Assessment of carbon export and mineralization

1
Assessment of carbon export and mineralization
during KEOPS (contribution of VUB MRAC,
Brussels)
N. Savoye (VUB) D. Cardinal (MRAC) S. Jacquet
(VUB) M. Elskens (VUB) F. Dehairs (VUB)
KEOPS meeting, Endoume, 23 March 2004
2
Context
Ocean surface
Euphotic zone
Mixed layer 
KEOPS meeting, Endoume, 23 March 2004
3
Context
Ocean surface
Euphotic zone
Mixed layer 
KEOPS meeting, Endoume, 23 March 2004
4
Export production estimated from 234Th-deficit
principle
238U 234Th (t1/224d) secular equilibrium
Thorium strong adsorption on particles
234Th flux (dpm m-2 d-1)
KEOPS meeting, Endoume, 23 March 2004
5
Mesopelagic BaXS informs on carbon mineralization
KEOPS meeting, Endoume, 23 March 2004
6
Particulate Ba CLIVAR-SR3 (140E) Spring 2001
Cardinal et al., submitted to DSR I
KEOPS meeting, Endoume, 23 March 2004
7
CLIVAR-SR3 (2001) 140E Early spring
ANTARES 4 (1999) Summer (Crozet-Kerguelen Basin
SAZ 98 (1998) 140E Summer
KEOPS meeting Endoume 23 March 2004
8

140E CLIVAR-SR3 SAZ98
Summer (SAZ 98)
Spring CLIVAR-SR3
KEOPS meeting Endoume 23 March 2004
9
Clivar SR3 cruise October 30 December 14, 2001
Tasmania
45S
50S
55S
60S
65S
Antarctica
150E
145
140
135
KEOPS meeting, Endoume, 23 March 2004
10
Primary and new production
From Savoye et al., GRL, 2004
KEOPS meeting, Endoume, 23 March 2004
11
234Th fluxes and export production
Collaboration with K. Buesseler (WHOI) T. Trull
(ACE-CRC) M. Rutgers van der Loeff (AWI)
KEOPS meeting, Endoume, 23 March 2004
12
mesopelagic BaXS and carbon mineralization
From Cardinal et al., submitted to DSR I
KEOPS meeting, Endoume, 23 March 2004
13
Carbon cycle from surface to mezopelagic layers
KEOPS meeting Endoume 23 March 2004
14
Carbon cycle from surface to mesopelagic layers
KEOPS meeting, Endoume, 23 March 2004
15
Mesopelagic C mineralization and diatoms
y 0.4938x 4.1764 R2 0.72
y 2.05 x0.66 R2 0.90
KEOPS meeting, Endoume, 23 March 2004
16
Future developments

• Comparison with deep ocean sediment trap flux
  data
• Focus on time series (EIFEX, KEOPS, VERTIGO, ..)
  to track the dependency of export and
  mineralization on production, processes that are
  not necessarily in phase
• Focus on O2 consumption measurements during time
  series to better constrain mesopelagic
  mineralization and BaXS accumulation

KEOPS meeting, Endoume, 23 March 2004