Envisat

Science/Envisat

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 Envisat
 Data assimilation
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= ASSET members and PAG only

= ASSET members and PAG; others may request access from the coordinators

Artist's impression of Envisat. Picture: ESA

Envisat was launched in March 2002. It carries a suite of instruments, some of which will measure temperature, ozone, water vapour and other chemical species from the troposphere to the thermosphere. ASSET science uses these Envisat instruments:

AATSR is an along-track viewing sounder which is designed to establish continuity with the ATSR-1 and -2 experiments. Among other measurements, it obtains information on boundary layer aerosol. ASSET will assimilate boundary layer aerosols from AATSR.

GOMOS is a stellar occultation sounder which measures temperature, ozone and other chemical species with a vertical resolution of 1.7 km; the vertical range for ozone is from the tropopause to the mesosphere. ASSET will assimilate temperature, ozone, water vapour, NOy and other chemical species from GOMOS.

MERIS is a pushbroom imaging spectrometer that measures the solar radiation reflected by the Earth. Among other measurements, MERIS measures aerosol load over land. ASSET will assimilate aerosol data from MERIS.

MIPAS is a limb sounder which measures temperature, ozone and other chemical species (including water vapour) with a vertical resolution of 3 km; several of these parameters are measured from the upper troposphere to the mesosphere. ASSET will assimilate the MIPAS products provided by ESA (i.e. the standard MIPAS products): temperature, ozone, water vapour, NO2, CH4, N2O and HNO3. To take advantage of the MIPAS spectral range (it is estimated that MIPAS may be able to deliver height-resolved information on about 30 species), ASSET will also assimilate non-standard stratospheric and T/LS MIPAS products.

SCIAMACHY is a limb- and nadir-sounder which measures vertical profile and total column amounts of temperature, ozone and other chemical species (see, e.g., Bovensmann et al. 1999, van der A 2001). SCIAMACHY can also make measurements in occultation sounder mode. The vertical range of the profile measurements extends from the troposphere to the middle atmosphere. ASSET will assimilate temperature, ozone (profiles, total column and radiances), water vapour, NO2 (profiles and/or total column), CH4, CH2O and CO. Some of these species will be assimilated in the troposphere as well as in the stratosphere.