Notes

Slide Show

Outline

1	What Drives Gulf of Maine Flow Variability? James M. Pringle / UNH
2	How do we compare different sources of variability?
3
4	How do we find “u” and “t” For wind and inflow conditions, use numerical model FVCOM from Chen et al. NCEP reanalysis wind stress CASP Scotian Shelf Inflow data, with BIO hydrography BIO hydrography
5	Alongshore wind response (2 day timescale)
6	Scotian Shelf Inflow (10 day timescale)
7	Density Driven Currents (3 months to a year)
8	Density Driven Coastal currents timescale ? Seasons?
9	What is ½ t^½u?
10	What hydrographic variability? 1970-2003 Climatology from BIO, 150m depth
11	Why continued….
12	What sets r gradient? Cooling Very roughly 25% of variance Winds Very roughly 16% of variance Inflow r variability (for T<year or so)
13	Conclusions (part 1) r gradient drives most variability on timescales longer than a month. r gradient governed by mixing r gradient variability strongly effected by Cooling Inflow Winds
14	Conclusions (part 2) Models simulations must have Accurate mixing and surface fluxes >year model integrations Resolved measurements of inflow density Or models must assimilate measurements of the density field in Gulf of Maine. Quarterly observations (almost) sufficient.
15	How do we find “u” and “t” For density driven flows, use BIO hydrography, only possible between basins 170m level of no motion, consistent with FVCOM