The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends
We use a fifty-year record of wintertime radiosonde observations at the South Pole to estimate the precipitable water vapor column (PWV) over the entire period. Humidity data from older radiosondes is of limited reliability; however, we think an estimation of PWV is possible using temperature data b...
Published in: | Journal of Geophysical Research: Atmospheres |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union
2012
|
Subjects: | |
Online Access: | https://authors.library.caltech.edu/32978/ https://authors.library.caltech.edu/32978/1/Chamberlin2012p19033J_Geophys_Res-Atmos.pdf https://resolver.caltech.edu/CaltechAUTHORS:20120807-103802636 |
id |
ftcaltechauth:oai:authors.library.caltech.edu:32978 |
---|---|
record_format |
openpolar |
spelling |
ftcaltechauth:oai:authors.library.caltech.edu:32978 2023-05-15T18:21:51+02:00 The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends Chamberlin, R. A. Grossman, E. N. 2012-07-07 application/pdf https://authors.library.caltech.edu/32978/ https://authors.library.caltech.edu/32978/1/Chamberlin2012p19033J_Geophys_Res-Atmos.pdf https://resolver.caltech.edu/CaltechAUTHORS:20120807-103802636 en eng American Geophysical Union https://authors.library.caltech.edu/32978/1/Chamberlin2012p19033J_Geophys_Res-Atmos.pdf Chamberlin, R. A. and Grossman, E. N. (2012) The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends. Journal of Geophysical Research D, 117 . Art. No. D13111. ISSN 0148-0227. doi:10.1029/2012JD017792. https://resolver.caltech.edu/CaltechAUTHORS:20120807-103802636 <https://resolver.caltech.edu/CaltechAUTHORS:20120807-103802636> other Article PeerReviewed 2012 ftcaltechauth https://doi.org/10.1029/2012JD017792 2021-11-11T18:50:34Z We use a fifty-year record of wintertime radiosonde observations at the South Pole to estimate the precipitable water vapor column (PWV) over the entire period. Humidity data from older radiosondes is of limited reliability; however, we think an estimation of PWV is possible using temperature data because the wintertime lower troposphere is very close to saturated. From temperature data we derived PWV_SAT which is the PWV if the troposphere was saturated over the entire column. Comparisons to recent radiosonde humidity data indicate that PWV ≃ 0.88PWV_SAT. Since 1998 a CMU/NRAO 860 GHz atmospheric radiometer has been operating at the South Pole producing zenith opacity data, τo. It is expected that τo ∝ PWV, and also τ_o ∝ PWV_SAT, since the lower atmospheric column is near to saturation. We compare trends in τo, PWV_SAT, and PWV. PWV and PWV_SAT showed little trend in the last fifty years, 1961 to 2010, except perhaps in the last two decades, when PWVSAT was below average, followed by an increasing trend to above average. This increasing trend in the last decade was also observed in τo, except for the final two years when it appears that something changed in the instrument response. PWV_SAT is a useful metric for estimating PWV in the earlier years of wintertime South Pole radiosonde, and it is generally useful for evaluating the wintertime performance of radiosonde humidity and atmospheric opacity instrumentation. Article in Journal/Newspaper South pole Caltech Authors (California Institute of Technology) South Pole Journal of Geophysical Research: Atmospheres 117 D13 n/a n/a |
institution |
Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
English |
description |
We use a fifty-year record of wintertime radiosonde observations at the South Pole to estimate the precipitable water vapor column (PWV) over the entire period. Humidity data from older radiosondes is of limited reliability; however, we think an estimation of PWV is possible using temperature data because the wintertime lower troposphere is very close to saturated. From temperature data we derived PWV_SAT which is the PWV if the troposphere was saturated over the entire column. Comparisons to recent radiosonde humidity data indicate that PWV ≃ 0.88PWV_SAT. Since 1998 a CMU/NRAO 860 GHz atmospheric radiometer has been operating at the South Pole producing zenith opacity data, τo. It is expected that τo ∝ PWV, and also τ_o ∝ PWV_SAT, since the lower atmospheric column is near to saturation. We compare trends in τo, PWV_SAT, and PWV. PWV and PWV_SAT showed little trend in the last fifty years, 1961 to 2010, except perhaps in the last two decades, when PWVSAT was below average, followed by an increasing trend to above average. This increasing trend in the last decade was also observed in τo, except for the final two years when it appears that something changed in the instrument response. PWV_SAT is a useful metric for estimating PWV in the earlier years of wintertime South Pole radiosonde, and it is generally useful for evaluating the wintertime performance of radiosonde humidity and atmospheric opacity instrumentation. |
format |
Article in Journal/Newspaper |
author |
Chamberlin, R. A. Grossman, E. N. |
spellingShingle |
Chamberlin, R. A. Grossman, E. N. The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends |
author_facet |
Chamberlin, R. A. Grossman, E. N. |
author_sort |
Chamberlin, R. A. |
title |
The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends |
title_short |
The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends |
title_full |
The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends |
title_fullStr |
The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends |
title_full_unstemmed |
The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends |
title_sort |
wintertime south pole tropospheric water vapor column: comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends |
publisher |
American Geophysical Union |
publishDate |
2012 |
url |
https://authors.library.caltech.edu/32978/ https://authors.library.caltech.edu/32978/1/Chamberlin2012p19033J_Geophys_Res-Atmos.pdf https://resolver.caltech.edu/CaltechAUTHORS:20120807-103802636 |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_relation |
https://authors.library.caltech.edu/32978/1/Chamberlin2012p19033J_Geophys_Res-Atmos.pdf Chamberlin, R. A. and Grossman, E. N. (2012) The wintertime South Pole tropospheric water vapor column: Comparisons of radiosonde and recent terahertz radiometry, use of the saturated column as a proxy measurement, and inference of decadal trends. Journal of Geophysical Research D, 117 . Art. No. D13111. ISSN 0148-0227. doi:10.1029/2012JD017792. https://resolver.caltech.edu/CaltechAUTHORS:20120807-103802636 <https://resolver.caltech.edu/CaltechAUTHORS:20120807-103802636> |
op_rights |
other |
op_doi |
https://doi.org/10.1029/2012JD017792 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
117 |
container_issue |
D13 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1766201183966330880 |