Contrasting inherent optical properties and carbon metabolism
in four northeastern (USA) estuary-plume systems
D. Vandemark, NASA/GSFC & UNH J. Salisbury, C. Hunt, J. Campbell, Univ. of New Hampshire
W. McGillis, Columbia University - LDEO
Program Goals
• Examine freshwater control upon Gulf of Maine coastal waters in terms of carbonate, nutrient, and productivity dynamics
• Develop techniques to retrieve metabolic information from inherent optical properties and eventually from satellite measurements
This talk : first observations
1. Contrast amongst four river systems
2. Empirically relate bio-optical & metabolic terms using clustering analysis
Observational program
• UNH/COOA : NOAA-sponsored (COTS)
• Flo-thru suite: physical + fluor. + IOP + metabolic (pCO2,O2) variables
• Discrete sampling and phys. + IOP profiling along salinity gradient
• Four rivers sampled seasonally in Gulf of Maine
• Hudson river also sampled 7/1-7/2, 2004 (see McGillis)
2004 COOA Gulf of Maine measurement program
COOA shipboard measurements
Fast-rate CO2 equilibrator
Profiler: AC-9, AC-S, fl_CDOM,CHL,PEB, and CTD
Infrared CO2 gas analyzer
Camden Belle -26’ riverine sampling vessel
R/V Gulf Challenger – majority of 2004 data set
Flo-thru O2, fl_Chl, fl_CDOM, beam_c, T, S
Four rivers in four days
Androscoggin- Kennebec
Penobscot
Pleasant
Merrimack
N
EW
S
50075010001250
DOC flux (kg km-2)
Aitkenhead and McDowell (2001)
- summer climatology
• varied watersheds, 3 of GoMaine’s largest sources
• Sampled plumes -> 0 psu, 27-30 July 2004Boston
Acadia
Androscoggin- Kennebec
Penobscot
Pleasant
Merrimack
N
EW
S
255075100
DIN flux (kg km-2)
Green et al., (2004)
Four rivers in four days
Contrasts between riversJuly 2004
Atm
120
110
100
90
80
70
BOUNDS Merrimac – autotrophic
Pleasant – strongly heterotrophic
Study in progress
• Diverse watersheds conditions in optical, trophic, and gas flux terms
• Some consistency with modeled basin attributes• Coming work - conservative mixing vs. localized
processing along salinity gradient and vs. season• …including profile & discrete data: nutrients, TA,
pH, DIC, DOC, DON, POC, HPLC
Classification via clustering analysis - end goal is to link satellite retrievals to ecosystem metabolism
4 Observables[ T, fl_CDOM, fl_CHL, c660 ]i = 1,n
Objective clustering n=30000 (S < 31 psu)
Present result: 22 classes
Metabolic indicator?
O2
pCO2
Top Related