Modeling the influence of local/external processes on nitrogen and phytoplankton dynamics in the GoM/GB region

R. Ji

With help from:
PI team: Davis, Chen, Beardsley, Townsend, Durbin, Runge, Flagg
UMASS-D modeling group: Q. Xu, G. Cowles, R. Tian, S. Hu, D. Stuebe
NMFS: D. Mountain, J. Hare, M. Taylor

Status
Completed 1995-1999 continuous run for FVCOM+NPZD; comparing data/model results
Completed 1995 Pseudocalanus model run; using “stage with mean age” method; Testing different implementation of CPD
Examining effect of freshening on phytoplankton dynamics (data analysis + numerical exp.)
1 ms. submitted to JMS + 1 ms. to be submitted to GRL + 1 new baby

Model structure

Surface - Nitrogen

Surface - Phytoplankton

Transect - Phytoplankton

Model skills

Model vs data on GB

Model vs data on GB

Model vs data on GB

Model vs data on GB

Model vs data in Basins

Model vs data at CMO

Sensitivity to IC
(GB crest)

Sensitivity to IC
(Wilkinson Basin)

Sensitivity to BC
(Scotian Shelf)

Sensitivity to BC

Nitrogen cycle

N demand and supply on GB

Modeled N flux on GB

Response to bottom N change

Bloom - freshening

Bloom “propagation”

Bloom “propagation”

Timing-SSS anomaly

Magnitude/NPP

Issues
Huge amount of model output, O(TB)
Very limited availability of data in GoM during GLOBEC year (N, Vertical profile)
Boundary conditions (N/P/Z/D, T/S)
Need free grad students