Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2
У статті порівнюються методологія та результати досліджень глибинних частин льодовиків, проведених різними дослідницькими командами, з метою визначення ізотопного складу елементів захоплених у полярній кризі газів та кисню самої криги. Результати з різних свердловин, які відповідають періодам часу,...
Збережено в:
| Дата: | 2008 |
|---|---|
| Автор: | |
| Формат: | Стаття |
| Мова: | Англійська |
| Опубліковано: |
Національна академія наук України
2008
|
| Онлайн доступ: | https://nasplib.isofts.kiev.ua/handle/123456789/5607 |
| Теги: |
Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 / Y. Nazarenko // Екологія довкілля та безпека життєдіяльн. — 2008. — № 4. — С. 85-88. — Бібліогр.: 3 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860245619761741824 |
|---|---|
| author | Nazarenko, Y. |
| author_facet | Nazarenko, Y. |
| citation_txt | Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 / Y. Nazarenko // Екологія довкілля та безпека життєдіяльн. — 2008. — № 4. — С. 85-88. — Бібліогр.: 3 назв. — англ. |
| collection | DSpace DC |
| description | У статті порівнюються методологія та результати досліджень глибинних частин льодовиків, проведених різними дослідницькими командами, з метою визначення ізотопного складу елементів захоплених у полярній кризі газів та кисню самої криги. Результати з різних свердловин, які відповідають періодам часу, що перекриваються, привели до порівняння альтернативних даних. Результати досліджень ізотопного складу зіставлено з відповідними кліматичними подіями минулого, так що їхній зв’язок із зміною клімату стає очевидним.
В статье сравниваются методология и результаты исследований глубинных частей ледников, проведенных различными исследовательскими командами, с целью определения изотопного состава элементов захваченных в полярных ледниках газов и кислорода самого льда. Результаты из разных скважин, отвечающие перекрывающимся периодам времени, привели к сопоставлению альтернативных данных. Результаты исследований изотопного состава сопоставлены с соответствующими климатическими событиями прошлого, так что их связь со сменой климата становится очевидной.
|
| first_indexed | 2025-12-07T18:36:20Z |
| format | Article |
| fulltext |
Екологія довкілля та безпека життєдіяльності, №4 2008
85
INTrODuCTION
In this paper, the author makes an attempt to investi-
gate methods and results of ice core-based research on
determination of trapped gas and oxygen of ice isoto-
pic composition in the polar ice cores over up to 420 kyr
before the present. The author tried to find alternative
studies from different ice core drills so that the time
periods covered would overlap at least partialy. This
allowed comparison of data from alternative sources.
This paper also describes types and applications
of data, obtained for particular isotope-research data.
The paper is structured in the way, the data for a
particular time period is interpreted in close concern
with the time period in the Past itself. This allows the
reader to trace and confront isotopic effects to certain
climatic events at a particular time in the past.
ISOTOpIC COMpOSITION OF ICE-TrAppED GASES, IN pArTICuLAr,
NITrOGEN AND ArGON, ALSO OXYGEN OF WATEr, AS AN INDICATOr
OF rApID TEMpErATurE AND GLACIATION-DEGLACIATEION CHANGES
Perhaps, the most well-known isotopic difference effect,
on the basis of which useful data about past climate
variations can be obtained is the 16O/18O one. Because
16O is lighter than 18O, H2
16O evaporates more readily
(due to lower vapor pressure) than H2
18O. For the same
reason, heavier H2
18O condenses and deposits more
readily than water with lighter oxygen isotope. This
effect causes World Ocean’s water to get depleted in
the lighter oxygen isotope as water is evaporated and
deposited in ice, which leads to 16O/18O ratio in the ice
cores to be different depending on depth (and thus,
the time period in the past) reflecting the current (at
that time) amount of ice in glaciers and the changes
in the hydrological cycle [1]. The 16O/18O ratio is also
affected by water vapor traveling to the poles and thus,
lighter water content in the vapor over poles is even
further increased. Water from polar snow will thus be
found to be most depleted in H
2
18
O. The temperature,
at which snow for that or another layer (that later
became bubbled ice) is formed, is thus “recorded” along
the depth of an ice core [2]. Hydrogen in the water
formulae above can be either 1H or 2H (Tritium is not
a concern here due to its very low concentration). The
ratio of isotopes in condensed (or deposited) water is in
dependence on the temperature at which condensation
(deposition) occurs. Such fractionation leads to greater
depletion of deposited water with Deuterium with the
decrease in temperature at which deposition occurs.
This effect causes polar ice cores to have varying 1H/2H
ratio depending on temperature [1].
Petit and colleagues [1] also conducted δD and
δ18Oatm determination in the framework of their Vostok
ice core research. The most important results for glacial
terminations I to IV and the subsequent interglacial
periods (Holocene, stage 5.5, stage 7.5 and stage 9.3)
are depicted in figure 1. As it is seen in the figure, the
last interglacial period (Holocene) is the most stable in
terms of δD and δ18Oatm and thus, temperature, which
is represented by much smoother δD and δ18Oatm lines.
Based on literature data, researchers concluded that
δ18Oatm tracks δ18Osw (SW stands for ‘surface water’) with
a lag of approximately 2 kyr. Authors suppose that this
interrelationship can be used to follow deglaciation-
associated large ice amount variations. In the obtained
уДК 551.510.4:543.27:(546.212.027+546.29.027):551.583
ISOTOpIC COMpOSITION OF ICE AND TrAppED GASES INDICATE rApID TEMpErATurE
БAND GLACIATION-DEGLACIATION CHANGES AS rEVEALED FrOM ICE COrES
part 2
Y. Nazarenko –
Rutgers, The State University of New Jersey, Department of Environmental Sciences
У статті порівнюються методологія та результати досліджень глибинних частин льодовиків,
проведених різними дослідницькими командами, з метою визначення ізотопного складу еле-
ментів захоплених у полярній кризі газів та кисню самої криги. Результати з різних свердло-
вин, які відповідають періодам часу, що перекриваються, привели до порівняння альтернатив-
них даних. Результати досліджень ізотопного складу зіставлено з відповідними кліматичними
подіями минулого, так що їхній зв’язок із зміною клімату стає очевидним.
В статье сравниваются методология и результаты исследований глубинных частей ледников,
проведенных различными исследовательскими командами, с целью определения изотоп-
ного состава элементов захваченных в полярных ледниках газов и кислорода самого льда.
Результаты из разных скважин, отвечающие перекрывающимся периодам времени, привели
к сопоставлению альтернативных данных. Результаты исследований изотопного состава
сопоставлены с соответствующими климатическими событиями прошлого, так что их связь со
сменой климата становится очевидной.
Екологія довкілля та безпека життєдіяльності, №4 2008
86
measurements, δ18Oatm changes in amplitude are par-
allel to those of δ18Osw for all terminations I to IV. In the
course of each termination, as seen in figure 1, δ18Oatm
decreases quickly, which should be caused by strong
deglaciation.
Based on the differences in thermal diffusion of
different Argon and Nitrogen isotopes through the
open-pore snow/firn/open-bubble ice system depend-
ing on the actual snow surface temperature, the study
of 15N/14N and 40Ar/36Ar provides record of rapid tem-
perature changes. The gas isotopes separate in firn
due to gravitational settling and temperature gradient-
induced fractionation (heavier gases and, in particu-
lar, heavy isotope-enriched 15N14N and heavy isotope
15N2 and 40Ar, tend to move to colder regions). In their
research, Severinghaus and colleagues [3] measured
these isotopes in trapped air bubble in the framework
of Greenland Ice Sheet Project 2 (GISP2). Laboratory
calibration allowed determining dependences of Argon
and Nitrogen isotope thermal diffusion-based fraction-
ation and thus, permitted application of these data to
determine temperature changes on the basis of these
isotopes in the ice-trapped air. One more advantage
is that atmospheric methane concentration changes
are recorded parallel with nitrogen isotope changes
because the diffusion intensity of both is close.
Additionally, temperature estimations based on
Argon and Nitrogen isotopes can be more precise
to determine snow surface temperature when other
gases were trapped because other methods of tem-
perature determination like oxygen-isotope had been
found to may not always correspond to temperature
changes but be caused by 16O/18O fluctuations, inferred
by other factors (e.g. ice amount changes).
Figure 2 shows the profile, taken in summer when
snow is significantly colder than the air above. Heavy
isotopes are driven by this temperature gradient down
the firn and mixed by diffusion with gases, already
there. The δ15N- and δ40Ar/4-enriched air, represented
by the peak around the depth of 6 m, is formed
because of gravitational settling.
Sudden temperature increases create a tempera-
ture gradient in the firn, which is ‘conserved’ for hun-
dreds of years (so-called “thermal equilibration time of
the firn”). This triggers thermal fractionation. Because
gas diffusion is tenfold faster than heat diffusion in
polar firn, temperature increase-related isotopic ratio
changes reach the firn bottom about 10 years before
thermal equilibration is set. There, at the firn bot-
tom, where air bubbles are finally enclosed, they trap
smoothed by diffusion abrupt increases in δ15N. These
increases are followed by a steady decrease in δ15N
Fig. 1. (adapted from [1]). “Vostok time series during glacial terminations. Variations with respect
to time of: a, dust; b, δD of ice (temperature proxy); c, CO2; d, CH4; and e, δ18Oatm for glacial termina-
tions I to IV and the subsequent interglacial periods (Holocene, stage 5.5, stage 7.5 and stage 9.3)”
Екологія довкілля та безпека життєдіяльності, №4 2008
87
Fig. 2. (adapted from [3]). “Depth profile of nitrogen and argon isotope ratios in air withdrawn
from the snow pack at Siple Dome, Antarctica, on 14 January 1998, δ15N is defined as [(15N/14Nsample)/
(15N/14Natmosphere) - 1] × 103 and is expressed in units of per mil (parts per thousand). δ40Ar is the corre-
sponding quantity for the 40Ar/36Ar ratio and is divided by 4 to facilitate comparison with δ15N
Fig. 3. (adapted from [3]). “The 400-year window encompassing the Bølling Transition (rapid warming around
14,5 kyr), showing high-resolution measurements of oxygen isotopes of ice and nitrogen, argon, and methane
measurements made on trapped air bubbles. The gas age is deduced by assuming that the abrupt change in ni-
trogen isotopes marked by the dashed vertical line corresponds to the shift in oxygen isotopes at 14.65 kyr”
Екологія довкілля та безпека життєдіяльності, №4 2008
88
over several hundred years, during which temperature
throughout firn stabilizes again [3].
An example of practical Nitrogen/Argon isotope
ice core data recovery is shown in figure 3, represent-
ing the period of so-called Bølling Transition when
rapid warming occurred 14.67 kyr before the present.
The start of this event marks the end of the last gla-
cial period, also called ‘Interstadial 1’. The cold period
before the Bølling Transition is the Oldest Dryas.
Researchers [3] found δ15N increase from +0.48
per mil to peak values of +0.63 per mil during this
time period. Researchers examined the model esti-
mates of the gas age-ice age difference as a part of
their study. They found a mismatch between model
and observed gas isotopes (as seen in figure 3 from
14.55 to 14.62 kyr). This is especially noticeable for δ15N
in figure 3. Authors attributed this to “gravitational
enrichment from transient firn thickening brought
about by the increase in snow accumulation, which
was not included in the model” [3]. This factor, thus,
should be considered during interpretation.
Figure 3 presents a good combination of data
to carry out δ15N and δ40Ar comparison with meth-
ane concentration changes (the reason for authors’
choice of methane is described above) and also with
δ18O. In the period from 14.65 to 14.60 kyr, methane
concentration grows. At the same time, δ15N first
grows noticeably out of the interval of Oldest Dryas
variability at 14.672 ky (1821.16 m depth). This is the
start of the warming and, as seen in the figure, it is
accompanied by 1.7 per mil growth of δ18Oice. Authors
also cite that evidence to the abrupt doubling of snow
accumulation at this time exists. At the same time,
during this period, CH4 concentration does not go out
of Oldest Dryas variability range of 470 to 510 p.p.b.v.
in 14.672 kyr ice sample and in the next sample at
14.655 kyr. Methane concentration goes out of this
only later (around 27 years after the corresponding
change in δ15N) at 14.645 kyr (1820.17 m). It was con-
cluded that methane concentration started rising only
after the start of the Greenland warming.
On the basis of δ15N and δ40Ar/4 values in the
Bølling interval, researchers [3] determined that air
temperatures warmed by 9 ± 3°C by 14.60 kyr. They
also assumed their δ18Oice data (δ18Oice increased by
3.4 per mil during the Bølling transition), from which
they were able to determine oxygen isotope tem-
perature sensitivity across the transition could serve to
verify the borehole calibration.
CONCLuSIONS
The most extensive coverage of the past climate 1.
change and in particular, atmospheric gas
composition and temperature change was fulfilled
in the framework of extended drilling project
at Vostok station, East Antarctica. It allowed
investigation of atmospheric composition and
climate ice record encompassing the past four
glacial–interglacial cycles. Researchers [1] found
repetitiveness of changes throughout all four climate
cycles. Moreover, change pattern during interglacial
terminations was similar, gas concentrations and
temperature changed roughly within particular
limits between stable limits.
Ice core research discovered that interglacials’ 2.
development and length were somewhat different
from cycle to cycle.
Present interglacial period, Holocene, appeared to be 3.
the most stable in terms of sharpness of atmospheric
composition and temperature changes when compared
to other interglacial periods over the past 420 kyr.
Petit and colleagues described that during the last 4.
four glacial terminations initially, temperature increased
accompanied by carbon dioxide and methane
concentration increase. Then, there was a rapid increase
in methane concentration that concurred with the
beginning of the δ18Oatm decrease that the authors
attributed to rapid melting of the Northern Hemisphere
ice sheets including warming in Greenland.
δ5. 18Oatm tracks δ18Osw (SW stands for ‘surface water’)
with a lag of approximately 2 kyr. It is supposed
that this interrelationship can be used to follow
deglaciation-associated large ice amount variations.
In the obtained measurements, δ6. 18Oatm changes in
amplitude are parallel to those of δ18Osw for all terminations.
In the course of each termination, δ18Oatm decreases quickly,
which should be caused by strong deglaciation.
Temperature estimations based on Argon and Nitrogen 7.
isotopes can be more precise to determine snow surface
temperature when other gases were trapped because
other methods of temperature determination like oxygen-
isotope had been found not always corresponding to
temperature changes but be caused by 16O/18O fluctuations,
inferred by other factors (e.g. ice amount changes).
Researchers [3] also determined on the basis of δ8. 15N and
δ40Ar/4 values in the Bølling interval that air temperatures
warmed by 9 ± 3°C by 14.60 kyr. They also assumed their
δ18Oice data, from which they were able to determine
oxygen isotope temperature sensitivity across the
transition, could serve to verify the borehole calibration.
LITErATurE CITED
Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, 1.
J.-M., Basile, I., Bender, M., Chappellaz, J., Davisk, M.,
Delaygue, G., Delmotte, M., Kotlyakov, V.M., Legrand, M.,
Lipenkov, V.Y., Lorius, C., Pépin, L., Ritz, C., Saltzmank, E.,
Stievenard, M. Climate and atmospheric history of the
past 420,000 years from the Vostok ice core, Antarctica,
Nature (1999), 399, 429–436.
Óskarsson, B.V. Ice core evidence for past climates 2.
and glaciation. Science Institute, Náttúrufræðahúsið,
University of Iceland, 101 Reykjavík. http://www.hi.is/~oi/
Nemendaritgerdir/Ice%20core%20evidence%20for%20
past%20climates%20and%20glaciation.pdf Document
created 20thof March 2004.
Severinghaus, J.P., Brook, E.J. Abrupt Climate Change at 3.
the End of the Last Glacial Period Inferred from Trapped
Air in Polar Ice. Science (1999), 286, Issue 5441, 930–934.
|
| id | nasplib_isofts_kiev_ua-123456789-5607 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1726–5428 |
| language | English |
| last_indexed | 2025-12-07T18:36:20Z |
| publishDate | 2008 |
| publisher | Національна академія наук України |
| record_format | dspace |
| spelling | Nazarenko, Y. 2010-01-27T15:44:35Z 2010-01-27T15:44:35Z 2008 Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 / Y. Nazarenko // Екологія довкілля та безпека життєдіяльн. — 2008. — № 4. — С. 85-88. — Бібліогр.: 3 назв. — англ. 1726–5428 https://nasplib.isofts.kiev.ua/handle/123456789/5607 551.510.4:543.27:(546.212.027+546.29.027):551.583 У статті порівнюються методологія та результати досліджень глибинних частин льодовиків, проведених різними дослідницькими командами, з метою визначення ізотопного складу елементів захоплених у полярній кризі газів та кисню самої криги. Результати з різних свердловин, які відповідають періодам часу, що перекриваються, привели до порівняння альтернативних даних. Результати досліджень ізотопного складу зіставлено з відповідними кліматичними подіями минулого, так що їхній зв’язок із зміною клімату стає очевидним. В статье сравниваются методология и результаты исследований глубинных частей ледников, проведенных различными исследовательскими командами, с целью определения изотопного состава элементов захваченных в полярных ледниках газов и кислорода самого льда. Результаты из разных скважин, отвечающие перекрывающимся периодам времени, привели к сопоставлению альтернативных данных. Результаты исследований изотопного состава сопоставлены с соответствующими климатическими событиями прошлого, так что их связь со сменой климата становится очевидной. en Національна академія наук України Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 Article published earlier |
| spellingShingle | Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 Nazarenko, Y. |
| title | Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 |
| title_full | Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 |
| title_fullStr | Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 |
| title_full_unstemmed | Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 |
| title_short | Isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. Part 2 |
| title_sort | isotopic composition of ice and trapped gases indicate rapid temperature and glaciation-deglaciation changes as revealed from ice cores. part 2 |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/5607 |
| work_keys_str_mv | AT nazarenkoy isotopiccompositionoficeandtrappedgasesindicaterapidtemperatureandglaciationdeglaciationchangesasrevealedfromicecorespart2 |