Transcript Exploring the spatial patterns of changing surface ocean conditions

Exploring the spatial patterns of
changing surface ocean conditions
in the Tropical Atlantic and Pacific
Kilbourne, K.H., D. E. Black, J. Nyberg, T. M.
Quinn, R. S. Webb, A. Winter
Main Points
• Don’t forget the rest of the tropics.
• Interactions between the ocean basins can
be important
• Atlantic Perspective on the LIA
Questions
• What is the state of knowledge of Caribbean
climate history?
• How do the spatial patterns tie into the
Pacific climate history
• Are the patterns consistent with known
inter-basin connection mechanisms?
• Earlier work in Tropical Atlantic SST
– Centennial resolution
– Short records
– Indicated cooler conditions during the Maunder
Minimum
– Some hint of changes in seasonal range
• Examples:
–
–
–
–
Keigwin et al., 1996 (Bermuda)
Winter et al., 2000 (Puerto Rico)
Watanabe et al., 2001 (Puerto Rico)
Nyberg et al., 2002 (Puerto Rico)
x
x
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
World Ocean Atlas 2001 Annual SST
Example of Resolution
Nyberg et al., 2002 - Artificial Neural Network
28.00
27.00
26.00
25.00
SST-August
24.00
23.00
1000
SST-February
1200
1400
1600
Date
1800
2000
1000
1200
1400
1600
1800
2000
9.3
9.6
9.9
T
e
m
p
e
r
a
t
u
r
e
Hasse-Schramm et al., 2003
Jamaican Sponge Sr/Ca (mmol/mol)
-4.8
New SST data:
High resolution
-4.4
-4.0
Kilbourne et al in process 2007
Puerto Rico Coral d18O
Puerto Rico Coral d18O
-3.6
29
28
27
26
25
Higher
Black et al., 2007
Cariaco Mg/Ca - SST
24
1000
1200
1400
1600
Date
1800
2000
Lower
Centennial-scale Puerto Rico
Coral d18O driven by SST
1000
8.9
9.0
1200
1400
1600
1800
2000
1800
2000
SST proxy
9.1
9.2
Sr/Ca (mmol/mol)
Puerto Rico Coral Sr/Ca
9.3
-4.8
-4.4
SST and SSS proxy
-4.0
-3.6
1000
Puerto Rico Coral d18O
Puerto Rico Coral d18O
1200
1400
1600
Galapagos P>E
1000
9.3
1400
1600
1800
2000
Pacific
MCA
9.6
9.9
1200
T
e
m
p
e
r
a
t
u
r
e
Hasse-Schramm et al., 2003
Jamaican Sponge Sr/Ca (mmol/mol)
-4.8
New SST data:
High resolution
All agree
2˚C cooler
-4.4
-4.0
Kilbourne et al in process 2007
Puerto Rico Coral d18O
Puerto Rico Coral d18O
-3.6
29
28
27
26
25
Higher
Black et al., 2007
Cariaco Mg/Ca - SST
24
1000
1200
1400
1600
Date
1800
2000
Lower
SST anomaly (ÞC)
Local and Regional Surface
Temperature Anomalies Track
Hemispheric Anomalies
La Parguera SSTA
sw Puerto Rico SSTA
WHWP SSTA
N.Hem Avg. (Mann et al., 1999)
1.0
0.0
-1.0
1900
1920
1940
1960
1980
Correlat ion
Coeff icient ( r)
WHWP Puert o Ric o La Parguera
Nort hern Hemisphere 0 .78
0 .66
0 .70
WHWP
0 .89
0 .79
Puert o Ric o
0 .75
2000
x
x
x
and a
xQuickTime™
TIFF
(LZW) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
World Ocean Atlas 2001 Annual SST
1000
9.3
1400
1600
1800
2000
Pacific
MCA
9.6
9.9
1200
T
e
m
p
e
r
a
t
u
r
e
Hasse-Schramm et al., 2003
Jamaican Sponge Sr/Ca (mmol/mol)
-4.8
Seasonal
Perspective
-4.4
-4.0
Kilbourne et al in process 2007
Puerto Rico Coral d18O
Puerto Rico Coral d18O
-3.6
29
28
27
26
25
Higher
Black et al., 2007
Cariaco Mg/Ca - SST
24
1000
1200
1400
1600
Date
1800
2000
Lower
Monthly Coral Data
LPTA 2004 - 1751
-5.0
-4.5
-4.0
-3.5
-3.0
8.6
8.8
9.0
9.2
9.4
1994
-5.0
-4.5
-4.0
-3.5
-3.0
1900
-5.0
-4.5
-4.0
-3.5
-3.0
1850
-5.0
-4.5
-4.0
-3.5
-3.0
1750
1996
1902
1852
1752
1998
1904
1854
1754
2000
1906
1856
1756
2002
1908
1858
1758
2004
1910
8.6
8.8
9.0
9.2
9.4
1912
1860
8.6
8.8
9.0
9.2
9.4
1862
1760
8.6
8.8
9.0
9.2
9.4
1762
E1P ~1673 - 1446
-5.0
-4.5
-4.0
-3.5
-3.0
1664
-5.0
-4.5
-4.0
-3.5
-3.0
1618
-5.0
-4.5
-4.0
-3.5
-3.0
1558
-5.0
-4.5
-4.0
-3.5
-3.0
1484
1666
1668
1670
1672
1674
8.6
8.8
9.0
9.2
9.4
1676
8.6
8.8
9.0
9.2
9.4
1620
1560
1486
1622
1562
1488
1624
1564
1490
1626
1566
1492
1628
1630
1568
8.6
8.8
9.0
9.2
9.4
1570
1494
8.6
8.8
9.0
9.2
9.4
1496
Seasonal Range in d18O
1489
1564
1624
1669
1757
1854
1907
1999
18
Coral d O (‰ VPDB)
-0.60
-0.40
-0.20
0.00
0.20
0.40
0.60
Mar
Apr May Jun
Jul
Aug Sep Oct
Nov Dec
Jan
Feb Mar
•No large changes in seasonality evident from the d18O
•Coral d18O = f( SST and d18Ow) so a seasonally resolved
independent temperature proxy is needed to confirm.
Atlantic -Pacific Linkages
Atmospheric Link
• Zhang and Delworth (2005)
–
–
–
–
Modeled a shut down of THC
Resulted in Anomalous Hadley Circulation
Cooling in tropical Atlantic => SLP
Across the Isthmus, SLP too
Atmospheric Link
• Chunzai Wang (2006) “An overlooked feature of
tropical climate: Inter-Pacific-Atlantic variability”
– Examined the effects of SST gradient between Pacific
and Atlantic equatorial regions
– Resulted in anomalous Walker Circulation
– Positive feedback
– Far field effects in Pacific
Amplification of
Pacific Walker
Anomalies Convergence
Warm
Wind Anomalies
South America
Cold Colder
Coral Data from NCDC
Site Name
Abraham Reef
Alina's Reef
Amedee
Britomart Reef
Ifaty Reef
La Parguera
Montego Bay
Rarotonga
Ras Umm Sidd
Ribbon Reef #10
Savusavu Bay
Secas Island
Urvina Bay
Longitude Latitude
153.0
279.8
166.5
146.7
43.6
293.0
282.0
200.2
34.3
145.7
179.2
278.0
268.8
-22.1
25.4
-22.5
-18.2
-23.2
17.9
18.5
-21.2
27.9
-14.7
-16.8
8.0
-0.4
Early
Period
1749-1799
1751-1799
1700-1799
1748-1798
1750-1799
1751-1799
1747-1795
1750-1799
1751-1799
1748-1796
1776-1799
1750-1798
1750-1799
Late Period
1900-1950
1900-1950
1900-1950
1903-1953
1900-1950
1900-1950
1904-1954
1900-1950
1900-1950
1900-1950
1900-1950
1900-1950
1900-1950
Diff. Sr/Ca Diff. d18O
Reference
(mmol/mol) (‰ VPDB)
0.09
Druffel and Griffin 1993
0.14
Swart et al., 1996
-0.033
0.08
Delong and Quinn unpublished data
-0.026
0.15
Hendy et al 2002
-0.07
Zinke et all 2004
0.05
0.26
This study
0.149
0.12
Haase-Schramm et al., 2003
-0.090
Linsley et al 2000
0.16
Felis et al 2000
0.01
Wörheide, G., 1998
0.18
Bagnato et al., 2005
0.18
Linsley et al 1994
-0.11
Dunbar et al 1994
Coral data available from NCDC
Difference ~1750-1800 from ~1900-1950
Summary of Tropical
LIA Spatial Pattern
• Cooler Caribbean and Gulf of Mexico
• Warmer and Drier in Southwestern Pacific
• Potentially warmer/wetter in cold Tongue
Enhanced SST Gradient between Atlantic and Pacific
Could This Mechanism
Be Working During the LIA?
What other processes could be at work?
Amplification of
Pacific Walker
Anomalies Convergence
Warm
Wind Anomalies
South America
Cold Colder
Suggestion
The way to really get at processes and
mechanisms is data assimilation
•Despite best efforts, data are often chosen because
they fit a story
•Need an objective way to handle the errors in proxies
and dating - cost functions
Selected Previous work in the
Caribbean
• Keigwin et al., 1996 (Bermuda)
– ~1˚C cooler during the Little Ice Age
• Winter et al., 2000 (Puerto Rico)
– Coral d18O in 5-year segments
– 2-3˚C cooler during Maunder Minimum
– The d18O is a combined signal of SST and d18Ow
• Watanabe et al., 2001 (Puerto Rico)
– Paired Mg/Ca and d18O
– Found 2-3˚cooler during 1699-1705 (really ~1499-1505)
– Hiatus visible in core x-ray - dating off by ~200 years
• Nyberg et al., 2002 (Puerto Rico)
– Foraminiferal abundances - artificial neural network
– Increased seasonal SST range ~1600-1400