Geoscience Reference
In-Depth Information
4. DISCUSSION
Bianchi, G. G., and I. N. McCave (1999), Holocene periodicity in
North Atlantic climate and deep-ocean
flow south of Iceland,
Results such as those presented by Viau et al. [2006] show
that the climate was continually changing during the Holo-
cene, at many timescales. Many of the
517.
Birks, H. J. B., and H. H. Birks (1980), Quaternary Palaeoecology,
Blackburn, Caldwell, N. J.
Bond, G., W. Showers, M. Cheseby, R. Lotti, P. Almasi, P. deMenocal,
P. Priore, H. Cullen, I. Hajdas, and G. Bonani (1997), A pervasive
millennial-scale cycle in North Atlantic Holocene and glacial
climates, Science, 278, 1257
Nature, 397, 515
-
ed in
some records are part of a continuous series of rapid climate
changes, including variations such as the Younger Dryas and
the latest of which are the MWP and LIA. For example, the
Holocene in North America can be divided into four general
periods, with abrupt transitions at ~8, 6, and 3 ka (Figure 4).
The millennial-scale variability, with a prominent spectral
peak at ~1000 ± 100 years (Table 1), varies as a function of
these four periods of time and shows increased variability
during the early Holocene and the past 3 kyr. Transitions
between these periods are abrupt in many cases. The LIA, for
example, is part of a continual series of events during the
Holocene and is especially prominent due to the scale inter-
action with the slower Milankovitch-forced variability. Rapid
events identified in some series, such as the 4.2 or 5.2
“
“
events
”
identi
1265.
Bond, G., B. Kromer, J. Beer, R. Muscheler, N. E. Evans, W.
Showers, S. Hoffman, R. Lotti-Bond, I. Hajdas, and G. Bonani
(2001), Persistent solar in
-
uence on North Atlantic climate dur-
ing the Holocene, Science, 294, 2130
2136.
Bouchard, G., K. Gajewski, and P. Hamilton (2004), Freshwater
diatom biogeography in the Canadian Arctic Archipelago, J.
Biogeogr., 31, 1955
-
1973.
Bourgeois, J. (2001), Seasonal and annual variation of pollen var-
iability in snow layers of Arctic ice caps, Rev. Palaeobot. Paly-
nol., 108,17
-
36.
Bourgeois, J., R. Koerner, K. Gajewski, and D. Fisher (2000), A
Holocene ice core pollen record from Ellesmere Island, Nunavut,
Canada, Quat. Res., 54, 275
-
events
are part of this continual variability.
These results suggest that the
”
283.
Bryant, V. M., and R. G. Holloway (1985), Pollen Records of Late-
Quaternary North American Sediments, Am. Assoc. of Stratigr.
Palynol., Dallas, Tex.
Chapman, M. R., and N. J. Shackleton (2000), Evidence of 550-
year and 1000-year cyclicities in North Atlantic circulation pat-
terns during the Holocene, Holocene, 10, 287
-
”
supposedly seen in records such as the Greenland ice cores
during the Holocene is overstated, and although the variabil-
ity during interglacial periods is less than that during glacial
regimes, it remains significant and large enough to be of
relevance to human activities. The fundamental causes of
this variability are not entirely explained; however, the evi-
dence suggests that rapid climate change may be related to
the interactions of changes in incoming solar radiation and
other forcing and may be ampli
“
relative climate stability
291.
COHMAP Members (1988), Climatic changes of the last 18,000
years: Observations and model simulations, Science, 241, 1043
-
-
1052.
Cowling, S. A., and M. T. Sykes (1999), Physiological signi
ed through internal feed-
cance
of low atmospheric CO
2
for plant-climate interactions, Quat.
Res., 52, 237
back mechanisms.
242.
deMenocal, P. B., J. Ortiz, T. Guilderson, and M. Sarnthein (2000),
Coherent high- and low-latitude climate variability during the
Holocene warm period, Science, 288, 2198
-
Acknowledgments. This research is funded by the Natural
Sciences and Engineering Research Council of Canada. We ac-
knowledge the contributors to the NAPD and other scientists for
contributing their data online.
2202.
Dansgaard, W., et al. (1993), Evidence for general instability of past
climate from a 250 kyr ice core, Nature, 364, 218
-
219.
Davis, B. A. S., S. Brewer, A. Stevenson, and J. Guiot (2003), The
temperature of Europe during the Holocene reconstructed from
pollen data, Quat. Sci. Rev., 22, 1701
-
REFERENCES
1716.
Davis, M. B. (1986), Climatic instability, time lags, and community
disequilibrium, in Community Ecology, edited by J. Diamond and
T. Case, pp. 269
-
Alley, R. B. (2004), GISP2 Ice Core Temperature and Accumula-
tion Data, IGBP PAGES/World Data Center for Paleoclimatology
Data Contrib. Ser. 2004-013, http:\\www.ncdc.noaa.gov/paleo,
NOAA/NCDC Paleoclimatol. Program, Boulder, Colo.
Alley, R. B., P. A. Mayewski, T. Sowers, M. Stuiver, K. C. Taylor,
and P. U. Clark (1997), Holocene climatic instability: A promi-
nent widespread event 8200 yr ago, Geology, 25, 483
284, Harper and Row, New York.
EPICA Community Members (2006), One-to-one coupling of gla-
cial climate variability in Greenland and Antarctica, Nature, 444,
195
-
486.
Battarbee, R. W. (2000), Palaeolimnological approaches to climate
change, with special regard to the biological record, Quat. Sci.
Rev., 19, 107
-
198.
Fisher, D. A. (1982), Carbon 14 production compared to oxygen
isotope records from Camp Century, Greenland and Devon Is-
land, Clim. Change, 4, 419
-
124.
Bernabo, J. C., and T. Webb III (1977), Changing patterns in the
Holocene pollen record of northeastern North America: A
mapped summary, Quat. Res., 8,64
-
426.
Fisher, D. A., R. M. Koerner, and N. Reeh (1995), Holocene
climatic records from Agassiz Ice Cap, Ellesmere Island, NWT,
Canada, Holocene, 5,19
-
-
96.
-
24.
Search WWH ::
Custom Search