Anders Moberg
Data for sub-daily sea level pressure (SLP) at the old astronomical observatory in Stockholm are provided for the period 1756 – 2012.
Three SLP values per day are typically available. Two variants are presented: (i) Homogenized SLP data, (ii) Non-homogenized SLP data. The non-homogenized data provide SLP values calculated directly from the observations.
The homogenized SLP data have been corrected for known or supposed biased barometers and have been adjusted such that the long term trend agrees with other long air pressure measurements from stations in Northern Europe. Nevertheless, the homogenized record is judged to not reliably represent long-term trends in air pressure throughout the entire period, but the short term day-to-day changes are likely rather accurate.
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Citation
Anders Moberg (2019) Stockholm Historical Weather Observations — Sub-daily sea level pressure since 1756. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/stockholm-historical-daily-slp-1
References
Moberg A, Bergström H, Ruiz Krigsman J, Svanered O. 2002: Daily air temperature and pressure series for Stockholm (1756–1998). Climatic Change 53: 171–212. https://doi.org/10.1023/A:1014966724670
Data description
The data are included in two files having 6 columns, available in two file formats:
1. plain text files (.txt)
2. tab-separated value files (.tsv)
File content:
Column 1: Year
Column 2: Month
Column 3: Date
Column 4: Morning SLP value
Column 5: Noon SLP value
Column 6: Evening SLP value
SLP unit: hPa. Code for missing value: NaN.
More detailed information about the data file content is found in a README text file.
Comments
The observation site is included in the national station network managed by the Swedish Meteorological and Hydrological Institute (SMHI), with station number 98210 (manual station) and 98230 (automatic station), but data in the current dataset can differ from those in the SMHI database.
Barometer observations have been made daily since 1756. The oldest barometer measured the height of the mercury column in Swedish inches (=29.69 mm). No thermometer was attached and the temperature near the barometer was not observed before 1785. The lack of temperature observations, an unknown exact height of the barometer position and other unkown properties of old barometers used make it difficult to convert the oldest barometer recordings to the modern unit of hPa reduced to 0°C, normal gravity and sea level. Despite these difficulties, efforts have been made to convert all individual observations to hPa back to 1756. Homogenization of the record has been done by adjustments such that the long term trend agrees with other long air pressure records from Northern Europe. Details of how this was achieved are provided in Moberg et al. (2002).
The sub-daily SLP series from Moberg et al. (2002) covers the period 1756 – 1998. Updating to the end of 2012 has been made here by merging with data obtained from the SMHI. No more recent values are included. However, sub-daily SLP values for 2013 – 2018 are available in the associated dataset with barometer observations in original units. Those data are in turn obtained from the SMHI resource Öppna Data. If required, those data files can be used to extend the long sub-daily SLP records in time to the most present.
The number of observations each day has changed through time, as follows:
1756-01-01 – 1784-05-31: 2 observations (morning and evening)
1785-06-01 – 2012-12-31: 3 observations (morning, noon, evening)
Information about instruments and original data sources is available in the comments to the associated dataset with barometer observations in original units.
GCMD science keywords
Earth science > Atmosphere > Atmospheric pressure > Sea level pressure
GCMD location
Continent > Europe > Northern Europe > Scandinavia > Sweden
Project
Digitization, quality control and development of daily and monthly air temperature and pressure data series until 1998 was undertaken as part of the project IMPROVE — Improved Understanding of Past Climatic Variability from Early Daily European Instrumental Sources. Project funding: EU 4th Framework Programme, 1998–1999. Contract: ENV4-CT97-0511. Co-ordinator: Dario Camuffo, Consiglio Nazionale delle Ricerche, Istituto di Scienze dell'Atmosfera e del Clima, Padova, Italy. PI at Stockholm University: Anders Moberg.
Publisher
Bolin Centre Database
DOI
10.17043/stockholm-historical-daily-slp-1
Published
2019-08-02 18:54:18