SMP WORKSHOP
Conceptual and Practical Issues in Modeling Oceanic N2 Fixation


Dates:  3.5 days- 27 Sep to 30 Sep, 1999
Location: Wrigley Laboratory, Catalina Island, CA 
Objectives: To bring together modelers interested in incorporating oceanic N2 fixation into their efforts with researchers familiar with the ecology and physiology (from direct field and laboratory studies)of oceanic (pelagic) N2 fixation in order to:
  1. Exchange information on biological, chemical and physical constraints on N2 fixation particularly as needed for mechanistic modeling
  2. Compare approaches for modeling, and incorporating remote sensing into models
  3. Consider directly approaches for parameterizing N2 fixation
  4. Identify relevant data sets for model testing and verification
Report to SMP Steering committee on the outcome of the workshop.

 
DAY 1
Intro / Overview / Objectives Capone & Hood (0830-0900)
I. Update - SCOPE Report Lipschultz
II.  Geochemical Aspects: Gruber (l), Montoya (r)
     A. Evolutionary / Paleo Aspects
          Molecular evolution of N Fixers Zehr
          Paleoecology Haug
     B. Stoichiometric Modeling / Approaches
          N* Gruber
          Ecological stoichiometry Michaels
          Time series Letelier
          DOC / DON Hansell
          Natural abundance Montoya
     C. Broad Scale Controls
          Fe Sanudo-Wilhelmy
          P Letelier
          Turbulence Letelier
     D. Dust / Aerosols
          Current ocean Siefert
          Paleo Mahowald
II. Basin Scale / Global Approaches: Sarmiento (l), Michaels (r)
     A. Incorporation of N2 Fixations into GCMs Hood / Capone
     B.  Predictive Modeling / N2 Fixation Sarmiento
DAY 2
IV. Physiological Aspects:  Armstrong (l), Villareal (r)
     A. Modeling Armstrong / Laws
     B.  N-metabolism of Trichodesmium Mulholland
     C. Physiological Controls Capone
     D. Buoyancy Controls Villareal
V. Ecosystem Aspects:  Hood (l), Letelier (r)
     A. Modeling Approaches Hood / Walsh
     B. Distributions and Diversity of Diazotrophs Carpenter, Zehr
     C. Remote Sensing (pigments, light, optical signature) Subramaniam
     D. Blooms Villareal
     E. N2 Fixation, Direct Measurement, Biogeochemistry Capone / Lipschultz
     F. CO2 Fixation Carpenter
Regroup & Plan  
At the end of the overview talks, organize into several working groups, which are challenged to:

1) Identify 1st order issues. (what are the key processes/constraints that must be represented in our models)
2) Discuss ways of formalizing these 1st order processes.
3) Suggest modifications to current and/or planned modeling efforts
4) Identify remaining outstanding problems.

Possible Working Groups (Subject to change!)

(l) = lead, (r) = rapporteur; (name) = participation uncertain

1. Physiological modeling               Armstrong (l), Villareal (r), Laws, Mulholland,  Carpenter, Zehr, Krauk
2. Ecosystem modeling                   Hood (l), Letelier (r), Capone, Clayton, Lipschultz, (Berelson), Burns, Kuska
3. Geochemical Modeling               Gruber (l), Montoya (r), Deutsch, Siefert, Sanudo-Wilhelmy
4. Basin & Global Scale Modeling Sarmiento(l), Michaels (r),  Hansell, Subramaniam, Haug
DAY 3 -AM
III. Modeling N2 fixation: Working groups meet
DAY 3- PM
Working groups report, group discussion, Regroup as necessary
Day 4 - AM
Plenary, Summary and Recommendations

Participants:
 
 1 Capone (Chair) Doug N2 fixation physiol,ecol & biogeochem WIES/ USC capone@cbl.umces.edu
 2 Hood (Co-chair) Raleigh Oceanic biogeochem models HPL/ UMCES raleigh@attila.hpl.umces.edu
 3 Armstrong Rob Physiol. modeling of phyto Princeton raa@splash.Princeton.edu
 4 Burns Jay N2 fixation physiol, ecol & biogeochem WIES/ USC burns@cbl.umces.edu
 5 Carpenter Ed Diazotroph biomass & C cycling MSRC/SUNY ecarpenter@notes.cc.sunysb.edu
 6 Clayton Tanya Modelling marine N2 fixation ODU clayton@ccpo.odu.edu
 7 Deutsch Curtis Geochem/ oceanic modelling Princeton deutsch@splash.princeton.edu
 8 Gruber Niki N geochem & geochem modelling Princeton gruber@splash.princeton.edu
 9 Hansell Dennis Organic N distributions & cycling BBSR dennis@bbsr.edu
10 Kleypas Joanie NCAR kleypas@ncar.ucar.edu
11 Krauk Jamie
12 Kuska Adam Trichodesmium Fe requirements
13 Laws Ed Physiol. modelling of phyto U. Hawaii laws@soest.hawaii.edu
14 Letelier Ricardo Tricho ecology, remote sensing U. Oregon letelier@oce.orst.edu
15 Lipschultz Fred N biogeochem BBSR fred@bbsr.edu
16 Mahowald Natalie Dust transport modeling UCSB natalie@bren.ucsb.edu
17 Michaels Tony N2 fix, oceanic biogeochem WIES/ USC tony@usc.edu
18 Montoya Joe N isotope biogeo & modeling Ga Tech j.montoya@biology.gatech.edu
19 Mulholland Margie N metabolism in Tricho SUNY/ MSRC margie@cbl.umces.edu
20 Sanudo-Wilhelmy Sergio Trace metals & N2 fixation SUNY/ MSRC ssanudo@notes.cc.sunysb.edu
21 Sarmiento Jorge Geochem/ oceanic modelling Princeton jls@splash.Princeton.EDU
22 Siefert Ron Atmospheric Fe transport/ chem CBL/ UMCES siefert@cbl.umces.edu
23 Subramaniam Ajit Remote sensing of Tricho, phyto WIES/ USC subraman@cbl.umces.edu
24 Villareal Tracy Tricho, Richelia ecology U Texas tracy@utmsi.utmsi.utexas.edu
25 Zehr Jon Molec ecol of N2 fixation RPI zehrj@rpi.edu
26 Gunderson Troy
27 Haug Gerald
28 Berelson Will
29 Stott Lowell