scholarly journals A high-resolution near-infrared extraterrestrial solar spectrum derived from ground-based Fourier transform spectrometer measurements

2013 ◽  
Vol 118 (11) ◽  
pp. 5319-5331 ◽  
Author(s):  
Kaah P. Menang ◽  
Marc D. Coleman ◽  
Tom D. Gardiner ◽  
Igor V. Ptashnik ◽  
Keith P. Shine
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Near Infrared ◽  
Solar Spectrum ◽  
Fourier Transform Spectrometer ◽  
Extraterrestrial Solar Spectrum

scholarly journals Observations of XCO<sub>2</sub> and XCH<sub>4</sub> with ground-based high-resolution FTS at Saga, Japan and comparisons with GOSAT products

2015 ◽  
Vol 8 (8) ◽  
pp. 8257-8294 ◽  
Author(s):  
H. Ohyama ◽  
S. Kawakami ◽  
T. Tanaka ◽  
I. Morino ◽  
O. Uchino ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Greenhouse Gases ◽  
Near Infrared ◽  
Infrared Region ◽  
Fourier Transform Spectrometer ◽  
Solar Absorption ◽  
Average Growth ◽  
Dry Air ◽  
Increasing Trends

Abstract. Solar absorption spectra in the near-infrared region have been continuously acquired with a ground-based (g-b) high-resolution Fourier transform spectrometer (FTS) at Saga, Japan since July 2011. Column-averaged dry-air mole fractions of greenhouse gases were retrieved from the measured spectra for the period from July 2011 to December 2014. Aircraft measurements of CO2 and CH4 for calibrating the g-b FTS data were performed in January 2012 and 2013, and it is found that the g-b FTS and aircraft data agree to within ±0.2 %. The column-averaged dry-air mole fractions of CO2 and CH4 (XCO2 and XCH4) show increasing trends, with average growth rates of 2.3 ppm yr−1 and 9.5 ppb yr−1, respectively, during the ~ 3.5 yr of observation. We compared the g-b FTS XCO2 and XCH4 data with those derived from backscattered solar spectra in the short-wavelength infrared region measured with Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observing SATellite (GOSAT). Average differences between TANSO-FTS and g-b FTS data (TANSO-FTS minus g-b FTS) are 0.40 ± 2.51 ppm and −7.6 ± 13.7 ppb for XCO2 and XCH4, respectively. Using aerosol information measured with a sky radiometer at Saga, we found that the differences between the TANSO-FTS and g-b FTS data are moderately negatively correlated with aerosol optical thickness and do not depend explicitly on aerosol size. In addition, from aerosol profiles measured with lidar located right by the g-b FTS, we were able to show that cirrus clouds and tropospheric aerosols accumulated in the lower layers of the atmosphere tend to overestimate or underestimate the TANSO-FTS data.

scholarly journals Solar observation with the Fourier transform spectrometer I : Preliminary results of the visible and near-infrared solar spectrum

2021 ◽  
Vol 21 (10) ◽  
pp. 267
Author(s):  
Xian-Yong Bai ◽  
Zhi-Yong Zhang ◽  
Zhi-Wei Feng ◽  
Yuan-Yong Deng ◽  
Xing-Ming Bao ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Spectral Resolution ◽  
Near Infrared ◽  
Solar Spectrum ◽  
High Spectral Resolution ◽  
Inversion Method ◽  
Fourier Transform Spectrometer ◽  
Solar Observation ◽  
The Fourier Transform ◽  
Sun Light

Abstract The Fourier transform spectrometer (FTS) is a core instrument for solar observation with high spectral resolution, especially in the infrared. The Infrared System for the Accurate Measurement of Solar Magnetic Field (AIMS), working at 10–13 μm, will use an FTS to observe the solar spectrum. The Bruker IFS-125HR, which meets the spectral resolution requirement of AIMS but simply equips with a point source detector, is employed to carry out preliminary experiment for AIMS. A sun-light feeding experimental system is further developed. Several experiments are taken with them during 2018 and 2019 to observe the solar spectrum in the visible and near infrared wavelength, respectively. We also proposed an inversion method to retrieve the solar spectrum from the observed interferogram and compared it with the standard solar spectrum atlas. Although there is a wavelength limitation due to the present sun-light feeding system, the results in the wavelength band from 0.45–1.0 μm and 1.0–2.2 μm show a good consistency with the solar spectrum atlas, indicating the validity of our observing configuration, the data analysis method and the potential to work in longer wavelength. The work provided valuable experience for the AIMS not only for the operation of an FTS but also for the development of its scientific data processing software.

scholarly journals Observations of XCO<sub>2</sub> and XCH<sub>4</sub> with ground-based high-resolution FTS at Saga, Japan, and comparisons with GOSAT products

2015 ◽  
Vol 8 (12) ◽  
pp. 5263-5276 ◽  
Author(s):  
H. Ohyama ◽  
S. Kawakami ◽  
T. Tanaka ◽  
I. Morino ◽  
O. Uchino ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Greenhouse Gases ◽  
Near Infrared ◽  
Lower Troposphere ◽  
Infrared Region ◽  
Fourier Transform Spectrometer ◽  
Solar Absorption ◽  
Average Growth ◽  
Dry Air

Abstract. Solar absorption spectra in the near-infrared region have been continuously acquired with a ground-based (g-b) high-resolution Fourier transform spectrometer (FTS) at Saga, Japan, since July 2011. Column-averaged dry-air mole fractions of greenhouse gases were retrieved from the measured spectra for the period from July 2011 to December 2014. Aircraft measurements of CO2 and CH4 for calibrating the g-b FTS data were performed in January 2012 and 2013, and it is found that the g-b FTS and aircraft data agree to within ± 0.2 %. The column-averaged dry-air mole fractions of CO2 and CH4 (XCO2 and XCH4) show increasing trends, with average growth rates of 2.3 and 9.5 ppb yr−1, respectively, during the ∼ 3.5 yr of observation. We compared the g-b FTS XCO2 and XCH4 data with those derived from backscattered solar spectra in the short-wavelength infrared (SWIR) region measured with Thermal And Near-infrared Sensor for carbon Observation–Fourier Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observing SATellite (GOSAT): NIES SWIR Level 2 products (versions 02.xx). Average differences between TANSO-FTS and g-b FTS data (TANSO-FTS minus g-b FTS) are 0.40 ± 2.51 and −7.6 ± 13.7 ppb for XCO2 and XCH4, respectively. Using aerosol information measured with a sky radiometer at Saga, we found that the differences between the TANSO-FTS and g-b FTS XCO2 data are moderately negatively correlated with aerosol optical thickness and do not depend explicitly on aerosol size. In addition, from several aerosol profiles measured with lidar located right by the g-b FTS, we were able to show that the presence of cirrus clouds tends to cause an overestimation in the TANSO-FTS XCO2 retrieval, while high aerosol loading in the lower troposphere tends to cause an underestimation.

scholarly journals A Photospheric Solar Iron Abundance from Weak FeII Lines

1988 ◽  
Vol 132 ◽  
pp. 425-427
Author(s):  
U. Pauls ◽  
N. Grevesse ◽  
M. C. E. Huber
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Branching Fractions ◽  
Solar Spectrum ◽  
High Light ◽  
Fourier Transform Spectrometer ◽  
Light Gathering Power ◽  
Iron Abundance ◽  
Light Gathering

The high resolution and the high light-gathering power of a Fourier–transform spectrometer (FTS) afford the observation of very weak lines in laboratory spectra. Thus it became possible to determine an accurate solar iron abundance from Fe II lines that are weak in the solar spectrum: we measured the branching fractions of a few such lines whose upper levels lifetimes are known.

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.

The spectrum of gaseous methane at 77 K in the 1.1 – 2.6 μm region: a benchmark for planetary astronomy

1989 ◽  
Vol 67 (11) ◽  
pp. 1027-1035 ◽  
Author(s):  
A. R. W. McKellar
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Low Temperature ◽  
Spectral Resolution ◽  
Fourier Transform Spectrometer ◽  
Absorption Cell ◽  
Model Calculations ◽  
Testing Model ◽  
Medium Resolution ◽  
Spectrometer Data

The spectrum of CH4 obtained in CH4 plus N2 mixtures at a temperature of 77 K has been recorded with a spectral resolution of 0.14 cm−1 in the region 3800 to 9100 cm−1. The experiments were performed with long paths (66 or 88 m) in a cooled absorption cell using a Fourier-transform spectrometer. Data are presented here at low and medium resolution, and examples of some spectral regions are also shown at high resolution. The complete results are available from the author in an Appendix. Comparisons are made with previous model calculations of CH4 absorption, and with the observed spectrum of Neptune's satellite, Triton. The results should be useful for the interpretation of the spectra of Triton, Titan, and Pluto. They will also be of value for testing model calculations of low-temperature CH4 absorption, which, thus verified, can be used with greater confidence to analyze observations of Jupiter, Saturn Uranus, and Neptune.

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