Thermal Emission Spectra of the Earth and Atmosphere from the Nimbus 4 Michelson Interferometer Experiment

Nature ◽  
1970 ◽  
Vol 228 (5267) ◽  
pp. 143-145 ◽  
Author(s):  
R. A. HANEL ◽  
B. J. CONRATH
Keyword(s):  
Thermal Emission ◽  
Michelson Interferometer ◽  
Emission Spectra ◽  
The Earth

scholarly journals Global carbonyl sulfide (OCS) measured by MIPAS/Envisat during 2002–2012

2016 ◽  
Author(s):  
Norbert Glatthor ◽  
Michael Höpfner ◽  
Adrian Leyser ◽  
Gabriele P. Stiller ◽  
Thomas von Clarmann ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Michelson Interferometer ◽  
Austral Summer ◽  
Emission Spectra ◽  
Set Covering ◽  
Boreal Summer ◽  
Systematic Bias ◽  
High Latitudes ◽  
Data Set ◽  
The Tropics

Abstract. We present a global OCS data set covering the period June 2002 to April 2012, derived from FTIR limb emission spectra measured with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the ENVISAT satellite. The vertical resolution is 4–5 km in the height region 6–15 km and 15 km at 40 km altitude. The total estimated error amounts to 40–50 pptv between 10 and 20 km and to 120 pptv at 40 km altitude. MIPAS OCS data show no systematic bias with respect to balloon observations, with deviations mostly below ±50 pptv. However, they are systematically higher than the OCS volume mixing ratios of the ACE-FTS instrument on SCISAT, with maximum deviations of up to 100 pptv in the altitude region 13–16 km. The data set of MIPAS OCS exhibits only moderate interannual variations and low interhemispheric differences. Average concentrations at 10 km altitude range from 480 pptv at high latitudes to 500–510 pptv in the tropics and at northern mid-latitudes. Seasonal variations at 10 km altitude amount up to 35 pptv in the northern and up to 15 pptv in the southern hemisphere. Northern hemispheric OCS abundances at 10 km altitude peak in June in the tropics and around October at high latitudes, while the respective southern hemispheric maxima were observed in July and in November. Global OCS distributions at 250 hPa (~ 10–11 km) show enhanced values at low latitudes, peaking during boreal summer above the western Pacific and the Indian Ocean, which indicates oceanic release. Further, a region of depleted OCS amounts extending from Brazil to central and southern Africa was detected at this altitude, which is most pronounced in austral summer. This depletion is related to seasonally varying vegetative uptake by the tropical forests. Typical signatures of biomass burning like the southern hemispheric biomass burning plume are not visible in MIPAS data, indicating that this process is only a minor source of tropospheric OCS. At the 150 hPa level (~ 13–14 km) enhanced amounts of OCS were also observed inside the Asian Monsoon Anticyclone, but this enhancement is not especially outstanding as compared to other low latitude regions at the same altitude. At the 80 hPa level (~ 17–18 km) equatorward transport of mid-latitude air masses containing lower OCS amounts around the summertime anticyclones was observed. A significant trend could not be detected in tropospheric MIPAS OCS amounts, which points to globally balanced sources and sinks.

scholarly journals Impact of temperature field inhomogeneities on the retrieval of atmospheric species from MIPAS IR limb emission spectra

2010 ◽  
Vol 3 (5) ◽  
pp. 1487-1507 ◽  
Author(s):  
M. Kiefer ◽  
E. Arnone ◽  
A. Dudhia ◽  
M. Carlotti ◽  
E. Castelli ◽  
...  
Keyword(s):  
Temperature Field ◽  
Temperature Gradient ◽  
Michelson Interferometer ◽  
Emission Spectra ◽  
Monthly Means ◽  
Atmospheric Species ◽  
Mixing Ratios ◽  
Observation Strategy ◽  
Ch4 And N2o ◽  
Relative Differences

Abstract. We examine volume mixing ratios (vmr) retrieved from limb emission spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board Envisat. In level 2 (L2) data products of three different retrieval processors, which perform one dimensional (1-D) retrievals, we find significant differences between species' profiles from ascending and descending orbit parts. The relative differences vary systematically with time of the year, latitude, and altitude. In the lower stratosphere their monthly means can reach maxima of 20% for CFC-11, CFC-12, HNO3, H2O, 10% for CH4 and N2O. Relative differences between monthly means of 1-D retrieval results and of the true atmospheric state can be expected to reach half of these percentage values, while relative differences in single vmr profiles might well exceed those numbers. Often there are no physical or chemical reasons for these differences, so they are an indicator for a problem in the data processing. The differences are generally largest at locations where the meridional temperature gradient of the atmosphere is strong. On the contrary, when performing the retrieval with a tomographic two dimensional (2-D) retrieval, L2 products generally do not show these differences. This suggests that inhomogeneities in the temperature field, and possibly in the species' fields, which are accounted for in the 2-D algorithm and not in standard 1-D processors, may cause significant deviations in the results. Inclusion of an externally given adequate temperature gradient in the forward model of a 1-D processor helps to reduce the observed differences. However, only the full tomographic 2-D approach is suitable to resolve the horizontal inhomogeneities. Implications for the use of the 1-D data, e.g. for validation, are discussed. The dependence of the ascending/descending differences on the observation strategy suggests that this problem may affect 1-D retrievals of infrared limb sounders, if the line of sight of the instrument has a significant component in the direction of the horizontal temperature variation.

scholarly journals Analysis of new species retrieved from MIPAS

2014 ◽  
Vol 56 ◽  
Author(s):  
Shaomin Cai ◽  
Anu Dudhia
Keyword(s):  
Fourier Transform ◽  
New Species ◽  
High Resolution ◽  
Trace Gases ◽  
Michelson Interferometer ◽  
Emission Spectra ◽  
Fourier Transform Spectrometer ◽  
Mid Infrared ◽  
The Third ◽  
Atmospheric Sounding

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument which operated on the Envisat satellite from 2002-2012 is a Fourier transform spectrometer for the measurement of high-resolution gaseous emission spectra at the Earth's limb. It operates in the near- to mid-infrared, where many of the main atmospheric trace gases have important emission features. The initial operational products were profiles of Temperature, H2O, O3, CH4, N2O, HNO3, and NO2, and this list was recently extended to include N2O5, ClONO2, CFC-11 and CFC-12. Here we present preliminary results of retrievals of the third set of species under consideration for inclusion in the operational processor: HCN, CF4, HCFC-22, COF2 and CCl4.

scholarly journals The horizontal resolution of MIPAS

2008 ◽  
Vol 1 (1) ◽  
pp. 103-125 ◽  
Author(s):  
T. von Clarmann ◽  
C. De Clercq ◽  
M. Ridolfi ◽  
M. Höpfner ◽  
J.-C. Lambert
Keyword(s):  
Michelson Interferometer ◽  
Elevation Angle ◽  
Emission Spectra ◽  
Horizontal Resolution ◽  
Atmospheric Composition ◽  
Trace Gas ◽  
Atmospheric Conditions ◽  
Tangent Point ◽  
High Vertical Resolution ◽  
Along Track

Abstract. Limb remote sensing from space provides atmospheric composition measurements at high vertical resolution while the information is smeared in the horizontal domain. The horizontal components of two-dimensional (altitude and along-track coordinate) averaging kernels of a limb retrieval constrained to horizontal homogeneity can be used to estimate the horizontal resolution of limb retrievals. This is useful for comparisons of measured data with modeled data, to construct horizontal observation operators in data assimilation applications or when measurements of different horizontal resolution are intercompared. We present these averaging kernels for retrievals of temperature, H2O, O3, CH4, N2O, HNO3 and NO2 from MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) high-resolution limb emission spectra. The horizontal smearing of a MIPAS retrieval in terms of full width at half maximum of the rows of the horizontal averaging kernel matrix varies typically between about 200 and 350 km for most species, altitudes and atmospheric conditions. The range where 95% of the information originates from varies from about 260 to 440 km for these cases. This information spread is smaller than the MIPAS horizontal sampling, i.e. MIPAS data are horizontally undersampled, and the effective horizontal resolution is driven by the sampling rather than the smearing. The point where the majority of the information originates from is displaced from the tangent point towards the satellite by typically less than 10 km for trace gas profiles and about 50 to 100 km for temperature, with a few exceptions for uppermost altitudes. The geolocation of a MIPAS profile is defined as the tangent point of the middle line of sight in a MIPAS limb scan. The majority of the information displacement with respect to this nominal geolocation of the measurement is caused by the satellite movement and the geometrical displacement of the actual tangent point as a function of the elevation angle. In none of the cases investigated, propagation of the horizontal smoothing on the vertical profile shape has been observed.

scholarly journals Features of the Earth surface deformations in the Kamchatka peninsula and their relation to geoacoustic emission

Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 1293-1300 ◽  
Author(s):  
I. A. Larionov ◽  
Y. V. Marapulets ◽  
B. M. Shevtsov
Keyword(s):  
Michelson Interferometer ◽  
Kamchatka Peninsula ◽  
Frequency Range ◽  
Near Surface ◽  
Geoacoustic Emission ◽  
Direction Change ◽  
The Earth ◽  
Deformation Processes ◽  
Rock Deformations ◽  
Artificial Water

Abstract. The paper presents the results of investigations of deformation processes in the near-surface sedimentary rocks, which have been carried out in a seismically active region of the Kamchatka peninsula since 2007. The peculiarity of the experiments on registration of geodeformations is the application of a laser strainmeter–interferometer constructed according to the Michelson interferometer scheme. Besides rock deformations, geoacoustic emission in the frequency range from several hertz to the first tens of kilohertz is under investigation. Piezoceramic hydrophones installed in artificial water reservoirs are applied. It is shown that periods of primary rock compression and tension with a duration of up to several months are distinguished in the geodeformation process at the observation site. During the direction change in the deformations, when the geodeformation process rate grows, an increase in geoacoustic radiation is observed.

scholarly journals Results from the Infrared Spectroscopy Experiment on Mariner 9

1974 ◽  
Vol 65 ◽  
pp. 293-294 ◽  
Author(s):  
J. Pearl ◽  
B. Conrath ◽  
R. Curran ◽  
R. Hanel ◽  
V. Kunde ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Spectral Range ◽  
Spectral Resolution ◽  
Thermal Emission ◽  
Emission Spectra ◽  
Spatial Coverage ◽  
Spectroscopy Experiment ◽  
Mariner 9

Over 20000 thermal emission spectra of Mars have been obtained, providing extensive diurnal, seasonal and spatial coverage of the planet. Each spectrum covers the spectral range from 200 to 2000 cm−1 with an apodized spectral resolution of 2.4 cm−1; the noise equivalent radiance of the instrument is 0.5 × 10−7 W cm−2 sr−1 (cm−1)−1.

Infrared Emission Spectra of Indium Phosphide at Elevated Temperatures

1997 ◽  
Vol 502 ◽  
Author(s):  
H. Rogne ◽  
P. J. Timans ◽  
H. Ahmed
Keyword(s):  
Elevated Temperatures ◽  
Semiconductor Device ◽  
Thermal Emission ◽  
Emission Spectra ◽  
Infrared Emission ◽  
Device Fabrication ◽  
Optical Measurements ◽  
Optical Data ◽  
Monitoring And Control ◽  
Process Monitoring And Control

ABSTRACTProcess monitoring and control during semiconductor device fabrication frequently relies on good knowledge of the optical properties of the substrate wafer and the surface coatings. However, these optical data are often unavailable, and as a consequence errors arise in pyrometric temperature measurements, as well as in thermal modelling of heating cycles. In this study, isothermal electron beam heating has been combined with in situ optical measurements to record thermal emission spectra of undoped InP specimens from 347 to 478°C, at wavelengths between I and 9 μm. The absorption coefficient was deduced from the emission spectra and reveals information about the temperature dependence of the infrared absorption mechanisms in InP.

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