Differences in mid-latitude stratospheric winds between reanalysis data and versus radiosonde observations at Prague
Reanalysis data are very useful for studying the stratosphere. They can be used for analysis of long-term trends (temperature, wind speed, humidity, etc.) or analysis of global atmospheric dynamics, etc. There are various reanalysis projects that provide outputs which are not identical. In this...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2014-04-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/32/353/2014/angeo-32-353-2014.pdf |
| _version_ | 1819275062820208640 |
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| author | M. Kozubek J. Laštovička P. Križan |
| author_facet | M. Kozubek J. Laštovička P. Križan |
| author_sort | M. Kozubek |
| collection | DOAJ |
| description | Reanalysis data are very useful for studying the stratosphere. They can be
used for analysis of long-term trends (temperature, wind speed, humidity,
etc.) or analysis of global atmospheric dynamics, etc. There are various
reanalysis projects that provide outputs which are not identical. In this
paper, we mutually compare three of them, ERA-40, ERA-Interim and NCEP/NCAR,
and compare them with balloon radiosonde observations from Prague, Port Hardy
and Valentia stations. This comparison is done for wind speed and direction
at pressure levels 100 and 10 hPa and for various periods between 1957 and
2009. The results show that the differences between reanalysis vary. Wind
speed data from all three analyses reasonably agree except for the 10 hPa
historical data before 1966 and particularly ERA-40 data at the end of the
data series (1998–2001). The quality of the ERA-40 10 hPa stratospheric
wind data has been proven to be substantially worse over the last four ERA-40
years of 1998–2001 (2002) compared to previous years, both in wind speed and
wind direction. The reanalysis data results are compared with radiosonde
observations from Prague, Port Hardy and Valentia stations at 10 hPa for the
months of February between 1989 and 2009. The results show that there are
sometimes surprisingly large differences, more for ERA-Interim versus Prague
measurements. Differences in wind direction greater than 45°
(outliers) between the reanalysis data and Prague observations in wind
direction occur in Februaries predominantly when winds in Prague are in
"minor" sectors, such as north, northeast and east (easterlies), whereas
"major" sectors, particularly the dominant W (westerlies) wind sector,
exhibit almost no outliers. |
| first_indexed | 2024-12-23T23:18:21Z |
| format | Article |
| id | doaj.art-59df28890ef3406a93ad26c0a3ed941d |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-23T23:18:21Z |
| publishDate | 2014-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-59df28890ef3406a93ad26c0a3ed941d2022-12-21T17:26:25ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762014-04-013235336610.5194/angeo-32-353-2014Differences in mid-latitude stratospheric winds between reanalysis data and versus radiosonde observations at PragueM. Kozubek0J. Laštovička1P. Križan2Institute of Atmospheric Physics ASCR, Bocni II, 14131 Prague, Czech RepublicInstitute of Atmospheric Physics ASCR, Bocni II, 14131 Prague, Czech RepublicInstitute of Atmospheric Physics ASCR, Bocni II, 14131 Prague, Czech RepublicReanalysis data are very useful for studying the stratosphere. They can be used for analysis of long-term trends (temperature, wind speed, humidity, etc.) or analysis of global atmospheric dynamics, etc. There are various reanalysis projects that provide outputs which are not identical. In this paper, we mutually compare three of them, ERA-40, ERA-Interim and NCEP/NCAR, and compare them with balloon radiosonde observations from Prague, Port Hardy and Valentia stations. This comparison is done for wind speed and direction at pressure levels 100 and 10 hPa and for various periods between 1957 and 2009. The results show that the differences between reanalysis vary. Wind speed data from all three analyses reasonably agree except for the 10 hPa historical data before 1966 and particularly ERA-40 data at the end of the data series (1998–2001). The quality of the ERA-40 10 hPa stratospheric wind data has been proven to be substantially worse over the last four ERA-40 years of 1998–2001 (2002) compared to previous years, both in wind speed and wind direction. The reanalysis data results are compared with radiosonde observations from Prague, Port Hardy and Valentia stations at 10 hPa for the months of February between 1989 and 2009. The results show that there are sometimes surprisingly large differences, more for ERA-Interim versus Prague measurements. Differences in wind direction greater than 45° (outliers) between the reanalysis data and Prague observations in wind direction occur in Februaries predominantly when winds in Prague are in "minor" sectors, such as north, northeast and east (easterlies), whereas "major" sectors, particularly the dominant W (westerlies) wind sector, exhibit almost no outliers.https://www.ann-geophys.net/32/353/2014/angeo-32-353-2014.pdf |
| spellingShingle | M. Kozubek J. Laštovička P. Križan Differences in mid-latitude stratospheric winds between reanalysis data and versus radiosonde observations at Prague Annales Geophysicae |
| title | Differences in mid-latitude stratospheric winds between reanalysis data and versus radiosonde observations at Prague |
| title_full | Differences in mid-latitude stratospheric winds between reanalysis data and versus radiosonde observations at Prague |
| title_fullStr | Differences in mid-latitude stratospheric winds between reanalysis data and versus radiosonde observations at Prague |
| title_full_unstemmed | Differences in mid-latitude stratospheric winds between reanalysis data and versus radiosonde observations at Prague |
| title_short | Differences in mid-latitude stratospheric winds between reanalysis data and versus radiosonde observations at Prague |
| title_sort | differences in mid latitude stratospheric winds between reanalysis data and versus radiosonde observations at prague |
| url | https://www.ann-geophys.net/32/353/2014/angeo-32-353-2014.pdf |
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