Simulation study for the Stratospheric Inferred Winds (SIW) sub-millimeter limb sounder

Baron, Philippe; Murtagh, Donal; Eriksson, Patrick; Mendrok, Jana; Ochiai, Satoshi; Pérot, Kristell; Sagawa, Hideo

doi:10.5194/amt-11-4545-2018

Cited by 18 publications

(16 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Zeeman model is only used within a bandwidth of 200 MHz encompassing the O 2 line (upper sideband). Outside this range, the non polarized radiative transfer 10 model described in Baron et al (2018) is used. In order to transform the Stokes vector (Eq.…”

Section: Measured Radiancementioning

confidence: 99%

“…1), allowing us to derive the 2D horizontal winds. The same method will be used for SIW and more information is given in Baron et al (2018). The limb geometry provides a high vertical resolution of 2-3 km, and the zonal and meridional samplings at the equator are about 20 • (2200 km) and 6 • (650 km), respectively.…”

mentioning

confidence: 99%

“…The band at 638 GHz contains a strong stratospheric and lower mesospheric signal from ozone (O 3 ). This band is the same as that selected for SIW and its main characteristics are described in Baron et al (2018). Two THz bands are measured alternatively, one contains OH lines and the second one an O line (Ochiai et al, 2017;Suzuki et al, 2019).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Potential for the measurement of MLT wind, temperature, density and geomagnetic field with Superconducting Submillimeter-Wave Limb-Emission Sounder-2 (SMILES-2)

Baron

Ochiai

Dupuy

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. Submillimeter-Wave Limb-Emission Sounder-2 (SMILES-2) is a satellite mission proposed in Japan to probe the middle and upper-atmosphere (20–160 km). The main instrument is composed of 4-K cooled radiometers operating near 0.7 and 2 THz. It could measure the diurnal changes of the horizontal wind above 30 km, temperature above 20 km, ground-state atomic oxygen above 90 km, atmospheric density near the mesopause, as well as abundance of about 15 chemical species. In this study we have conducted simulations to assess the wind, temperature and density retrieval performance in the mesosphere and lower thermosphere (60–110 km) using the radiometer at 760 GHz. It contains lines of water vapor (H2O), molecular oxygen (O2) and nitric oxide (NO) that are the strongest signals measured with SMILES-2 at these altitudes. The Zeeman effect on the O2 line due to the geomagnetic field (B) is considered, otherwise, the retrieval errors would be underestimated by a factor of 2 above 90 km. The optimal configuration for the radiometer’s polarization is found to be vertical linear. The line-of-sight wind is retrieved with a precision of 2–5 m/s up to 90 km (30 m/s at 110 km) and a vertical resolution of 2.5 km. Temperature and atmospheric density are retrieved with a precision better than 5 K (30 K) and 7 % (20 %) up to 90 km (110 km), respectively. Errors induced by uncertainties on the vector B are mitigated by retrieving it. The retrieval of B is described as a side-product of the mission. At high-latitudes, precisions of 30–100 nT on the vertical component and 100–300 nT on the horizontal one could be obtained at 85 and 105 km (vertical resolution of 20 km). SMILES-2 could therefore provide the first measurements of B close to the electrojets' altitude, and the precision is enough to measure variations induced by solar storms in the auroral regions.

show abstract

Section: Measured Radiancementioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Potential for the measurement of MLT wind, temperature, density and geomagnetic field with Superconducting Submillimeter-Wave Limb-Emission Sounder-2 (SMILES-2)

Baron

Ochiai

Dupuy

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Stratospheric inferential wind (SIW) is a small submillimeter wave limb sounder developed in Sweden, which is mainly used to measure wind, temperature, and trace gases in the stratosphere. Its superheterodyne radiometer works with a DSB receiver, with the system noise of 1000-1200 K. The bandwidth of the backend autocorrelation spectrometer of SIW is 8 GHz, and the spectrum resolution is 1 MHz [24].…”

Section: Introductionmentioning

confidence: 99%

Simulation of the Spectrum Response for the THz Atmosphere Limb Sounder (TALIS)

Duan

Wang

et al. 2020

Sensors

View full text Add to dashboard Cite

The THz atmospheric limb sounder (TALIS) is a microwave radiometer developed by the National Space Science Center of the Chinese Academy of Sciences for the detection of atmospheric trace gases. The observation range of the instrument mainly focuses on the middle and upper atmosphere (10–100 km above the earth’s surface). The detection targets include the temperature, pressure, and more than 10 kinds of atmospheric components. Its scientific goal is to improve our comprehension of atmospheric chemical composition and dynamics, and to monitor environmental pollution and sources in the atmosphere. The TALIS instrument is composed of an antenna, superheterodyne radiometers, and digital fast Fourier transform (FFT) spectrometers. By measuring the atmospheric thermal radiance in the wide frequency band with 118, 190, 240, and 643 GHz as the center frequency, the required volume mixing ratio (VMR) of atmospheric chemical species can be obtained. This paper introduces the characteristics of the TALIS instrument, and establishes a simulation model for the TALIS spectrometer. Through a joint simulation with an atmosphere radiative transfer simulator (ARTS), the TALIS instrument performance is evaluated from the aspects of calibration, the imbalance of two sidebands, the spectrum resolution, and quantization. The simulation results show that the two-point calibration can well-restore the radiance spectrum of the scene target and remove the influence of the spectral response function (SRF); the double side band (DSB) receiver with a 2 MHz resolution can meet the sensitivity and spectrum resolution requirements. Finally, the sensitivity errors of different quantization bits are given by the simulation and the results show that at 8-bit, the sensitivity and its degradation ratio are 1.251 K and 1.036 at a 2 MHz spectrum resolution and 100 ms integration time, respectively.

show abstract

“…Stratospheric Inferred Winds (SIW) is a Swedish mini sub-millimetre limb sounder for measuring wind, temperature, and molecules in the stratosphere. It can provide horizontal wind vectors within 30-90 km, as well as the profiles of temperature, O 3 , H 2 O and other abundant chemical species (Baron et al, 2018).…”

mentioning

confidence: 99%

Performance Evaluation of THz Atmospheric Limb Sounder (TALIS) of China

Wang¹,

Wang²,

Duan³

2019

Preprint

View full text Add to dashboard Cite

THz Atmospheric Limb Sounder (TALIS) is a microwave limb sounder being developed for atmospheric high precision observation by the National Space Science Center, Chinese Academy of Sciences (NSSC, CAS). It is designed to measure the temperature and chemical species such as O 3 , HCl, ClO, N 2 O, NO, NO 2 , HOCl, H 2 O, HNO 3 , HCN, CO, SO 2 , 10 BrO, HO 2 , H 2 CO, CH 3 Cl, CH 3 OH, and CH 3 CN with high vertical resolution from surface to about 100 km to improve our comprehension of atmospheric chemistry and dynamics, and to monitor the man-made pollution in the atmosphere. Four heterodyne radiometers including several FFT spectrometers of 2 GHz bandwidth with 2 MHz resolution are employed to obtain the atmospheric thermal emission in broad spectral regions centred near 118, 190, 240, and 643 GHz. A theoretical simulation is performed to estimate the retrieval precision of the main targets. Single scan measurement and averaged 15 measurement are considered in simulation, respectively. Temperature profile can be obtained with the precision of < 2K for a single scan from 15 to 85 km by using 118 GHz radiometer, and the 240 and 643 GHz radiometer can provide temperature information in the upper troposphere. Chemical species such as H 2 O, O 3 , HCl, N 2 O, and HNO 3 show high single scan retrieval precision of 1-50% at most altitudes. The other species should be retrieved by using averaged measurements because of the weak intensity or low abundance. 20 IntroductionHigh precision observation of the Earth's atmosphere is essential to the numerical weather prediction and climate change studies. The satellite can provide global coverage atmospheric monitoring in a short time. Instruments such as nadir microwave sounder and infrared sounder have been applied to measure the atmospheric temperature and humidity but with the poor vertical resolution and altitude range (Swadley et al., 2008). Terahertz limb sounder can not only provide the 25 temperature profile with better vertical resolution but gather information on chemical composition in a wide altitude range and independent of the day-night cycle. Microwave limb sounding is a particularly useful technique in detecting stratospheric and mesospheric temperature and chemistry, and also has large potential for global wind measurement in the middle and upper atmosphere (Ochiai et al., 2017). Bands selectionThe spectral bands of TALIS are selected with the following criterions: (1) maximizing the number of species which will exert a strong influence on atmospheric chemistry and dynamics, (2) necessary space between the passband, (3) trade-off between realizable bandwidth and resolution. TALIS covers most spectral bands of EOS MLS and extends them. The broader bandwidth, finer resolution, and lower noise of TALIS can provide higher retrieval precision and effective altitude 15 range compared with EOS MLS. More chemical species can be measured by TALIS, such as NO 2 , NO, H 2 CO, and SO 2 (normal concentration).The 118 GHz radiometer, covering the strong O 2 line at 118.75 GH...

show abstract

Simulation study for the Stratospheric Inferred Winds (SIW) sub-millimeter limb sounder

Cited by 18 publications

References 53 publications

Potential for the measurement of MLT wind, temperature, density and geomagnetic field with Superconducting Submillimeter-Wave Limb-Emission Sounder-2 (SMILES-2)

Potential for the measurement of MLT wind, temperature, density and geomagnetic field with Superconducting Submillimeter-Wave Limb-Emission Sounder-2 (SMILES-2)

Simulation of the Spectrum Response for the THz Atmosphere Limb Sounder (TALIS)

Performance Evaluation of THz Atmospheric Limb Sounder (TALIS) of China

Contact Info

Product

Resources

About