Japan’s weather forecasting technology continues to improve each year. It relies on land surface observation, supercomputers, and weather satellites in space.
Currently, two geostationary weather satellites (GMS series) are operated by the Japan Meteorological Agency. They support the country’s weather forecasting, tropical cyclone tracking and meteorology research.
Japan has launched a number of meteorological satellites since the 1970s. They have been used for weather monitoring, climate research, and atmospheric analysis. In addition, they have been instrumental in advancing the international exchange of weather data and information through the World Meteorological Organization (WMO).
The GMS series of geostationary meteorological satellites, operated by the Japan Meteorological Agency (JMA), has been in operation since 1977. These satellites are positioned at an altitude of about 36,000 km above the equator and observe a vast area within a 6,000-km radius of the spacecraft.
These satellites also collect information on cloud cover and wind speed, which are useful for short-term weather forecasting. They are capable of producing high-resolution imagery for every 5 to 15 minutes.
In addition, they can produce an animation of clouds. This animation allows the viewer to see how the weather develops and changes throughout the day.
This information is then used by scientists and other experts to make better forecasts of future weather conditions. During extreme weather, such as hurricanes, these satellites can be a lifesaver for people living in the affected areas.
Another useful capability is the ability to map hazard zones in real time. This is done by combining rainfall data with radar observations to create color-coded images that show areas where heavy rain or flooding may occur.
Japanese weather satellites can also be used to monitor volcanic activity in the country and across the Pacific region. They recently relayed images of an eruption on Kuchinoerabu Island in southern Japan, showing light gray smoke drifting southeastward.
One of the most recent satellites, Himawari-8, was launched in October 2014. It is the first geostationary meteorological satellite and orbits at a height of about 36,000 km above the Earth. This makes it possible to record observations in vivid color, which is important for identifying and analyzing weather phenomena.
Himawari 8 will be a critical tool for helping Japan monitor and respond to natural disasters. It will help predict the timing and intensity of a storm’s arrival, as well as its likely severity.
Weather Forecasting Technology
Weather forecasting technology is used for determining when and where to expect heavy rain, typhoons, tornadoes, and other hazards. It is important to know this information to protect people and property. In Japan, this is done through a system called AMeDAS (Automated Meteorological Data Acquisition System). It analyzes rainfall, wind, air temperature, humidity, and other data from more than 1,300 stations around the country. It then creates color-coded images that show areas of risk every 10 minutes.
A new research project uses data from a Japanese weather satellite to improve forecasting and give officials the ability to issue warnings before disasters. Researchers paired data from Himawari-8, which orbits at the same speed as the Earth, with a programme run on a supercomputer.
Infrared radiation from clouds is a key piece of information that helps predict weather patterns in areas where there are no other observations, such as under heavy cloud cover. However, this type of data is rarely available from weather satellites because they can’t reach the lower atmosphere. The project partners have found a way to solve this problem by pairing Himawari-8’s observation data with infrared radiation luminance data from a supercomputer at Riken, a Japanese science institute.
Since ancient times, Japan has been a country that is hit with heavy rain and typhoons, so its ancestors engaged in a variety of efforts to develop technology for forecasting the weather. Today, in Japan, weather forecasters make comprehensive decisions by collecting multiple kinds of observational data and making numerical forecasts using supercomputers or other devices.
Currently, two Japan Meteorological Agency-owned weather satellites–Himawari-8 and Himawari-9–operate in space to observe the weather. These satellites orbit at the same speed as the Earth and continuously monitor typhoons, low pressure systems, and other meteorological phenomena. They also perform a service called Himawari Request for meteorological agencies in other countries, helping them to stay alert and carry out measures against natural disasters at an early stage.
Weather forecasting is an essential component of the disaster management efforts of Japan and the world, allowing for timely action to minimize losses. The Japan Meteorological Agency has conducted many studies to promote better understanding of weather systems and develop technology for forecasting. Its aim is to develop a precise numerical prediction model with high resolution so that it can predict storm and heavy rain associated with typhoons as well as local downpours including linear precipitation zones that cause major disasters, and provide appropriate disaster prevention information.
The Multi-functional Transport Satellite (MTSAT) series is a set of geostationary weather satellites operated by the Japan Meteorological Agency. MTSATs fulfill a meteorological mission and a weather monitoring function for air navigation control in addition to a telecommunications mission.
MTSATs are three-axis stabilized satellites with momentum wheels in the two horizontal axes and reaction wheels in the vertical axis, allowing them to be rotated into different orbits. They are also able to correct for roll, pitch and yaw by changing the rotational speed of any of the wheels.
The satellites are designed to operate for a period of about five years. They are based on SS/L’s standard SSL-1300 spacecraft and use a variety of state-of-the-art technologies developed for the U.S. GOES program, for which SS/L is the prime contractor.
In addition to the imager, MTSATs carry a number of other instruments for weather analysis. These include radiometers, thermometers, and barometers that measure atmospheric pressure and humidity. They also carry a spectrometer that measures solar radiation and ultraviolet radiation.
To acquire images from the Earth, the MTSATs use the Japanese Advanced Meteorological Imager (JAMI). The imager is comprised of a gimballed, two-axis scan mirror that relays the scene to an off axis focal telescope. The focal telescope has a resolving power of 4 km for the infrared channels and 1 km for the visible channel. The imager can produce a full disk scan in about 20 minutes.
Another important instrument on MTSATs is the Land and Sea Surface Temperature Infrared Sensor (LSSIRS). The LSSIRS is designed to observe both the surface of the Earth and the ocean. Its spectral response extends from the thermal infrared to the visible spectrum and it can detect fog at nighttime and measure the temperature of sea surfaces.
A further instrument on MTSATs is the Cloud and Aeolian Dust Observation System (CADOS). This system uses a cloud-resolving sensor, which takes measurements of cloud top height, density, and thickness to help in numerical weather forecasting. It can also be used to monitor volcanic ash and Aeolian dust.
The data from MTSATs are processed to generate products that can be distributed and disseminated to users worldwide. The MTSAT data are processed and analyzed by the Meteorological Satellite Center of the Japan Meteorological Agency. The results are then distributed to international organizations such as the World Meteorological Organization and the Coordination Group for Meteorological Satellites.
Himawari-8 is the latest Japanese satellite weather satellite. It was launched in October 2014 and will be replacing MTSAT-2 as the primary geostationary weather satellite for the Asia-Pacific region until 2029.
Himawari-8 will have 16 spectral bands and will be capable of full disk imagery every 10 minutes, as well as regional images at shorter intervals. It will also have an energetic particle spectrometer (SEDA) that can measure radiation.
AHI (Advanced Himawari Imager) is the primary image sensor on Himawari-8. It is a multipurpose moderate resolution sensor that aims to provide imagery for NWP (Numerical Weather Prediction) utilisation and environment monitoring, as well as wind derivation by tracking clouds and water vapour features.
The Advanced Himawari Imager on Himawari-8 has 16 observation bands in the visible, near-infrared and infrared regions. Its spatial resolution varies between 0.5 km and 2 km depending on the band.
It has the capability to scan the Earth’s surface every ten minutes, and to produce multi-band color images that can be used for vegetation monitoring. These data can be useful for drought monitoring and assessing the impact of heavy rainfall events.
In addition, the Himawari-8 instrument can detect changes in the atmospheric temperature and water vapor pressure that are related to land-atmosphere carbon dioxide budgets. This information can be used to improve model performance and forecasts.
Himawari-8 also has a unique capability to detect thermal variation on the Earth’s surface at a frequency of every ten minutes, which is very useful for detecting land/forest fire hotspot. This paper uses Himawari-8 data to investigate the possibility of detecting such hotspot in Ogan Komering Ilir, South of Sumatra.
Himawari-8 can also be used to monitor the distribution of volcanic ash and aerosols in the atmosphere. This is useful for volcano hazard assessment and climate change research. It also has the ability to observe water vapor in lower-pressure layers, which can help to indirectly gage rainfall.