VESPA-22: a ground-based microwave spectrometer for long-term measurements of polar stratospheric water vapor
The new ground-based 22 GHz spectrometer, VESPA-22 (water Vapor Emission Spectrometer for Polar Atmosphere at 22 GHz) measures the 22.23 GHz water vapor emission line with a bandwidth of 500 MHz and a frequency resolution of 31 kHz. The integration time for a measurement ranges from 6 to 24 h, depen...
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ftdoajarticles:oai:doaj.org/article:677202d0389c454cb24a22350d8cd95d 2023-05-15T15:18:04+02:00 VESPA-22: a ground-based microwave spectrometer for long-term measurements of polar stratospheric water vapor G. Mevi G. Muscari P. P. Bertagnolio I. Fiorucci G. Pace 2018-02-01T00:00:00Z https://doi.org/10.5194/amt-11-1099-2018 https://doaj.org/article/677202d0389c454cb24a22350d8cd95d EN eng Copernicus Publications https://www.atmos-meas-tech.net/11/1099/2018/amt-11-1099-2018.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-11-1099-2018 1867-1381 1867-8548 https://doaj.org/article/677202d0389c454cb24a22350d8cd95d Atmospheric Measurement Techniques, Vol 11, Pp 1099-1117 (2018) Environmental engineering TA170-171 Earthwork. Foundations TA715-787 article 2018 ftdoajarticles https://doi.org/10.5194/amt-11-1099-2018 2022-12-31T02:29:03Z The new ground-based 22 GHz spectrometer, VESPA-22 (water Vapor Emission Spectrometer for Polar Atmosphere at 22 GHz) measures the 22.23 GHz water vapor emission line with a bandwidth of 500 MHz and a frequency resolution of 31 kHz. The integration time for a measurement ranges from 6 to 24 h, depending on season and weather conditions. Water vapor spectra are collected using the beam-switching technique. VESPA-22 is designed to operate automatically with little maintenance; it employs an uncooled front-end characterized by a receiver temperature of about 180 K and its quasi-optical system presents a full width at half maximum of 3.5°. Every 30 min VESPA-22 measures also the sky opacity using the tipping curve technique. The instrument calibration is performed automatically by a noise diode; the emission temperature of this element is estimated twice an hour by observing alternatively a black body at ambient temperature and the sky at an elevation of 60°. The retrieved profiles obtained inverting 24 h integration spectra present a sensitivity larger than 0.8 from about 25 to 75 km of altitude during winter and from about 30 to 65 km during summer, a vertical resolution from about 12 to 23 km (depending on altitude), and an overall 1 σ uncertainty lower than 7 % up to 60 km altitude and rapidly increasing to 20 % at 75 km. In July 2016, VESPA-22 was installed at the Thule High Arctic Atmospheric Observatory located at Thule Air Base (76.5° N, 68.8° W), Greenland, and it has been operating almost continuously since then. The VESPA-22 water vapor mixing ratio vertical profiles discussed in this work are obtained from 24 h averaged spectra and are compared with version 4.2 of concurrent Aura/Microwave Limb Sounder (MLS) water vapor vertical profiles. In the sensitivity range of VESPA-22 retrievals, the intercomparison from July 2016 to July 2017 between VESPA-22 dataset and Aura/MLS dataset convolved with VESPA-22 averaging kernels shows an average difference within 1.4 % up to 60 km altitude and increasing to about ... Article in Journal/Newspaper Arctic Greenland Thule Air Thule Air Base Thule Directory of Open Access Journals: DOAJ Articles Arctic Greenland New Ground ENVELOPE(-55.215,-55.215,49.567,49.567) Thule Air Base ENVELOPE(-68.703,-68.703,76.531,76.531) Atmospheric Measurement Techniques 11 2 1099 1117 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
spellingShingle |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 G. Mevi G. Muscari P. P. Bertagnolio I. Fiorucci G. Pace VESPA-22: a ground-based microwave spectrometer for long-term measurements of polar stratospheric water vapor |
topic_facet |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
description |
The new ground-based 22 GHz spectrometer, VESPA-22 (water Vapor Emission Spectrometer for Polar Atmosphere at 22 GHz) measures the 22.23 GHz water vapor emission line with a bandwidth of 500 MHz and a frequency resolution of 31 kHz. The integration time for a measurement ranges from 6 to 24 h, depending on season and weather conditions. Water vapor spectra are collected using the beam-switching technique. VESPA-22 is designed to operate automatically with little maintenance; it employs an uncooled front-end characterized by a receiver temperature of about 180 K and its quasi-optical system presents a full width at half maximum of 3.5°. Every 30 min VESPA-22 measures also the sky opacity using the tipping curve technique. The instrument calibration is performed automatically by a noise diode; the emission temperature of this element is estimated twice an hour by observing alternatively a black body at ambient temperature and the sky at an elevation of 60°. The retrieved profiles obtained inverting 24 h integration spectra present a sensitivity larger than 0.8 from about 25 to 75 km of altitude during winter and from about 30 to 65 km during summer, a vertical resolution from about 12 to 23 km (depending on altitude), and an overall 1 σ uncertainty lower than 7 % up to 60 km altitude and rapidly increasing to 20 % at 75 km. In July 2016, VESPA-22 was installed at the Thule High Arctic Atmospheric Observatory located at Thule Air Base (76.5° N, 68.8° W), Greenland, and it has been operating almost continuously since then. The VESPA-22 water vapor mixing ratio vertical profiles discussed in this work are obtained from 24 h averaged spectra and are compared with version 4.2 of concurrent Aura/Microwave Limb Sounder (MLS) water vapor vertical profiles. In the sensitivity range of VESPA-22 retrievals, the intercomparison from July 2016 to July 2017 between VESPA-22 dataset and Aura/MLS dataset convolved with VESPA-22 averaging kernels shows an average difference within 1.4 % up to 60 km altitude and increasing to about ... |
format |
Article in Journal/Newspaper |
author |
G. Mevi G. Muscari P. P. Bertagnolio I. Fiorucci G. Pace |
author_facet |
G. Mevi G. Muscari P. P. Bertagnolio I. Fiorucci G. Pace |
author_sort |
G. Mevi |
title |
VESPA-22: a ground-based microwave spectrometer for long-term measurements of polar stratospheric water vapor |
title_short |
VESPA-22: a ground-based microwave spectrometer for long-term measurements of polar stratospheric water vapor |
title_full |
VESPA-22: a ground-based microwave spectrometer for long-term measurements of polar stratospheric water vapor |
title_fullStr |
VESPA-22: a ground-based microwave spectrometer for long-term measurements of polar stratospheric water vapor |
title_full_unstemmed |
VESPA-22: a ground-based microwave spectrometer for long-term measurements of polar stratospheric water vapor |
title_sort |
vespa-22: a ground-based microwave spectrometer for long-term measurements of polar stratospheric water vapor |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/amt-11-1099-2018 https://doaj.org/article/677202d0389c454cb24a22350d8cd95d |
long_lat |
ENVELOPE(-55.215,-55.215,49.567,49.567) ENVELOPE(-68.703,-68.703,76.531,76.531) |
geographic |
Arctic Greenland New Ground Thule Air Base |
geographic_facet |
Arctic Greenland New Ground Thule Air Base |
genre |
Arctic Greenland Thule Air Thule Air Base Thule |
genre_facet |
Arctic Greenland Thule Air Thule Air Base Thule |
op_source |
Atmospheric Measurement Techniques, Vol 11, Pp 1099-1117 (2018) |
op_relation |
https://www.atmos-meas-tech.net/11/1099/2018/amt-11-1099-2018.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-11-1099-2018 1867-1381 1867-8548 https://doaj.org/article/677202d0389c454cb24a22350d8cd95d |
op_doi |
https://doi.org/10.5194/amt-11-1099-2018 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
11 |
container_issue |
2 |
container_start_page |
1099 |
op_container_end_page |
1117 |
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1766348306955370496 |