EVROPSKÁ UNIE Evropské strukturální a investiční fondy Operační program Výzkum, vývoj a vzdělávání MINISTEHSTVO ŠKOLSTVÍ, MLÁDEŽE A TĚLOVÝCHOVY Geochemistry on the Earth's surface for analytical geochemists 2b. Geochemistry of the atmosphere Tento učební materiál vznikl v rámci projektu Rozvoj doktorského studia chemie č. CZ.02.2.69/0.0/0.0/16_018/0002593 Topics • Contemporary atmosphere — Structure of the atmosphere (temperature-pressure distribution) — Composition , mass and energy transfer — Photochemical reactions — Ozone layer • Evolution of the atmosphere in the geological past — The origin of the atmosphere — Oxygenation of the atmosphere — The atmosphere in the Phanerozoic CONTEMPORARY ATMOSPHERE Atmosphere • Earth's gravitationally maintained gaseous envelope • Without a sharp outer boundary - it gradually thins out into outer space • 120 km - the limit of influence on space flights • 100 km limit - atmosphere too thin to fly — machines at this height must have orbital velocity to maintain - insufficient aerodynamics Partial pressure • Expression of component ratios • Equivalent expression: - 21% 02 -PO2=0.21 - 210000 ppmv - 296 g/m3 The mass of the atmosphere • 5.2x10 18 kg • 50% within 5.6 km from the surface • 75% within 11 km of the surface • 99.99997% within 100 km of the surface • The "thick" part of the atmosphere lies within 30 km — Pressure over 0.01 bar Building atmosphere • Division based on temperature distribution a) Troposphere b) Stratosphere c) Mesosphere d) Thermosphere • Heating from solar radiation - Esp. visible and UV radiation - Different parts absorb different wavelengths 120 110 100 90 80 2 70 CD E 0 £ 60 m -o 1 50 < 40 30 20 10 Ozone maximum Thermosphere 0.001 mbar 70 — 60 0.01 mbar — 50 Mesosphere 0.1 mbar 1 mbar= 30 10 mbar Stratosphere 100 mbar - Tropopause 0 -100 -80 Troposphere 11000 [mbar 40 20 10 0 -40 -20 0 20 Temperature (°C) 40 60 80 Adapted from Misra (2012) Properties of radiation Penetrates Earth's Atmosphere? Frequency (Hz) Temperature of objects at which this radiation is the most intense wavelength emitted Radiation Type Radio Wavelength (m) 103 Approximate Scale of Wavelength Microwave Infrared Visible Ultraviolet X-ray Gamma ray 10 -8 10 -io 10 .-12 Buildings Humans Butterflies Needle Point Protozoans Molecules Atoms Atomic Nuclei 10' 10* 1012 1015 10Le 10 18 id" IK 100 K 10,000 K -272 °C -173 °C 9,727 °C 10,000,000 K 10,000,000 °C Distribution of radiation according wavelengths infrared IR, IR 790 nm - 1 mm far away 25 |iim - 1 mm medium 2.5 |iim - 25 |iim _ close 0.79 |iim - 2.5 |iim _ red ~ 650 nm Orange ~ 600 nm optical spectrum Visible, VID, VIS yellow ~ 580 nm 390-790 nm green ~ 525 nm blue ~ 450 nm purple ~ 400 nm ultraviolet region, UV close 200 nm -400 nm 1 nm -400 nm distant 1 nm - 200 nm__ Troposphere Exobase- (thermDpause-1} KG-SCO km o o Tropos - Greek to rotate, mix Closest to the surface 7 km (poles) to 17 km (equator) - avg. 11 km Heated by radiation reflected from the Earth's surface Temperature decreases with altitude The most extensive vertical movements - Most meteorological phenomena 80-90% of the mass of the atmosphere Most of the water in the atmosphere The upper boundary is the tropopause Thermosphere Noctiluscent cloud SO km Mesosphere Stratosphere Troposphere International Space Station 330 410 km Nacreous cloud 15-25 km Cirrus clouds 6-12 km o 3 c 3 O Karrnan line 100 km Me&Dpaj5E 30 km StratopausE 50 km □zone layer Tropopause 1 2 km -Cumulonimbus douds Contr, 6-12 km Weather balloon m km OBJECTS WITHIN LAYERS NOT DRAWN TO SCALE Stratosphere Exobase- (thermDpause-1} KG-SCO km o o Stratos - Greek for layer Up to ca. 50 km Ozone layer - protection against UV radiation - Most at 20-25 km Temperature increases with altitude — Ozone absorbs UV and emits IR (thermal) radiation Pressure at the upper edge (stratopause): 0.001 bar Thermosphere International Space Station 330 410 km Noctiluscent cloud SO km Mesosphere Stratosphere Troposphere Nacreous cloud 15-25 km Cirrus clouds 6-12 km o 3 c 3 O Karrnan line 100 km Me&Dpaj5E 30 km StratopausE 50 km □zone layer Tropopa jse 1 2 km -Cumulonimbus douds Contri 6-12 km Weather balloon m km OBJECTS WITHIN LAYERS NOT DRAWN TO SCALE Mesosphere Exobase- (thermDpause-1} äEG-SCO km o o Mesos - Greek „the middle Up to 80-85 km Burning meteorites in the atmosphere Without O3- temperature decreases with altitude — Minimum in the mesopause • -ioo°c • The coldest place on earth High for aircraft (balloons) and low for satellites -difficult to study Thermosphere International Space Station 330 410 km o 3 c 3 O Noctiluscent cloud SO km Mesosphere Stratosphere Troposphere Nacreous cloud 15-25 km Cirrus clouds 6-12 km Karrnan line 100 km Me&Dpaj5E 30 km StratopausE 50 km □zone layer Tropopa jse 1 2 km -Cumulonimbus douds Contr, 6-12 km Weather balloon m km OBJECTS WITHIN LAYERS NOT DRAWN TO SCALE Thermosphere Exobase (thermopause} rt 350-SOukm 3 Iß O Q. Q- Variable altitude (up to 800 km) Satellites - ISS at an altitude of 320-380 km The temperature rises up to 1500 °C - Absorption of high-energy UV radiation (A< 0.12 jL/m) by oxygen and nitrogen Thermosphere Noctilustem cloud 80 km Mesosphere Stratosphere Troposphere International Space Station 330 410 km Nacreous cloud 15-25 km Cirrus clouds 6-12 km Contrails 6-12 km TD CD £ o E E o q rri < 1/1 I > m (J u >■ CO Kärmän line 100 km MesopausE 30 km Stratopause 50 km □zone layer Tropopause 12 km Cumulonimbus clouds Weather balloon 40 km OBJECTS WITHIN LAYERS NOT DRAWN TO 5CALE Exobase- (thermDpause-1} äEG-SOOkm Exosphere o o The outermost edge of the atmosphere — Variable definitions Very diluted - limited moiecuiar collisions 500-1000 km to 10,000 km Thermosphere International Space Station 330 410 km o 3 c 3 O Noctiluscent cloud SO km Mesosphere Stratosphere Troposphere Nacreous cloud 15-25 km Cirrus clouds 6-12 km Karrnan line 100 km MesDpausE 30 km StratopausE 50 km □zone layer Tropopa jse 1 2 km -Cumulonimbus clouds Contri 6-12 km Weather balloon m km OBJECTS WITHIN LAYERS NOT DRAWN TO SCALE Other parts of the atmosphere • Defined by other properties • Ionosphere - ionized region important for the propagation of radio waves — Overlap with mesosphere and thermosphere Absorption of radiation in the atmosphere Solar Energy Distribution solar energy curve at top of the atmosphere Solar Readiation Curve 5% ultraviolet (300-400 nm) 43% visible light (400-700 nm) 52% near infrared (700-2500 nm) Yellow color shows energy absorbed by gases in air including water vapor, carbon dioxide,ozone and other greenhouse gases. 250 500 UV visible 750 1000 near infrared 1250 1500 1750 2000 2250 2500 3000 -►!— Wavelenght (nanometers) thermal infrared Absorption of radiation in the atmosphere • Thermosphere (UV with A < 0.12 \xm ) - O 2+ UV photon => O 2 + + e--02 + +e-=>0 + 0 + heat • Mesosphere and stratosphere (UV with A = 0.12-0.3 jL/m ) - Absorbed by 02, 03 • UV with A > 0.3 jU/n penetrates into the troposphere • IR radiation is significantly absorbed by water Photochemical reactions • Reaction of a photon with a molecule • Photolysis - breakdown of molecules by photochemical reaction • Formation of free radicals - an unpaired electron in the valence layer — Very reactive - E.g. hydroxyl radical OH- Ozone layer • Steady-state amount of 03 in the stratosphere - A series of reactions with balanced production and consumption of 03 • Production: 302 + UV photon =>203 - A catalyst molecule (receives energy) and a photon of A = 0.185-0.22 \xm are needed - All UV consumed within 20 km above the surface • Consumption: 2O3 + UV photon =>302 - A photon of A = 0.23-0.32 \im - It goes all the way to the earth's surface Ozone layer • Total concentration is a combination of: — Amount of UV radiation (decreasing towards the surface) — Atmospheric density (decreasing from the surface) • Optimum between 15 and 35 km (equator) • Ozone layer-90% of 03 on Earth — About 10 ppmv (lOOx more than on the surface) Destructi on of 03 Expected 03 concentrations do not correspond with observation Catalyzing substances decompose 03 in the atmosphere Especially free radicals - HOx - NOx - ClOx In the upper atmosphere, a molecule of NOxdecomposes ~105 molecules of 03 before it naturally decomposes (below it is about 10) Anthropogenic damage LU Catalyst A substance entering a reaction that is not consumed by the reaction and remains unchanged after A small amount of the substance is enough Lowers energy barriers, helps with particle orientation for easier interaction... t x,y jr 1 j \ z Ea (with catalyst) AG Reaction Progress Exercises • Look around, think and try to describe: • 3 ways in which some substances enter the atmosphere • 3 ways in which some substances get out of the atmosphere • What effect do they have on air quality? The composition of the atmosphere Table 13.2 Average composition of the Earth's unpolluted lower atmosphere (up to an altitude of 25 km). Gas Volume% Source Estimated residence time c 78.084 I Biologic 106-107yr o2 20.946 C 99% | Biologic 3000-10,000 yr Ar 0.934 J Radiogenic Forever <=°2 1 0.0383 Biologic, geologic, anthropogenic 2-10yr Ne 1 0.00182 | Earth's interior Forever He 1 0.000524 | Radiogenic ~106yr CH4 1 0.00017 Biologic, geologic, anthropogenic 2-10yr Kr 1 0.000114 | Radiogenic Forever H2 1 0.000055 | Biologic, chemical 4-8 yr IM20 1 0.00003 | Biologic, anthropogenic 5-200 yr Xe 1 0.000009 Radiogenic Forever N02 1 0.0000002 | Biologic, anthropogenic 0.5-2 days °3 lOto 0.000007 Chemical 100 days Water vapor (H20) is -0.40% by volume for the whole atmosphere, typically 1 to 4% near the surface. Other species present in the atmosphere at parts per trillion level concentrations include: NO, S02, CO, NH3, H2S, CS2, (carbonyl sulfide), CH3SCH3 (dimethyl sulfide), methyl chloride (CH3CI), methyl bromide (CH3Br), methyl iodide (CH3I), hydrogen chloride, CCI3F (CFC-11 Freon), CCI2F2 (CFC-12 Freon), and carbon tetrachloride (CCI4). Sources of data: Hobbs (2000); Railsback (2006). Adapted from Misra (2012) The composition of th here Table 13.2 Average composition of the Earth's unpo -a Source Gas Volume% f" 78.084 1 20.946 C Ar 1 0.934 J C02 1 0.0383 Ne 1 0.00182 He 1 0.000524 CH4 1 0.00017 Kr 1 0.000114 H2 1 0.000055 IM20 1 0.00003 Xe I 0.000009 N02 1 0.0000002 °3 lOto 0.000007 99% Biologi Biologi Radiog Biologi* Earth's Radiog< Biologi< Radiog< Biologi* Biologi Radiogeň Biologic, an Chemica 25 km). Water vapor (H20) is -0.40% by volume for the whole atmospl present in the atmosphere at parts per trillion level concentration! sulfide), CH35CH3 (dimethyl sulfide), methyl chloride (CH3CI), methyl chloride, CCI3F (CFC-11 Freon), CCI2F2 (CFC-12 Freon), and carbon tetra Sources of data: Hobbs (2000); Railsback (2006). N2 (nitrogen) s,™ t:me 780 840 ppm (78.084%r 02 (oxygen) 209 460 ppm (20.946%) Ar (argon) 9 340 ppm (0.934%] C02 (carbon dioxide) 370 ppm (fj.037%) Ne . pm (0.001§%f He (heliums 5 ppm4€r:0005%) CH 4 (methane) 2 ppm (0.0002%) Kr (krypton) 1 ppm (0.0001%) N20 (nitrous oxide) 0.5 ppm (0.00005%) H2 (hydrogen) 0.5 ppm (0.00005%) . ^species -^"tcarbonyl Rcle (CH3I), hydrogen By Cmglee - Own work, CC BY-SA 3.0, https://commons.wikimedia.Org/w/in dex.php?curid=17514333 Adapted from Misra (2012) The composition of the atmosphere • The composition is very homogeneous • It differs from other planets mainly in the presence of abundant 0 2 • Rock environment: reducing conditions vs. atmosphere: oxidizing conditions • The composition reflects the balance between volcanic, biological and sedimentary processes — Thermodynamic equilibrium? Thermodynamic equilibrium of the atmosphere Can be judged from substance concentrations - do they correspond to equilibrium concentrations in terms of TD? E.g. methane oxidation CH4(g) + 202(g) <=> C02(g) + 2H20(g) ; K = (^H2o)Z ecl D (p \2 CH4 \102> The value of Kp = 10140 t:L] What should dominate in equlibrium ? Thermodynamic equilibrium of the atmosphere CH4(g) + 202(g) <^> C02(g) + 2H20(g) ; _ ^C02 (^H2o) K = CH4 ^02/ The value of Keq=10140 Eq. partial pressure of CH4 = 3.5 x io-148 atm Real value 1.7 x 10"6atm The constituents of the atmosphere are in a steady state with residence times ranging from days to millions of years Residence times Tabic 13.2 Average composition of the Earth's unpolluted lower atmosphere (up to an altitude of 25 km). Gas Volume% Source Estimated residence time 78.084 Biologic Jl06-107yr | o2 20.946 Biologic J 3000-10,000yr| Ar 0.934 Radiogenic Forever <=°2 0.0383 Biologic, geologic, anthropogenic J 2-10yr | Ne 0.00182 Earth's interior Forever He 0.000524 Radiogenic [~106yr | CH4 0.00017 Biologic, geologic, anthropogenic J2-10yr | Kr 0.000114 Radiogenic Forever H2 0.000055 Biologic, chemical J4-8yr | IM20 0.00003 Biologic, anthropogenic [ 5-200 yr | Xe 0.000009 Radiogenic Forever N02 0.0000002 Biologic, anthropogenic [ 0.5-2 days | Oto 0.000007 Chemical MOO days | Water vapor (H20) is -0.40% by volume for the whole atmosphere, typically 1 to 4% near the surface. Other species present in the atmosphere at parts per trillion level concentrations include: NO, S02, CO, NH3, H2S, CS2, (carbonyl sulfide), CH3SCH3 (dimethyl sulfide), methyl chloride (CH3CI), methyl bromide (CH3Br), methyl iodide (CH3I), hydrogen chloride, CCI3F (CFC-11 Freon), CCI2F2 (CFC-12 Freon), and carbon tetrachloride (CCI4). Sources of data: Hobbs (2000); Railsback (2006). Adapted from Misra (2012) EVOLUTION OF THE ATMOSPHERE IN THE GEOLOGICAL PAST The evolution of the atmosphere • A difficult topic - We do not know all mechanisms - Reconstruction of a series of assumed successive equilibrium states - Are they even possible? Even today there is no equilibrium... NASA photo Primal atmosphere First tens of millions of years after formation Gas composition of the original nebula Similar to gas giants - H, He, H20, CH4, NH3 Blown away with the demise of the nebula — The influence of the solar wind Secondary atmosphere • Formed by outgassing of the mantle — Mantle-like representation of volatiles — Metals have not yet separated into the core • More reductive than today — It is gradually approaching the current volcanism (also thanks to the decrease in temperature) • Material from meteorites — Water contained in hydrated silicates or adsorbed on dust grains Secondary atmosphere • Especially nitrogen and carbon - Based on preserved weathering products • Almost no free oxygen • Increased concentrations of greenhouse gases (C02 and CH4) - E.g. from the absence of glacial sediments (the Sun had a lower luminosity than today) - The oldest glacial 2.5 Ga - PC02 drop from 1-10 bar to 0.3-0.03 bar - Information from marine sediments, banded Fe ores - Methane could be released by living organisms (reduction of C02) Oxygenation of the atmosphere The oxic/anoxic nature of the environment indicates the balance of oxygen input/output from the system Abiotically: H,0, . + UV photon => H\ + OH;. 2 (g) * (gj (g) C02(g, + UV photon => CO(g) + 0(g) (g) (g) 2(g) (g)\ ' Free H escapes into space - it does not react back into H20 Released 02 consumed by weathering, oxidation of volcanic gases and Fe in seawater Little overal input! Without oxygen there is no ozone layer - Life underground or in the sea, chemotrophic Phototroph ic organisms Anoxygenic photosynthesis • Sunlight and reducing agents (H2, H2S) as a source of energy for synthesis of organic matter from CO 2 • The by product is oxidized sulfur or water - not oxygen! By daveyn from United States - Morning Glory Pool, Yellowstone National Park, CC BY 2.0, https://commons.wikimedia.org/vv/index.php?curid=29855827 Today, chemotrophic bacteria inhabit extreme environments -for example, geysers. CO, , + 2H.S, . + sunlieht 2(g) 2 M & 2" Cyanobacteria > Synthesis of organic matter from solar energy, water and C02 > 02 is a waste product ^^2(g) + H2Ofh + sunlight fi) CH.O (carbohydrate) + O Oxygenation of the atmosphere Increase in 02in the atmosphere given by the absorption of 02 - Reoxidation of organic matter - Oxidative reactions in the environment (weathering, oxidation of volcanic gases) - Oxidation products re-reduced by bacteria Today approx. 99% of 02 recaptured (respiration and decomposition of organic matter) 0.1% Organic matter retained in sediments Iron oxides in sand. Oxygenation of the atmosphere Expected sharp increase in the 02 content in the atmosphere in the period of 2.4-2.2 Ga Older paleo-soils have lost most of their iron (Fe 2+ leaching) Continental red sediments appear by 2.2 Ga Banded iron ores (BIF) -abundant before 2.4 Ga, Fe2+must have been abundant in water to form Isotopic traces - Sulfur isotopes - Carbon isotopes Causes of the increase Cyanobacteria documented 2.7 Ga - 400 mil. year gap to increase Increased 02 input - More intensive burial of organic matter (shelf development?) Decreased 02 output - Reduction of volcanic activity (decrease in gas oxidation) - Gradual change in the oxidation conditions of the upper mantle and the composition of volcanic gases The great unknown... Nunaiupercontinent Rodiniaslupercontinent Earth's early atmosphere and tectonics assembly Breakup Assembly- Great Oxidation Event First oxygen-producing bacteria appear ß First eu First life appears Glaciation 4.5 4,0 3.5 3.0 2.5 Billions of years ago ka-yotes ppear "Boring billion" 2!Ö 1I8 L5~ Breakup First animals appear Glaciations _ 100 % SB hi ho.oi! I 1.0 0.8 0.5 Modern day Hadean Archean Paleo- Meso- Neo- Phanerozoic Proterozoic ENVIRONMENTAL ASPECTS Atmospheric pollution • Can be divided into three types: - Inorganic gases • Nitrogen oxides (N20, NO, N02) • Sulfur oxides (S02/ S03) • Carbon oxides (CO, C02) • 03, NH3/ H2S, HF, HCI,CI2, Rn - Volatile organic substances • Methane, freon... - Particulate matter (PM 10) Air pollution as a tragedy of the commons • https://www.youtubexom/watch?v=0b2Tl0x-niw • https://youtu.be/CxC161GvMPc The ozone hole • Ozone in the upper parts of the atmosphere, necessary for the existence of life • Most at the equator, decreasing towards the poles • In the 1970s and 1980s, a significant decrease was observed over Antarctica • Seasonal phenomenon (mostly in spring) • Decomposition by free radicals and halogens The ozone hole NOAA, Public Domain , https://commons.wikimedia.Org/w/index.php?curid=515657 540 20.0 HCFC-141b CFC-12 490 250 CFC-11 240 5.0 H-1211 Halogenated hydrocarbons End of production by Montreal Protocol (1987) Gradual restoration in the following century 1.0 2008 q-q. g t 0.5 2008 ft j o3 CIO M » 1 - 2.5 2.0 1.5 1.0 0.5 o o o " -o c g 3 ° -o H on -§>ö Ir ni -q cl cl CD C O N O u J < ^ 4-1 OJ o u -a u n 3 c *^ ■— 'c s 5 _o < r- OJ _C ~ •£ -f u aj i) P > *-» aj ^ > S o n ö po •3 8 j < cos 63°S 72°S Development of concentrations of ozone-depleting Approximate latitude o g- -c ffl s a "5 E o O u ^ J3 N 1> *-* 00 ^ (5 4j £ 8 S ■- "o -a m O * c £ O g a O V1H 5f. Adapted from Misra (2012^ d a, O O 3 > u u The ozone hole • Still, there are other complications - just look at the headlines from the Guardian : • Ozone layer not recovering over populated areas, scientists warn (February 2018) • Mysterious rise in banned ozone-destroying chemical shocks scientists (May 2018, someone in East Asia is producing CFCs) • Mysterious source of illegal ozone-killing emissions revealed, say investigators (July 2018,18 out of 21 companies in China use banned substances in production) - "We confirmed companies use CFC, while acknowledging the illegality and being very blase about its use (...) These companies, again and again, told us everybody else does this/' - "Despite efforts to get rid of this activity, it continues." - "The profit margins were very high, the demand was high and the risks were very low." • Beijing is playing its part in cracking down on the use of banned ozone-depleting CFC-1 (August 2018) • Record-size hole opens in ozone layer above the Arctic (April 2020, though it was allegedly more of a natural geophysical curiosity) Smog Smoke + fog Smoke - an aerosol created by burning, a mixture of solids, gas and liquid Fog - is formed by the condensation of water vapor on aerosol particles (condensation nuclei) Dispersed particles (0.2-2 |am) cause reduced visibility (haze) They may contain substances harmful to health _By Bobak - Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=2190112 London smog Sulphurous, winter, reducing... Burning fossil fuels CO production Sulfur oxides - coal 0.2 7% sulphur S02forms an acid on contact with water Today on the decline -developing countries Rw MT Qf^hhc CC RV_QA Ofl hHnc//rr\mmnnc \a/íľímoHi^ nra /\A//inHov nh rOri iriH->inQ>l07R GreatSmog of Londo ©Getty Images Great Smog of London 1000 750 TD "Ž8 500 ■C H—1 CO CD Q 250 0 London fog — episode / \ i JT \ \ ' y \ •J^. Deaths if ~ Deaths j / Smoke\ \ 1 □ \ ! so2 // 1 1 1 1 \\ 1 S02 ......... E Q. Q. OJ O co 0.75 0.50— 2.0 — 0.25 — 1.0 1 0 —iQ CO I 0 o E 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Date, December 1952 Adapted from Misra (2012) December 1952 Cloudiness over the city caused cooling and formation of mist Further cooling led to thickening of smog by heating exhalations A combination of circumstances leading to 4,000 deaths and 100,000 illnesses Photochemical smog • Los Angeles, Californian, oxidative... • No smoke, no fog • Varied composition: dust particles, NOx, 03, CO, hydrocarbons... • It is created by photochemical reactions - daily cycles, mostly at noon • The primary sources are exhalation of NOxand hydrocarbons from industry and transport • Due to sunlight interaction, other harmful substances are produced • Damage to plants, human health (esp. respiratory) Particulate matter • A mixture of solid particles and droplets - defined by size, not composition • The smaller the particles, the more dangerous - PM10(10 |im) - PM2.5 (2.5 |im) - get deep into the lungs and irritate (the smallest particles even in the bloodstream) • Internal combustion engines, coal burning, fires, road/tyre abrasion, dust from operations, windblown dust... Fly ash from coal power plants. Acid rains • Acid rain is created by the interaction of gases, aerosol particles and rain • Sulfuric acid, nitric acid and hydrochloric acid • Volcanic activity, biological processes, human activity • It damages the water environment, soils, vegetation, buildings, but also human health. Acid rains • On the example of H2S04 • In the gas phase: 1. Oxidation of gaseous S02 to H2S04 2. Condensation of gaseous H2S04 and water to solution (aerosols or clouds) 3. Dissociation of H2S04 to S042~ and H+ • In the liquid phase: 1. Dissolving gaseous S02 into solution 2. Conversion to H2S03 and dissociation 3. Conversion of sulfites to sulfates • The result is acidification of precipitation - H+ increase Greenhouse gases • They maintain the average temperature of the planet at today's level (+15 °C) - Without an atmosphere, the temperature is -18 °C • Visible sunlight (radiation) passes to the Earth's surface • Reflected IR radiation (thermal radiation) absorbed by greenhouse gases • Especially. C02, CH4, N20 and H20 • Anthropogenic supply of greenhouse gases — Increase in avg. temperatures during the 20th century by0.7°C EVROPSKÁ UNIE Evropské strukturální a investiční fondy Operační program Výzkum, vývoj a vzdělávání MINISTERSTVO ŠKOLSTVÍ, MLÁDEŽE A TELOVÝCHOVY Tento učební materiál vznikl v rámci projektu Rozvoj doktorského studia chemie č. CZ.02.2.69/0.0/0.0/16_018/0002593 Resources • Images without a specified source are public domain, with a free license or copyright or used with the permission of doc. Zeman. • Misra , K. (2012). Introduction to geochemistry: principles and applications. Wiley-Blackwell. 438 p. ISBN 978-1-4443-5095-1.