06 August 2008

Science on the way

No, not articles I'm going to be writing, but a sampling of sessions that are coming at the fall meeting of the American Geophysical Union:

Session names here, descriptions below.

Satellite Geodesy of the Polar Oceans
Progress in Quaternary Geochronology in Polar Regions
Cryospheric Climate Data Records
Rapid Arctic Environment Change
Environmental Impacts of a Shrinking Arctic Sea Ice Cover
Long-Term Trends in the General Circulation of the Atmosphere: Observations, Simulations, Mechanisms, and Impacts
Large Scale Cryosphere – Climate Connectivity
Ice Sheet Hydrology and Dynamics

This is just a small sampling of the sessions that will be going on. To see more, check out the AGU for the Fall meeting's program. The sessions turn on those good science questions: what are the data, how good are they, how can we get and retain better, what does it mean, how well do we understand what's already going on, what might happen in the future, and what would that mean, etc.

Now for the details, happy reading:

Satellite Geodesy of the Polar Oceans
New satellite geodetic techniques and observations are providingunprecedented views of the polar oceans, their ice cover as well as the topography and tectonic fabric of the seafloor below. Satellite altimeter measurements of ice and snow elevation from radar and laser
systems, such as Envisat and ICESat are providing wide area, continuous, information on ice thickness changes. Satellite measurements of sea surface topography and gravity for example from GRACE offer the potential for significant advances in our understanding of the Polar
Oceans, particularly when combined with in-situ observations. Marine gravity fields from satellite altimetry as well as satellite and surface gravimetry are also providing new maps of the tectonic structure and bathymetry of the poorly mapped polar oceans. The current satellite
capabilities will be significantly enhanced in the near future with the launch of new missions such as GOCE, CryoSat-2 and IceSat-2. We welcome contributions on all aspects of satellite geodesy of the polar oceans with emphasis on applications of these data to science problems in the
areas of oceanography, the marine cryosphere and tectonics.

Progress in Quaternary Geochronology in Polar Regions
The main purpose of this session is to provide an opportunity for discussion of recent progress and challenges in developing chronologies in Arctic and Antarctic regions. Session organizers hope to include, but are not limited to: research in the fields of ice-core chronology,
tephrochronology, dendrochronology and DNA analysis, as well as cosmogenic nuclide, radiocarbon and luminescence dating. Session conveners encourage a discussion of new developments in chronological methods with regard to different paleoclimate archives and the advantages and weaknesses of various methods.

Cryospheric Climate Data Records
The generation of cryospheric climate data records (CDRs) is a critical step in providing the necessary information for scientists, decision-makers, and stakeholders to make adaptive choices that could improve the nation's resiliency to environmental change and variability, maintain our economic vitality, and improve the safety and comfort of U.S. citizens. This session will bring together recent efforts in the development of CDRs over Arctic and Antarctic ocean, ice, and
terrestrial surfaces, including snow cover, sea and land ice, melt onset, surface temperature, sea surface temperature, etc. Contributions are encouraged covering the full spectrum of CDR development and use, including initial formulation of algorithms, validation of CDRs, and use
of CDRs for scientific inquiry.

Rapid Arctic Environment Change
The extent of Arctic perennial sea ice was reduced by another million square kilometers between the winters of 2007 and 2008 with seasonal ice occupying the North Pole region in mid-winter for the first time in the observational record. There were major warm temperature anomalies in the
central Arctic in fall 2007 and accelerated ice drift along the Transpolar Drift Stream in spring and summer 2007. Many impellent science issues remain: Is the summer ice extent more influenced by
initial conditions or by summer forcing? What is the relative role of dynamics, thermodynamics, and feedbacks in Arctic ice reduction? Will the current change continue, accelerate, or decelerate? Has Arctic change crossed into a new state or can it be reversed? What are the
regional and global impacts? Fortunately, the International Polar Year program has been ongoing with international research efforts providing new and crucial results on Arctic change and its impacts. In this regard, this session calls for presentations on 2007-2008 Arctic change, the historical context of recent change, predictions of change, and impacts of Arctic change on ocean, land, and atmosphere.

Environmental Impacts of a Shrinking Arctic Sea Ice Cover
Arctic sea ice extent at the end of the summer melt season has declined sharply over the period of satellite observations and is projected to disappear entirely as concentrations of atmospheric greenhouse gases continue to rise. The record low ice extent of September 2007 served as an exclamation point on the downward trend and further raised concern that the Arctic may be on the verge of rapid transition to a seasonal ice cover. While the factors forcing this trend have and will continue to be widely studied, less attention has been paid to the environmental impacts of current and future sea ice loss. Continued loss of the ice cover may result in strong rises in atmospheric temperature and water vapor content, not just at and near the surface, but extending through a considerable depth of the troposphere. Changes in humidity and the
boundary layer structure are likely to alter cloud conditions, a key determinant of the surface energy balance. Through atmospheric transports, warming will likely extend well beyond areas of ice loss, potentially influencing arctic land areas, glaciers, ice caps, and the Greenland ice sheet. Extensive open water areas will promote increased wave action and coastal erosion. Ice loss may in turn have impacts on patterns of atmospheric circulation and precipitation not just within
the Arctic, but potentially extending into middle latitudes. While evidence is growing that some of these effects are already occurring, they are likely grow in coming decades. This session will address emerging and projected environmental impacts of arctic sea ice loss through both observational and modeling studies.

Long-Term Trends in the General Circulation of the Atmosphere: Observations, Simulations, Mechanisms, and Impacts
An increasing body of evidence indicates that key-elements of the large-scale atmospheric general circulation have undergone significant change over the past several decades, which may be an important indicator of climate change. Examples include widening of the Hadley cell, changes in the position of the subtropical jets and extratropical storm tracks, lifting of the tropopause, and trends in the annular modes. However, there is still much to be learned about the observational evidence of these changes, their causes, and their societal and environmental impacts. Several causal mechanisms have been suggested, such as changes in tropospheric stability, extratropical eddy activity, and stratospheric dynamics. But it is still unclear which may
be most appropriate and whether there exists a single unifying theory. This session will bring renewed focus to this issue by examining further evidence for these processes, exploring their cause(s), and improving our theoretical understanding of their linkages. We invite studies on all aspects of long-term change in the general circulation, particularly papers that combine observational, modeling, and theoretical approaches.

Large Scale Cryosphere – Climate Connectivity
High-latitude regions are recognized as being critically sensitive to anthropogenic climate change, and are also subject to large scale climate phenomena such as the northern and southern annular modes. The cryosphere is a dominant but highly variable feature in these regions, and exists in numerous forms including snow cover, ice sheets, permafrost and sea ice. Therefore components of the cryosphere can be expected to interact with climate variability and change, either as a passive responder to climate, as an instigator of climate perturbations, or through feedback mechanisms that affect both facets of the polar environment. Moreover, this cryosphere – climate connectivity is not constrained to high latitudes, but can also occur in snow-covered mid-latitudes and hence potentially affect the global climate system. This session brings cryospheric, atmospheric, hydrologic and climate scientists together to share recent advances in our current understanding of this connectivity. Investigations are solicited involving all components of the cryosphere, and both climate variability and change. Studies that target large, regional – continental scales are particularly encouraged.

Ice Sheet Hydrology and Dynamics
The extent to which fluctuations in basal and surface hydrology affect ice sheets is a topic of widespread and recent concern; changes in the flow of the Greenland Ice Sheet correlate with changes in its surface hydrology. Melting at the Antarctic Peninsula has factored in the disintegration of ice shelf sections, and exchanges of water between lakes at the base of the Antarctic Ice Sheet could modulate mass losses through episodic drainage and lubrication. Although relationships between the hydrology and flow of mountain glaciers have been studied for much of the past century, attention has only recently turned to ice sheets, so a detailed understanding is lacking. This session will explore the effects hydrology has on ice sheet dynamics by collating the results of field experiments, satellite observations, and numerical modeling. Contributions from each of these areas are encouraged.


Bella Green said...

I'm impressed with what I've read, and am looking forward to more. Please do stick with your rules re links for commenting; it will indeed put your blog a cut above the rest. Best of luck!

Hank Roberts said...

Will you be among those blogging from the AGU, for those of us on the outside?

As an aside, perhaps for another thread -- I'm curious also if you have thoughts about the work coming out of the Naval Postgrad School, as mentioned recently for example here:http://www.realclimate.org/index.php/archives/2008/06/north-pole-notes/langswitch_lang/wp#comment-95198

I've watched their theses and other publications show up in Google/Scholar searches over the years but rarely see them discussed.

Penguindreams said...

Thanks Bella.

Hank: I won't be at the AGU. Just that I'm on the mailing lists and a member. I thought it'd be interested for people to see what kinds of things are being discussed. And that they are being discussed rather than 'case closed'.

I think you've lead me to two different threads. One about sociology of science (scientists are people, so some things happen for that reason rather than if we were machines), and another about sea ice modeling. The latter I'm nervous about as it's too close to what I do professionally. Hard to keep to my own rules for this blog in those areas.

To your realclimate post, I can at least answer this much. I don't think Maslowski et al. have access to data that the rest of us don't relevant to making sea ice predictions. It's a different ocean model than most, a different atmospheric model than most (normally NOGAPS, iirc), and a slightly different ice model. Each of the three is somewhat to the tail of the distribution, but none are unreasonable. Nor is the combination unreasonable. Speaking for myself (well, I always am, here especially), I take their work seriously. Not without question, but serious.