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Sources of information on climate

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Presentation on theme: "Sources of information on climate"— Presentation transcript:

1 Sources of information on climate
"proxy data" – indirect data on phenomenas related to climate Biological Geomorphological Physical Artefacts

2 Physical....

3 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. Mass number Element symbol Atomic number

4 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). Here are also two stable isotopes of oxygen:

5 H218O, H216O and HD16O in 0,2% of H218O and in 0,03% of HD16O.
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, H216O and HD16O Standard Mean Ocean Water (SMOW) consists in 99,76% of H216O, in 0,2% of H218O and in 0,03% of HD16O.

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7 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:

8 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.

9 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.

10 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.

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12 Volcanic eruptions leave dust and acids on the surface of glaciers
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.

13 Ice cores

14 Ice cores

15 What we know about greenhouse gases Climatic records in ice cores
History of Earth climate can be reconstructed on the basis of analysis of ice cores on Greenland and Anctarctic. Temperatures from measurements of oxygen isotopes. Greenhouse gases in air bubbles trapped in ice cores.

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19 Ice cores and climate Elisabeth Isaksson Dmitry Divine
Lomonosovfonna drilled in April 1997 121 m deep, about 800 yrs Project participants: Norway, The Netherlands, Sweden, Finland, Estonia Svalbard drill sites Austfonna drilled in 1998 and 1999 289 m deep, about 800 yrs Project participants: Japan, Norway Ice cores and climate Elisabeth Isaksson Dmitry Divine Holtedahlfonna (Snøfjellafonna) drilled in April 2005 125 m deep, about 400 yrs Project participants: Norway, The Netherlands, Sweden, Finland, Estonia

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21 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

22 Ice cores and climate Elisabeth Isaksson Dmitry Divine
Using specific events for dating ice cores Examples from Svalbard ice cores Volcanic eruptions Nuclear weapon tests Ice cores and climate Elisabeth Isaksson Dmitry Divine Laki 1783 Kekonen and others, 2002 Pinglot and others, 2003

23 Depth –age relationship
Ice cores and climate Elisabeth Isaksson Dmitry Divine 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

24 Oldest ever ice cores origin from Antarctica

25 Last Glacial Maximum

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30 CO2 concentration and temperature
370 320 31 30 CO2 (ppm) Antarctica SST (°C) Tropical Pacific 270 29 28 Is there a correlation between carbon dioxide levels and temperatures? If we compare  carbon dioxide measurements from Antarctica with  sea surface temperatures from the tropical Pacific, we find that there is a high coincidence of carbon dioxide levels and temperatures in the past.  220 27 26 170 25 600000 400000 200000 czas (lata BP)

31 Sea level during last 450 000 years
20 31 30 -20 29 -40 Sea Level (m) 28 SST (°C) Tropical Pacific -60 27 -80 This graph shows  sea levels of the Red Sea over the last 450,000 years. If we overlay  sea surface temperatures, we can see a direct correlation between sea levels and temperature. In fact, most of the rise in sea levels is due to the expansion of water at higher temperatures, rather than the melting of ice.  26 -100 -120 25 450 400 350 300 250 200 150 100 50 time (thousand years BP)

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39 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. growing glaciers deep-sea foraminifera shadow.eas.gatech.edu/~kcobb/isochem/lectures/lecture8.ppt SPECMAP – standard benthic d18O record, used to date marine sediments of unknown age

40 Coral records of paleo-precipitation
Theory: 1) more rain = lighter d18O “amount” effect 2) surface seawater d18O will become lighter 3) coral d18O lighter shadow.eas.gatech.edu/~kcobb/isochem/lectures/lecture8.ppt Cole and Fairbanks, 1990

41 Water isotopes in speleothems (cave stalagmites)
Theory: 1) δ18O of speleothem = δ18O of precipitation 2) δ8O of precipitation function of temperature (mid- to high-latitudes) and/or amount of rainfall (low latitudes) shadow.eas.gatech.edu/~kcobb/isochem/lectures/lecture8.ppt Wang et al., Science , 2001

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

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

44 Borehole temperature profiles in central Greenland

45 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

46 HISTORICAL DOCUMENTS

47 Corn prices C. Pfister, R. Brazdil (2006)

48 Brazdil i in., 2005

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

50 Pfister

51 Weather diary, Jan from Kunowice, 1538, Czech Republic

52 From the diary of Marcin Biem

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54 Jones, Osborn and Briffa (2001) Science
Potential sources of information about temperature before 1800 Jones, Osborn and Briffa (2001) Science

55 Potential sources of information about humidity before 1800

56 Archive measurements element Instrumental Direct T, P, SLP Historical
Records/diaries etc. T, P, storms Tree rings Widths Density Isotopes T, P T Ice cores Accumulation Melt layers Chemical composition P Circulation Corals Growth SST, Salinity caves Varves in lakes Biological composition/pollen Varves in the ocean Biological/chemical cmposition

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59 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

60 Mariners’ logs, recording dates and positions of iceberg sightings
Cape Spear Mariners’ logs, recording dates and positions of iceberg sightings, can also be used. Sea ice effectively cut navigation between Greenland and Iceland after (Unfortunately, Cabot didn’t keep good records, so his notes are of no use). In Iceland, correlation between bad ice years and good years for sheep, and vice versa. Mariners’ logs, recording dates and positions of iceberg sightings

61 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

62 Western Brook Pond, Gros Morne
Glacial features, eg troughs & striations, indicate climate change in areas no longer covered by glaciers. Both these areas were deglaciated about 12,000 years ago Hearts Delight

63 Okres połowicznego rozpadu
rozpad beta W wyniku rozpadu beta otrzymujemy pierwiastek o wyższej liczbie atomowej rozpad alfa w wyniku rozpadu alfa otrzymujemy pierwiastek o niższej liczbie atomowej

64 Fluktuacje długości Grosser Aletsch w Alpach Szwajcarskich w ciągu ostatnich 2000 lat.
Brazdil i in. 2005

65 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

66 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


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