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Dynamics of European Climate
over the last 500 years
Jürg Luterbacher and collaborators
NCCR Climate und Institute of Geography
University of Bern, Switzerland
[email protected]
Outline
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The goal
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Types of archives
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Methods and data
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Selected results
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Quality of archives
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European temperatures
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Regional impact of tropical volcanic eruptions
Challenges for (southern) South America
The goal
The Goal:
Regional temperature evolution over
the past millennia
(example: northern hemishpere)
Wikipedia, 2005
Types of archives
a) Natural archives and proxies
b) Documentary data, early
intrumental data
Summary:
Historical Climatology of Europe: Combination of different
climate information
Type of data
Natural archives
Documentary archives
Direct data
Indirect or proxy
data
- Impact of climate on
ecosystems and
processes
Biological,
organic
Inorganic
- Tree rings - Ice cores
- Glaciers
- Pollen
- Chironomids - Lake sediments
- Speleothems
- Diatoms
-…
-…
Historical documents
- Measurements
-…
Descriptions,
narratives
Early instrumental
data
- Diaries
- Ship log books
- catastrophes
- paintings
-…
- Temperature
- Precipitation
- Pressure
-…
Biological,
Inorganic
phenological data
- Blossoms
- Vine quality
- Harvest dates
-…
- Water levels rivers and
lakes
- Ice out dates
-…
Religious
- Paintings
- Rogations
- Processions
- Flood marks
-…
Pfister 1999
Data and methods
Examples from Europe
Reconstruction method
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Climate information from Europe
Selected results
Examples from Europe
- Which one of the proxies is the ‚best‘ in a given
area and for a given season?
- How did temperatures change in winter and summer?
- What is the spatial structure of extreme events
(cold summers, hot summers)?
- What is the influence of tropical volcanic eruptions on
temperatures?
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European winter temperature
variability
1500-2005
Luterbacher et al. 2004
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1708/1709, the coldest European
winter
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Winter anomaly composite of
temperature and precipitation after
major volcanic eruptions
Temperature
Precipitation
Fischer et al. 2005
LOTRED approach:
The way to paleoclimatology
If once the spatial patterns of different
climatic state variables are known through
time (‚series of maps, climate fields‘) the
synoptic-scale atmospheric mechanisms
and processes may be studied and
climate regimes assessed.
This is „paleoclimatology“.
Open questions
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Which data sets are available?
What is the ‚best‘ resolution? (annual - decadal)
Can the proxy be seasonally resolved?
What is the spatial structure and the amplitude of
climate change during the last 500 to 1000 years?
• Is the 20th century unusual?
• Can we improve the ENSO Index time series?
• Can we attribute climate anomalies to forcings?
http://www.pages.unibe.ch/science/initiatives/lotred-sa/