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See detailThe Sun-earth Imbalance radiometer for a direct measurement of the net heating of the Earth
Dewitte, S; Chevalier, A; Meftah, M et al

Conference (2012)

Although it is generally accepted that the climate on earth is changing due to a radiative energy imbalance at the top of the atmosphere, up to now this radiation imbalance has not been measured directly ... [more ▼]

Although it is generally accepted that the climate on earth is changing due to a radiative energy imbalance at the top of the atmosphere, up to now this radiation imbalance has not been measured directly. The measurement is challenging both in terms of space-time sampling of the radiative energy that is leaving the earth and in terms of accuracy. The incoming solar radiation and the outgoing terrestrial radiation are of nearly equal magnitude – of the order of 340 W/m² – resulting in a much smaller difference or imbalance of the order of 1 W/m². The only way to measure the imbalance with sufficient accuracy is to measure both the incoming solar and the outgoing terrestrial radiation with the same instrument. By reanalyzing data from the NASA LARC Earth Radiation Budget Experiment, we have been able to demonstrate that the sampling problem can be overcome, even with the low resolution Wide Field of View radiometer. We have combined the measurements of the precessing ERBS satellite for midlatitude and equatorial regions with measurements of the sun synchronuous NOAA9 satellite for the polar regions. For the accuracy requirement an improved instrument design is needed. We propose a new instrument, which we call the Sun-earth IMBAlance (SIMBA) radiometer. It is an improved wide field of view cavity radiometer based on our long experience with the DIARAD type of instrument for the measurement of Total Solar Irradiance. Currently we have two DIARAD instruments in space, on SOHO and on the ISS, and a third one will be launched this year on the Picard microsatellite. In this paper, we will present the ERBE sampling study and the SIMBA instrument and nanosatellite design [less ▲]

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See detailThe DynaMICCS perspective. A mission for a complete and continuous view of the Sun dedicated to magnetism, space weather and space climate
Turck-Chièze, S.; Lamy, P.; Carr, C. et al

in Experimental Astronomy (2009), 23

The DynaMICCS mission is designed to probe and understand the dynamics of crucial regions of the Sun that determine solar variability, including the previously unexplored inner core, the radiative ... [more ▼]

The DynaMICCS mission is designed to probe and understand the dynamics of crucial regions of the Sun that determine solar variability, including the previously unexplored inner core, the radiative/convective zone interface layers, the photosphere/chromosphere layers and the low corona. The mission delivers data and knowledge that no other known mission provides for understanding space weather and space climate and for advancing stellar physics (internal dynamics) and fundamental physics (neutrino properties, atomic physics, gravitational moments...). The science objectives are achieved using Doppler and magnetic measurements of the solar surface, helioseismic and coronographic measurements, solar irradiance at different wavelengths and in-situ measurements of plasma/energetic particles/magnetic fields. The DynaMICCS payload uses an original concept studied by Thalès Alenia Space in the framework of the CNES call for formation flying missions: an external occultation of the solar light is obtained by putting an occulter spacecraft 150 m (or more) in front of a second spacecraft. The occulter spacecraft, a LEO platform of the mini sat class, e.g. PROTEUS, type carries the helioseismic and irradiance instruments and the formation flying technologies. The latter spacecraft of the same type carries a visible and infrared coronagraph for a unique observation of the solar corona and instrumentation for the study of the solar wind and imagers. This mission must guarantee long (one 11-year solar cycle) and continuous observations (duty cycle > 94%) of signals that can be very weak (the gravity mode detection supposes the measurement of velocity smaller than 1 mm/s). This assumes no interruption in observation and very stable thermal conditions. The preferred orbit therefore is the L1 orbit, which fits these requirements very well and is also an attractive environment for the spacecraft due to its low radiation and low perturbation (solar pressure) environment. This mission is secured by instrumental R and D activities during the present and coming years. Some prototypes of different instruments are already built (GOLFNG, SDM) and the performances will be checked before launch on the ground or in space through planned missions of CNES and PROBA ESA missions (PICARD, LYRA, maybe ASPIICS). [less ▲]

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