Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)
The Michelson Interferometer for Passive Atmospheric Sounding
is one of the core experiments on ESA's Envisat satellite, launched on 1st
March 2002.
MIPAS measures atmospheric limb emission spectra from 685-2410 cm-1
(14.5 to 4.1um) over a tangent altitude range 6-68 km.
After suitable ground processing, these spectra allow quantification of
concentration profiles of numerous atmospheric trace species. In addition,
atmospheric temperature as well as the distribution of aerosol particles,
tropospheric cirrus, and stratospheric ice clouds (including polar
stratospheric clouds) can also be derived from MIPAS data.
The objectives of MIPAS are:
Measurements of geophysical
parameters in the middle atmosphere; Stratospheric chemistry: O3, H2O, CH4, N2O,NO2,
and HNO3; and Climatology: Temperature, CH4, N2O, O3 ;
Study of chemical composition, dynamics, and
radiation budget of the middle atmosphere;
Monitoring of stratospheric O3 and
CFCs.
As a unique feature of MIPAS, the atmospheric parameters
are determined:
simultaneously as colocated profiles
with complete global coverage
during day- and nighttime conditions (allowing observations of the
diurnal variation of trace species), and
throughout its mission duration.
MIPAS Data: current status and coverage
Jul02-Mar04: FR17
MIPAS operated at full spectral resolution (0.025cm-1)
with a nominal 17 step scan pattern, giving 3km steps in
the lower atmosphere (now known as "FR17" mode).
ESA have processed all these data to L2. Coverage
maps for this period
can be found on "MIPAS ESA
L2 Profile Maps"
Aug04-Sep04: RR17
MIPAS operated at reduced spectral resolution (0.0625cm-1)
but keeping the original scan pattern (3km steps).
ESA have also processed this data to L2.
Jan05-present: RR27
Still at reduced spectral resolution but with a nominal scan pattern
consisting of 27 steps with 1.5km spacing in the lower atmosphere.
In practice, a significant amount of time is also spent in "UTLS1", "MA"
and "UA" modes with different altitude ranges and scan patterns
[List of new Modes].
The instrument originally (2005) operated on a 35% duty cycle but
since Dec 2007 has been operating full-time with a standard 10 day sequence of
8 days nominal mode, 1 day MA, 2 day UA.
ESA routinely process the data up to L1B (ie spectra), available
approximately 2 weeks after acquisition, shown on
"MIPAS L1B Data"
Since Feb08 ESA have also been producing a Near Real Time (NRT) version
of L1B data, available a few hours after acquisition.
ESA have also processed a limited amount of these data to L2, as
shown in the "MIPAS L2
Profile Maps".
MIPAS Mission Planning Documents show the observations that have been
planned:
[2005]
[2006]
[2007]
[2008]
Jul02-Present
The Oxford L2 processor MORSE
is being used to process the complete MIPAS mission (standard
ESA products plus additional molecules), including the NRT L1B data.
See "List of Processed Days" for current product
availability.
