The EEGLE Program held an all-hands meting at the Homestead Conference Center
in Glen Arbor, MI. Approximately 40 participants spent three plus days (Sep 25-28)
discussing results, issues and potential collaborations. A 130 page workbook was
generated prior to the meeting and is available on the EEGLE website, in four parts,
Monday, September 25
2:00 - Plenary
- Goals for this meeting are to:
- Distribute Workbook of results to date
- Refresh everyone on the breadth of activities and foster interdisciplinary thinking
- New Strategy for use of the website to organize information (e.g.Schwab)
- Charge to the Workgroups (below)
2:30 - Brief overviews of all 20 PI Reports (Schwab, Eadie and Fahnenstiel)
4:30 - General discussion
5:00 - Unstructured time
Tuesday, September 26
Plenary - presentations of preliminary modeling results to focus interdisciplinary
8:30 - Data synthesis (optimal integrated use of data sets and models), McCormick and Murthy
9:00 - Physical - ecological modeling, Chen et al.
9:45 - Sediment transport modeling, Schwab et al., Bedford et al.
10:00 - Charge to Workgroups
- Physical - Ecological [Chair - Kerfoot & Bundy]
- Sediment [Chair - Klump]
- Physical data assimilation [Chair - McCormick & Meadows]
Wednesday, September 27
8:00 - Reconvene Plenary to discuss progress
9:00 - Reconvene Workgroups
1:45 - Bus trip to Sleeping Bear Dunes National Park
5:00 - Workgroups or unstructured time
Thursday, September 28
8:00 - Reconvene Plenary - Workgroup reports (~20 minutes)
9:30 - General discussion consensus on dedicated issue (venue [JGR,
Continental Shelf Research, other], participants, and timing)
11:00 - Adjourn
After several thought-provoking presentations, the participants broke up into three
workgroups: Data Assimilation, Sediments Transport, and Physical-Ecological
Interactions. Separate brief reports from each workgroup follow at the end of
this report, after a brief summary of meeting accomplishments.
Summary of Meeting Accomplishments
First, our program timing has been fortunate; 1998 and 2000 were years that had large
sediment resuspension events while 1999 had only small events (figure 1). This provides
excellent data for a comparison of transport and impacts. Second, our data and sample
collection success rate was quite high, as illustrated in figure 2 and table 1.
Figure 1. NOAA AVHRR (Channel 1 - Channel 2) reflectance for sediment resuspension
events for the three EEGLE field years (1998-2000). Subjectively, these were the
maximum events for the three years that were observed by satellite.
Figure 2. Selected EEGLE field activities. The figure provides information on
temporal coverage for several types of program activities.
Table 1. EEGLE Cruise, Web, & Data Statistics as of August, 2000
1997 - 2000
Plankton Survey Tows
Presentations - Public
Presentations - Professional
Data Objects Submitted
871 (540 MB)
Visits to EEGLE web site
RecommendationsAt the meeting wrapup, we agreed that:
- substantial progress was made in interdisciplinary communication among the programs participants
- a Joint EEGLE-KITES Special Issue of a journal was desirable. Some suggestions were made for journals and schedules
- we have decided to make a significant revision to the EEGLE webpage. Products and activities will be moved to be under each of the appropriate proposals and PIs are being required to take more responsibility for keeping their pages up to date. Greg Lang will assist with this, moving existing materials and implementing additions provided by PIs.
- we would like to create an explicit matrix of PI interactions (current, planned, or merely desirable but unexplored). We hope this will stimulate interdisciplinary thinking.
- and that continued communication was crucial in developing our products - this should occur at several levels:
- Direct PI with PI
- Groups (e.g. Sediments) or smaller sub-groups
- Another EEGLE all-hands - tentatively scheduled for 1-2 days before the 2001 EEGLE-KITES all-hands next fall
- Meetings thus far:
Special Sessions at:
- ASLO-99, Sante Fe, NM, Feb, 1999
- IAGLR-99, Cleveland, OH, May, 1999
- Ocean Sciences, San Antonio, TX, Feb, 2000
- SIL, Melbourne, Australia, Feb, 2001
EEGLE All-hands meetings (3 day workshops)
Some PIs thought that a specific writing workshop would be useful, this will be explored and potential participants/schedules organized by the management team. This could range from days to weeks and perhaps be associated with the delivery of products for the Special Issue
- Milwaukee, WI, Oct, 1997
- Ann Arbor, MI, Oct, 1998
- Minneapolis, MN, Oct, 1999
- Glen Arbor, MI, Sep, 2000
- Argonne National Lab, Dec, 2000
Sediment Workgroup Report
Success in collection of a good suite of data - both spatially and temporally
Caveat: "even with great ingredients you can make a lousy cake", K. Orlandini
Availability of a number of types of data to constrain models, e.g. in the case
of particle fields:
--direct TSM measurements
--tripod measurements and moored transmissometers
** challenge is to integrate/concatenate - importance of cross-linking our data sets and interacting with one another
Issues being worked on:
Transport models - 2 general types
--Simpler 2D - pc based - long term (years - decades) simulations to test ideas
--Coupled 3D - supercomputer based for event simulations
Initial conditions & boundary conditions for modeling efforts
--materials available for resuspension
--source - time series of inputs of erosional material
--particle size distribution effects
--better "mapping" of bottom type/character
Improving estimates of mass fluxes in resuspension events ~ 106 MT
-- alternatives/cross checks on sat data
Particle residence times, settling rates and horizontal transport rates -
promising radionuclide tracer data + integrating into models
Agreement for the need to meet on periodic basis - next for sediment bunch is the day before EEGLE-KITES @ Argonne - November 29 (our 4th group meeting).
Suggest making explicit links and collaborations among all PIs
Some Issues under discussion:
-- Linking time scales & transport to transformation of biogeochemically important materials
-- tracking particles
-- offshore transport; again initial conditions important
Linking time scales and transport to transformation of BIMs
Tracking sources of material
Better "mapping" of bottom type and physical composition
How tie biogeochemical data to hydrodynamics
Questions for other groups -- coming
Physical-Ecological Interactions Workgroup Report
What we know:
--The recurrent coastal plume (RCP) does not significantly stimulate phytoplankton growth and productivity.
--Initially, the RCP does not significantly change phytoplankton nutrient status. However, over time, phytoplankton do seem to be more P-deficient post-RCP than pre-RCP
--Major issues to be resolved are:
- the importance of P utilization by bacteria and
- the role of P scavenging by particles
What we know:
--Phytoplankton diversity is higher during the RCP
Because growth is not stimulated in the plume, this suggests this is a "source" issue
Direct resuspension of meroplankton strongly influences (controls?) phytoplankton community structure in the RCP.
--Resolve ecological significance of central-lake "donut hole" phenomenon
(charge to HAV, WCK, GAF - with WCK having the lead to initiate something)
--Qualify dynamics of phytoplankton community during resuspension event using:
representative species as tracers
material from water column and sediment traps
--Heterotrophic vs. autotrophic activity
Emerging Issues and Questions
--N uptake and regeneration vs. light and P regime show that heterotrophic activity dominated during winter-spring except in region influenced by St. Joseph River
--Phosphorus was not limiting to rates of heterotrophic activity outside of regions of riverine influence
--In areas of riverine influence, autotrophic activity dominated and responded positively to phosphorus additions
--How close will nutrient cycling rates and patterns relate to microbial food web composition at the riverine vs.. non-riverine sites?
The Microbial Food Web (MFW)
What we know:
--Biomass and growth rates of heterotrophic components increase with respect to RCP
--Abundance and biomass of protozoans seems to be correlated with spatial distribution of sediment associated with the RCP
--Protozoan grazing rates are tightly coupled to bacterial and algal biomass and production
Emerging Issues and Questions
--If the protozoa are consuming so much production, where does it originate?
--Over time, does bacterial biomass accumulate in the plume?
--Is there a significant contribution of resuspended meroplanktonic bacteria????
--Are there differences in grazing rates on particle-associated vs. free bacteria?
--Is there evidence that the organisms (including resting stages) associated with the nearshore plume are transported offshore?
--Initial measurements show a substantial amount of production occurs on particles (ca. 60%), but only a few of the proposed measurements have been made thus far.
The BIG question...
To what degree does the RCP shift the nearshore environment from autotrophy toward heterotrophy by:
- "turning off the lights"
- modifying the nutrient regime
- shifting community structure as a result of resuspension?
Mesozooplankton (copepods, cladocera) provide a link to higher trophic levels
Late winter/early spring is time of high mesozooplankton reproduction
Calanoid copepods are long-lived (generation times of months), therefore, success of juveniles in late winter/early spring is key to success of population in spring
In the spring, copepods are the major prey of larval and juvenile fish
What we know:
--The RCP occurs at a critical time during zooplankton reproduction and recruitment.
--Copepod clearance (e.g. feeding rates) of MFW organisms are higher than clearance rates of phytoplankton.
--Egg production and survival rates of offspring of dominant calanoids can be enhanced if females and juveniles are feeding on microzoplankton.
--There is a significant resuspension of zooplankton resting stages in the RCP.
--PSS data reveal that there can be shifts in species dominance from year to year
Emerging Issues and Questions
--Does enhanced microbial food web production enhance new mesozooplankton production in the RCP? (Consider time and spatial scales)
--How does the RCP impact zooplankton recruitment through resuspension of resting stages if the epiphia don't hatch at cold temperatures? Does it "set the table" for later hatching?
BIG questions and issues:
--Need to resolve Chen's food web model with ground-truth data and satellite data. How much error is there in the satellite data and model data?
--During a single event, are there multiple resuspension events that move and resuspend resting stages?
--If recruitment (i.e., fecundity and survival of offspring, and injection of resting stages) is stimulated, what is its relevance to the entire lake food web? To higher trophic levels later in year?
Data Assimilation Workgroup Report
1999 data reduction complete
2000 data reduction underway
Statistical/dynamical analysis of 1999 data completed
1997-1999 GLERL data on web - 2000 GLERL data in production
1997-2000 CCIW data on web
Mar/Apr 1998 and 1999 modeling completed - provided to Chen
OSU Sediment transport modeling
Coding completed for coupled model, parallel version implemented
Bottom sediment mapping and particle tagging completed
First week of March 1998 completed
Can we qualitatively/quantitatively characterize:
The conditions necessary to initiate a major event ?
The physical conditions within the lake during a major event ?
How well do the numerical model hindcasts compare to in-situ and remotely sensed data ?
Six Months Plans
Surrogate climatology of Lake Michigan events (Schwab et al.)
1998-99 major event analysis (Saylor et al) based on observations and models in support of offshore sediment transport
Statistical/dynamical analysis of 1998-99 EEGLE data (Murthy et al)
March 1998 Sediment model completed (Bedford et al)
Meteorological model case studies (Roebber et al)
One year Plans
Statistical analysis of drifter data (McCormick et al)
Statistical data comparison (HF, ADCP, Drifter (Vesecky et al)
2000 major event analysis (Saylor et al)
Statistical/dynamical analysis of 2000 EEGLE data (Murthy et al)
Comparison of HF data with hydrodynamical model (Vesecky et al)
Comparison of Sediment model with EEGLE data (Bedford et al)
Event Climatology - Integrating wave hindcast, wind data/model output, remote imagery, and in-situ measurements
--Meteorological, hydrodynamic, and sediment dynamic
--Integration with observations
Major event physics integrating physical measurements
Encourage publications in open literature to assure visibility
What would we do differently?
Abandon point measurements in favor of profiling devices (ADCP)
Alter frequency of some data collection devices (example PSS)
Increase number of over-water or near-water met stations
Include vessel-mounted ADCP transects
Obtain micro-structure measurements
Improve HF hardware design for freshwater
Ecological model (Fahnenstiel and McCormick, others)
Dictated by data
Null hypothesis: Plume has no biological impacts on Lake Michigan
Homestead (Sept 2000)