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No 30
Introduction of the research of Dr.Akinori Ito and Dr.Kentaro Ishijima
We have got the ability beyond other animals by controlling ignition. We used fires to
clear land for our living. Now, most of the biomass burning takes place in the tropical
belt and is associated with human practices. Warming and earlier spring will increase
wildfire activity in boreal and temperate forests. The biomass burning is one of the most
significant sources of trace gases and aerosols on a global scale and influence an air quality
and climate. I deliver the "hot" research topics at the joint IGAC/CACGP/WMO Symposium, September
2006, Cape Town, South Africa. (Akinori Ito)
Since the industrialization in the 19th century, atmospheric concentrations of greenhouse gases
such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)
have much increased due to human activities. Therefore, possible bad impacts on global environment,
such as global warming and following climate change are the recent concerns. N2O has 300
times global warming potential of that of CO2, and is related to depletion of ozone layer,
so recently the N2O research is getting important. At FRCGC, I am trying to understand the global cycle
of N2O and to quantify its sources, by numerical simulation using a global model. (Kentaro Ishijima) |
No 29
| We are happy to introduce
Dr. Masanori Niwano, who has joined our program in October.
During his graduate-school years, he revealed seasonal and interannual
variations of the Lagrangian upward velocity in the tropical
lower stratosphere by using water vapor and methane data from
HALOE on board UARS satellite, and contributed to the understanding
of the transport processes and dynamics in the lower stratosphere.
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| During the post-doctoral years in
Kyoto University, he examined geographical distribution of cirrus
clouds, aerosol, and upwelling in the tropical tropospause region.
In FRCGC, he will engage in establishing the regional chemical
weather forecast system for Kanto region and study the role
of transport in the occurrence of photochemical oxidant. |
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No 28
| The Acid Rain 2005 Conference was held on 12-17 June 2005 in Prague, Czech Republic, andbrought together more than 600 scientists from more than 40 countries. Three researchers,i.e., DrsBin Zhu, Pakpong Pochanart and Xiaoyuan Yan, and one sub-leader, Dr. Toshimasa Ohara, fromAtmospheric Composition Program, attended the conference. Acid Rain is a series conference takingplace every 5 years. The previous Acid Rain was held in Tsukuba Japan, and the next one will be heldin Beijing, 2010 and chaired by Dr. Zifa Wang, an alumnus of Atmospheric Composition Program. |
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The focus of these conferences has evolved over the years starting with focus on questions regarding the causes and effects of acidrain, to measures required to reduce the problems, to the degree and rate of recovery, and now to the complicating role of otherpollutants. And it was proposed that the next conference be named Acid Rain and Air Pollution.The Acid rain problem originated from Europe and North America in 1970s withextensive damage to fish and risk to forest. Now in these regions, emissions of sulphurand nitrogen has declined, acidification of soil and surface water has ceased in large areas,and ecosystems are beginning to recover. However, emissions are increasing rapidlyelsewhere, especially in regions such as China, Japan, and the Indian sub-continent arenow at risk for damage to human health and to freshwater and terrestrial ecosystems.Thus more research and policy response are needed in these regions. |
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No 27
Prabir Patra attended AGU Chapman Conference on The Science and Technology
of Carbon Sequestration at San Diego, 16-20 January 2005. This meeting
was different in some sense from the conventional ones. All presentations
were directed towards the application of our understanding of carbon
cycle science, either in verification or assessment of natural and
deliberate carbon sinks. The issue of forced increase in natural carbon
sinks, such as the ocean sediments or terrestrial biosphere, and deliberate
sinks in the oil wells or earth's crust were discussed in details.
The consensus is multiple methodologies have to be implemented to
control atmospheric CO2 increase. Note that the carbon sequestration
science and technology are being developed to mitigate CO2 increase
in our atmosphere, and to comply with the commitments each countries
have made under the Kyoto Protocol. Though there may be technologies
available at hand to sequester carbon, but its longer-term repercussions
are not known, such as how to inject CO2 in the ocean without affecting
the marine life. The verification of carbon-credit claims by each
country is another serious problem, where he thinks we can contribute
through inverse and forward modeling of CO2.
No 26
| Two scientists, Dr. Hitoshi Irie and Dr. Donald
Lucas, have joined the Atmospheric Composition Research Program
this year. Before this March, Dr. Hitoshi Irie was working at
National Institute for Environmental Studies (NIES) to address
the issue on the formation process of polar stratospheric clouds,
which play a central role in the Arctic ozone depletion, by
using satellite data (ADEOS/ILAS) and a cloud microphysics model. |
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From these
experiences, Dr. Irie would like to analyze satellite
data at FRCGC to investigate temporal/spatial variations
of atmospheric composition and to contribute to solving
global environment issues. Dr. Donald Lucas joined our
program in May. Dr. Lucas was previously at MIT, where
he used a variety of computer models to study the atmospheric
chemistry of dimethylsulfide, an important biogenic
sulfur compound. At the FRCGC, Dr. Lucas plans to incorporate
a size-resolved description of aerosols into a global
3D chemistry-climate model, which he will then use to
quantify the production and fate of secondary aerosols
in the troposphere.
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No 25
A major goal of the Global Chemical Transport
Modelling Group is to investigate and quantify the links between
air quality and climate through the impacts of tropospheric ozone.
Ozone is the third most important trace gas affecting climate, after
CO2 and methane, and has been increasing
much more quickly - by a factor of 3-4 over the past century. This
change has been accompanied by increasing levels of 'smog' ozone
near the Earth's surface, which affect human health and agricultural
crop yields, and has been principally attributed to human activities.
To address this goal, Dr. Oliver Wild participated in the NASA TRACE-P
atmospheric measurement campaign over the Western Pacific in Spring
2001, and has recently provided detailed analyses of the production
of ozone in the highly polluted air transported out of East Asia
which was intercepted over the Western Pacific by measurement aircraft.
While sunny, anticyclonic conditions were found to contribute substantially
to the build-up of pollutant ozone over China, the impacts on climate
were found to be larger under cloudy conditions when regional build-up
was small. This unexpected result highlights the complex relationships,
which exist between regional pollution and global climate, and demonstrates
the additional insight that can be gained by combining high-resolution
chemistry model studies with detailed measurements of tropospheric
trace gases and aerosols.
No 24
One of the activities in Atmospheric Composition Data Analysis Group
is to study the changes in ozone variabilities (seasonal as well as
long-term) over three continents, i.e. Europe, North America and Asia,
which would help in estimating the influences of regional pollution
and intercontinental transport. Recent numerical simulations suggest
that ozone level in the Far East Asia is determined by regional scale
photochemical buildup superimposed to the "northern-hemispheric
background" that is controlled by the precursor emissions in
Europe, North America and Asia itself. In this regard, it becomes
necessary to formulate a suitable and versatile technique to analyze
observational data. The residence times and sectoral classifications
based analysis of ozone data shows that ozone, which is produced within
European boundary layer decreases sharply after the year 1990. This
is consistent with the change in NOx emissions over Europe. However,
almost no change in ozone abundance in European lower troposphere
is due to intercontinental transport of precursors from U.S.A. Large
contribution of Chinese outflow has been observed in the ozone abundances
over Japan in late spring/summer in the boundary layer and lower troposphere.
Significant contribution of European outflow is also observed over
Japan throughout the year. These observational proofs of long-range
transport have important implications on deciding the background ozone
levels and air-quality standards over a particular continent.
No 23
Croplands have been identified as a very important source of atmospheric trace
gases such as N2O (nitrogen monoxide),
NO (nitric oxide), NH3 (ammonia), and CH4
(methane). Agriculture in East, Southeast and South Asia exhibits
unique factors related to the generation of these gases. Although
this region accounts for only 36% of the world's cropland area, it
consumes more than half of the world's nitrogen fertilizers. Moreover,
approximately 90% of the world's rice fields, a source of CH4,
are located in this region. Therefore, emissions of N2O,
NO, NH3 and CH4 from croplands in this
region merit the close scrutiny of Xiaoyuan Yan in the Emission Inventory
Sub-Group. By analyzing the relationships between emissions and fertilizer
use, soil properties, water management and climate, and by drawing
upon agricultural activity data, we have developed a fine emission
inventory of N2O, NO, NH3
and CH4 from croplands for each country
in this region. For China and India, the inventory was developed for
each province or state. In addition, we are trying to predict future
emissions of these gases by considering changes in land use and population
as well as economic growth.
No 22
A task team for atmospheric composition observation has been founded within the
atmospheric composition research program. The observational work,
which is a part of Ministry of Education, Culture, Sports, Science
and Technology (MEXT) Research Revolution 2002 project, will focus
on two topics, the long-term observation of large-scale air pollution
in East Asia and intensive observation of the atmospheric radical
species. Here we would like to introduce the long-term observation.
As a result of fast economic growth in East Asia, massive amounts
of air pollution, including those having direct impact on global warming,
natural environment change, agricultural production loss, and human
health, are being released into the atmosphere and are predicted to
continue increasing. The study of the long-term variation of such
large-scale air pollution in this region and the process and mechanism
controlling such variations are in urgent need. Starting from the
end of this fiscal year, continuous monitoring of ozone and carbon
monoxide will be carried out in the highly populated region of China.
The observation of background conditions of these species in remote
Siberia will also be made. The observation results would give us the
new information that helps validate and improve the atmospheric chemical-transport
modeling and strengthen the capability to predict the status of air
pollution in the future.
No 21
Report by Drs. Prabir K. Patra and Shamil Maksyutov. In the Greenhouse Gases Modeling
Group, we are aiming to estimate the regional fluxes of carbon dioxide
(CO2) by using the information from atmospheric
data and its variability. Since most of the present CO2
measurement stations are located to keep track of the long-term background
changes, the inverse model estimates of surface fluxes are not well
determined on the regional scale. Our attention is focused on improving
present measurement network of CO2 optimally
for better regional source distribution. Such study is also recommended
to observe the changes occurring under the Kyoto Protocol for mitigating
the anthropogenic component of greenhouse gas emission, while increasing
the terrestrial CO2 uptake in biomass.
The implementation of optimal network simulation is generally probabilistic
and computer-time consuming at present. We have introduced "incremental"
optimization technique to study the dearth in currently operating
CO2 measurement network and propose possible
extensions in order to estimate regional fluxes of CO2
with greater confidence using inverse models. We have identified that
the continental South America, Africa and some parts of Asia require
more CO2 observations. Since new algorithm
is less computer-time demanding, fifteen transport models are utilized
in the inverse model calculations. This helps reducing uncertainties
in the optimal extensions due to the inaccuracies in model transport.
These results are in use while selecting the new observation sites
under the recently funded CO2 observation
projects.
No 20
10th Symposium of the IAMAS/CACGP (Commission of Atmospheric
Chemistry and Global Air Pollution) and 7th Scientific Conference
of the International Global Atmospheric Chemistry Project (IGAC)
were jointly held during 18th-25th September in Crete Island,
Greece.
Program Director, Dr. Hajime Akimoto, and 10 other colleagues
of ACRP joined the meeting and contributed their latest achievements.
The meeting, as it is titled "Atmospheric Chemistry within the
Earth System: From Regional Pollution to Global Change," covers
a wide range of issues on the tropospheric compositions -greenhouse
gases, oxidants, acidic substances, and aerosols -including
their natural variability, anthropogenic impacts exerted, and
their roles in the context of global change. One of the highlights
in this meeting was a cluster of presentations on ongoing as
well as completed regional field studies across the globe, in
which well-instrumented aircraft/ships/ground-based stations
are intensively coordinated according to their scientific objectives.
Atmospheric chemists in Japan have surely contributed a lot
in such activities especially in Asia and the western Pacific
region. Huge database collected in field studies has helped
and will keep helping a lot for validating and refining chemical-transport
models.
At the end of the Symposium, Dr. Anne Thompson of NASA/GSFC
succeeded as the next CACGP chair from Dr. Akimoto who had been
serving as the chair since 1998. |
No 19
Program Director, H. Akimoto attended "Air Pollution as a Climate
Forcing Workshop" held in Honolulu during Aril 29 and May 3, midst
of Golden Week. The venue was East West Center located in the cam-pus
of University of Hawaii. The workshop was co-sponsored by IPRC together
with NASA, NOAA, EPA, etc., and IPRC staff members took care of
more than 100 participants.
The workshop theme was a link between non-CO2
air pollutants such as methane, ozone and aerosol, and climate change.
Wide range of topics including atmospheric chemistry, mitigation
technology, and health effects were discussed.
Akimoto met all Japanese members of IPRC during a session interval
as well as the IPRC Director, Dr. McCeary, at the reception. It
was very good to have had a chance to get acquainted directly with
IPRC with which we usually do not have close contact.
No 18
 How
the airborne pollutants produced over the Asian continent are
entering the western Pacific region? To answer this question,
NASDA, in co-operation with domestic and foreign researchers,
conducted the aircraft observation,The Pacific Exploration of
Asian Continental Emission phase-A (PEACE-A), from 6 to 23 January.
During that period, Dr. Masayuki Takigawa, a researcher of our
program stayed at the base of operations in Kagoshima. He provided
the chemical weather forecast, which contributed greatly to
the route making of the airplane. The forecasting system, developed
by Dr. Takigawa, incorporated the emission, dispersion, and
photochemical processes of about 30 chemical species into atmospheric
general circulation model (AGCM).
It can thus predict the global distribution of photochemical
oxidants, sulfate aerosols, and their precursors for up to 4
days. The system predicted the atmospheric flow of pollutants
accompanying the cold front passage, which agreed well with
the observation. |
No 17
 A
Russian scientist Dr. Leonid Yurganov, who expertises a remote
sensing technique of atmospheric trace elements, has joined
FRCGC since last October. During the past several years of his
stay in US and Canada, he has been working for the data validation
team for a satellite sensor MOPITT (Measurements Of Pollution
In The Troposphere). Satellite remote sensing of tropospheric
chemical species is one of the promising and growing subjects,
and atmospheric chemists worldwide are gathering around this
"cutting edge" field.
By MOPITT horizontal distributions of CO and CH4
in the troposphere have been successfully retrieved on a global
scale, which reveal their emissions into the atmosphere as well
as their long-range transport across the globe. Dr. Yurganov
is also challenging a retrieval of other tropospheric pollutants
including NO2. At FRCGC, he will
collaborate with chemical-transport modelers to make inter-comparisons
between model results and satellite data. |
No 16
In June, the Workshop on Emissions of Chemical Species and Aerosols was held in Paris. Program Director Dr. Akimoto, Sub-leader Dr. Ohara, researcher Dr. Yan, and research staff Ms. Yamaji attended the workshop and the emission inventory subgroup gave its first presentation.
Dr. David Streets was invited from Argonne National Laboratory in the U.S. for a seminar at our institute on September 3. In collaboration with Dr. Streets, the Atmospheric Composition Research Program aims to develop a high-resolution emission inventory for the Asian region.
In July, seven members of the research program participated in the 8th Scientific Assembly of InternationalAssociation of Meteorology and Atmospheric Sciences (IAMAS) in Innsbruck. The seven participants included Program Director Dr. Akimoto and researchers Drs. Wild, Takigawa, Zhang, Pochanart, Kanaya, and Naja.
Preparations in the research program are also under way for the Symposium on Atmospheric Composition Change: Toward the Integration of Observation and Modeling, which will be held on November 19 and 20 at the Yokohama Institute for Earth Sciences.
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