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Use of regularly migrating non-biological Use of regularly migrating non-biological platforms as vehicles for spatio-temporal platforms as vehicles for spatio-temporal
sampling of Southern Ocean systemssampling of Southern Ocean systems
Simon Wright, Brian Griffiths, Bronte Tilbrook,Simon Wright, Brian Griffiths, Bronte Tilbrook,Steve Rintoul, Alain Poisson Steve Rintoul, Alain Poisson
25 Jan 2003 10 Feb 2003 26 Feb 2003
How to model microbial populations?
Recognize different types of communities
Key species and associations
When and where do they occur?
Time of season
Oceanographic conditions
MLD, nutrients, ice, etc
Parameterize the community properties
Primary production, respiration
Aggregation
Sedimentation
Size distribution
What would a Southern Ocean Observing System look like?
Regularly Migrating Non-Biological Platforms
Seagoing Hydro-Investigative Platforms
(SHIPs)
(RMNBPs)
Aurora Australis
L’Astrolabe
Programmable
Ecological
Observing
Package
(Live Elements)
(PEOPLE)
Three pronged approach
Monitoring on repeat transects l’Astrolabe
Intensive oceanographic surveys Aurora Australis
Process studies in minicosms
Coupled with laboratory experiments
Aurora Australis
-65.6 -65.4 -65.2 -65.0 -64.8 -64.6 -64.4 -64.2 -64.0 -63.8 -63.6 -63.4 -63.2 -63.0
Latitude
Total Chlorophyll a 112E
-200
-180
-160
-140
-120
-100
-80
-60
-40
-20
0
Dep
th (
m)
0.1
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
ice
ASF
Tmin
Pycnocline
-65.6 -65.4 -65.2 -65.0 -64.8 -64.6 -64.4 -64.2 -64.0 -63.8 -63.6 -63.4 -63.2 -63.0
Latitude
Prasinophytes 112E
-200
-180
-160
-140
-120
-100
-80
-60
-40
-20
0
Dep
th (
m)
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.10
0.11
0.12
0.13
0.14
ice
ASF
Tmin
Pycnocline
Disadvantage of Aurora Australis
erratic migratory route
Three pronged approach
Monitoring on repeat transects l’Astrolabe
Intensive oceanographic surveys Aurora Australis
Process studies in minicosms
Coupled with laboratory experiments
Sokolov & Rintoul 2002
Regular monitoring of Hobart - Dumont d’Urville
3 – 4 repeat transects per season
Astrolabe lab in hold
Astrolabe lab interior
l’Astrolabe repeat transects
– Oceanography: • XBT sections, nutrients: Steve Rintoul, CSIRO • alkalinity
– Alain Poisson IPEV, Paris
– Phytoplankton: • Chlorophyll fluorometry , FRRF
– Brian Griffiths, CSIRO• HPLC pigments, Species ID and counts (whole
and net), coccolithophorid counts
– Australian Antarctic Division – Carbon dioxide: pCO2
• Bronte Tilbrook, CSIRO
CO2 drawdown
Chlorophyll a
Astrolabe2002/03
CO2 drawdown
Chlorophyll a
Astrolabe2002/03
2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0 1 6 0
D a y s s i n c e 1 O c t 2 0 0 2
- 6 5
- 6 0
- 5 5
- 5 0
- 4 5
Lat
itu
de
0
0 . 2
0 . 4
0 . 6
0 . 8
1
1 . 2
1 . 4
1 . 6
1 . 8
2
2 . 2
A s t r o l a b e 2 0 0 2 - 0 3 T o t a l C h l a ( u g / L )
Oct | Nov | Dec | Jan | Feb | Mar
Date of bloom at mid latitude (53- 60ºS)
Season Bloom peak
1997-98 3 Dec
1998-99 19 Dec
1999-00 01 Jan
2000-01 09 Jan
2001-02 25 Jan
2002-03 10 Feb
2003-04 10 Jan
2004-05 15 Dec
3 0 5 0 7 0 9 0 1 1 0 1 3 0 1 5 0
D a y s s i n c e 0 1 O c t 2 0 0 3
- 6 5
- 6 0
- 5 5
- 5 0
- 4 5
Lat
itu
de
0
0 . 2
0 . 4
0 . 6
0 . 8
1
1 . 2
1 . 4
1 . 6
1 . 8
A s t r o l a b e 2 0 0 3 - 0 4 T o t a l C h l a ( u g / L )
Oct | Nov | Dec | Jan | Feb | Mar
20 30 40 50 60 70 80 90 100 110 120 130 140 150-66
-64
-62
-60
-58
-56
-54
-52
-50
-48
-46
-44
00.10.20.30.40.50.60.70.80.911.11.21.3
Astrolabe 2004 -05 Total Chl a (ug/L)
Days since 01 Oct 2004
Lat
itu
de
Oct | Nov | Dec | Jan | Feb | Mar
Bloom dynamics at mid latitude (53- 60ºS)
2002 - 2003• Bloom in Feb• about 1 ug Chl a/ L• Dominant species
– F. kerguelensis, Phaeocystis, Trichotoxon, Thalassiothrix, Pseudonitzschia
2003 – 2004, 2004 – 2005 (Typical)• Bloom in Dec - Jan• about 0.8 - 1 ug Chl a/ L• Dominant species
• F. kerguelensis, Pseudonitzschia, Trichotoxon, Chaetoceros dichaeta
2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0
D a y s s i n c e 1 O c t
- 6 6
- 6 4
- 6 2
- 6 0
- 5 8
- 5 6
- 5 4
- 5 2
- 5 0
- 4 8
- 4 6
- 4 4L
atit
ud
e (S
)
- 2
0
2
4
6
8
1 0
1 2
1 4
1 6
S u r f a c e T e m p . 2 0 0 3 - 0 4
2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0
D a y s s i n c e 0 1 O c t
- 6 6
- 6 4
- 6 2
- 6 0
- 5 8
- 5 6
- 5 4
- 5 2
- 5 0
- 4 8
- 4 6
- 4 4
Lat
itu
de
(S)
- 2
0
2
4
6
8
1 0
1 2
1 4
1 6
S u r f a c e T e m p . 2 0 0 4 - 2 0 0 5
Oct | Nov | Dec | Jan | Feb | Mar Oct | Nov | Dec | Jan | Feb | Mar
2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0
D a y s s i n c e 0 1 O c t
- 6 6
- 6 4
- 6 2
- 6 0
- 5 8
- 5 6
- 5 4
- 5 2
- 5 0
- 4 8
- 4 6
- 4 4
Lat
itu
de
(S)
- 2
0
2
4
6
8
1 0
1 2
1 4
1 6
S u r f a c e T e m p . 2 0 0 2 - 2 0 0 3
2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0
D a y s s i n c e 1 O c t
- 6 6
- 6 4
- 6 2
- 6 0
- 5 8
- 5 6
- 5 4
- 5 2
- 5 0
- 4 8
- 4 6
- 4 4
Lat
itu
de
(S)
- 2
0
2
4
6
8
1 0
1 2
1 4
1 6
S u r f a c e T e m p . 2 0 0 3 - 0 4
Oct | Nov | Dec | Jan | Feb | MarOct | Nov | Dec | Jan | Feb | Mar
33.633.733.833.93434.234.334.434.634.83535.235.435.5
Salinity 2003-04
1 2 3 4 5 6
Transect No.
-62
-61
-60
-59
-58
-57
-56
-55
-54
-53
-52
-51
-50
-49
-48
-47
-46
-45
-44
La
titu
de
(S
)
33.633.733.833.93434.234.334.434.634.83535.235.435.5
Salinity 2004-05
1 2 3 4 5 6
Transect No.
-62
-61
-60
-59
-58
-57
-56
-55
-54
-53
-52
-51
-50
-49
-48
-47
-46
-45
-44
Lat
itu
de
(S)
33.633.733.833.93434.234.334.434.634.83535.235.435.5
Salinity 2003-04
1 2 3 4 5 6
Transect No.
-62
-61
-60
-59
-58
-57
-56
-55
-54
-53
-52
-51
-50
-49
-48
-47
-46
-45
-44
La
titu
de
(S
)
1 2 3 4 5 6
Transect No.
-62
-61
-60
-59
-58
-57
-56
-55
-54
-53
-52
-51
-50
-49
-48
-47
-46
-45
-44
Lat
itu
de
(S)
33.633.733.833.93434.234.334.434.634.83535.235.435.5
Salinity 2002-2003
2003-04 Silicate
0
10
20
30
40
50
60
70
80
43 47 51 55 59 63 67
Latitude
R0_S
R0_N
R1_S
R1_N
R3_S
R3_N
2002-03 Silicate
0
10
20
30
40
50
60
70
80
43 47 51 55 59 63 67
Latitude
R0_S
R0_N
R2_S
R2_S
R4_S
R4_N
Bloom dynamics at mid latitude (53- 60ºS)
The late bloom in 2002-2003 was associated with relatively warm, very low salinity water
This water had low nutrient concentrations.
A bloom developed only after nutrient concentrations
increased
Conclusions
Regular sampling of Southern Ocean from l’Astrolabe identified seasonal patterns in microbial populations
–relationship to carbon dioxide uptake
–Relationship to nutrient drawdown
Substantial interannual differences in bloom dynamics appeared to be driven by seawater chemistry
An anomalous late bloom developed only after nutrient concentrations increased in a large area of warm low salinity water.
A small subset of total data: made possible by repeated sampling of many parameters in a collaborative program
l’Astrolabe repeat transects
– Organization: – Alain Poisson IPEV, Paris– Bronte Tilbrook, CSIRO
– Acknowledgements– Captain and crew S.V. l’Astrolabe– Many volunteer samplers
What should a SOOS look like?
– Regular transects along the same transect
What should a SOOS look like?– Oceanography:
• Thermosalinograph
• XBT sections, nutrients• Alkalinity• Carbon dioxide: pCO2
– Atmospheric• Carbon dioxide, oxygen, DMS• Dust
– Environment• Temperature, radiation, wind speed, wave height, ice
– Plankton: • Chlorophyll fluorometry, FRRF • HPLC pigments, Species ID and counts (whole
and net)• Continuous plankton recorder
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