectives of the program, which concentrates on semi-permanent gases and anthropogenic halocarbons (i.e., trace-gases measurements). Observations from Mace-Head (Ireland) were shown as an example of ways in which pollution from Europe has been studied (and ways in which observations could be designed to study pollution from Asia). Results from two ground-based monitoring stations in Hateruma Island and Cape Ochi-Ishi (www-cger2.nies.go.jp) were presented as well. Dr. Ramanthan indicated that the station in Cape Ochi-Ishi (located in the northern part of Japan) could constitute an ideal location for studying dust transport.
P-Y. Whung (S.E. Asia)
Dr. Whung first clarified some issues concerning the difference between baseline stations and background stations. Information was shared on the fact that 20 monitoring stations in Mongolia were going to be funded in the near future. The relevance of Quality Control and Quality Assurance during the operation of the ABC Project was discussed.
H. Maring (NASA Network)
Dr. Maring described the AERONET and MPLNET networks together with their primary goals and objectives (i.e., primary goal: satellite validation; secondary purpose: climatological database). Also, he indicated that very few MPLNET sites are currently in operation.
K.R. Kim (Project Korean ABC)
Dr. Kim briefly described the main goals and ideas of the Project Korean ABC (K-ABC), also indicating proposed and operational sampling sites in Jeju, Ieodo, Kwangju, Seoul, Tae-An (Anmyondo), and Mt. Baekdu (~ 2800m). Information on research stations in Jeju Island, namely Kosan, Hallim, and Seoguipo, was presented. The Korean Program SEES BK21 was discussed in some detail. This program counts with a funding of approximately U$S 2 M per year (with U$S 339,000 per year being directed for student training abroad, and U$S 80,000 per year for international cooperation).
Y. J. Kim (Project Korean ABC)
Dr. Kim summarized results from measurements carried out during the intensive operation period of the ACE-Asia field campaign, with particular emphasis placed on the measurements from two locations: Kwangju and Jeju. He also highlighted the presence of associations between dust and soot on observed aerosols, and the consequent effect on the single scattering albedo.
Chair: V. Ramanathan
Rapporteur: G. Roberts
G. Carmichael report biomass burning is most important for latitudes less than 30 degrees north and up to 3 km in the boundary layer.
NOx limited to the south (S.E. Asia) and NMHC limited to the north (mainland China)
Aerosol loading from 2 to 4 km over India as shown by lidar observations
Eastern Asia is source of fine aerosol loading
High AOD over central China with plume extending east over Japan and Hong Kong
Black Carbon highest over Nepal, Southern India and China
Primary Soil Dust emissions from Gobi, Dun Huang and Takbimalu(?) deserts
April à increasing dust storm trends in China
Largest aerosol forcing in Central China
Decline in direct solar radiation over 20-30 years by 1-2 W m-2
Not sufficient aeronet sites in China
Major dust outflow in N. Japan
Long-range transport to Hawaii, Aleutian Islands and N.W. U.S.
Major questions to be identified by aerosol working group
i. Ability of nations to evaluate models
ii. Estimate aerosol forcings
iii. Model Evaluation
1. Models used to predict climate changes
2. Feed models with emissions inventories – stress importance of characterizing sources
3. Source characterization – upstream effects and evolution of aerosols
iv. Gradients to couple satellite observations with in-situ measurements
i. Climate / weather – most human influence in coastal regions
1. how does radiative forcing change surface and top of atmosphere
2. precipitation – monsoon.hydrological cycle – efficiency on cloud impact and cloud formation
3. feedback of aerosols on climate – boundary layer thickness
4. to get information on relevance of surface measurements
5. individual sites to look at trends – make clear individual responsibility of observatories
ii. Agriculture – ozone (managed to unmanaged ecosystems)
1. meteorological parameters
2. radiation budget & ozone
iii. Health – fine particles – biodiversity and direct impact on ecosystems
1. need to study health effects in cities – regional influences – choice of sites will influence measurements and interpretation
Stress long term, continuous measurements to obtain enough information on climate change.
Absolute calibration and trends
Share data immediately
Archival and sharing data an important part of ABC
Data documented and centralized via protocol
Suggested to reverse method of study à to provide impact study first
Use first phase to plan second phase (3-5 years)
Select sites for chemical diversity – pollution in southern Asia and dust in the north
Capture meteorological diversity
Site on border of Mongolia and China – concern on the accessibility of the data if in Mongolia
20 sites to be established in Mongolia – not know what measurements will be done – suggestion of using the ABC project to help guide the development of this project.
Suggestions to put site downwind of city to look at the evolution of aerosol
Use existing sites where possible
Fund 6-8 observatories must rely on other institutions to provide data for ABC.
Primary sites – to exploit regional differences
Measurements of aerosol to focus on chemical and meteorological diversity
Use one site for calibration and training – either Maldives or Hateruma
Or training the PI at site
Chose sites with meteorological sondes available
More intense process study with ship and aircraft campaign
- how does the aerosol get up to 3 km
- biomass burning / fossil fuel emissions??
Policy control, standards, and calibrations
Before choosing sites use inverse model to select surface sites
Chair. P. Crutzen
Rapporteur: R. von Glasow
The main discussion topics were the species to be sampled, the required instrumentation and possible sites.
Minimum set of O3 and CO with short time resolution needed. Also desired for other gases such as HNO3, NO2, SO2, NH3, low molecular weight organics (C5 – C9). However, all these gases except for CO can be measured with inexpensive passive samplers that provide time integrated concentrations of these species. Passive samplers have been used successfully for some years.
Additional gases that would be helpful but would require more elaborate equipment are radon and acetonitrile. Acetronitrile is a specific tracer for biomass burning and can be measured online with – expensive – PTR-MS or offline with GC/MS if it is stable in canisters. Rn222 is a tracer for continental emissions.
The analysis of precipitation should include the major ions SO42-, NO3-, NH4+, Cl- and carbonaceous aerosol esp. soot.
The following groups should be contacted for this task: precipitation – Galloway, passive samplers – group of Martin Ferm, Swedish Environmental research Institute. He pioneered the use of the passive sampler probes and has a lot of experience with the analysis and quality control. He is willing to participate in ABC. Contacts for quality control procedures should be developed with the Global Atmosphere Watch (GAW/WMO).
Sites both within the source region of the Asian Brown Cloud as well as on its edge to measure the integrated effects would be needed. Vertically resolved information would be very helpful. This can be achieved with the help of sites at different altitudes (one in the boundary layer, another in the free troposphere), tethered balloons, lidar (costly!) or small aircraft. Russell Schnell mentioned that NOAA would provide funds for the deployment of regular vertical soundings with small aircraft, i.e. the costs for the payload and the analyses without the costs for the flight hours, which are expected to be modest if small aircraft are used (about $100/hour).
A tentative list of sites was proposed: