US Long-Term Ecological Research Network


Ice Phenology Workshop: Comparing change in Scandinavia and the Great Lakes region

Long term observations of freeze and breakup dates for lakes and rivers across the northern hemisphere show consistent and widespread changes in ice phenology3. Recent analyses have focused on understanding geographic patterns in such changes4,5, and their consequences for aquatic communities6. Two regions of the world have a sufficient quantitiy of long term ice phenology records to allow for a detailed regional approach to understanding their patterns: the Laurentian Great Lakes region and Scandinavia. In both regions, ice phenology has changed more rapidly in warmer locations4,7; however, the influence of other meteorological variables (e.g., timing of snowfall, snow depth, and cloud cover) is not well understood. Overlain on this complexity is the combined impact of long term climate change and decadal scale oscillations.

We propose a workshop to begin a comparative investigation of ice phenology changes in Scandinavia and the Laurentian Great Lakes region. Ice phenology has been an active area of research for scientists at the NTL LTER site and its analogs in Sweden, Finland, and Switzerland. Using spatial analysis and time series techniques, we will investigate relationships between ice phenology, meteorological variables (snow and solar radiation), and large scale climate drivers (SOI, NAO, PDO, etc.). The contribution of individual lake characteristics (depth, surface area, and elevation) to these relationships will also be explored. The results will allow us to identify lake characteristics and geographic locations that are sensitive to climatically-induced changes in ice phenology. The workshop will also provide an opportunity to discuss available biological time series (zooplankton, fish recruitment, etc.) that may be compared with ice phenology, further develop aquatic research within the ILTER network and strengthen ties with long term ecological research sites in Sweden (potential ILTER sites).

This workshop is proposed for October 2007 at the Lake Erken field station of Uppsala University, Sweden with Barbara Benson, John Magnuson, Olaf Jensen (Ph.D. candidate) attending from the University of Wisconsin and, at a minimum, Gesa Weyhenmeyer (Uppsala University, Sweden), David Livingstone (Swiss Federal Inst. of Environmental Sci. and Tech.) and Johanna Korhonen (Finnish Environment Institute) attending as European partners.

3Magnuson, J.J. et al. 2000. Science 289:1743-1746; 4Jensen, O.P. et al. Limnology & Oceanography In review; 5Magnuson, J.J. et al. 2005. Verh. Internat. Verein. Limnol. 29:521-527; 6Weyhenmeyer, G. 2001. Ambio 30:565-571; 7 Weyhenmeyer, G. et al. 2004. Geophysical Research Letters 31:L07203.


April 1

  • Arrivals
  • 6pm     Dinner

April 2

  • 7:30am Breakfast
  • 8:30am Welcome, logistics (Thorsten, Barbara)
  • Presentations on current research (related to ice) (15 min each)
  • Discuss goals for the week
  1. Go over available data, make accessible to everyone at workshop
  2. List of possible paper titles and data needs for each
  3. Preliminary list of people working on each topic in (2) and leader for each
  • 12-1pm Lunch
  • 1-5pm    Divide into smaller groups (~3 people each) focused around topics
    • Outline tasks associated with each topic (data compilation, analyses, figure generation, writing, etc
    • Kaffe Pause
    • Repeat small groups
  • 6pm Dinner

April 3

  • 7:30am  Breakfast    
  • 8:30am  Reports from groups
    • Analysis, outlining, writing, literature search, additional discussion
    • Possible submission of session proposal for ASLO (Jan 2009)
  • 12-1pm Lunch
  • 1-5pm   Analysis, outlining, writing, literature search, additional discussion
  • 6pm Dinner

April 4

  • 7:30am Breakfast     
  • 8:30am Reports from groups (with outlines, key findings, and results!)
  • 12-1pm Lunch
  • 1-5pm    Divide into topic groups and discuss plans for finishing manuscripts
    • Review proposal for ASLO meeting session
    • Discuss plans for future workshops, collaborations, etc.    
LTER Keyword
NTL Keyword