Final Agenda

August 16-19, 2004

Monday

Tuesday

Wednesday

Thursday

The purpose of this meeting is to facilitate discussion.  Workshop participants should define & refine the important issues regarding ²³⁴Th, and then devise a strategy to resolve them.  Thus, there will only be a few scheduled talks that are designed to provide an overview of the state of the field with regard to four main subject areas:

1. New methodologies and techniques. What are the current methods for collecting and measuring ²³⁴Th in fresh and marine ecosystems? What is the best way to convert these measurements into integrated ²³⁴Th deficiencies? Can we assess and reduce the uncertainty in making this conversion?

2. ²³⁴Th/C ratios. In the application of ²³⁴Th as a POC flux proxy, how should ²³⁴Th/C ratios be collected and measured?  Are all phases of POC in equilibrium with ²³⁴Th?  Can POC fluxes inferred from ²³⁴Th be biased by cycling of ²³⁴Th through a limited portion of the POC pool that has a turnover time significantly different from that of the "average" POC?  How should ²³⁴Th results be compared to other indices of sinking particle flux?   

3. Modeling. Models are used to quantify ²³⁴Th cycling and removal. The complexity, uncertainty, and assumptions in these models need to be reevaluated and expanded. What are the appropriate models for understanding particle residence times, aggregation/coagulation rates, and sinking losses of ²³⁴Th?  Do current models deal adequately with 3-D transport of ²³⁴Th (both particulate and dissolved) and with temporal variability of the processes involved?

4. ²³⁴Th speciation in seawater. What is the speciation of ²³⁴Th with respect to dissolved and particulate inorganic and organic phases in seawater? How does ²³⁴Th speciation impact aggregation and flux? Can a better understanding of the geochemistry of ²³⁴Th improve our use of ²³⁴Th as a particle cycling and flux proxy? Are all phases of ²³⁴Th in chemical equilibrium with one another?  What is necessary to achieve this better understanding?

The remaining time will be spent in discussion.  The goal of the open discussions is for the community to: 1) Identify the major issues facing the application and understanding of ²³⁴Th in aquatic systems, 2) Develop mechanisms or plans of action that the community may then use to solve the discussed issues (future experimental work?), and 3) Disseminate the results of this discussion to the wider community via an overview article in EOS and a series of working group articles in Geochemistry, Geophysics and Geosystems (G³) or similar journal..

Monday August 16^th

8:00- 9:00 am   Breakfast, Clark 5^th floor Foyer

9:00-9:30         Opening Remarks, Clark 507

9:30-10:00       History of ²³⁴Th and particle export (Dr. Claudia Benitez-Nelson)

10:00-10:30     Coffee Break

10:30-11:30     New methodologies and techniques. (Dr. Michiel Van Der Loeff)

(45 min talk followed by 15 min discussion)

11:30-12:30     C/²³⁴Th ratios and their application. (Drs. K. Buesseler & B. Moran)

                        (Two 25 min. talks followed by 15 min discussion)

12:30-1:30       Lunch, Clark 5^th floor Foyer

1:30-2:30         Modeling. (Dr. Nicolas Savoye)          

(45 min talk followed by 15 min discussion)

2:30-3:00         Coffee Break

3:00-4:00         ²³⁴Th speciation in seawater.  (Dr. Peter Santschi)

(45 min talk followed by 15 min discussion)

4:00-4:30         Schedule for remaining week
4:30-6:00 pm   Reception, Clark 5^th floor Foyer

Dinner on own

Tuesday August 17^th

8:00- 9:00 am   Breakfast, Clark 5^th floor Foyer

9:00-9:30         Opening Remarks, split into Working Groups, Clark 507

9:30-12:30       Working Groups 1 & 2: New methodologies and techniques, ²³⁴Th/C ratios (WG1 DL: Dr. M. M. Sarin, WG2 DL: Drs. Bob Anderson and Kelly Falkner), Clark 507 & 509

(10:15-10:45    Coffee Break)

12:30-1:30       Lunch, Clark 5^th floor Foyer

1:30-3:00         Continue working group meetings

3:00-3:30         Coffee Break

3:30-5:00 pm   Overview of Working Group Discussions (30 min each) and Joint Discussion (30 min overall)

Dinner on own

Wednesday August 18^th

8:00- 9:00 am   Breakfast, Clark 5^th floor Foyer

9:00-9:15         Opening Remarks, Clark 507

9:15-12:30       Working Groups 3 & 4: Modeling, ²³⁴Th speciation, Clark 507 & 509

                         (WG3 DL: Dr. Kirk Cochran, WG4 DL: Dr. Jim Murray)

(10:15-10:45 Coffee Break)

12:30-1:30       Lunch, Clark 5^th floor Foyer

1:30-3:00         Continue working group meetings

3:00-3:30         Coffee Break

3:30-5:00         Overview of Working Group Discussions (30 min. each) and Joint Discussion (30 min overall)

6:00 pm            Group Clam Bake Dinner

Thursday August 19^th

8:00- 9:00 am   Breakfast, Clark 5^th floor Foyer

9:00-9:30         Plan for papers, WG #1, New methodologies and Techniques, Clarke 507

                         Discussion Leader: Dr. M. M. Sarin

9:30-10:00       Plan for papers, WG #2, ²³⁴Th/C ratios

                         Discussion Leader: Drs. Kelly Falkner and Bob Anderson

10:00-10:30     Coffee Break

10:30-11:00     Plan for papers, WG #3, Modeling

                         Discussion Leader: Dr. Kirk Cochran

11:00-11:30     Plan for papers, WG #4, ²³⁴Th speciation

                         Discussion Leader: Dr. Jim Murray

11:30 -13:00    Future meetings and proposals.

Recommendations and where do we go from here

Meeting Adjourned

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Last Updated July 2004 by C. Benitez-Nelson