Transcript Document

What have we
Learned from
ACE-Asia?
The ACE-Asia Science Team
Tim Bates (NOAA PMEL),
Phil Russell (NASA Ames), and
Barry J. Huebert
Department of Oceanography
University of Hawaii
Honolulu, HI 96822 USA
[email protected]
BJH supported by NSF-ATM
What have we learned from ACE-Asia?
1. Air pollution changes dust aerosols in many ways, adding
black carbon, toxic materials, and acidic gases to the mineral
particles. These change its impact on health, climate, and the
delivery of nutrient iron to the remote Pacific ocean.
2. The dust that goes from East Asia to the Pacific does not
absorb nearly as much light as the dark aerosol from South
Asia or some previous Saharan dust data. There are dramatic
regional differences in the optical properties of aerosols.
3. Combining ACE-Asia suborbital and satellite measurements
yields monthly average (April 2001), cloud-free aerosol
radiative forcing at the surface in ACE-Asia exceeding -30
W m-2 in a plume downwind of Japan and in the Yellow Sea,
East China Sea, and Sea of Japan.
B.Huebert, ACE-Asia, 12/02
B. Huebert, ACE-Asia, 12/2002
Observations by all these platforms were coordinated to
connect surface and profile measurements.
Korean Kosan
NSF/NCAR C-130
Photo: A. Clarke
Photo: B. Huebert
Navy/CIRPAS Twin Otter
NOAA R/V Ron Brown
Photo: B. Huebert
Photo: T. Bates
Dust acts like a sponge, soaking up pollutant gases
and aerosols. It can then transport these
materials to other continents.
These SEM micrographs by Jim Anderson (ASU) show
the way soot balls (pollution) coat mineral dust particles
Many different forms of soot
stuck on a particle of quartz
(SiO2).
B. Huebert, ACE-Asia, 12/2002
Complex aggregate of soot,
mineral particles (upper), and a
non-soot carbonaceous particle.
In April, 2001, the dust cloud from a Chinese storm passed over the
Midwest, over NE US, and across the Atlantic to the Azores.
This Chinese dust storm had such a large impact on visibility
in Colorado that it was featured in national newscasts.
GOES8 (East) view of dust streak
on the evening of Friday 13th
From: http://capita.wustl.edu/AsiaDust0104/reports/ThePerfectStorm.htm
B. Huebert, ACE-Asia, 12/2002
SO2 and Scattering
Profiles
D
Total Scattering <10um
SO2_1_sec_pptv
Submicron Scattering
5000
D
Not all layers are the
same: some dust
layers are more
modified by pollution
than others.
C-130 sounding over Yellow Sea
4000
Blue = Total Scatt
Green= <1um Scatt
Red = SO2
D
3000
D
P
2000
P
SO2 and dust co-exist
from 4-5 km, but dust has
scavenged all SO2 from
the 3-4 km layer.
1000
P
0
Courtesy of Blomquist, UH; Bandy, Drexel;
Masonis & Anderson, U. Washington
B. Huebert, ACE-Asia, 12/2002
10
20
30
40
50
60
70
80
XTSG10
0
1000
10
2000
SO2_1_sec_pptv
20
30
3000
40
XTSG1
4000
50
60
Light absorbed by aerosols is also highly variable regionally.
Unpolluted dust does not absorb much.
Asian pollution is much blacker than North American.
Co-Albedo (Absorption)
0.20
1
2
3
Fine_Only____All_Aerosols____Coarse_Only
0.15
0.10
0.05
0.00
Asian Fine Polln
Indian Ocean
N America
PollutedDust
1 km Dust
6 km Dust
Courtesy P. Quinn (NOAA-PMEL) and S. Masonis (UW)
This absorption warms layers of the air, potentially
inhibiting rainfall in places. This has implications for
agriculture, fire suppression, and many other
issues.
B.Huebert, ACE-Asia, 12/02
Combining ACE-Asia suborbital and satellite
measurements yields monthly average (April 2001),
cloud-free aerosol regional direct radiative forcing at
the surface in ACE-Asia
exceeding -30 W m-2 (strong cooling!)
in a plume downwind of Japan and in the Yellow Sea, East
China Sea, and Sea of Japan. By contrast,
warming by all greenhouse gases is +3 W m-2.
However, recall that this aerosol cooling is regional,
while the warming is global.
Several optical properties of aerosols are needed to calculate
this direct radiative forcing. They are very different in air
exiting East Asia for the Pacific than in other locations.
B.Huebert, ACE-Asia, 12/02
AOD can be derived from satellites
(although they only see radiation emerging from the top of the atmosphere, TOA)
Energy changes differ for surface, TOA, and absorbing layers.
B.Huebert,
ACE-Asia
12/02
Combining the SeaWiFS data and ACE-Asia in situ aerosol optical
properties allows us to estimate the direct surface aerosol forcing:
about -30 w/m2, large and negative (cooling)
However, absorption causes atmospheric warming !
B.Huebert, ACE-Asia, 12/02
What does this mean to general public?
1. We can observe "dust" transport half way around the globe by
satellite. However it is not just dust, it is dust mixed with
pollution.We have to think of atmospheric chemistry and its
impact on air quality and climate change as global issues.
2. We can not measure dust in one region and assume that dust
everywhere around the Earth will have the same impacts on
climate. Dust and pollution aerosol properties vary regionally.
3. The regional net surface cooling effect of aerosols downwind
of Asia (-30 w/m2) is much higher (by 10x) than the TOA
warming by greenhouse gases. The climatic impact of this
cooling is still being assessed.
ACE-Asia data is publicly available at http://saga.pmel.noaa.gov/aceasia/
[email protected]
B.Huebert, ACE-Asia, 12/02
Funding Agencies - THANKS!!
Australia
UK
ARC - Australian Research Council
COSSA - CSIRO Office of Space Science Applications
CoA-MNRF Program (Major National Research facilities of the Commonwealth of Australia)
Australian Government Analytical Laboratories
Institute of Earth Environment, Xian
Institute of Atmospheric Physics, Beijing
Chinese Natural National Science Foundation
Chinese Academy of Sciences
State Science & Technology Committee
Academia Sinica, Environmental Change Research Project (ECRP)
National Science Council, NSC
CNRS/INSU/PNCA (Programme National Chimie Atmosphérique)
Japan Science & Technology Corporation (JST)
National Space Development Agency of Japan (NASDA)/ADEOS-II satellite program
University of Kyoto, Graduate School of the Environment
Core Research for Environmental Science and Technology (CREST)
Ministry of Education, Science, Sports and Culture of Japan
Korea Science and Engineering Foundation
Korean Meteorological Administration
Natural Environment Research Council
US
NSF Atmospheric Chemistry Program
China
Chinese Taipei
France
Japan
Korea
NSF Atmospheric Sciences Facilities
NOAA OGP – Aerosol Project
NOAA OAR
ONR
NSF Large Scale Dynamic Meteorology Program
NSF Climate Dynamics Program
NASA SIMBIOS Project
NASA Radiation Program
NASA Global Aerosol Climatology Project
NASA CERES (EOS)
NASA ACMAP
DOE Atmospheric Chemistry Program
DOE ARM
University of California Pacific Rim Program
Photo: B. Huebert, Asian aerosols color a sunset over the Pacific
B. Huebert, ACE-Asia, 12/2002