Disaster Risk Reduction

Developing an early warning system tomitigate temperature stress on rice production
Yoshiji Yokote, Director, Climate Prediction Division, Global Environment and Marine Department,
Japan Meteorological Agency

Arecent pilot project jointly conducted by the Japan
Meteorological Agency and the National Agriculture
and Food Research Organization’s Tohoku Agricultural
Research Center saw the development of climate information
services for the agricultural sector in the Tohoku region.
The accuracy of seasonal forecasts issued by the Japan
Meteorological Agency (JMA) has increased thanks to improved
prediction techniques and advances in understanding regarding
the predictability of climate-related phenomena. However, seasonal
forecasts have not been effectively deployed in some user sectors.
One reason for this is that JMA’s seasonal forecast is probabilistic
in three categories (below-normal, near-normal and above-normal)
on a regional scale, meaning that it is not necessarily easy to use
or comprehend. Against such a background, JMA sought ways todevelop easy-to-use information tailored to users’ requirements
in order to support their decision-making activities in varioussectors. As part of such efforts, JMA began issuing Early Warning
Information on Extreme Weather (EWIEW) in March 2008.
EWIEW indicates the possibility of very high or low temperatures
up to two weeks ahead, and contributes to the implementationof farming measures against damage caused by extreme weather
phenomena such as very cold conditions.
The National Agriculture and Food Research Organization(NARO) is Japan’s largest research organization addressing agriculture, food and rural communities. Its Tohoku Agricultural
Research Center (TARC) is one of the leading institutions in thefield of studies on the use of weather and climate informationfor the agricultural sector and provides such data to end users(farmers). NARO/TARC’s recent activities have included consideration of how to supply improved information with a greaterlevel of tailoring to end users. In addition, there have been goodlong-term relationships between NARO/TARC and local JMA
observatories in the Tohoku region (in the northern part ofJapan’s mainland).
In July 2009, JMA hosted an international event titled The Tokyo
Climate Conference: Better Climate Information for a Safe andSustainable Society. The aims of the conference were:• To identify actions and methods for the development of aneffective framework involving users and providers in order tocreate user-oriented products and promote their utilization witha focus on the Asia-Pacific region• To contribute to the World Climate Conference-3, which
initiated the establishment of the Global Framework for
Climate Services.

[ 131 ]

Building on the favourable long-term relationships
between NARO/TARC and local JMA observatories in
the Tohoku region, the conference provided an ideal
opportunity for the two organizations to discuss how
the use of climate information in the agricultural
sector could be enhanced, and this exchange led to theidea of a pilot project that would benefit both JMA andNARO/TARC in their service and research activities.
As a result, the two organizations initiated a pilot
project to promote the effective use of seasonal forecast data in Japan. The aims of the initiative were todevelop climate information applicable to agriculturein the Tohoku region, which tends to be greatly affectedby cold conditions, to provide customized climate
information to end users (farmers) via a website, andto evaluate the information’s effectiveness using a questionnaire survey. Future goals include enhancing theuse of climate prediction information in various user
sectors through lessons learned from the pilot project.
Dialogue and development
In the first stage of the project, JMA and NARO/TARC
engaged in dialogue to determine related requirements
and to exchange knowledge and information. JMA
considered how to promote the better use of predictions covering the period up to two weeks ahead in user
sectors, based on recent improvements in prediction
skill. NARO/TARC also sought to improve the customized information it provides to end users so that bettercountermeasures could be taken to protect rice crops
against the adverse effects of extreme temperatures, especially in the occasional cold summer conditions affecting
its area of responsibility. As a result of this dialogue, thetwo organizations decided to target climate information
towards the development of the pilot project for thefarming of rice crops in the Tohoku region in summer.
There were three key reasons for this choice:•T he Tohoku region is frequently affected insummer by cold north-easterly winds (known asYamase winds), which have a great impact onrice crops•C ontrolling water temperatures in rice fields byadjusting water levels is an effective countermeasure
to combat the adverse effects of extreme
temperatures on rice crops – for example, farmers

Disaster Risk Reduction

may increase the quantity of water to reduce the sterility effectthat low temperatures can cause• Climate prediction information is considered useful for watertemperature control, as farmers require one to two weeks
to prepare for the water level adjustment countermeasure
mentioned above.
In the development phase, JMA and NARO/TARC first discussedthe content of new climate prediction information suitable for thepurposes at hand. JMA provided temperature predictions covering
the period up to two weeks ahead and expertise on prediction skill.
NARO/TARC provided:• 1 km-resolution temperature analysis data formulated using JMA
observation and local geographical data
• Information on the adverse effects of extreme temperatures onrice crop cultivation• Information on countermeasures to protect rice crops in eachgrowth stage.
Based on these exchanges of information and expertise, JMA andNARO/TARC developed a method to predict probability density
functions (PDFs) of seven-day mean temperatures (T7d) at aresolution of 1 km for the Tohoku region covering the period up
to two weeks ahead. The T7d prediction was based on a combination of two data sets: the climatological normal of T7d with

Key processes of the JMA NARO/TARC pilot project

Source: JMA[ 132 ]a 1 km resolution covering the 30-year period from1981 to 2010 (produced by NARO/TARC), and thePDF prediction for regional-scale T7d anomalies onthe Sea of Japan side and the Pacific Ocean side of theTohoku region (produced by JMA).
JMA and NARO/TARC then discussed criteria foralarming temperatures at which countermeasures
should be taken in consideration of related issues suchas the various growth stages of paddy rice, impacts
on its development and countermeasures to be taken.
The discussions in this phase were based on NARO/
TARC’s expertise and experience in agro-meteorology.
As a result, two criteria were defined: temperatures of20° C or below from the middle of July to the beginning of August, which increase the risk of sterility
in rice crops; and temperatures of 27° C or above inAugust, which increase the risk of poor grain fillingin rice crops.
To evaluate the effectiveness of this new prediction
approach, JMA verified T7d prediction skill at a 1 km
resolution using hindcast experiment (re-forecast) data
for the 30-year period from 1981 to 2010. The predictedvalues were compared to actual temperatures recorded at
17 surface stations in the Tohoku region, and the results
confirmed that the mean of the T7d predictions indicatedDisaster Risk Reduction

a higher level of skill than the climatological value of T7d for theperiod up to two weeks ahead. It was also found that the prediction
skill for the probability of T7d values, at 20° C or below and 27° C orabove, was reasonable. JMA verified this in relation to past extreme
events, including the very high temperatures seen in 1994 and thevery low temperatures seen in 2003, and found realistic temperature
distributions and variations of the prediction comparable to actuallyobserved values.
Experimental provision of climate information
During summer 2011, JMA and NARO/TARC experimentallyprovided the new climate information through a website to registered users (see map image on next page). In fact, NARO/TARC,
in collaboration with the Faculty of Software and Information
Science at Iwate Prefectural University (IPU) had operated awebsite providing weather and related tailored information
aimed at reducing rice crop damage even before the pilot project
was implemented. Under the project, NARO/TARC further
customized information to users and improved the web system
to provide new climate information covering the period up totwo weeks ahead. The data included mean T7d predictions andthe predicted probability of T7d values at 20° C or below and27° C or above for each 1 km grid, covering the period from one
to two weeks ahead. On the website, users could also view timesequence information for specific registered points, including
predicted T7d values and their variability (standard deviation)and the predicted probability of T7d values at the levels describedabove. The site also included maps showing the climatologicaloccurrence of the high and low temperatures andrelated interpretation. When the predicted probabilityof T7d reaching the alarming temperature was highat a registered point, an alert was automatically sent
to users’ e-mail terminals and mobile phones. For
example, if the possibility of temperatures at or below
20° C was high, users received an alert so that they
could increase water levels in rice fields to protect
against low-temperature-related damage.
After the experiment of July 2011, NARO/TARC andthe IPU conducted an e-mail questionnaire survey. Thequestionnaire was distributed to the 154 users who participated in the experiment, and 89 replies were received.
Unfortunately (as far as the experiment is concerned),
no remarkably high or low temperatures occurred during
the trial period, meaning that few alert messages weresent. Nonetheless, a number of respondents clearly indicated the usefulness of the information provided during
the experimental period. Others underlined the needfor climate information covering the period up to two
weeks ahead. The results of the survey indicated that theexperimental provision was fruitful, in that it highlighted
agricultural users’ need for longer-range forecasts in theTohoku region and clarified that the provision of tailored
climate information offers potential benefits to farmers.
These findings were an important outcome of the pilot
project. However, as no extremely cold conditions wereseen during the experimental period in 2011, it is prema-

Seven-day mean temperature (T7d) prediction at a 1 km resolution in the Tohoku region of Japan(a) Climatological normal of T7d at(b) Mean value of predicted regional-scale(c) Mean value of predicted T7d at a 1 kma 1 km resolution

T7d anomalies

resolution (= (a) + (b))

Source: JMA[ 133 ]

Disaster Risk Reduction

ture to conclude the effectiveness of the new climate information
services and identify possible related problems. JMA and NARO/TARC
will continue to supply the new information on a trial basis in summer2012 towards its operational provision in the near future.
Success factors
The pilot project was successful both for JMA and for NARO/TARC.
In particular, JMA gained significant expertise on developing betterclimate information services. Some keys to the initiative’s successand lessons learnt from it are summarized below:• It is critical for climate information users and providers toengage in close and productive dialogue and to share knowledge
due to the nature and difficulty of climate prediction andinformation. JMA and NARO/TARC frequently shared relevant
information both by e-mail and at face-to-face meetings, which
supported the success of the project.
• Intermediaries linking providers and end users of climate
information are very important in promoting its use. In the pilot
project, NARO/TARC and its researchers acted as intermediaries
between JMA and end users in the agricultural sector.
• Effective use of existing systems, as well as support from partners,
contributes to the smooth and successful launch of new services.
In the project, experimental provision of the new information waseffectively carried out using existing systems operated by NARO/
TARC in collaboration with the IPU, which offered useful support
as it specializes in information technology. Making the most of its
experience to implement the pilot project, NARO/TARC took steps toimprove its agro-meteorology information based on user feedback.
Future plans and expectations
Based on the success of the pilot project with NARO/TARC, JMA held
discussions with NARO (the higher authority of NARO/TARC) with aA map for the experimental provision of temperature
prediction to specific users (in Japanese)

Users can select mean values of the seven-day mean temperature (T7d) and thepredicted probability of T7d values at or below (above) 20 (27)° C at a 1 km resolution
for the period from one to two weeks ahead of 27 July, 2011, on the website
Source: JMA[ 134 ]

view to efficiently expanding such collaboration to initiate similar projects in other regions. Currently, JMA isinvolved in four pilot projects in conjunction with four
regional agricultural research centres under NARO. In
addition, recognizing the effectiveness of tailored climate
information in the agricultural sector, JMA has begun
discussions with Japan’s Ministry of Agriculture, Forestry
and Fisheries (which oversees and connects all stakeholders in the agricultural sector, including those within
local governments) to develop better partnerships withthe sector and promote further development and effective
use of climate information services beneficial to various
agricultural activities.
JMA is further seeking opportunities to collaborate withoperators in other fields, including the energy sector, inorder to provide greater levels of usefulness and tailoringin its climate information services. Such collaboration isexpected to promote efficient climate information servicesthat are beneficial in a variety of socioeconomic activities.

Temperature prediction at a 1 km resolution
T7d prediction at a 1 km resolution was made based on
a combination of two data sets: NARO/TARC provided
climatological normals of T7d at a 1 km resolution
covering the 30-year period from 1981 to 2010, while
JMA provided PDF prediction data for regional-scale
T7d anomalies for the Sea of Japan side and the Pacific
Ocean side of the Tohoku region.
The climatological normals of T7d in more than
70,000 1 km grids in the Tohoku region were calculatedfrom historical records of daily mean temperatures(T1d), which were statistically estimated using surface
observation data of T1d and geographical information ata 1 km resolution. These observation data were obtained
from a network of automated weather stations operated
by JMA, known as the Automated Meteorological Data
Acquisition System (AMeDAS).
JMA provided predicted PDFs of regional-scale T7d
anomalies that are made twice a week for EWIEW. The
PDFs were calculated using both numerical prediction
data from JMA’s operational one-month Ensemble
Prediction System (EPS) and regression coefficients
estimated from hindcast experiments (re-forecasts)
for 1981-2010, which were carried out with the same
system as that in operational use. To calculate thepredicted PDFs of T7d at a 1 km resolution with respect
to actual temperatures (rather than in three operational
categories), two steps must be completed: statistical
downscaling for predicted PDFs of T7d anomalies from a
regional scale to a 1 km resolution, and addition of thePDFs to the climatological normal.
When the predicted PDFs were changed from a regional
scale to a 1 km resolution, the mean values wereassumed to be uniform and equal to that in each region.
However, PDF variances are thought to differ for each 1km grid even in the same region. Accordingly, differencesin variances caused by the different spatial scale were
estimated using historical records of temperature at
a 1 km resolution provided by NARO/TARC. Based on
this estimation, PDFs of the T7d anomaly at a 1 km
resolution were calculated from the regional-scalevalues. After this process, the PDFs were added to theclimatological normals for each 1 km grid so that users
could use the PDFs in view of actual temperatures rather
than anomalies. This facilitated user understanding andsupported use in decision-making.