ACRIMSAT
The Active Cavity Radiometer Irradiance Monitor Satellite ( ACRIMSat ) A started on 20 December 1999 research satellite of the U.S. air and space agency NASA, which examined the energy radiation of the sun and its effect on the Earth's climate.
ACRIMSat was part of the Earth Observing System (EOS ), a comprehensive number of missions, long-term research program of NASA.
- 3.1 The Active Cavity Radiometer Irradiance Monitor
Information on the orbit
The satellite moves in a polar, sun-synchronous orbit (SSO). This type of orbit has the advantage that the satellite never enters the Earth's shadow, and can so around the clock to observe the sun.
Mission
From the sun, the center of our solar system, the energy goes out, which can occur on the earth winds, ensures currents in the seas, heats the land and therefore is responsible for the global weather.
Scientists who deal with global climate change, are of the opinion that only small fluctuations during some decades in the energy radiation of the sun, and Total Solar Irradiance (TSI ) called, played a role in climate change could. By measuring the total amount of energy from the sun reaches the earth and enters the Earth's atmosphere, are better models of the climate system of our planet are possible, which are an important piece in the puzzle of global climate change.
ACRIMSats task is for five years to monitor the energy radiation of the sun and thus continue the recovery of data after two previous missions with the same instrument.
Fluctuations in the energy dissipation
With the first version of the instrument ACRIM, ACRIM -I, aboard the research satellite Solar Maximum Mission ( SMM) in 1980, it was clearly proved that the energy radiation of the sun is not constant, and stir the fluctuations of magnetic activity in the sun. However, these fluctuations are so small ( less than 0.00425 percent of the total energy of a year, on time scales of days each ) that were powerful instruments for continuous monitoring needed to obtain correct data.
There are theories that up to 25 percent of the global warming of the 20th century are due to those fluctuations in the energy output of the sun. Already fluctuations in the size range of 0.25 percent in a century could cause significant climate changes. For example, climate scientists believe that the Little Ice Age that struck in the 17th century Europe and North America, may be associated with the ruling at the same time minimum in the solar activity (see Maunder Minimum ).
The significance of these data in climate studies
The knowledge acquired over time data on the energy radiation of the sun can be involved in the creation of global climate models to increase their accuracy. In order to develop climate models, data from two separate measurements are required:
- The total amount of solar energy that reaches the earth; consisting of the visible light (approx. 85%), ultraviolet ( about 10 %), and near-infrared wavelengths ( about 5%)
- The amount of energy which is reflected back into space from the ground and is therefore not part of the energy system of the earth
The first measurement is carried out by the instrument ACRIM III aboard ACRIMSat while other satellite NASA are responsible for the second measurement. The difference between the energy which reaches the earth, and that which is reflected back into the space, resulting in the amount of energy on the earth is responsible for the processes in the environment. Combined with measurements of ocean currents, winds and surface temperatures, climate models can be created, which can make statements about the future of the terrestrial climate.
The satellite
The satellite is a total of 115 kilograms and was developed by Orbital Sciences Corporation ( OSC), developed and manufactured in Dulles ( Virginia).
The Active Cavity Radiometer Irradiance Monitor
The analyzing the radiation of energy is performed by the Active Cavity Radiometer Irradiance Monitor ( ACRIM ), a powerful instrument that the third time is already used in the observation of our central star. It is developed and manufactured by the Jet Propulsion Laboratory (JPL ), a division of the California Institute of Technology (Caltech ) for NASA. The instrument is capable of measuring electromagnetic waves with wavelengths of between 200 nm and 2 microns. This includes both the visible light and ultraviolet and infrared radiation.