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Physics-based correction of inhomogeneities in temperature series related to the change from Wild screens to Stevenson screens (TWIST)

English title Physics-based correction of inhomogeneities in temperature series related to the change from Wild screens to Stevenson screens (TWIST)
Applicant Brönnimann Stefan
Number 146599
Funding scheme Project funding (Div. I-III)
Research institution Geographisches Institut Universität Bern
Institution of higher education University of Berne - BE
Main discipline Climatology. Atmospherical Chemistry, Aeronomy
Start/End 01.02.2014 - 31.01.2016
Approved amount 166'188.00
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All Disciplines (3)

Discipline
Climatology. Atmospherical Chemistry, Aeronomy
Other disciplines of Environmental Sciences
Meteorology

Keywords (3)

temperature extremes; homogenisation; climate data

Lay Summary (German)

Lead
Physics-based correction of inhomogeneities in temperature series related to the change from Wild screens to Stevenson screens (TWIST)
Lay summary
Detecting trends in weather extremes requires a high quality of the underlying weather data. It is well known that almost all long time series of weather variables are affected by artificial breaks and changes, which need to be corrected. Most currently used methods use statistical methods to correct such breaks, i.e., they correct for changes in the mean (possibly including an annual cycle in the correction). Some methods address also the distribution of the measurements, but only in a statistical sense. In this project we develop a new correction method for temperature that relies, at least partly, on a very simple physical model of the underlying error rather than on statistics. The method has been developed on behalf of one specific case (Basel, Switzerland) for the change of the shelter from a "Wild screen" to a "Stevenson screen". This change, however, is a wide-spread change in the observing networks of Central and Eastern European series, thus the methods may potentially be used in many cases. For this purpose, however, the method needs to be adapted and simplified. We then will apply the correction to other Swiss series in order to prepare for a future, more widespread application of the approach. Similarly, the change from the "Stevenson screen" to automated stations, a network-wide change that took place in the late 1970s, will be analysed based on a 30-yr series of parallel measurements from Basel using the same basic approach. Two main sources of artificial breaks in weather time series will therefore be better understood and better corrected.
Direct link to Lay Summary Last update: 29.08.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Trends of mean and extreme temperature indices since 1874 at low-elevation sites in the southern Alps
Brugnara Yuri, Auchmann Renate, Brönnimann Stefan, Bozzo Alessio, Berro Deaniele Cat, Mercalli (2016), Trends of mean and extreme temperature indices since 1874 at low-elevation sites in the southern Alps, in J. Geophys. Res., 121, 3304-3325.
A collection of sub-daily pressure and temperature observations for the early instrumental period with a focus on the “year without a summer” 1816
Brugnara Yuri, Auchmann Renate, Brönnimann Stefan (2015), A collection of sub-daily pressure and temperature observations for the early instrumental period with a focus on the “year without a summer” 1816, in Climate of the Past, 11(8), 1027-1047.
The International Surface Pressure Databank version 2
Cram Thomas A., Compo Gilbert P., Yin Xungang, Allan Robert J., McColl Chesley, Vose Russell S., Whitaker Jeffrey S., Matsui Nobuki, Ashcroft Linden, Auchmann Renate, Bessemoulin Pierre, Brandsma Theo, Brohan Philip, Brunet Manola, Comeaux Joseph, Crouthamel Richard, Gleason Byron E. Jr., Groisman Pavel Y., Hersbach Hans, Jones Philip D., Jonsson Trausti, Jourdain Sylvie, Kelly Gail, Knapp Kenneth R., Kruger Andries (2015), The International Surface Pressure Databank version 2, in GEOSCIENCE DATA JOURNAL, 2(1), 31-46.
A framework for benchmarking of homogenisation algorithm performance on the global scale
Willett Kate, Brönnimann Stefan, Venema Victor, Auchmann Renate (2014), A framework for benchmarking of homogenisation algorithm performance on the global scale, in Geoscientific Instrumentation, Methodes and Data Systems, 3, 187-200.

Collaboration

Group / person Country
Types of collaboration
International Surface Temperature Initiative United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
EarthTemp Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
EUSTACE/UK MetOffice Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
COST Action "HOME" France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
ACRE/UK Met Office Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
10th EUMETNET Data Management Workshop Poster The Parallel Observations Science Team (POST) compiling a global database with parallel measurements to study non-climatic changes 28.10.2015 St. Gallen, Switzerland Venema Victor Karel; Auchmann Renate;
10th EUMETNET Data Management Workshop Talk given at a conference Biases found in temperature records by the transition from Conventional to automatic measurements in European and American parallel datasets 28.10.2015 St. Gallen, Switzerland Auchmann Renate; Venema Victor Karel;
10th EUMETNET Data Management Workshop Talk given at a conference Biases in precipitation records found in parallel measurements 28.10.2015 St. Gallen, Switzerland Auchmann Renate; Venema Victor Karel;
10th EUMETNET Data Management Workshop Poster EU Surface Temperature for All Corners of Earth (EUSTACE) project: break-detection algorithm for a global daily temperature dataset 28.10.2015 St. Gallen, Switzerland Auchmann Renate; Brönnimann Stefan;
10th EUMETNET Data Management Workshop Poster Daily and sub-daily homogenization of temperature data in Switzerland 28.10.2015 St. Gallen, Switzerland Brönnimann Stefan; Croci-Maspoli Mischa; Auchmann Renate;
10th EUMETNET Data Management Workshop Poster A collection of sub-daily pressure and temperature observations for the early instrumental Period with a focus on the "year without a summer" 1816 28.10.2015 St. Gallen, Switzerland Brönnimann Stefan; Auchmann Renate;
Meeting of WMO Task Teams on Homogenisation (TT HOM) and on Definition of Extreme Weather and Climate Events (TT DEWCE) Talk given at a conference EUSTACE activities and approaches 20.04.2015 Geneva, Switzerland Auchmann Renate;
Extremes Workshop, Riederalp 2015 Talk given at a conference Impact of daily temperature homogenization on cold extremes in Switzerland 25.03.2015 Riederalp, Switzerland Auchmann Renate;
International workshop on Metrology for Meteorology and Climate Talk given at a conference Parallel Station Dataset 15.09.2014 Brdo, Slovenia Venema Victor Karel; Auchmann Renate;
International workshop on Metrology for Meteorology and Climate Poster A PHYSICS-BASED CORRECTION MODEL FOR HOMOGENIZING SUB-DAILY TEMPERATURE SERIES (FOR THE TRANSITION FROM THE WILD TO THE STEVENSON SCREEN) 15.09.2014 Brdo, Slovenia Auchmann Renate; Brönnimann Stefan;
The International Surface Temperature Initiative Workshop: July 8-16, 2014 Talk given at a conference The homogeneity and homogenization of daily temperature data 08.07.2014 Boulder, United States of America Auchmann Renate; Venema Victor Karel;
SEMINAR FOR HOMOGENIZATION AND QUALITY CONTROL IN CLIMATOLOGICAL DATABASES Talk given at a conference Inhomogeneities in daily data 12.05.2014 Budapest, Hungary Venema Victor Karel; Auchmann Renate;
SEMINAR FOR HOMOGENIZATION AND QUALITY CONTROL IN CLIMATOLOGICAL DATABASES Talk given at a conference Homogenisation algorithm skill testing with synthetic global benchmarks for the International Surface Temperature Initiative 12.05.2014 Budapest, Hungary Auchmann Renate; Brönnimann Stefan; Venema Victor Karel;
European Geosciences Union, General Assembly 2014 (EGU) Poster Break Correction of Swiss Daily and Sub-Daily Temperature Series 27.04.2014 Vienna, Austria Brönnimann Stefan; Auchmann Renate;
European Geosciences Union, General Assembly 2014 (EGU) Talk given at a conference Homogenisation algorithm skill testing with synthetic global benchmarks for the International Surface Temperature Initiative 27.04.2014 Vienna, Austria Brönnimann Stefan; Venema Victor Karel; Auchmann Renate;
Swiss Global Change Day Poster Break Correction of Swiss Daily and Sub-Daily Temperature Series 02.04.2014 Bern, Switzerland Auchmann Renate; Brönnimann Stefan;


Self-organised

Title Date Place
10th EUMETNET Data Management Workshop 28.10.2015 St. Gallen, Switzerland

Associated projects

Number Title Start Funding scheme
169676 Swiss Early Instrumental Measurements for Studying Decadal Climate Variability (CHIMES) 01.11.2016 Project funding (Div. I-III)

Abstract

For analyzing trends in extreme events, homogenized sub-daily temperature series are re-quired. However, homogenization methods for sub-daily data are only now being devel-oped. Most current approaches rely on statistical methods to correct inhomogeneities, but extreme events may be affected differently by errors than the bulk of the data and hence other approaches may be more suitable. Here we propose to further develop a new correc-tion method for sub-daily temperature time series that relies, at least partly, on a very simple physical model of the underlying error. The method has been developed for the case of the change of the shelter from a Wild screen to a Stevenson screen, which is a frequent reason for inhomogeneities in Central and Eastern European series. As the method was developed for one specific case (Basel, Switzerland), it first needs to be demonstrated that the approach is applicable to other stations. Here we propose to apply the method to other Swiss series, to adapt and to simplify it, and to compare it with other, statistics-based ap-proaches in order to prepare for a future, more widespread application of the approach. Finally, the change from conventional observations in a Stevenson screen to automated stations, a network-wide change that took place in the late 1970s, will be analysed based on a 30-yr series of parallel measurements from Basel using the same basic approach.
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