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No 30
Report of the overseas trip by Dr. Tatsuo Suzuki
I attended World Climate Research Program (WRCP) workshop of "understanding of sea level rise and variability" held in Paris,
France from 6 to 9 June, 2006. The objectives of this workshop are given the present and projected future rates of global sea-level
rise, and the associated variability ranging from long time scale, such as climate change, to short timescales, such as storm surges, in
order to improve monitoring of the state of the Earth in Global Earth Observation System of Systems (GEOSS). I presented some
work focusing on the high-resolution modeling of steric sea level rise. The results of high-resolution modeling resemble that in the
medium-resolution version on a large scale. However, a high-resolution model can represent more details ocean structure changes
under global warming. The changes in the ocean structure affect not only the spatial distribution of sea level but also the change in the
local sea level variability. It is important to consider the change in the sea level variability when assessing possible impacts on human
activities. In this workshop, the latest studies covering from the mechanism of sea level change to the impact are discussed. This
discussion was very helpful to get useful information. |
No 29
Report of the 2005 American Geophysical Union (AGU) Fall Meeting,
by Dr. Wing-Le Chan.
Every year, during December, the AGU Fall Meeting offers an opportunity
to discuss the latest research covering various fields in the geophysical
sciences. A number of FRCGC members, including some from the Global
Warming Research Program attended the conference. I presented some
work focusing on the variability of the North Atlantic meridional
overturning strength in response to increased levels of atmospheric
CO2 concentration. A series of experiments using a coupled atmosphere-ocean
model showed that a total recovery of the North Atlantic thermohaline
circulation is delayed when CO2 concentration is increased eight-fold.
Strong centennial variability in the overturning strength and sea
surface temperature and salinity in the Labrador Sea appear. When
the thermohaline circulation has completely recovered, strong variability
is limited to decadal timescale, in the northern North Atlantic and
the Nordic Sea, as in the control experiment. However, this variability
increases in magnitude with CO2 concentration. I was able to exchange
many ideas with other researchers. Sessions such as those on past
and future changes of thermohaline circulation, and the meeting as
a whole, proved both informative and enjoyable. |
No 28
Two scientists, Dr. Fuyuki Saito and Dr. Minoru Chikira, have joined the Global
Warming Research Program.
Dr. Fuyuki Saito had been studying at CCSR until this March. He has developed an ice-sheet model called IcIES and
also someparts of CCSR/NIES FRCGC atmosphere-ocean coupled model (MIROC). In FRCGC, he continue to develop the ice
sheet modelfurther as well as develop a coupling model of IcIES and MIROC.
Dr. Minoru Chikira had been studying at
CCSR until this March. He developed a multiple cloud base Arakawa-Schubert schemeand applied it to the study on the
greening of the Sahara during the mid-Holocene. In FRCGC, He studies on stratocumulus cloudsin the southeast Pacific
to the west of Peru with his experience in improving parameterization in the general circulation model. It isknown
that these clouds cannot be well simulated in models. He is going to stay at IPRC in Hawaii University from this
October fora half year and compare the models of both institutes.
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No 27
Report of the American Geophysical Union (AGU) Fall Meeting
by Dr. Kurahashi
2004 American Geophysical Union (AGU) Fall Meeting was held in San
Francisco, U.S.A from 13, December to 17, 2004. Six
people of our program had participated. Four of them belong to the
paleoclimate group; Group Leader Dr. Abe, technical stuffs Mr. Segawa
and Ms. Ohgaito, and myself. We had a lively discussion for 5 days.
| At a session featuring the paleoclimate,
we presented our research results of effects of ocean to the
atmospheric circulation. Our study was based on the simulation
of climatic conditions of two periods using our Coupled Atmosphere-Ocean
General Circulation Model (CGCM). One is warm climate period
in relatively near past (Mid- Holocene) of which we have enriched
paleoenvironmental data. The other is cold climate period (the
last glacial maximum). In another session, we presented our
research result of roles of the ice sheet in the climate system.
In this study, we simulated ice sheet behaviors in climate variations
of 100,000 year cycles using the ice sheet model. Many researchers
who were interested in our studies came to us and made active
discussions. We also listened to a lot of presentations and
understand the latest research trends. I think it was very significant
meeting as we could exchange opinions with many researchers
in our field. It will help us to develop our research and models
in the future. |
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No 26
Report of the Symposium by Dr. Tsushima
I attended International Radiation Symposium (IRS) held in
Pusan, South Korea from 23 to 28 August, 2004, and made a
poster presentation. In this symposium, specialists in various
fields of Radiation meet once every 4 years. During the poster
session, Dr. Wielicki, National Aeronautics and Space Administration
(NASA), approached to me and said, "I am going to analyze
the same annual variation by using CERES data." I replied
willingly, "I want to know if we get the same result
with the new data or not. if you conduct the analysis, please
tell me the result." At the night banquet, Dr. Ramaswamy,
Geophysical Fluid Dynamics Laboratory (GFDL) said to me, "Have
you got any advances in analysis of K-1 model of low- and
high-sensibility versions?" Indeed, the increased amounts
of earth's temperature caused by doubled CO2 that were calculated
in models studies at other laboratories are very close; 2.9
degrees in GFDL's model and 2.7degrees in NCAR's model. However,
both models showed differences in cloud behavior; lower cloud
increases in GFDL's model, but decreases in NCAR's model.
There is a strong possibility that the cause of the difference
in cloud behavior will be depended on used models, even though
both climate resolutions are similar. It is very interesting
theme to study the contributions of short-wavelength and long-wavelength
radiation to the climate sensitivity as the first stage, and
to compare and analyze the cloud feedback mechanisms as the
second stage. If the difference of cloud response in warmed
models can be related to the difference of cloud distributions
and feedback in the models that show present climate, it will
be possible to get a clue to identify the causes of global
warming resolution's indeterminacy. I am very much looking
forward to future studies.
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No 25
 The
Carbon Cycle Research Group conducts chlorofluorocarbons (CFCs)
simulation, using an eddyresolving (0.1 degrees horizontal)
ocean general circulation model (OGCM), jointly developed by
the Climate Variations Research Program and the Earth Simulator
Center. CFCs are absorbed at the sea surface and are carried
within the oceanic circulation and mixing processes. The Figure
below illustrates the results of simulated CFC-11 concentration
in the deep North Atlantic Ocean. High concentration water of
CFC-11 (shown in warm colors) is revealed to have recently absorbed
CFCs from the atmosphere and then been ventilated into the northern
North Atlantic, where is formed deep water which is important
to global climate variations. Injecting CFCs into this sea area
can visually capture the formation and spreading of deep water. |
No 24
From this summer to fall, many researchers from our programs participated
in various study meetings. Active discussions were made about important
topics on global warming, such as typhoon, Baiu, winter snow, and
cloud feedback effect. In addition, CFC simulation had been performed
using a global ocean eddy-resolving model, which is very unique in
the world. As a result, it became possible to study absorption process
of anthropogenic CO2 in the western boundary
current region and coastal region, that had been unable to represent
well before. In the paleoclimate study, for Quaternary in Cenozonic
era, the presentation was made that an advanced atmosphere-ocean-ice
sheet coupled model, which could simulate super long period numerical
integrations of hundred thousand years was developed and reconstruction
of climate conditions in the Last Glacier Maximum was attempted. In
addition, the cause of the glacial termination was discussed. For
Tertiary in Cenozonic era, result of the sensitivity experiment on
the climate model about opening and closing of the Panama Isthmus
was presented. From this experiment, it was found out for the first
time that when the Panama Isthmus is open, deep-water formation region
is shifted from the North Atlantic to the North Pacific, and the thermohaline
circulation became active in the North Pacific, and became inactive
in North Atlantic. Those research outputs will be expected to make
contribution for the further development of climate models and to
increase accuracy on global warming projections.
No 23
From May 5 to 8, Researcher Dr. S. Lan Smith, participated in the JGOF Open Science
Conference held in Washington, D.C., in the United States. He presented
a paper on the simulation results of a marine chemical and ecosystem
model in four observation points in the North Pacific Ocean.
From May 20 to 30, group leader Dr. Yamanaka, researcher Dr. Kishi,
and research promotion staff Ms. Aita participated in the Third International
Zooplankton Production Symposium held in Gijon, Spain. They made a
presentation on the effect of primary production and carbon flux on
the seasonal vertical movement of zooplankton, based on the ocean
general circulation model that incorporates the Northpacific Ecosystem
Model Understanding Regional Oceanography (NEMURO) ocean ecosystem
model. The conference enabled group members to obtain valuable information
on the role of zooplankton in the circulation of marine substances.
During the meeting, it was decided that the next conference in 2006
will be held in Japan.
No 22
The Carbon Cycle Research Group is conducting tracer experiments using high-resolution ocean general circulation models (OGCM). Carbon dioxide absorbed in the ocean is not only transported by large-scale ocean circulation, but also re-distributed by western boundary currents and mesoscale eddies. Therefore, it is important to understand its behavior. So far, by an idealized tracer experiment using the model with resolution of 0.25 degree longitude and latitude, we have found that the large vertical mixing is induced by eddy activity in the deep ocean and materials absorbed in the high latitude area are transported to the tropical region not only in the interior ocean but also by the western boundary currents. These results were presented in some science meetings. Currently, we have started a new experiment with the chlorofluorocarbon as a tracer using the super high-resolution model (horizontal 0.1 degree) developed jointly by the Climate Variation Research Program and the Earth Simulator Center, which will make us possible to study more detailed transportation process. Using the Earth Simulator, we are expecting new progress for our research on not only for the physical process but also for the material transport in the ocean.
No 21
 We would like to introduce Dr. Wing-Le Chan, a researcher in the Paleoclimate Group.
My main interests originally lay in the numerical modeling of stellar atmospheres, including simple radiative and convective processes, which I carried out while I was at the University of London. Since working in Japan, my field of research has become much closer to home. As a member of the paleoclimate group within the Global Warming Research Program, I have been studying the effects of changes in saline water input to the North Atlantic resulting from land changes on global climate. A geophysical fluid dynamics laboratory (GFDL) coupled atmosphereocean model, comprising of an R15 atmospheric model and a Cox ocean model, has enabled our team to obtain experimental data spanning several thousands of years for various sensitivity experiments within a reasonable amount of time. In particular, I am investigating the separate roles of the Mediterranean outflow water and the Agulhas Current in the maintenance of the North Atlantic thermohaline circulation and their influences on global ocean circulation and climate. |
No 20
Report of the Paleoclimate Modelling Intercomparison Project (PMIP)
Meeting by Rumi Ohgaito
Dr. Abe-Ouchi, Dr. Hargreaves and I attended the PMIP meeting held
from 23 to 26 June 2002 in Cambridge University, England. The aim
of the PMIP project is to evaluate paleoclimate experiments and
improve our understandings of the past climate changes under international
cooperation. Research on both observational data and model experiments
for the Last Glacier Maximum (about 21,000 years ago) and the climate
optimum period (about 6,000 years ago) were compared and investigated.
Under the clear sky yet in a little chilly weather, the conference
was held at one of the University halls, which was designed in "Japanese
style". The presentations of each group were made and the setting
of PMIP new subjects was discussed substantially.
In the evening, Dr. Hargreaves who spent her graduate school period
in Cambridge University kindly showed us around the beautiful campus.
No 19
 We would like to introduce Dr. Julia Hargreaves, a new researcher in the paleoclimate group.
Exactly one year ago I came to FRCGC to work as a visiting scien-tist
in the paleoclimate group of the Global Warming Research Program.
Prior to coming to Japan, I worked as a researcher at the Proudman
Oceanographic Laboratory near Liverpool in the UK for 6 years,
studying ocean surface waves, with emphasis on the effects of
climate change and impacts on the coastal environment. During
my sabbatical, I have focussed on analysing paleo-data with
the aim of gaining understanding the ice age terminations. Now
I am employed as a Researcher and I am becoming more involved
with the work program of the group.
My particular interest is in under-standing the mechanisms and
feed-backs responsible for the very large climate changes apparent
in the paleo-record over the last half-mil-lion years or so.
At a technical level, my work tends to be in the area of model-data
comparison. |
No 18
The PICES MODEL/REX Task Team Workshop was held in two places in
Japan, namely Nemuro, Hokkaido from 26-27 January, and at Frontier Research Center for Global Change, Yokohama on 29th January.
Dr.Kishi of the Global Warming Research Program served as a convenor.
Funded by the Heiwa-Nakajima Foundation, nine participants come
from abroad: three each from United Stated and Russia, one each
from Canada, China and Korea. The ten participants from Japan included
five from FRCGC (Drs. Kishi, Yasuhiro Yamanaka, Lan Smith, Sanae
Chiba, and Kazuaki Tadokoro).
This workshop built upon the NEMURO (North pacific Ecosystem Model
for Understanding Regional Oceanography) developed at the previous
NEMURO workshop in 2000 (Yamanaka's group has developed a carbon
cycle model based on the original NEMURO).
This time, by including a bioenergetics model of high catch fishes,
we developed the NEMURO.FISH model (NEMURO For Incorporating Saury
and Herring). The model is not yet complete, but we look forward
to further developing and applying it. Unfortunately, our return
flight was cancelled because of heavy snow, and we therefore had
to cancel some of the presentations at FRCGC.
No 17
 A Report from the 10th PICES Meeting in Victoria, B.C., Canada, 05-12 October, 2001 by Dr. S. Lan Smith, Carbon Cycle Group.
I recently attended the tenth annual meeting of North Pacific
Marine Science Organization (PICES) with Dr. Kishi of our group
to participate in the MODEL task team, which develops marine
ecosystem models of the North Pacific Ocean.
Both of us participated in the NEMURO workshop that this task
team held (Nemuro, Hokkaido, Japan, February 2000), where a
lower-trophic (phytoplankton, zooplankton, etc.) model was formulated.
This time, we attended task team meetings with groups working
to couple the NEMURO model to models of highertrophic levels
such as fish, and discussed how this might be done.
A major goal of the MODEL task team is to study how climate
change may impact the carrying capacity of the ocean such as
stocks of fish. This is relevant to society, and to the purpose
of FRCGC. I also recommend highly the city of Victoria as a
beautiful place for a meeting (or for a vacation). |
No 16
Following is the report by Mr. Yoshiharu Iwasa after participating in an overseas
conference.
I attended the 8th Scientific Assembly of InternationalAssociation
of Meteorology and Atmospheric Sciences(IAMAS), in Innsbruck, Austria
from July 10 to 18. The conference began with lectures from invited
speakers, who spoke about the latest issues from the IPCC Report,
followed by presentations spanning a wide range of research fields
within atmospheric science.
During the session on climate models, I delivered an oral presentation
on circulation mechanisms determining water vapor distribution in
the radiative-convective equilibrium of the Earth's atmosphere. Although
many presentations of research results using large-scale GCMs, while
I presented results of research using a simple model, I was pleased
with the number of people who gathered to hear my talk. I received
questions and comments from several people in the audience, but only
afterwards was I to discover that they were well-known and eminent
experts. Istill feel a mixture of excitement and shivers thinking
about it.
On Sunday, I visited Stubaital, and from the STB(train) window on
the return journey, I was able to see a beautiful rainbow over a church
in an Alpine village.
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