FATE OF MERCURY IN THE ARCTIC Michael Evan ... - COGCI

Recommendations

Info

Fate of Mercury in the Arctic 14 After polar sunrise, in Barrow, Alaska, KCl coated manual RGM denuders were used as the accumulator with the REA system. At 3 m above the snow pack significant RGM fluxes measured during March 29 th – April 12 th 2000 were directed toward the snow surface. Overall mean deposition was found to be - 0.4 +/- 0.2 pg m -2 s -1 ; N=9, +/1 SE and re-evasion was also observed. Using measured total RGM concentrations; depositional velocities were then computed and found to be on the order of 1 cm s -1 . Upon closer examination of field data, a relative rate study (paper 3, Skov et al., submitted) and utilizing knowledge from recently published reaction kinetics (Ariya et al., 2002), an updated mechanism is suggested (paper 4, Goodsite et al., submitted). The proposed reaction mechanism is that gaseous elemental mercury, Hg (0) combines with Br atoms, called X, coming from the polar sunrise destruction of ozone, in a reversible reaction, forming the energised HgBr*. Through a third body reaction, M, where M is N2 or O2, the HgBr radical is formed. The HgBr radical can live long enough at the low temperatures of the Arctic to combine with O2 forming the HgBrOO peroxy radical or can combine with Br forming HgBr2. It is not likely to react with Cl, since this reaction would be endothermic. Similarly, the product cannot be Hg2Br2 since this would imply a tri molecular reaction, which is highly unlikely to occur in the atmosphere given the very low concentrations of the reactants. Nor would the end product be HgO, since this formation is similarly thermodynamically not favourable. The final product is the divalent gaseous mercury unknown, HgXY. By modelling the reaction of Hg and Br in the atmosphere, with current reaction constant data, and BrO and Br measurements, we find that assuming 20 ppt BrO and 2 ppt in the atmosphere during a depletion event that the lifetime of Hg is 4.6 hrs against forming HgBr, The lifetime of HgBr is 0.35 hrs. against forming HgBr2; comparing with the lifetime of HgBr of 0.75 hrs means that 68% of the time HgBr will form HgBr2. Thus the overall lifetime of removal of Hg to HgBr2 is 4.6 hrs. / .68 = 6.7 hrs. This is in good agreement with the observed 10 hr lifetime of Hg under depletion.
Fate of Mercury in the Arctic 15 We learned from our experiences measuring gaseous elemental mercury on the Faroe Islands that measuring gaseous elemental mercury is not trivial. Care must be taken in choosing appropriate measurement procedures (paper 5, Skov et al., accepted). Mercury in environmental archives, peat in the Arctic Mercury was measured in peat cores from S. Greenland, the Faroe Islands, Denmark, and from the high Arctic (Bathurst Island and Carey Islands) samples from Bathurst Islands were given to N. Givelet, University of Berne, and will not be discussed. Samples from Nordvestø, Carey Islands, Greenland, are still being investigated, so preliminary results only will be treated. Cores from S. Greenland, Denmark and the Faroe Islands had sufficient new growth to examine the geochemistry during the last 50 years with high resolution. To do this, a new, direct, approach to high time resolution dating was developed and applied to peat from sub-arctic southern Greenland and Denmark. The advantages of direct, high time resolution dating are thoroughly discussed (paper 6, Goodsite et al., 2002). An analytical method was developed to best determine the amount of mercury in the peat (paper 7, Roos-Barraclough et al., 2002). The first long term terrestrial record of mercury on Greenland (paper 8, Shotyk et al., accepted) and the Faroe Islands are produced (Shotyk, Goodsite et al., unpublished data, manuscript in preparation). Hg fluxes in the Greenland core (0.3 to 0.5 µg m -2 yr -1 ) were found in peats dating from AD 550 to AD 975, compared to the maximum of 164 µg m -2 yr -1 in 1953. Atmospheric Hg accumulation rates have since declined with the value for 1995, 14 µg m -2 yr -1 comparable to published depositional rates. Lead and stable lead isotopes were measured in these cores, showing coal burning was the predominant source of lead. Mercury depositional trends in the cores follow the lead trends suggesting that the profile is dominated with mercury from coal burning and that the peat cores are faithfully reproducing depositional trends, in agreement with what is known about
Page 1 and 2: Fate of Mercury in the Arctic FATE
Page 3 and 4: Fate of Mercury in the Arctic 3 Dan
Page 5 and 6: Fate of Mercury in the Arctic 5 atm
Page 7 and 8: Fate of Mercury in the Arctic 7 Pre
Page 9 and 10: Fate of Mercury in the Arctic 9 Tab
Page 11 and 12: Fate of Mercury in the Arctic 11 an
Page 13: Fate of Mercury in the Arctic 13 Im
Page 17 and 18: Fate of Mercury in the Arctic 17 1.
Page 19 and 20: Fate of Mercury in the Arctic 19 ex
Page 21 and 22: Fate of Mercury in the Arctic 21 hy
Page 23 and 24: Fate of Mercury in the Arctic 23 Th
Page 29 and 30: Fate of Mercury in the Arctic 29 At
Page 31 and 32: Fate of Mercury in the Arctic 31 Ar
Page 37 and 38: Fate of Mercury in the Arctic 37 in
Page 43 and 44: Fate of Mercury in the Arctic 43 sw
Page 45 and 46: Fate of Mercury in the Arctic 45 Fr
Page 47 and 48: Fate of Mercury in the Arctic 47 ap
Page 51 and 52: Fate of Mercury in the Arctic 51 dr
Page 53 and 54: Fate of Mercury in the Arctic 53 de
Page 55 and 56: Fate of Mercury in the Arctic 55 fo
Page 59 and 60: Fate of Mercury in the Arctic 59 we
Page 61 and 62: Fate of Mercury in the Arctic 61 St
Page 65 and 66:
Fate of Mercury in the Arctic 65 Pg
Page 67 and 68:
Fate of Mercury in the Arctic 67 pg
Page 69 and 70:
Fate of Mercury in the Arctic 69 4.
Page 71 and 72:
Fate of Mercury in the Arctic 71 4.
Page 73 and 74:
Fate of Mercury in the Arctic 73 4)
Page 75 and 76:
Fate of Mercury in the Arctic 75 Ta
Page 77 and 78:
Fate of Mercury in the Arctic 77 Fi
Page 79 and 80:
Page 81 and 82:
Fate of Mercury in the Arctic 81 ap
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Fate of Mercury in the Arctic 87 To
Page 89 and 90:
Fate of Mercury in the Arctic 89 Di
Page 91 and 92:
Fate of Mercury in the Arctic 91 am
Page 93 and 94:
Fate of Mercury in the Arctic 93 un
Page 95 and 96:
Fate of Mercury in the Arctic 95 Cx
Page 97 and 98:
Fate of Mercury in the Arctic 97 Th
Page 99 and 100:
Fate of Mercury in the Arctic 99 Si
Page 101 and 102:
Fate of Mercury in the Arctic 101 s
Page 103 and 104:
Fate of Mercury in the Arctic 103 T
Page 105 and 106:
Fate of Mercury in the Arctic 105 A
Page 107 and 108:
Fate of Mercury in the Arctic 107 R
Page 109 and 110:
Fate of Mercury in the Arctic 109 R
Page 111 and 112:
Fate of Mercury in the Arctic 111 G
Page 113 and 114:
Page 115 and 116:
Fate of Mercury in the Arctic 115 r
Page 117 and 118:
Fate of Mercury in the Arctic 117 5
Page 119 and 120:
Fate of Mercury in the Arctic 119 G
Page 121 and 122:
Fate of Mercury in the Arctic 121 B
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Fate of Mercury in the Arctic 129 P
Page 131 and 132:
Fate of Mercury in the Arctic 131 F
Page 133 and 134:
Page 135 and 136:
Fate of Mercury in the Arctic 135 a
Page 137 and 138:
Fate of Mercury in the Arctic 137 t
Page 139 and 140:
Fate of Mercury in the Arctic 139 A
Page 141 and 142:
Fate of Mercury in the Arctic 141 c
Page 143 and 144:
Page 145 and 146:
Fate of Mercury in the Arctic 145 c
Page 147 and 148:
Submitted to Atmospheric Environmen
Page 149 and 150:
1. Introduction Mercury in the atmo
Page 151 and 152:
For all flux measurements, heating
Page 153 and 154:
esponse switching valves supplied b
Page 155 and 156:
3.1 RGM flux measurements The resul
Page 157 and 158:
estimating for Alert an average spr
Page 159 and 160:
References 1. Businger J.A. and Onc
Page 161 and 162:
Table captions Table 1. RGM mass ra
Page 163 and 164:
Figure 2. RGM pg m-3 350 300 250 20
Page 165 and 166:
Table 2 DAYHOURMON avg.temp avg.WS
Page 167 and 168:
Fate of Mercury in the Arctic Paper
Page 169 and 170:
FIGURE 1. Schematic diagram of the
Page 171 and 172:
mass flow controller to 10 L/min an
Page 173 and 174:
FIGURE 3. Trends in Hg 0 (upper plo
Page 175 and 176:
FIGURE 6. Trends in several Hg spec
Page 177 and 178:
FIGURE 7. Spatial patterns in month
Page 179 and 180:
(51) Ebinghaus, R.; Kock, H. H.; Te
Page 181 and 182:
The fate of elemental mercury in Ar
Page 183 and 184:
Ozone was measured with an UV absor
Page 185 and 186:
demonstrating that BrO and ClO with
Page 187 and 188:
In the model the removal of GEM lea
Page 189 and 190:
15. Kemp, K. and Wåhlin, P. Applic
Page 191 and 192:
GEM, ng/m 3 Fig 3. GEM against ozon
Page 194 and 195:
Fig. 6 Comparison of measured surfa
Page 196 and 197:
Page 198 and 199:
Introduction The perennial oxidatio
Page 200 and 201:
Ariya et al. (11) have shown recent
Page 202 and 203:
Table 1 lists the binding energies
Page 204 and 205:
and a classical densities of states
Page 206 and 207:
The third point demonstrated in Fig
Page 208 and 209:
7. Lamborg, C. H.; Fitzgerald, W.;
Page 210 and 211:
Figure 1. k rec / cm 3 molecule -1
Page 212 and 213:
Page 214 and 215:
Asian Chemistry Letters vol. XX, No
Page 216 and 217:
Page 218 and 219:
Page 220 and 221:
Page 222 and 223:
Page 224 and 225:
496 M E Goodsite et al. In the pres
Page 226 and 227:
498 M E Goodsite et al. Figure 1 Th
Page 228 and 229:
500 M E Goodsite et al. observed a
Page 230 and 231:
502 M E Goodsite et al. Table 1 14C
Page 232 and 233:
504 M E Goodsite et al. annual reso
Page 234 and 235:
506 M E Goodsite et al. Table 2b Sa
Page 236 and 237:
508 M E Goodsite et al. Going from
Page 238 and 239:
510 M E Goodsite et al. dry mass. T
Page 240 and 241:
512 M E Goodsite et al. Figure 4 Hg
Page 242 and 243:
514 M E Goodsite et al. Koenig B, L
Page 244 and 245:
Page 246 and 247:
130 F. Roos-Barraclough et al. / Th
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
ABSTRACT Mercury concentrations are
Page 260 and 261:
INTRODUCTION Atmospheric pollution
Page 262 and 263:
and the relative importance of natu
Page 264 and 265:
corresponding to the alkaline igneo
Page 266 and 267:
edges cut off the slices were dried
Page 268 and 269:
Age dating using 14 C Plant macrofo
Page 270 and 271:
espectively (Naucke et al., 1993).
Page 272 and 273:
200 was in the range 1 to 3 :g/m 2
Page 274 and 275:
unpublished data for these paramete
Page 276 and 277:
leachable fraction, and 32.1 µg/g
Page 278 and 279:
indicator of the concentration of a
Page 280 and 281:
caused by the introduction of gasol
Page 282 and 283:
porewaters reveals the influence of
Page 284 and 285:
For example, Hg may become adsorbed
Page 286 and 287:
of the GL profile. Comparison with
Page 288 and 289:
further improve our knowledge of pr
Page 290 and 291:
which are derived from them. In con
Page 292 and 293:
ACKNOWLEDGEMENTS We are grateful to
Page 294 and 295:
Bindler, R. (2003) Estimating the n
Page 296 and 297:
of Southern Denmark. Goodsite, M.E.
Page 298 and 299:
MacKenzie AB, Farmer JG, Sugden CL.
Page 300 and 301:
Schroeder, W.H. and Munthe, J. (199
Page 302 and 303:
Table 1. AMS 14 C dating of plant m
Page 304 and 305:
Table 3. Pb isotope data of leachat
Page 306 and 307:
esidual fractions of the “B” co
Page 309 and 310:
Depth (cm) Depth (cm) a b 0 -10 -20
Page 311 and 312:
Hg accumulation rate (µg/m2/yr) 10
Page 313 and 314:
Depth (cm) a Pb/Zr = UCC Depth (cm)
Page 315 and 316:
Depth (cm) a Depth (cm) b 0 -10 -20
Page 317 and 318:
Depth (cm) Depth (cm) a b 0 -10 -20
Page 319 and 320:
Saturday, 28 December 2002 (Revised
Page 321 and 322:
INTRODUCTION Recent research utiliz
Page 323 and 324:
In addition, the coring system incl
Page 325 and 326:
and testing prior to the Carey Isla
Page 327 and 328:
ACKNOWLEDGEMENTS Development of thi
Page 329 and 330:
Fig. 5. The stainless steel (AISI 3
Page 331 and 332:
Fig. 2. 13
Page 333 and 334:
Fig. 4. 15
Page 335:
Fig. 6. 17
show all

FATE OF MERCURY IN THE ARCTIC Michael Evan ... - COGCI

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?