The Bermuda Atlantic Time

The Bermuda Atlantic Time‐
The Bermuda Atlantic Time‐series Study: A Research Platform to Study Change in y
g
the subtropical North Atlantic
Michael W. Lomas, Nicholas R. Bates, Rodney J. Johnson, and Anthony H. Knap
CINTOO: Center for Integrated Ocean Observations
Bermuda Institute of Ocean Sciences
BATS/ location& sampling frequency/
BATS/ location& sampling frequency/ 1988
1990
1992
1994
Year
1996
1998
2000
2002
2004
2006
2008
2010
Jan
Feb
Mar
Apr
May
Jun
July
Month
http://bats.bios.edu
Aug
Sep
Oct
Nov
Dec
Core Cruises
Bloom Cruises
BATS/ Original Motivation and Objectives/
BATS/ Original Motivation and Objectives/
The Bermuda Atlantic Time-series Study (BATS) was initiated under the
JGOFS umbrella with the overall motivation
motivation…
“ To determine and understand the time
time--varying fluxes of
carbon and associated biogenic elements in the ocean and to
evaluate
l t the
th related
l t d exchanges
h
with
ith th
the atmosphere,
t
h
sea flfloor
and continental boundaries .” (SCOR, 1987)
Original Objectives:
 To understand the seasonal and interannual variations in ocean physics, chemistry and biology
 To understand the processes that control surface pCO
T
d t d th
th t
t l
f
CO2
 To understand the physical controls on biological rate processes
 To provide a test‐bed for the validation of new methods and technologies
p
g
OBJECTIVES OF THIS TALK…
1. Present patterns in the 22-year data records.
2 Id
2.
Identify
tif what
h t we now think
thi k we are missing
i i (e.g.,
(
eddies,
ddi
mesopelagic ecosystem) to understand the original objectives.
3. Present brief overview of a future “integrated
g
time-series
platform”
McGillicuddy et al. 2007
Depth (m
m)
# of Observattions
BATS/ Mesoscale variability/ Eddies
Chlorophyll (ug/kg)
Primary Production (mgC/m3/d)
Depth
h (m)
Cyclone Anticyclone
Ewart et al. 2008
Longitude (oW)
Bacterial Biomass Baacterial Production
(m
(mgC/m3/d)
mgC/m3)
Phytoplankton community (% changes)
C export (g m‐2 d‐1)
Mourino‐Carballido 2009
On an annual scale, eddies appear to ‘average out’ their impact on biogeochemistry.
BATS/ Multi-year Variability/ Hydrography/
Depth
h (m)
0
250
500
1990 1994 1998 2002 2006 2010
SST (oC)
32
28
26
24
22
20
18
16
14
Repeatable annual Repeatable
annual
pattern, with a seasonal cycle of ~9oC
MLD driven by temperature ranging from 150‐300m.
150
300m. 28
24
20
J
F M
A
M J
J
A
S O
N D
No clear long‐term pattern, although deep MLD i 1991 d 1995
MLD in 1991 and 1995 are the cause. Interactive effects of eddies and convection?
BATS, unpubl.
BATS/ Multi-year Variability/ Hydrography/
Deepth (m)
0
Heat content anomaly ‐ low pass annual filter
x 106
5
20
4
40
3
60
2
80
1
100
0
120
‐1
Long‐term changes in heat content ‐
Seasonal cycle but apparent increase in surface waters at BATS
‐2
140
‐3
160
‐4
180
‐5
1990 1994 1998 2002 2006 2010
Longer HS record suggests warming subsurface waters within the gyre.
BATS, unpubl.
BATS/ Multi-year Variability/ Dissolved inorganic carbon/
ΔnDIC = 1.22 ± 0.09 µmol kg‐1 y‐1
Bates 2010
Bates 2010
Inorganic carbon content has
increased to a level exceeding
g annual
variability.
Surface ocean pCO2 increasing at the
same rate as atmosphere,
p
, but notice
‘stutters’
Surface ocean is acidifying.
Annual sink increasing overall due to
increasing winter flux which offsets
summer.
Bates et al. 2007
DJFM NA
AO Index
BATS/ Multi-year Variability/ Particulate Matter Production/
6
3
0
-3
-6
1990
1995
2000
2005
2010
Lomas et al. 2010
Summer net p
primary
yp
production ((NPP)) doesn’t change
g significantly.
g
y
Winter NPP inversely related to NAO via mechanism of convective
nutrient inputs.
BATS/ Multi-year Variability/ Particulate Matter Composition/
NPP increase due to
biomass accumulation
during the winter/spring
bloom.
NO3
PO4
Increased nutrient drawdown
i. Autotrohic biomass has become more efficient.
ii. Increase in supply –
frequency of mixing?
Lomas et al. 2010
1
10
25
0
0
80
(D)
60
40
-2
20
60
0
0
1990
1995
2000
2005
1990
1995
2000
2005
-2
0
cells m )
(mg
gm )
-2
50
11
25
10
(B)
(x10
50
(C)
20
Synech
hococcus
20
0
%Chla
aSyn
ChlaSyn
0.0
(mg m )
2
0.5
Chlahapto
-2
(mg m )
3
(A)
%Chlahapto
o
FluxPIC/POC
1.0
%Chladiat
Chladiat
BATS/ Multi-year Variability/ Particulate Matter Composition/
Lomas et al. 2010
Casey, Lomas unpubl.
POC (ugC l‐1)
NAO +ive
40
30
20
10
POC Flu
ux
2 d-1)
(mmol-C m-2
50
9
6
3
0
1990
1995
2000
2005
2010
Lomas et al. 2010
0
2005 2006 2007 2008 2009
BATS/ Multi-year Variability/ Particulate Matter Remineralization/
Lomas et al. 2010
POC more extensively
remineralized,
[DOC] higher, deeper and not
being consumed as completely
through the year.
Figure courtesy of Dennis Hansell, modified.
BATS/ Multi-year Variability/ Particulate Matter Remineralization/
BATS unpubl.
Changes in bacteria in response to
dissolved organic matter inputs via
convection.
What about in response to enhanced
availability due to POC
remineralization?
Carlson et al. 2009
POC and BCD (in
nt. 150-300m)
P
AOU (int. 200
0-300m)
(all mmol-C m-2 d-1)
BATS/ Multi-year Variability/ Particulate Matter Remineralization/
12
8
POC
BCD
AOU
Col 1 vs Col 2
4
0
1990
1995
2000
2005
Lomas et al. 2010
+ 0.013 g m‐2 y‐1, 44% increase over 15 yrs
Steinberg et al. in prep.
OBJECTIVES OF THIS TALK…
1. Present patterns in the 22-year data records.
2 Id
2.
Identify
tif what
h t we now think
thi k we are missing
i i (e.g.,
(
eddies,
ddi
mesopelagic ecosystem) to understand the original objectives.
3. Present brief overview of a future “integrated
g
time-series
platform”
Future research topics to understand original objectives:
Future research topics to understand original objectives:
1.
What are drivers of episodic/patchy biogeochemical events –
atmospheric inputs, eddies, convergent zones? 2.
Eddies: mesoscale variability of the Sargasso Sea potentially masks the impact of atmospheric forcing over annual or shorter timescales, but what about year over year predictions of climate forcing?
but what about year‐over‐year predictions of climate forcing?
3.
How does plankton community structure change in response to short‐term
short
term and long
and long‐term
term forcing and how does this affect C flux forcing and how does this affect C flux
(events vs. trends)?
4.
The mesopelagic: What are the regeneration length scales of p g
g
g
individual elements? Role of chemoautotrophy?
5.
How do we define the right timescales to assess the natural versus anthropogenic signal?
6.
Have we defined all the ecosystem processes?
Integrated Time‐series Platform: coordinated integration of ship‐based Integrated
Time‐series Platform: coordinated integration of ship‐based
underway sensors, moorings and floats.
Topic 1 & 2, episodic events over time
Bermuda Testbed Mooring (e.g., Dickey et al. 2001)
Integrated Time‐series Platform: coordinated integration of ship‐based Integrated
Time‐series Platform: coordinated integration of ship‐based
underway sensors, moorings and floats.
Topic 1 & 2, episodic events over time
“Future” Bermuda Mooring
Particulate matter sampler (McLane)
sampler (McLane)
Submersible flow cytometer
(Cytobuoy, Inc)
UV nitrate analyzer (S tl ti )
(Satlantic)
Submersible i b i d i
incubation device (Craig Taylor, WHOI)
Environmental sample processor
Integrated Time‐series Platform: coordinated integration of ship‐based Integrated
Time‐series Platform: coordinated integration of ship‐based
underway sensors, moorings and floats.
Topic
p 3 (p
(parts of))
SeaFLOW – position sensitive
underway flow cytometer.
Highlights small scale spatial
variability (great for
coordinating with satellite data
p
products.
Integrated Time‐series Platform: coordinated integration of ship‐based Integrated
Time‐series Platform: coordinated integration of ship‐based
underway sensors, moorings and floats.
NOAA underway pCO2 VOS program
Topics 1 & 3
23 24 25 26
Day in August 2006
Wanninkhof et al. 2007
Integrated Time‐series Platform: coordinated integration of ship‐based Integrated
Time‐series Platform: coordinated integration of ship‐based
underway sensors, moorings and floats.
APEX Float program p g
((Johnson et al.))
Topics 1, 2 & 4 (parts of)
Floats provide a combination of
temporal data and ‘drifting’ spatial data
Photo credit: Ken Johnson
Eddy heaving?
Future research topics to understand original objectives:
Future research topics to understand original objectives:
5.
How do we define the right timescales to assess the natural versus anthropogenic signal?
6.
Have we defined all the ecosystem processes?
Year when ‘global
global warming’
warming signal can be detected
detected.
Henson et al. 2010
Thanks to:
All the BATS technicians and project scientists, past and present, whose
diligence and dedication have assisted in the collection of the data and
publication of the results presented in this talk.
Members of the international oceanographic community who have
supported BATS both in the peer‐review
peer review process and through ancillary
projects.
U.S. National Science Foundation Chemical and Biological
Oceanography Programs for funding BATS through the
most recent award OCE‐0326885.