LOTRED South AmericaLOTRED South America

Long-term multi-proxy climate reconstruction and diagnostics

The following presentation is a sample of results that emerged from a similar research project in Europe conducted by Juerg Luterbacher, Heinz Wanner and colleagues.

It gives an idea about the methods, types of data, and the results that might be expected.

Dynamics of European ClimateDynamics of European Climateover the last 500 yearsover the last 500 years

Jürg Luterbacher and collaborators

NCCR Climate und Institute of GeographyUniversity of Bern, Switzerland

juerg@giub.unibe.ch

OutlineOutline

The goal

Types of archives

Methods and data

Selected resultsQuality of archives

European temperatures

Regional impact of tropical volcanic eruptions

Challenges for (southern) South America

The Goal:Regional temperature evolution over

the past millennia(example: northern hemishpere)

Wikipedia, 2005

The goal

Example

Types of archivesTypes of archives

a) Natural archives and proxies

b) Documentary data, early intrumental data

Summary:Summary:Historical Climatology of Europe: Combination of different Historical Climatology of Europe: Combination of different

climate informationclimate information

Type of data

Natural archives

Documentary archives

Descriptions, narratives - Diaries - Ship log books - catastrophes - paintings - …

Early instrumental data - Temperature - Precipitation - Pressure - …

Biological, phenological data - Blossoms - Vine quality - Harvest dates - …

Inorganic - Water levels rivers and

lakes - Ice out dates - …

Direct data - Measurements - …

Indirect or proxy data - Impact of climate on

ecosystems and processes

Biological, organic - Tree rings - Pollen - Chironomids - Diatoms - …

Inorganic - Ice cores - Glaciers - Lake sediments - Speleothems - …

His

torica

l doc

umen

ts

Religious - Paintings - Rogations

- Processions - Flood marks - …

Data and methodsData and methodsExamples from EuropeExamples from Europe

Reconstruction methodReconstruction method

Climate information from EuropeClimate information from Europe

Selected resultsSelected results

Examples from EuropeExamples 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?

Example

Importance of proxies forImportance of proxies forsummer temperature reconstructionssummer temperature reconstructions

Pauling et al. 2003

Comment:

Andreas Pauling took some proxy records (data set above) and assessed which proxy has the best skill to estimate summer TT for the different grid points (below). Tree rings show best skill in most areas.

NOTE: In this Figure, e.g. lake sediments do a very poor job, not because they are useless, but because there was just ONE data series accessible to the authors of this study!! This „message“ is likely to have implications.

Therefore it is in every community‘s own interest to make the data available.

European winter temperature European winter temperature variabilityvariability15001500--20052005

Luterbacher et al. 2004

1708/1709, the coldest European winter

Example

Winter anomaly composite of temperature and precipitation after

major volcanic eruptions

Fischer et al. 2005

Temperature Precipitation

LOTRED approach:LOTRED approach:The way to paleoclimatologyThe 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 questionsOpen questions

• 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/