Stockholm Historical Weather Observations — Barometer observations in original units since 1756

Anders Moberg

Weather observations have been made continuously at the old astronomical observatory in Stockholm since 1754. The dataset provided here contains individual barometer readings in their original units for the period 1756⁠ – 2018.

The dataset mostly contains three observations per day. Over time, different barometers have been used and measurements have been made in different units.

These data have been used to derive continuous series of sub-daily sea level pressures for Stockholm since 1756.

Citation

Anders Moberg (2019) Stockholm Historical Weather Observations — Barometer observations in original units since 1756. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/stockholm-historical-barometer-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

Data with barometer observation values are provided in separate files for the following time periods:

1756⁠ – 1858

1859⁠ – 1861

1862⁠ – 1937

1938⁠ – 1960

1961⁠ – 2012

2013⁠ – 2018

For the last period, data are provided separately for both a manual and an automatic weather station.

All data are availabe in two file formats:

1. plain text files (.txt)

2. tab-separated value files (.tsv)

Detailed description of the content in each file is found in a README text file.

The data have been quality controlled as described by Moberg et al. (2002), but are not subject to any homogenization or correction for known instrumental biases.

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.

The original unit for barometer readings has varied over time, as follows:
1756⁠ – 1858: Mercury height in Swedish inches (=29.69 mm)
1859⁠ – 1861: Mercury height in 0.1*Swedish inches (=2.969 mm)
1862⁠ – 1937: Air pressure in mm Hg
1938⁠ – 2018: Air pressure in hPa

Data files for the period February 1785 to December 1861 also contain temperature readings made at the barometer, which are needed to reduce barometer readings to 0°C. Before February 1785, temperatures at the barometer have been estimated from outdoor temperatures using a statistical model but these estimated temperatures are not included here. See Moberg et al. (2002; section 5) for further discussion. Data from 1961 onwards were reduced to sea level in the original source used to create the current dataset. Earlier air pressure data are not reduced to sea level.

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 – 2018-12-31: 3 observations (morning, noon, evening)

Observation times for all morning, noon and evening observations are provided in a separate dataset.

From January 2013 onwards, data are presented for both the manual station and the automatic weather station. Although the automatic station records air pressure every hour, the current dataset only contains data for the same three observation times as for the manual observations for the sake of consistency.

Original data sources used to produce this dataset:
1756⁠ – 1858: Handwritten observation journals from the archive of the Royal Swedish Academy of Sciences.
1859⁠ – 1861: Handwritten observation journals from the archive of the SMHI.
1862⁠ – 1960: Printed tables in the meteorological year-books "Meteorologiska Iakttagelser i Sverige", published by the SMHI or its predecessors.
1961⁠ – 2012: Computer files provided by the SMHI through personal contacts.
2013⁠ – 2018: Data files downloaded from the SMHI resource Öppna Data, subject to subsequent checking and correction for errors.

A small number of individual barometer values in the data files may deviate from the ones given in the handwritten sources, in cases when the latter were judged to be incorrect by Moberg et al. (2002; see section 3.2).

No air pressure measurements were made at the Stockholm old astronomical observatory between 1939-07-01 and 1950-02-28. Following Moberg et al. (2002), data for this period are taken from Stockholm/Bromma airport, as given in the printed year books.

Barometer observation data in this dataset are used to derive the corresponding dataset with sub-daily sea level pressure.