FORMATION, TRANSPORT, PARTITIONING AND FATE OF ORGANOHALOGENS IN - PowerPoint PPT Presentation

FORMATION, TRANSPORT, PARTITIONING AND FATE OF ORGANOHALOGENS IN ANTARCTICA ANTARCTICA Vladim ir Bogillo g Dep a rtm ent of Anta rctic Geology a nd Geoecology gy Institute of Geological Sciences, National Academy of Sciences, Kiev, Ukraine e-mail: vbog@carrier.kiev.ua

This study is a part of project “Past and future of Antarctic atmosphere” • Antarctica is the highest (mean elevation = 2.300 m), coldest (minimum temperature = -89.6°C), geographically most isolated land mass on Earth most isolated land mass on Earth • By virtue of its geographical isolation and unique meteorological conditions, this most southerly of continents meteorological conditions this most southerly of continents provides unparalleled opportunities for monitoring globally integrated geophysical and ecological processes • The key atmospheric issues in the Antarctica are the depletion of the stratospheric ozone layer, the long-range transport of air pollutants and warming associated with global climate change. These problems are mainly due to anthropogenic activities in other parts of the world anthropogenic activities in other parts of the world.

Role of Antarctic snowpack and ice sheet in formation partitioning and fate of volatile organic formation, partitioning and fate of volatile organic pollutants • Accumulation of anthropogenic persistent organic pollutants (pesticides, PAHs, PCB/Ns, PCDD/Fs, PBDEs) • Enrichment of anthropogenic volatile freons, halons, their E i h t f th i l til f h l th i substitutes and chloro-containing solvents • Formation of volatile halogen and sulfur containing • Formation of volatile halogen- and sulfur-containing compounds in biochemical processes of ice microalgaes, coastal macroalgaes and phytoplankton g p y p • Formation of alkenes, halocarbons, aldehydes, ketones, carboxylic acids, alkyl nitrates, hydroperoxides in y y y p photochemical and redox reactions of organic matter in snowpack

Transport of OCs to Antarctica T Trade winds and cyclones d i d d l directions

Galindez island Galindez island 65 o 15’ S, 64 o 16’ W 65 15 S, 64 16 W

Greenhouse gases: CO CO 2 , N 2 O, propene N O propene Sulfur-containing gases: 0-70 years COS, CS 2 , CH 3 SCH 3 , CH 3 SSCH 3 Natural halocarbons: С F 4 , CH 3 Cl, C 2 H 5 Cl, CH 2 =CHCl, CH 3 Br, CH 2 Br 2 , 470 years CHBr 3 , CH 3 I, CH 2 =CHI, C 2 H 5 I CHBr CH I CH =CHI C H I 1110 years Anthropogenic halocarbons: CHCl 3 , CH 2 Cl 2 , CCl 4 , CH 3 CCl 3 , Cl 2 C=CCl 2 1860 years Chlorofluorocarbons and their replacements: 2780 years С F 2 Cl 2 (CFC-12), CFCl 3 (CFC-11), 30 m 3685 years 3685 years CCl FCClF (CFC 113) CClF CClF (CFC 114) CCl 2 FCClF 2 (CFC-113), CClF 2 CClF 2 (CFC-114), CHClF 2 (HCFC-22) 4220 years 4760 years 4760 years

GC-MS analysis of volatile compounds in ice layers of coastal glacier, Galindez Island (1998-2003) • More than 200 organic compounds have been identified in young layer o e a 00 o ga c co pou ds a e ee de ed you g aye • 13 industrial HFCs, CFCs, HCFCs and halons • 63 natural and anthropogenic F, Cl, Br and I -halocarbons • 13 S- and Se-containing compounds • 13 S and Se containing compounds • 26 acyclic and cyclic alkanes • 35 acyclic and cyclic alkenes • 6 alkynes and halogenated acetylenes • 6 alkynes and halogenated acetylenes • 19 substituted benzenes • 5 carboxylic acids • 28 aliphatic and aromatic aldehydes and ketones 28 li h ti d ti ld h d d k t • 13 alcohols, phenols, ethers and esters • 25 O-, S- and N-containing heterocyclic compounds They are characterized by very large enrichment factors in comparison with their atmospheric mixture ratio in air comparison with their atmospheric mixture ratio in air (from 4 to 50000)

Wet extraction, cryofocusing, thermal desorption and GC MS analysis and GC-MS analysis of the volatile impurities in the ice blocks 2 5 6 8 9 1 1 7 4 6 2 10 3 6 14 15 13 13 11 12

Atmospheric mixing ratio of the impurities p g p ∆ X corr Compound X fresh X old X air CO 2 (ppm) 10850 2600 375 CF (ppt) CF 4 (ppt) 35 35 75 75 35 70 35-70 C 3 H 6 55300 0-1740 CHClF 2 170 5 120-170 1-30 CF Cl CF 2 Cl 2 1000 1000 40 40 520-560 10-535 520-560 10-535 CFCl 3 380 70 250-340 10-170 CCl 2 FCClF 2 125 40 80-90 5-120 CClF 2 CClF 2 CClF 2 CClF 2 10 10 0 0 10-15 10 15 0 2 0-2 CH 3 Cl 4430 7930 550 100-730 C 2 H 5 Cl 450 200 2 CH 3 CCl 3 1000 0 60-90 0-15 3 3 CH 2 =CHCl 180 2350 50 170-990 CH 3 Br 100 150 10 1-20 CH 3 I 130 600 0-1 1-80 3 C 2 H 5 I 1000 480 0.2 4-70 COS 5800 74800 500 3500-50500 CS 2 16800 6700 2-20 140-1900 CH 3 SCH 3 12000 10-600 CH 3 SSCH 3 44000 2-300

Change of concentrations for volatile atmospheric impurities after their deposition on snow surface and during snow metamorphism their deposition on snow surface and during snow metamorphism С атм , глоб С атм , лок Плотность Возраст 3 ( кг / м ) ( лет ) С С снег 0,6 200 1 400 600 20 С С фирн 100 800 840 120 С лед

• Snowpack includes three phases: solid ice, water and airs • Three main parameters determine behavior of chemical in snowpack: ee a pa a ete s dete e be av o o c e ca s owpac : vapor pressure, water/air partition coefficient (Henry law constant) and ice surface/air partition coefficient • One of possible reason of the enrichment in the warm glacier may be • One of possible reason of the enrichment in the warm glacier may be dissolution of the gases in meltwater percolating through the underlying firn layers, subsequent refreezing of the enriched solution during cold season and repeating of the melt-freeze cycles season and repeating of the melt freeze cycles • The dependence of CO 2 enrichment factor on age of the ice reflects the number and intensity of repetitive melt-freeze cycles, the enrichment has maximum in young ice and this correlates well with climatic history of i i i i i i i i f coastal Western Antarctica • However, the enrichment for most other species decreases as this value grows for CO 2 . Even corrected on the solubility in meltwater, the content of the species is in large excess in comparison with their atmospheric level

Influence of the solubility in water and adsorption on ice/air interface in ice samples on enrichment coefficients interface in ice samples on enrichment coefficients of the impurities 70 years 4000 years 3,0 4 dard] dard] 2,5 2,5 ent factor, Xe is stand ent factor, Xe is stan 3 2,0 2 1,5 1,0 1 g [Relative enrichme g [Relative enrichme 0,5 0 0,0 -1 -0,5 -1,0 Log Log -2 2 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0 2,5 -5 -4 -3 -2 -1 0 Log [Henry's law constant at 273K] Log [ice/air partition constant at 273 K], cm ln F = 0.9×ln H + 0.4×ln K IA + 4.9 ln F = 0.5×ln H + 0.3×ln K IA + 4.2 (R (R = 0.699) 0 699) (R = 0.639)

Simulation of enrichment for soluble impurities in snowpack t=16 days Depth: 80 cm -1 mg l 5 oncentration m Diameter of grains: 5 mm Snow density: 0.275 g/cm 3 4 t=12 days Snow porosity: 0.70 Co 3 3 Snow temperature: 272 K S t t 272 K C o = 0.2 mg/l C 0 2 d л = 0.917 g/cm 3 t=8 days S S 0 = 0 0 t=4 days 1 p c = -400 N/m 2 t=0 g = 10 m/s 2 , d = 1.0 g/cm 3 0 σ = 0 0075 N/m σ 0 = 0.0075 N/m 0 0 20 20 40 40 60 60 80 80 Depth from Snow Surface (cm) Calculation of enrichment for water-soluble impurity in snowpack due to repetitive melting- impurity in snowpack due to repetitive melting freezing cycles during 20 days of warm season

TREND OF ANNUAL AIR TEMPERATURE (GALINDEZ, 1947 – 1997) Annual Temperature, C Annual Temperature, C -1 -2 -3 -4 -5 -6 -7 -8 -9 9 1940 1950 1960 1970 1980 1990 2000 Year = ± × − ± o [ [ Temperatur p e , , C ] ] ( ( 0 . 052 0 . 013 ) ) [ [ Years ] ] ( ( 107 . 6 25 . 6 ) ) = = = = R 0 . 4993 ; sd 1 . 36651 ; N 51 ; P 0 . 000191 = ± ± + + ± ± × × [ [ RAIN RAIN ] ] ( ( 85 85 . . 8 8 6 6 . . 3 3 ) ) ( ( 6 6 . . 01 01 1 1 . . 25 25 ) ) [ [ TEMP TEMP ] ] = = = 0 . 50047 ; 39 . 74125 ; 71 R sd N

Dependence of СО 2 enrichment coefficient on age of the ice p g 2 2 35 я СО 30 30 огащени 25 циент об 20 15 Коэффиц 10 5 0 0 1000 2000 3000 4000 Возраст воздуха в блоке льда , лет р у

Taking into account the effect for solubility of the impurities In infiltration water on calculated atmospheric mixing ratio ( СО 2 - standard) [ [ ] ] [ ] [ ] [ ] [ ] × × + + + + H X X X X [ [ X X ] ] K K 1 1 χ = = w g g X [ [ ] ] [ [ ] ] + + × × + + X H CO CO [ [ CO CO ] ] [ [ CO CO ] ] K K 1 1 2 2 2 2 g 2 2 g CO CO 2 2 w [ [ ] ] χ × × + H [ CO ] K 1 = X 2 g CO 2 [ [ ] ] [ X ] + g g H H K K 1 1 X