What Drives Gulf of Maine Flow Variability?
| James M. Pringle / UNH | |
How do we compare different sources of variability?
| 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 | ||
Alongshore wind
response
(2 day timescale)
Scotian Shelf
Inflow
(10 day timescale)
Density Driven
Currents
(3 months to a year)
Density Driven Coastal
currents
timescale ? Seasons?
What hydrographic
variability?
1970-2003 Climatology from BIO, 150m depth
| Cooling | ||
| Very roughly 25% of variance | ||
| Winds | ||
| Very roughly 16% of variance | ||
| Inflow r variability | ||
| (for T<year or so) | ||
| 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 | ||
| 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. | ||
| For density driven flows, use BIO hydrography, only possible between basins | ||
| 170m level of no motion, consistent with FVCOM | ||