Peter Huybers cv

Department of Earth and Planetary Sciences
Harvard University
20 Oxford St., Cambridge, MA 02138 USA
 phuybers@fas.harvard.edu, (617)495-8391








Publications
  • Huybers and Tziperman, Integrated summer insolation forcing and 40,000 year glacial cycles: the perspective from an icesheet/energy-balance model, Paleoceanography, 2008. pdf and code
  • Huybers and Molnar, Tropical cooling and the onset of North American glaciation, Climate of the Past, 2007. pdf
  • Huybers, Gebbie, and Marchal, Can paleoceanographic tracers constrain meridional circulation rates?, Journal of Physical Oceanography, 2007. pdf
  • Gebbie and Huybers, Meridional circulation during the Last Glacial Maximum explored through a combination of South Atlantic d18O observations and a geostrophic inverse model, G-cubed, 2006. pdf
  • Tziperman, Raymo, Huybers, and Wunsch, Consequences of pacing the Pleistocene 100 kyr ice ages by nonlinear phase locking to Milankovitch forcing, Paleoceanography, 2006. pdf
  • Huybers and Curry, Links between annual, Milankovitch, and continuum temperature variability, Nature, 2006. pdf and supplemental material
  • Huybers, comment on ``Hockey sticks, principal components, and spurious significance'' by McIntyre and McKitrick [2005], Geophysical Research Letters, 2005. pdf and supplemental material (An edited version of this paper was published by AGU. Copyright 2005 American Geophysical Union.)
  • Huybers and Wunsch, Obliquity pacing of the late Pleistocene glacial terminations, Nature, 2005. pdf
  • Huybers and Wunsch, A depth-derived Pleistocene age-model: uncertainty estimates, sedimentation variability, and nonlinear climate change, Paleoceanography, 2004. pdf
  • Huybers, Comments on: 'Coupling of the hemispheres in observations and simulations of glacial climate change': by A. Schmittner, O.A. Saenko, and A.J. Weaver [Quaternary Science Reviews 22 (2003) 659-671], Quaternary Science Reviews, 2004. pdf
  • Huybers and Wunsch, Rectification and precession-period signals in the climate system, Geophysical Research Letters, 2003. pdf

Manuscripts
  • Huybers and Denton, Interpolar climate symmetry at orbital time scales and the duration of Southern Hemisphere summer, submitted. pdf
  • Stine, Huybers, and Fung, Changes in the phase of the annual cycle of surface temperature , submitted. pdf
  • Huybers and Langmuir, Feedback between deglaciation and volcanic emissions of CO2 , submitted. pdf
  • Perron and Huybers, Is there an orbital signal in the polar layered deposits on Mars? , submitted. pdf
  • Tingley and Huybers, The spatial mean and dispersion of surface temperatures over the last 1200 years: warm intervals are also variable intervals , submitted. pdf

Downloads
Research
    Glacial cycles. Over the last three million years the amount of ice on the Earth has alternately waxed so as to cover much of the high-latitude continents and waned to the relatively ice-free conditions in the North which we have today. The cause of these massive shifts in climate remains unclear, not for lack of hypotheses, of which there are many, but instead for lack of any single compelling theory. Thus one aim is to distinguish between the competing hypotheses (e.g. Huybers and Wunsch, 2005; Huybers, 2007). Another is to explore the causes of glaciation during the Plieocene and early Pleistocene, associated with seemingly more regular 40,000 year variations in ice-volume (Huybers, 2006; Huybers and Tziperman, 2008). Glacial cycles are unlikely to be understood in isolation, and I've also found it useful to explore their relationship with changes in tropical Pacific sea surface temperatures (Huybers and Molnar, 2007), as well as with changes in Antarctic temperature (Huybers and Denton, submitted). Most recently Taylor Perron and I have looked at whether orbital variation control the layered deposits on the North Polar Cap of Mars (submitted). Much more remains to be done.
    Past atmospheric conditions. How do recent surface air temperature variations compare to past variations? Instrumental records of temperature are sparse before 1850 and wholly absent before 1600, so that tracing out the history of past temperature variability requires the use proxies for temperature. Proxies include tree rings, ice-cores, corals, and lake and marine sediments. How best to determine temperatures from these proxies has been the subject of some research and much debate (e.g. Huybers, 2005). Martin Tingley and I are working on a Bayesian Hierarchical model to estimate spatial average temperature from noisy proxies of local temperature variability. Konrad Hughen and I are exploring Arctic surface temperatures and modes of atmospheric circulation over the last four centuries.
    Past ocean circulation. Reconstruction of past ocean circulation provides allows us to gauge the natural range and modes of ocean circulation, permits testing of our models over a wider range of conditions, helps place modern changes in context, and (to me) is of inherent interest. That said, reliably deducing ocean circulation from paleoceanographic data is challenging (see e.g. Huybers et al., 2006), but if you ask the right questions and make some suitable assumptions, progress is always possible (e.g. Gebbie and Huybers, 2007). Along with Carl Wunsch, Jake Gebbie, and Eli Tziperman, we are continuing to study the past ocean circulation using a combination of modeling and data analysis.
    Climate change across space and time scales. Many fascinating phenomena straddle modern and paleo-climate time-scales. Indeed, climate variability is intimately linked across an enormous range of time-scales (e.g. Huybers and Curry, 2006). Determination of the spatial and temporal scaling associated with climate variability seems fundamental to understanding the relevant physics. I'm now attempting to assess how the spectrum of climate variability changes with the background climate state. I'm also trying to better assess the spatial extent associated with the Younger-Dryas event.


People

    Graduate Students: Martin Tingley and Eddie Haam.
    Research Staff: Geoffrey (Jake) Gebbie.


Opportunities

    Feel free to contact me if you are interested in conducting either graduate or postdoctoral work with me.

Last updated in August, 2007.
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