Sources of information on climate

"proxy data" – indirect data on phenomenas related to climate

Biological

Geomorphological

Physical

Artefacts

Physical....

Isotopes

Atomic nucleus occupies only tiny part of the whole atom.

Nucleus consists on nucleons: protons – with a positive electric charge, and neutrons – electrically neutral.

The electric charges of proton and electron are equall. The mass of nucleons is about 2000 times bigger than mass of electron, the mass of proton is slightly bigger than the mass of proton (neutron = proton + electron)

Atoms with the same number of protons, but differ with the number of neutrons are called isotopes

Atomic number of element represents the number of protons in its nucleus.

Mass number of element represents the number of nucleons (protons and neutrons) in its nucleus.

Cl3717

Mass number

Atomic number

Element symbol

Isotope measurements

Some elements can have several stable isotopes – different types of atoms with different numbers of neutrons. (Number of protons in the nucleus define the element, number of neutrons define the isotope). The more neutrons in the nuclues the haviers the atmos.

There are three stable isotopes of hydrogen, they are called: hydrogen(H), deuterium (D) i tritium (T).

HH 11 HD 2

1 HT 31

Here are also two stable isotopes of oxygen:

OO 168

16 OO 188

18

The particle of water consists of two atoms of hydrogen and one atom of oxygen. In relation of their isotopes three different water particles can be found:

H218O, H2

16O and HD16O

Standard Mean Ocean Water (SMOW) consists in 99,76% of H216O,

in 0,2% of H218O and in 0,03% of HD16O.

1/

/1000 16

216

162

16

SMOW

sample

OHOHD

OHOHDD

1/

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162

182

162

18218

SMOW

sample

OHOH

OHOHO

The snow falling of Greenland glaciers has 18O in the range 23 -38‰.

The snow falling of Antarctic glaciers has 18O in the range -18 -60‰.

In the case of HDO:

00018 /108 OD

Ratio 18O/16O

Isotope 16O is lighter and evaporates faster than 18O. In normal conditions it returns to ocean together with precipitation. In glacial times 16O is trapped in the ice and a relative increase of 18O is observed in oceans. In warm periods, ice melts and the percentage of 16O increases.

How can we use oxygen isotopes to tell air temperature in the distant past? In high latitude climates the 18O concentration in precipitation varies linearly with mean annual temperature.Assuming this relationship holds for the distant past, the 18O record in ice cores can therefore be used as a proxy for mean annual temperature at the time of precipitation of the snow on the glacier.

During evaporation, the vapor, and hence clouds and precipitation, are poorer in 18O water than the rest of the water left behind. Precipitation preferentially removes more 18O, so later precipitation is still poorer in 18O. The tops of icecaps, which are cold and at high elevation, receive the most 18O-poor water as precipitation. 18O in ice therefore records air temperature.

In contrast, the oceans accumulate excess 18O as 18O-poor water is transferred to the ice sheets. The more ice, the richer the water becomes in 18O. Foraminifera and other organisms growing from the water also become richer in 18O, so their skeletons in ocean sediment record the 18O concentration in sea water and so, indirectly, record ice volume.

Ice and ocean sediment records are therefore complementary, each supplying different information about ice and ice formation.

Volcanic eruptions leave dust and acids on the surface of glaciers. High winds over dry land blow dust onto glaciers. High winds over open ocean water produces lots of sea salt spray that can also become incorporated into glacial ice. The snow and ice itself contain oxygen and hydrogen isotopes, and bubbles of trapped air. All these can be analyzed to get an idea of what is going on around the mass of glacial ice.

Ice cores

Ice cores

History of Earth climate can be History of Earth climate can be reconstructed on the basis of reconstructed on the basis of analysis of ice cores on Greenland analysis of ice cores on Greenland and Anctarctic. and Anctarctic.

• TemperaturTemperatures from measurements of es from measurements of oxygen isotopesoxygen isotopes..• Greenhouse gases in air bubbles Greenhouse gases in air bubbles trapped in ice cores. trapped in ice cores.

What we know about greenhouse gasesClimatic records in ice cores

Lomonosovfonna

drilled in April 1997

121 m deep, about 800 yrs

Project participants: Norway, The Netherlands, Sweden, Finland, Estonia

Holtedahlfonna

(Snøfjellafonna)

drilled in April 2005

125 m deep, about 400 yrs

Project participants: Norway, The Netherlands, Sweden, Finland, Estonia

Svalbard Svalbard drill sitesdrill sites

Austfonna drilled in 1998 and 1999drilled in 1998 and 1999 289 m deep, about 800 yrs289 m deep, about 800 yrsProject participants: Japan, Norway

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Methods of Dating Ice Cores

• Stratigraphy• Annual layers• Ratio of 18O / 16O• Electrical conductivity methods• Using volcanic eruptions as Markers

– Marker: volcanic ash and chemicals washed out of the atmosphere by precipitation

– use recorded volcanic eruptions to calibrate age of the ice-core

– must know date of the eruption

Using specific events Using specific events for dating ice coresfor dating ice cores

Examples from Svalbard ice cores

Depth (m )

3H (Bq/kg)137Cs (mBq/kg)

0

5

10

15

20

25

0 10 20 300

20

40

60Tritium(Bq/kg)137 Cs

Lomonosovfonna 2000

1963

Kekonen and others, 2002 Pinglot and others, 2003

Volcanic eruptions Nuclear weapon tests

0

1

2

3

4

5

1770 1780 1790 1800

Year (AD)

NO

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0

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Laki 1783

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Depth –age relationship

Ice cores have layer thinning due to pure shear which means that if sample size is consistant the number per time unit will decrease with depth

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Oldest ever ice cores origin from Antarctica

Last Glacial Maximum

170170

220220

270270

320320

370370

00200000200000400000400000600000600000czas (lata BP)czas (lata BP)

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2525262627272828292930303131

SS

T (

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ST

(°C

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CO2 concentration and temperature

time (thousand years BP)time (thousand years BP)

Sea

Lev

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m)

Sea

Lev

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m)

2020

00

-20-20

-40-40

-60-60

-80-80

-100-100

-120-120

Sea level during last 450 000 years

450450 400400 350350 300300 250250 200200 150150 100100 5050 002525

2626

2727

2828

2929

3030

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SS

T (

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growing glaciersdeep-seaforaminifera

Water isotopes in deep-sea cores

The “Ice Volume” effect-Light isotope removed from ocean, locked into large ice sheets. Ocean d18O shift (+1.5‰) recorded in marine carbonates that grew during glacial.

SPECMAP – standard benthic d18O record,used to date marine sediments of unknown age

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Coral records of paleo-precipitation

Theory: 1) more rain = lighter d18O“amount” effect2) surface seawater d18O will become lighter3) coral d18O lighter

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Water isotopes in speleothems (cave stalagmites)

Theory: 1) δ18O of speleothem = δ18O of precipitation2) δ8O of precipitation function of temperature (mid- to

high-latitudes) and/or amount of rainfall (low latitudes)

Wang et al., Science , 2001

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After: Reconstructing & simulating past climate variability., J.F. Gonzales Rouco

After: Reconstructing & simulating past climate variability., J.F. Gonzales Rouco

Borehole temperature profiles in central Greenland

Historical data

notes about harvest, corn prices

blooming dates (cheeries from Japan more than 1000 years)

sailing conditions (ice bergs aroud Iceland)

dates of lakes freezing(Japan)

notes about weather in old church cronicles (calendars)

cave paintings

characteristic features of houses

weather descriptions

HISTORICAL DOCUMENTS

C. Pfister, R. Brazdil (2006)

Corn prices

Brazdil i in., 2005

On the wall of this house in Wertheim, Germany, there are marks of 24 high water events at riversTauber and Ren

Pfister

Pfister

Weather diary,Jan from Kunowice, 1538, Czech Republic

From the diary of Marcin Biem

Potential sources of information about temperature beforePotential sources of information about temperature before 18001800

Jones, Osborn and Briffa (2001) Science

Potential sources of information about humidity before Potential sources of information about humidity before 18001800

Archive measurements elementInstrumental Direct T, P, SLP

Historical Records/diaries etc. T, P, storms

Tree rings WidthsDensity

Isotopes

T, PTT, P

Ice cores AccumulationMelt layers

IsotopesChemical composition

PTT, PCirculation

Corals GrowthIsotopes

Chemical composition

SST, SalinitySST, SalinitySST, Salinity

caves AccumulationIsotopes

P

T, P

Varves in lakes AccumulationBiological composition/pollen

TT, P

Varves in the ocean AccumulationBiological/chemical cmposition

P

T, P

Źródła wiedzy o klimacie i środowisku

Dane instrumentalne

Dane historyczne

Dane pośrednie

Dane pośrednie rzadko niosą informację o jednym tylko elemencie pogody (klimatu).

Odczytanie informacji wymaga datowania i kalibracji

Cape Spear

Mariners’ logs, recording dates and positions of iceberg sightings

pierścienie przyrostów drzew

proporcje izotopów tlenu 18O/16O w wapiennych muszlach mikroorganizmów oceanicznych

skład powietrza uwięzionego w lodzie grenlandzkim i antarktycznym

zasięgi gatunków o wyraźnych preferencjach klimatycznych

Western Brook Pond, Gros Morne

Hearts Delight

Okres połowicznego rozpadu

rozpad beta

rozpad alfa

W wyniku rozpadu beta otrzymujemy pierwiastek o wyższej liczbie atomowej

w wyniku rozpadu alfa otrzymujemy pierwiastek o niższej liczbie atomowej

HeThU 42

23490

23892

Fluktuacje długości Grosser Aletsch w Alpach Szwajcarskich w ciągu ostatnich 2000 lat.

Brazdil i in. 2005

Datowanie za pomocą węgla C-14 powstawanie węgla C-14 w przyrodzie

bombardowanie atmosfery przez promieniowanie kosmiczne

Węgiel C-14 ulega rozpadowi beta

okres połowicznego rozpadu węgla wynosi 5730 lat

Źródła wiedzy o klimacie w przeszłości

"proxy data" – dane pośrednie o czynnikach zależnych od panujących warunków klimatycznych:

pierścienie przyrostów drzew

proporcje izotopów tlenu 18O/16O w wapiennych muszlach mikroorganizmów oceanicznych

skład powietrza uwięzionego w lodzie grenlandzkim i antarktycznym

zasięgi gatunków o wyraźnych preferencjach klimatycznych