Estimation of atmospheric water vapour content from direct measurements of radiance in the thermal infrared region

2012 ◽  
Vol 3 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Vicente García-Santos ◽  
Joan Miquel Galve ◽  
Enric Valor ◽  
Vicente Caselles ◽  
César Coll
Keyword(s):  
Water Vapour ◽  
Thermal Infrared ◽  
Infrared Region ◽  
Atmospheric Water ◽  
Water Vapour Content ◽  
Atmospheric Water Vapour ◽  
Direct Measurements

scholarly journals Atmospheric water vapour content over La Silla Paranal Observatory

2009 ◽  
Vol 5 (H15) ◽  
pp. 537-537
Author(s):  
R. Querel ◽  
F. Kerber ◽  
R. Hanuschik ◽  
G. Lo Curto ◽  
D. Naylor ◽  
...  
Keyword(s):  
Real Time ◽  
Water Vapour ◽  
Atmospheric Water ◽  
Water Vapour Content ◽  
Atmospheric Water Vapour ◽  
Infrared Wavelengths ◽  
Long Term Monitoring ◽  
Term Monitoring ◽  
Principle Source

Water vapour is the principle source of opacity at infrared wavelengths in the earth's atmosphere. Measurements of atmospheric water vapour serve two primary purposes when considering operation of an observatory: long-term monitoring of precipital water vapour (PWV) is useful for characterizing potential observatory sites, and real-time monitoring of PWV is useful for optimizing use, in particular for mid-IR observations.

scholarly journals Retrieval of δ<sup>18</sup>O and δD in atmospheric water vapour from ground-based FTIR

2014 ◽  
Vol 7 (1) ◽  
pp. 195-231 ◽  
Author(s):  
N. V. Rokotyan ◽  
V. I. Zakharov ◽  
K. G. Gribanov ◽  
F.-M. Bréon ◽  
J. Jouzel ◽  
...  
Keyword(s):  
Water Vapour ◽  
General Circulation ◽  
Near Infrared ◽  
A Priori ◽  
Circulation Model ◽  
Infrared Region ◽  
Atmospheric Water ◽  
Atmospheric Water Vapour ◽  
Δ18o And Δd ◽  
Atmospheric Transmittance

Abstract. This paper investigates the possibility of retrieving isotopic composition of atmospheric water vapour from high-resolution ground based measurements of atmospheric transmittance spectra in the near-infrared region (4000–11 000 cm−1). Simulated measurements of atmospheric transmittance were analyzed in order to find clear spectral signatures of H218O, HDO and H216O. Appropriate signals of the species of interest were found and also identified in measured spectra recorded by ground-based Fourier transform infrared spectrometer (FTIR) at the Institute of Environmental Physics of Bremen University. A set of H218O, HDO and H216O spectroscopic windows is presented. Theoretical estimations of the retrieval precision indicate that spectra recorded by ground-based FTIR spectrometers can be used to measure the seasonal cycle of δ18O and δD in the atmosphere. Studying the influence of the a priori on retrieval results shows low sensitivity to a priori assumptions. Impact of the uncertainties in spectroscopic line parameters of water isotopologues on precision of the retrieval of δ18O and δD is investigated. Time series of δ18O retrieved from ground-based FTIR spectra are represented for the first time. Comparison with the results of ECHAM5-wiso isotopic general circulation model simulations demonstrates a good agreement for "summer" measurements. Conversely, the comparison of "winter" measurements and modeling result show a discrepancy that demonstrate worse agreement that may be connected with incorrect temperature dependence of spectroscopic parameters.

scholarly journals Atmospheric water vapour and its effect on aerosol Extinction at a coastal station – Visakhapatnam

MAUSAM ◽  
2022 ◽  
Vol 44 (3) ◽  
pp. 243-248
Author(s):  
K. NIRANJAN ◽  
Y. RAMESH BABU
Keyword(s):  
Water Vapour ◽  
Solar Flux ◽  
Radiosonde Data ◽  
Aerosol Extinction ◽  
Atmospheric Water ◽  
Precipitable Water Vapour ◽  
Water Vapour Content ◽  
Coastal Station ◽  
Atmospheric Water Vapour ◽  
Flux Measurements

Integrated atmospheric water vapour content. has been evaluated from the spectral optical depths around the PaT band of water vapour by making directly transmitted solar flux measurements at 800, 935 and 1025 nm. The temporal variation of the total precipitable water vapour shows significant seasonal variation with maximum during~ pre-monsoon and monsoon months and minimum during winter months. The integrated content shows a positive correlation with surface humidity parameters and the correlation is better during monsoon months compared to other seasons. The experimentally derived variations of water vapour are compared with the model variations formulated using radiosonde data. The aerosol extinctions derived from the, multi-spectral solar flux measurements in the visible and near IR regions increase with increasing atmospheric water vapour and this increase shows .a seasonal dependence the surface temperature also seems to affect the, aerosol extinction probably through Its effect on the mixing heights.

scholarly journals Effect of water vapour absorption on hydroxyl temperatures measured from Svalbard

2017 ◽  
Vol 35 (3) ◽  
pp. 481-491 ◽  
Author(s):  
Joshua M. Chadney ◽  
Daniel K. Whiter ◽  
Betty S. Lanchester
Keyword(s):  
Water Vapour ◽  
Atmospheric Water ◽  
Echelle Spectrograph ◽  
Water Vapour Content ◽  
Atmospheric Water Vapour ◽  
Transmission Coefficients ◽  
Hydroxyl Airglow ◽  
Water Vapour Absorption ◽  
Vibrational Bands ◽  
High Throughput Imaging

Abstract. We model absorption by atmospheric water vapour of hydroxyl airglow emission using the HIgh-resolution TRANsmission molecular absorption database (HITRAN2012). Transmission coefficients are provided as a function of water vapour column density for the strongest OH Meinel emission lines in the (8–3), (5–1), (9–4), (8–4), and (6–2) vibrational bands. These coefficients are used to determine precise OH(8–3) rotational temperatures from spectra measured by the High Throughput Imaging Echelle Spectrograph (HiTIES), installed at the Kjell Henriksen Observatory (KHO), Svalbard. The method described in this paper also allows us to estimate atmospheric water vapour content using the HiTIES instrument.

Millimetre Astronomy and Antarctica

1996 ◽  
Vol 13 (2) ◽  
pp. 189-189
Author(s):  
Michael Burton
Keyword(s):  
Water Vapour ◽  
Thermal Emission ◽  
Spectral Features ◽  
Atmospheric Water ◽  
Water Vapour Content ◽  
Atmospheric Water Vapour ◽  
Dense Molecular Cloud ◽  
Molecular Lines ◽  
Days Open ◽  
The Antarctic

The thermal emission from a cold, dense molecular cloud peaks in the far IR, and the spectrum is rich in molecular lines in the submillimetre and millimetre bands. Observation of these bands is hindered, however, by atmospheric water vapour, which absorbs the incoming radiation. Ground-based mm observations from Australia, where the atmospheric water vapour content typically contains ~10 mm precipitable (ppt) H2O, can only probe a few of the molecular transitions from the heavier molecules, such as CO, CS, HCO+ and HCN. Sub-mm observations would enable the higher rotational lines from many of these molecules to be studied, and open up other spectral features to scrutiny, such as the lines from hydrides (e.g. CaH, NH, SH) and neutral carbon at 370 and 610 μm. However, they cannot be made from Australia. While sites such as Mauna Kea, which has ~1 mm ppt H2O on the best days, open the sub-mm band to partial viewing, their utility is limited in comparison to the opportunities possible from the Antarctic Plateau. Here the column of H2O drops to 100–250 μm.

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