Winter 2009

No. 15
Contents
Global Temperature in 20081

Highlights of the Global Climate for 20082

Summary of Japan’s Climate in 2008

3

TCC Activity Report for 2008

4

Upgrade of OneOne-monthmonth-forecast GPV Products

5

Improvement of JMA’s El Niño Prediction System

5

Global Temperature in 2008
The annual anomaly of the global average surface temperature in 2008 was +0.20ºC – the tenth highest since records began in 1891.
The Japan Meteorological Agency (JMA) monitors
global warming by analyzing surface temperature over landand oceans. The annual anomaly of the global average surface temperature in 2008 was 0.20°C±0.13°C above normal(based on the 1971 – 2000 average). The year 2008 ranks
the tenth highest since 1891, although the anomaly was thelowest since 2001 due in particular to the La Niña eventthat occurred from spring 2007 to spring 2008.
On a longer time scale, global average surface temperatures have been increasing at a rate of 0.67°C per century(Figure 1), and surface temperatures have been above normal for most of the last two decades. High-latitude regionsof the Northern Hemisphere have continued to experience
warmer-than-normal conditions over the last several years(Figure 2).
Annual surface temperatures have varied along different time scales ranging from a few years to several decades. The increasing trend is very likely due to humanactivity – particularly the emission of greenhouse gases.
For more information, please refer to http://
ds.data.jma.go.jp/tcc/tcc/products/gwp/temp/ann_wld.html.
(Toshiyuki Kitajima, Climate Prediction Division)+1.0

Anomaly (℃)

+0.5

0.0

-0.5

-1.0
1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Year

Figure 1 Annual anomalies in global average surface temperature from 1891 to 2008
The bars indicate the annual anomaly of the global
average surface temperature and 90% confidence
intervals for each year. The blue line indicates fiveyear running mean, and the red line shows the longterm linear trend.

Figure 2 Annual anomalies of surface temperatures in 2008
The circles indicate temperature anomalies from theclimatological normal (i.e., the 1971 – 2000 average) averaged in 5° x 5° grid boxes.

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No. 15 | Winter 2009

Highlight of the Global Climate for 2008
Annual mean temperatures were above normal in mostareas of the world except Alaska, the northern USA andAustralia (Figure 3). Extremely high temperatures were
frequently observed across wide areas from eastern Siberia
to northern Africa, while extremely low temperatures wererecorded from China to central Asia from January to February. Extremely low temperatures were also frequently seen
in eastern Australia until August.
Annual precipitation amounts were above normal from
Siberia to northern Europe, from Central America to northern South America and in Southeast Asia, while they were
below normal in the Middle East and Australia (Figure 4).
Extremely heavy precipitation amounts were frequently
observed from Siberia to northern Europe, from Central
America to northern South America and in Southeast Asia,
while extremely light precipitation amounts were observed
frequently in the Mediterranean area, northern Argentina
and southern Australia.
Major extreme events and weather-related disasters in2008 are as listed below (Figure 5):(1) Low temperatures from China to central Asia (Jan. –Feb.)(2) High temperatures from southeastern Siberia to northern
Africa (Mar. – Nov.)(3) Torrential rains in southern China (May – Jun.)(4) Typhoons and torrential rains from southern China to thePhilippines and in Vietnam (Jun. – Nov.)(5) Heavy precipitation from Malaysia to eastern Indonesia(year-long)(6) Cyclone in Myanmar (May)(7) Torrential rains around northern India (Jun. – Sep.)(8) Torrential rains around western Ukraine (Jul.)(9) Heavy precipitation in northwestern Europe (Jun. – Aug.)(10) Heavy precipitation around the western Mediterranean(July, Sep. – Nov.)(11) Torrential rains in Yemen (Oct.)(12) Cyclone in Madagascar (Feb.)(13) High temperatures in southeastern Africa (Aug. – Dec.)(14) High temperatures around Greenland (Jun. – Dec.)(15) Heavy precipitation in the northeastern and central USA(Feb. – Mar., May – Jun., Sep.)(16) Hurricanes from the southern USA to the Caribbean(Aug. – Sep.)(17) Forest fires in California, USA (Oct.)(18) Heavy precipitation from southern Central America tonorthern South America (year-long)(19) Low temperatures in eastern Australia (Mar. – May,
Aug.)(20) Light precipitation in southern Australia (year-long)

Figure 3 Annual mean temperature anomalies for 2008
Categories are defined by the annual mean temperature anomaly
against the normal divided by its standard deviation and averaged
in 5° x 5° grid boxes. The thresholds of the categories are -1.28σ,-0.44σ, 0, +0.44σ and +1.28σ, as shown in the legend. The normal values and standard deviations are calculated from 1971 –2000 statistics. Land areas without marks represent regions
where observation data are insufficient or normal data are unavailable.

Figure 4 Annual total precipitation amount ratios for 2008
Categories are defined by annual precipitation ratio to the normal
averaged in 5° × 5° grid boxes. The thresholds of the category are
70%, 100% and 120%, as shown in the legend. Land areas without marks represent regions where observation data are insufficient or normal data are unavailable.

(Hidehiko Isobe, Climate Prediction Division)

Figure 5 Extreme events and weather-related disasters in 2008
Major extreme climatic events and weather-related disasters occurring during the year are indicated schematically.

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No. 15 | Winter 2009

Summary of Japan’s Climate in 2008
● Above-normal annual mean temperature nationwide● Light annual precipitation in northern Japan and on the Sea
of Japan side of eastern Japan● Light snowfall amounts on the Sea of Japan side
● Repeated localized torrential rainfall in summer● Hot and dry weather in eastern and western Japan in Julyand August● Below-normal incidence of typhoon formation and approach, and no typhoon landfall(1) Annual temperature, precipitation and sunshine
duration (Figure 6)
The annual anomaly of the average surface temperature
over Japan (averaged over 17 observatories confirmed as
being relatively unaffected by urbanization) in 2008 was
0.46˚C above normal (i.e., the 1971 – 2000 average), andwas the eleventh highest since 1898. Area-averaged annual
mean temperature anomalies were +0.6°C in northern andeastern Japan, +0.5°C in western Japan and +0.4°C in Okinawa/Amami. Annual precipitation amounts were nearnormal nationwide except in northern Japan and on the Sea
of Japan side of eastern Japan, where they were significantly below normal. Annual sunshine durations were below normal on the Pacific side of northern Japan, above
normal on the Sea of Japan side of eastern Japan, and nearnormal on the Sea of Japan side of northern Japan, on the
Pacific side of eastern Japan, in western Japan and in Okinawa/Amami.
(2) Seasonal climate features (Figure 7)
North-westerly winter monsoon patterns rarely appearedwith cyclones and anticyclones periodically passing near
Japan in the first half of winter, bringing warm and cloudy
weather. In contrast, north-westerly monsoon patterns weresignificant in February, bringing unusually cold weather.
As a result, seasonal mean temperatures were near normal
in northern, eastern and western Japan. Storms repeatedly
passed the Japanese archipelago in mid-to-late February,
resulting in frequent bouts of rain and snow. However,seasonal snowfall amounts were below normal on the Sea

Figure 6
2008(Noriaki Watanabe, Climate Prediction Division)

Figure 7 Time series of five-day running mean temperature
anomalies for subdivisions
The normal is the 1971 – 2000 average.

Annual climate anomalies/ratios over Japan inTokyo Climate Centerof Japan side because of significantly below-normal snowfall in December and January.
Although temperatures fluctuated widely in May, seasonal mean temperatures were above normal because warm
weather was dominant in March and April. On the Pacificside of eastern and western Japan, precipitation amounts
were above normal due to cyclones passing frequently near
the Pacific coast of the main islands in April and May,
while they were below normal on the Sea of Japan side ofnorthern and eastern Japan because cyclones rarely passed
over the north of the country.
In eastern and western Japan, cloudy or rainy weather
was dominant due to active fronts in June, whereas hot andsunny weather was dominant in July and August due to aprevailing high-pressure system. On the other hand, innorthern Japan, sunny weather was dominant in June, whilecloudy or rainy days prevailed in July. Some areas of themainland were sometimes hit by torrential rains and thunder-storms in August. In particular, at the end of August,some parts of eastern Japan experienced record-breaking
heavy rainfall. In Okinawa/Amami, hot and sunny days
were dominant throughout the season.
In autumn, fluctuations in temperature were wide in November, and hot or warm weather was dominant in September and October. As a result, seasonal mean temperatures
were above normal nationwide. Sunny weather was dominant in northern Japan due to prevailing migratory anticyclones, and precipitation amounts were significantly below
normal. In particular, the Pacific side of northern Japan
experienced its lowest precipitation amounts since 1946
when area-averaged statistics first started. Meanwhile, typhoons struck Okinawa/Amami repeatedly, and precipitation amounts were significantly above normal.
In December, north-westerly winter monsoon patterns
rarely appeared, and cyclones periodically passed over the
Sea of Japan with warm air masses. Monthly mean temperatures were extremely above normal in northern andeastern Japan.

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No. 15 | Winter 2009

TCC Activity Report for 2008
The Tokyo Climate Center (TCC) of the Japan Meteorological Agency (JMA) has prepared the Activity Report of theTokyo Climate Center for 2008, covering climate-related activities by TCC in 2008 and its plans for 2009.

it was agreed that other candidates (India, Iran and RussianFederation) should be encouraged to participate in the RA
II RCC Network on a pilot-mode working with BCC and
TCC.

1.

7. Capacity building
JMA has conducted training courses in meteorology forexperts of National Meteorological and Hydrological Services (NMHSs) since 1973 on an annual basis as one of the
training initiatives provided by the Japan International Cooperation Agency (JICA). The 2008 course was held from
September to December with an emphasis on the operational use of numerical weather prediction, satellite meteorology and climate information. In the climate information
session, staff members from the Climate Prediction Division gave lectures on climate system monitoring, longrange forecasting, the El Niño outlook and global warming
projection.
At the request of the Malaysian Meteorological Department (MMD), JMA/TCC ran a hands-on training course on
climate data communication and application for three
weeks in July – August. Two officers from MMD’s Climate Section participated in the course to learn the use ofLinux machines and data processing for GRIB and GRIB2.
Another four-week training course on climate forecastingand its application was conducted in September with theparticipation of another two officers from MMD to learn
how to use seasonal forecasting models.
TCC convened the Training Seminar on Climate Information and Forecasting at JMA Headquarters from 4 – 6
November 2008 with 13 invited participants from 12 countries and territories who were engaged in operational longrange forecasting at NMHSs in East and Southeast Asia.
The participants learned how to use the data and products
available on the TCC website for long-range forecasting.

TCC website and products
TCC updated its website (http://ds.data.jma.go.jp/tcc/tcc/
index.html) in March 2008 with several new features including downscaled products for one-month prediction inSoutheast Asia.
A new publication, Annual Report on Climate System
2007 was issued in March 2008, covering topics on extreme
climate events around the world and giving a summary of
the climate system in 2007. Other publications, such as
Climate Change Present and Future and Climate Change
Monitoring Report for 2007, were also made available on
the TCC website.
2. JRA-25 Atlas
The joint project between JMA and the Central ResearchInstitute for Electric Power Industry on long-term global
atmospheric reanalysis (called the Japanese 25-year Reanalysis (JRA-25)), was completed in March 2006. In
March 2008, maps of annual, seasonal and monthly averaged climate fields for various meteorological variablesfrom JRA-25 products have been made available in the
JRA-25 Atlas at http://ds.data.jma.go.jp/gmd/jra/atlas/eng/
atlas-tope.htm.
3. Extended- and long-range EPS
In January 2008, new elements of GPV data (700-hPa
temperature and its anomaly) were added as one-monthpredictions, and have been made available to registered
NMHSs.
4. ODAS and El Niño prediction system
The Meteorological Research Institute (MRI) of JMA
has been developing a new Ocean Data Assimilation System (ODAS), named MOVE (Multivariate Ocean Variational Estimation), and an ocean prediction model named
MRI.COM (MRI Community Ocean Model) since 1999.
The new ocean analysis system and the ocean-atmosphere
coupled prediction system were put into operation in March
2008.

8. International conference and workshop
JMA held a meeting of WGCRM for RA II of WMO at
JMA in Tokyo from 7 – 8 August 2008. The meeting reviewed the implementation of climate-related activities in
RA II, and an agreement was made to further develop cooperative relationships among members.
The Ninth Meeting for the Seasonal Prediction of theEast Asian Winter Monsoon took place at JMA from 6 – 7
November 2008 with more than 30 participants from
NMHSs in East and Southeast Asia. Attendees discussed
the latest outlook for the 2008 – 2009 winter monsoon andexchanged information and knowledge about the East Asian
Winter Monsoon System, El Niño/La Niña outlook, longterm trends and decadal variability/seasonal outlooks using
statistical and dynamic forecast models.

5. Global warming projection
JMA has implemented a projection of the atmosphericand oceanic climate around Japan for the end of the current
century using a regional coupled ocean-atmosphere model
developed by JMA/MRI and an improved version of the
global ocean-atmosphere coupled model known as MRICGCM2.3.2. Global Warming Projection Volume 7, published in March 2008 includes the climate and ocean currents projected in and around Japan.

9. Future plans
In the first quarter of 2009, TCC will publish a gridded
dataset of annual and monthly mean temperature anomalies
worldwide from 1891 onward on the TCC website. The
data, which covers 5° x 5° grid boxes worldwide can be
downloaded and displayed on a map. This resource will
enable users to monitor and analyze climate change on aregional scale.
In the second quarter of 2009, TCC’s newly developed
software, Interactive Tool for Analysis of the Climate System (ITACS), will be made available on the TCC website,enabling registered NMHSs to display various kinds ofmaps with selected parameters and to make statistical

6. RCCTCC and the Beijing Climate Center (BCC) of the China
Meteorological Administration (CMA) were recommended
for designation to Regional Climate Center (RCC) status in
WMO RA II at the Working Group on Climate-Related
Matters (WGCRM) meeting in Beijing in April 2007. In
close cooperation with the BCC, the Regional Climate Center Network in RA II (http://www.rccra2.org/detail/index.htm) website went live in June 2007.
At another WGCRM meeting in Tokyo in August 2008,

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No. 15 | Winter 2009

analysis.
In April 2009, the data format of one-month-forecast
GPV products will be changed from GRIB1 to GRIB2.
Daily GPV data for individual ensemble members will also
be made available on the TCC website for the first time.
JMA is preparing for the upgrade of its seasonal forecast
model scheduled for early 2010. The upgraded version will
introduce a one-tier coupled system instead of the current
two-tier system. It is expected that the forecast skill of the
new model will be improved, particularly for precipitation
over the tropics and the Asian monsoon/winter Australian

winter monsoon.
In February 2009, JMA will update the El Niño prediction system, which consists of a global ocean data assimilation system and a coupled atmosphere-ocean global circulation model (CGCM).
TCC plans to hold a training seminar on the utilizationof JRA-25 data for NMHSs in East and Southeast Asia inlate 2009 or early 2010.
(Kumi Hayashi, Climate Prediction Division)

Upgrade of One-month-forecast GPV Products
JMA improved its one-month ensemble prediction system in March 2008 (please refer to TCC News No. 12 for details). Accordingly, GPV products for one-month forecasts will be upgraded in April 2009 with the change of data format from GRIB1 to
GRIB2 and the provision of new products (daily GPV data for individual ensemble members and hindcast data).
The main upgrades to the GPV products are outlined below.
1. Change of data format (from GRIB1 to GRIB2)
New data file in GRIB2 format will be available from April 2009. In connection, the following definitions will bechanged.
- Unit of rainfall amount (from [kg m-2 7days-1] will be changed to [kg m-2 day-1]).
- Method of calculating time-mean values: Time mean values will be made on the basis of 6-hourly data (at 00, 06, 12
and 18 UTC), as opposed to the current method that uses only values at 12 UTC.
The provision of data files in GRIB1 format will cease in September 2009 after a six-month transition period.
2. Addition of daily GPV data for individual ensemble members
TCC will newly provide daily GPV data for individual ensemble members in addition to currently available ensemble
mean data.
Ensemble size: 50
Element: comparable to ensemble mean data
Data format: GRIB2
3. Provision of hindcast data
Daily GPV data for individual ensemble members will be made available.
Target period: from 1979 to 2004 (the initial dates are the 10th, 20th and last day of every month)Ensemble size: 5
Element: comparable to ensemble mean data
Data format: GRIB2
Sample data sets are available at
http://ds.data.jma.go.jp/tcc/tcc/gpv/model/1mE.Grib2/1mE_ens_grib2.html (ensemble statistics) andhttp://ds.data.jma.go.jp/tcc/tcc/gpv/model/1mE.Grib2/1mE_mem_grib2.html (forecasts by individual ensemble members).
For the details, please refer to http://ds.data.jma.go.jp/tcc/tcc/gpv/model/1mE.Grib2/1mE_GPV_outline.html.
For related enquiries, please contact TCC at tcc@climar.kishou.go.jp.
(Yukiko Naruse, Climate Prediction Division)

Improvement of JMA’s El Niño Prediction System
In February 2009, JMA improved its El Niño prediction
system, which consists of a global ocean data assimilation
system and a coupled atmosphere-ocean global circulation
model (CGCM). In March 2009, the creation of new Model
forecast of SST anomalies for Niño regions products isscheduled, and these will be made available on the TCC website(http://ds.data.jma.go.jp/tcc/tcc/products/elnino/
nino_fcst/indices/indexninofcst.html).

(one member with twelve initial dates)[New] Combination of perturbations and LAF ensemble(five members with six initial dates)
The ensemble size will therefore increase from 12 to 30,
and the lag period will be shortened from 55 to 25 days.
2. Update of statistics- Elaboration of statistics for the variational method of
ocean data assimilation- Update of statistics for the CGCM, such as flux correction and bias correction of SSTs

What’s new
1. Improvement to the ensemble method (Figure 8)- Introduction of ensemble perturbations for oceans (fivemembers with one initial date)- Change of ensemble member aggregation[Present] Lagged Average Forecasting (LAF) ensemble

Tokyo Climate Center

Performance
To examine the impacts of refining the ensemble
method, the performances of the following two ensemble

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No. 15 | Winter 2009

methods were compared in a hindcast experiment (Figure
9):
LAF5: A 10-day LAF ensemble consisting of five members
PTB10: A combination of the 25-day LAF ensemble andperturbations consisting 10 members.
Four initial dates per year were set for the experiment (31January, 1 May, 30 July and 28 October) for the period
from spring 1996 to spring 2006 (10 years). The ensemble
size of PTB10 was larger than that of LAF5, and lag period
for PTB10 was shorter than that of LAF5. It can be estimated that the difference in performance of both methods

corresponds approximately to the improvement in forecast
skills brought about by this update.
It is found that PTB10 improves on the prediction SSTs
over the western tropical Pacific and the Indian Ocean(Figure 10). This improvement can mainly be attributed tothe increased ensemble size compared with the results ofother methods in aggregating ensemble members (notshown). Perturbations used in the new ensemble method
are important to increase ensemble size within a limitedtime.
(Masayuki Hirai, Climate Prediction Division)

Figure 8 Schema of showing the aggregationof ensemble members under the old (left) andnew El Niño prediction system (right)

PTB10 vs. LAF5
■

■

○
○
●
○
○

■

■

○
○
◎
○
○

02p
01p
non-perturbation
01m
02m

LAF -45 -40 -35 -30 -25 -20 -15 -10 - 5 0 day

initial date

◎ : control run○ : perturbation run●, ■: LAF (non - perturbation with past initial dates)
PTB10: ◎＋●＋○
LAF5: ◎＋■

Figure 9 Schema of two ensemble methods(PTB10 and LAF5) in the hindcast experiment

LAF5

PTB10

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.7

0.8

0.9

Figure 10 Anomaly correlation coefficient of the SST prediction by PTB10 (left) and LAF5 (right)
Lead time is six months.

Any comments or inquiries on this newsletter and/or the Tokyo Climate Center (TCC), Climate Prediction Division, JMA
TCC website would be much appreciated. Please e-mail Address: 1-3-4 Otemachi, Chiyoda-ku, Tokyo 100-8122, Japan
to: tcc@climar.kishou.go.jp
TCC website: http://ds.data.jma.go.jp/tcc/tcc/index.html(Chief Editor: Kumi Hayashi)Tokyo Climate Center

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No. 15 | Winter 2009