Earth Observation Research Center (EORC)
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Earth Observation Center（EOC)
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Earth Observation and EORC
What is "Earth Observation"?
"Earth Observation" means to observe the surface of the Earth such as land, ocean and atmosphere by using "Earth Observation Satellites" on orbit.
JAXA (the former NASDA) already launched seven "Earth Observation Satellites" including MOS-1, MOS-1b, JERS-1, ADEOS, TRMM, ADEOS-II and ALOS. Out of these satellites, TRMM and ALOS are still in operation and keeps sending observed data everyday. Additionally AMSR-E aboard NASA's Aqua satellite is in operation and keeps sending observed data everyday.
Most "Earth Observation Satellites" observe particular region periodically from the orbit of 400 - 1,000 km altitude, and observe whole the Earth in some days. Each satellite carries many kinds of instrument as the eye to discriminate the surface of the Earth such as vegetation, sea surface temperature, etc.
The weather satellite "Himawari" is one of "Earth Observation Satellites" and keeps watching the Earth from the geo-stationary orbit of about 36,000 km altitude.
Please refer to the page of "about Earth Observation" for more Information.
What do you understand by using "Earth Observation"?
It depends on what kind of instrument (sensor) you use.
If you use visible and near-infrared sensor, you can measure the strength of solar light reflection by some objects on the Earth. By analyzing these data, you can understand land use classification, vegetation coverage, etc.
If you use thermal infrared sensor, you can observe thermal infrared rays radiated by ground, sea surface, clouds, etc., and can understand sea surface temperature, cloud distribution, etc. day and night to utilize them for weather forecasting.
If you use passive microwave sensor that is "microwave radiometer," you can observe microwave radiated by ground surface, sea surface, clouds, etc., you can understand sea surface temperature, precipitation distribution, etc. day and night.
If you use SAR (Synthetic Aperture Radar) out of active microwave sensor, you can understand forest distribution, topography, etc. You can understand sea surface wind direction and velocity by using scatterometer.
Would you tell me the system of weather satellite "Himawari"?
The weather satellite "Himawari" observes the Earth from the geo-stationary orbit about 36,000 km high. It carries three types of sensor. One of them is visible sensor to observe shape and brightness of clouds. The second is thermal infrared sensor to observe temperature of clouds, land and sea. The last is intermediate infrared sensor to observe non-visible water vapor distribution in the atmosphere.
You can derive cloud thickness from cloud brightness observed by visible sensor, and cloud top height from cloud temperature respectively, then you can estimate the kind of cloud based on these data. Also you can estimate upper layer wind direction and velocity from cloud movement every one hour by watching each cloud shape. By combining these data and ground based observed data you can estimate weather distribution and utilize them for weather forecasting.
Which is the highest ground resolution, you can achieve using an Earth Observation Satellite sensors"?
It depends on the object and the region to be observed, and type of sensor to be used onboard "Earth Observation Satellite."
If you use optical type sensor, how to see is affected by the weather such as cloudy or not cloudy.
The ground resolution of PALSAR (Pachromatic Remote-sensing Instrument for Stereo Mapping) aboard ALOS (Advanced Land Observation Satellite) launched by JAXA on January 24, 2006 is 2.5 m. That is you can see 2.5 m size object on the ground. Additionally some private sector's commercial Earth Observation Satellite has the ground resolution of 0.6 m.
What are the roles of Earth Observation Research Center (EORC)?
Is there any contact point for further questions on "Earth Observation"?
Relation to the Global Environment Problems
What is the relation between "Earth Observation" and "the Global Environment Problems"?
Global environmental changes such as the melting of the polar ice sheet due to global warming, the worldwide occurrence of anomalous climate, the enlargement of the ozone hole, the reduction of tropical forests due to deforestation, the progress of desertification, acid rain, and the decrease of wild bio-species are beginning to cause big concern for the future of the planet. Among these phenomena, global warming is the most serious problem
for humankind. IPCC (Inter-governmental Panel for Climate Change) that consists of governmental persons and world prominent scientists, reports that global warming caused by the increase of atmospheric carbon dioxide is actual and ascribed to human activities.
To keep acquiring accurate, long-term, consistent data by using "Earth Observation Satellites" and analyzing them helps us to grasp these anomalous phenomena globally, to understand and predict the global environmental changes.
Would you tell me the problems, the cause and the effects of "Ozone Hole"?
The ozone layer is a thin band in Earth's upper atmosphere. It blocks out the Sun's harmful ultraviolet (UV) rays. If it gets too thin, the harmful UV rays can damage crops, wild animals, and our skin.
We humankinds have damaged the ozone layer with chemicals (called
chlorofluorocarbons or CFCs) that are used in refrigerators and air conditioners.
This has been proved by a long series of measurements from space and on the ground.
It isn't really a "hole", but a large decrease in the total amount of ozone
overhead. It is truly a large decrease over Antarctica in spring of Southern Hemisphere that is around September to October, but there are significant general reductions in ozone elsewhere, including the Northern Hemisphere.
It is predicted that it will be the latter half of 21 century that the ozone layer recovers to the status before ozone hole appeared, there is a need for systematic and sustained observations.
Please see Antarctic ozone hole images etc. observed by ADEOS satellite on the following Pages:
Is "the Global Warming" true?
IPCC (Inter-governmental Panel for Climate Change) that consists of governmental persons and world prominent scientists, estimates in its latest report that the global average surface temperature (the average of near surface air temperature over land, and sea surface temperature) has increased 0.6 +/-0.2 degree C over the 20th century. And the report says that the globally averaged surface temperature is projected to increase by 1.4 to 5.8 degree C over the period 1990 to 2100.
What causes " Global Warming"?
Changes in climate including global warming occur as a result of both internal variability within the climate system and external factors (both natural and anthropogenic).
For example, increasing concentrations of greenhouse gases such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) because of human activities tends to warm the surface by their greenhouse effect.
On the other hand, some types of aerosols (microscopic airborne particles) such as soot generated by fossil fuel (petroleum and coal) and biomass burning tends to cool the surface because they shut out the solar radiation. As natural factor, fumes by volcanic eruption are kinds of aerosols and also tend to cool the surface. IPCC reports that most of the warming observed over the last 50 years is likely to the increase in greenhouse gas concentrations and is attributable to human activities.
Please see a global distribution of carbon monoxide concentration in the troposphere near the surface observed by ADEOS satellite on the following Page:
What is the influence of "the Global Warming"?
IPCC predicts that many kinds influence will emerge accompanying with the global warming as follows:
- It is very likely that nearly all land areas will warm more rapidly than the global average, particularly those at northern high latitudes in the cold season.
- Global average water vapor concentration and precipitation are projected to increase during the 21st century.
- Global warming is likely to lead to greater extremes of drying and heavily rainfall and increase the risk of droughts and floods that occur with El Nino events in many different regions.
- Northern Hemisphere snow cover and sea-ice extent are projected to decrease further.
- Glaciers and ice caps are projected to continue their widespread retreat during the 21st century.
- The Antarctic ice sheet is likely to gain mass because of greater precipitation, while the Greenland ice sheet is likely to lose mass because the increase in runoff will exceed the precipitation increase.
- Global mean sea level is projected to rise. (Please refer to the next item.)
Is the sea level rising? What are the causes and the influences?
IPCC (Inter-governmental Panel for Climate Change) that consists of governmental persons and world prominent scientists, estimates in its latest report that the global average sea level rose between 0.1 and 0.2 meters during the 20th century. And the report says that the global mean sea level is projected to rise by 0.09 to 0.88 meters between 1990 and 2100.
This is due primarily to thermal expansion of seawater accompanying the global warming and increasing of seawater accompanying loss of mass from glaciers and ice caps.
Rising of sea level will make typhoon and high tide more dangerous. Maldives in the Indian Ocean, Tuvalu in the Pacific Ocean, other island countries, Bangladesh, the Netherlands have their most territories near sea level, then it is likely that they will suffer major damage.
In Japan, many people live in low ground in coastal zones and also infrastructure for socio-economical activities is concentrated there, then we are worried the major impact.
Are the ices decreasing in the Arctic and in the Antarctic?
IPCC's latest report says that satellite data show that there are very likely to have been decreases of about 10% in the extent of snow cover since the late 1960s. The report also says as follows:
- There has been a widespread retreat of mountain glaciers in non-polar regions during 20th century.
- Northern Hemisphere spring and summer sea-ice extent has decreased by about 10 to 15% since the 1950s. It is likely that there has been about a 40% decline in Arctic sea-ice thickness during late summer to early autumn in recent decades.
Melting of ice sheet is one of clear indices of how the global warming progresses. Earth observation satellites have observed acute melting of ice in parts of Antarctica.
Please see the Arctic and Antarctic sea ice cover and the status of Shirase Glacier observed by ADEOS and other satellite on the following Page:
What is "El Nino"? What are the causes and the effects?
The "El Nino" is a phenomenon that the sea surface temperature over the middle part to the east part of the tropical Pacific Ocean, including off shore Peru rises on a large scale once a several years.
Originally fishermen in Peru and Ecuador called a phenomenon "El Nino" that the sea surface temperature rises around Christmas once a several years and they could not catch fishes. "El Nino" means "boy" especially Jesus Christ in Spanish. But it has been recognized as a large scale climate change phenomenon keeping more than a half years all over the Pacific Ocean rather than a small scale local event as observation progressed.
Since 1980, El Nino occurred on the spring of 1982 to the summer of 1983, the autumn of 1986 to the winter of 1987/1988, the spring of 1991 to the summer of 1992, the spring to the summer of 1993, the spring of 1997 to the summer of 1998 and the spring of 2002 to the winter of 2002/2003.
On the contrary, when "La Nina" that means "girl" in Spanish and is the phenomenon reverse to El Nino, occurs, sea surface temperature decreases in a large scale over the middle part to the east part of the tropical Pacific Ocean once a several years.
"El Nino" phenomenon occurs as the result of the strong interaction between the atmosphere and the sea. When there is no El Nino, trade winds move surface water west across the tropical Pacific Ocean and warm seawater is gathered to the western tropical Pacific Ocean. Then in the western part up stream of air occurs and the air pressure decreases, and in reverse in the eastern part of the tropical Pacific Ocean where the sea surface temperature is lower, down stream of air occurs and the air pressure increases.
For this reason trade wind blows from east to west on the sea. In this way the atmosphere circulates in the tropical Pacific Ocean. At this time cold water is brought from deep below to the top off shore Peru. The cold water from the ocean floor has food in it that the fish eat, such as plankton and algae.
Now some kind of trigger (Scientists have not yet made this trigger clear) makes this atmospheric circulation and makes trade wind weak, then warm seawater is not gathered so much to the western part of the tropical Pacific Ocean. This status is when "El Nino" happens. At this time, surface seawater off shore Peru warms up and cold water does not rise any more from the deep and fish food is not replaced. Since the fish don't have food to eat, they swim to other oceans where they can find food.
Please see El Nino event observed by ADEOS satellite and TRMM satellite on the following Page:
What are the procedures to utilize JAXA's images and/or data within JAXA/EORC's Home Page?Q3-2
Please tell us about the proceedings of the case to obtain the data.Q3-3
Would you tell me any websites to retrieve any Earth Observation data?
You can retrieve Earth Observation data that is archived at JAXA/EORC by accessing the following web site:
G-Portal URL: http://www.gportal.jaxa.jp/gp/top.html
Some Earth Observation data is stored at "Images & Data" corner of this Home Page.
Would you tell me the launch schedule of Earth Observation Satellites in future?Q4-2
Would you tell me the schedule of conferences and events on Earth Observation in future?
Please see the "NEWS" corner of the top page of this Home Page. We will keep publishing the latest information on the schedule of conferences and events on Earth Observation in future.
Are there any procedures to link to JAXA/EORC's Home Page?Q5-2
What kind of web-browsing software do you recommend to see JAXA/EORC's Home Page?
We recommend the latest version for both of Internet Explorer and Firefox.