Comparative Analysis of Upper Ocean Heat Content
Variability from an Ensemble of Operational Ocean Analyses
Yan Xue (1), Magdalena A. Balmaseda
(2),
Tim Boyer(6) ,Nicolas
Ferry (3) , Simon Good (4), Ichiro Ishikawa (5) , Arun Kumar(1)
Michele Rienecker (7), Tony Rosati(8), Yonghong Yin(9)
(1)
NOAA/NCEP, 5200 Auth Rd, Camp Springs, MD 20746, USA, Yan.Xue@noaa.gov, Arun.Kumar@noaa.gov
(2)
(3)
Mercator-Océan, 8-10 rue Hermès, 31520 RAMONVILLE ST AGNE (France), Nicolas.Ferry@mercator-ocean.fr
(4)
(5)
ECMWF, Shinfield Park, Reading RG2 9AX (UK), Magdalena.Balmaseda@ecmwf.int
Met Office Hadley Centre, FitzRoy Road, Exeter, Devon, EX1 3PB (UK), Simon.Good@metoffice.gov.uk
Japan Meteorological Agency, 1-3-4 Ootemachi, Chiyoda-ku, Tokyo, 100-8122 (Japan), iishikawa@met.kishou.go.jp
(6)
NOAA/ NESDIS/NODC, 1315 East-West Highway, Silver Spring, MD 20910, USA, Tim.Boyer@noaa.gov
(7)
(8)
NASA/GSFC/GMAO, Greenbelt, MD 20771 (USA), Michele.Rienecker@.nasa.gov
NOAA/GFDL, Princeton University, P.O. Box 308, Princeton, NJ 08542. Tony.Rosati@noaa.gov
(9)
CAWCR , GPO Box 1289, Melbourne, VIC 3001 (Australia), Y.Yin@bom.gov.au
Workshop on Observing System Evaluation and Intercomparisons, June 13-17, 2011, Santa Cruz, CA
1
GSOP Upper 300m Heat Content Comparison, Reading, 2006
(call for validation of climate signals)
North Pacific
North Atlantic
12m-rm seasonal anom: NATL Averaged temperature over the top 300m
12m-rm seasonal anom: NPAC Averaged temperature over the top 300m
Focus regions
0.6
0.4
ukdp
ukoi
cfcs2
cfas2
ecco50y
0.2
50N
NPAC
NATL
gfdl
soda
ecmfa
ecmfc
ukgs
ingv
mrieccoSIO
cfasa
mct2
mct3
eccoJPLa
eccoJPLc
eccoMIT
GMAO
0.4
ukdp
ukoi
cfcs2
cfas2
ecco50y
0.2
gfdl
soda
ecmfa
ecmfc
ukgs
ingv
mrieccoSIO
cfasa
mct2
mct3
eccoJPLa
eccoJPLc
eccoMIT
GMAO
0.0
Latitude
TRPAC
TRATL
0.0
-0.2
EQIND
0
EQPAC
EQATL
-0.2
-0.4
-0.4
50S
-0.6
sdv ensm = 0.117
s/n ensm = 0.780
100E
160W
60W
Longitude
-0.8
1950
Tropical Pacific
1960
sdv all = 0.156
s/n all = 1.040
1970
spread
1980
Time
-0.6
= 0.150
1990
2000
sdv ensm = 0.164
s/n ensm = 1.620
-0.8
1950
1960
Tropical Atlantic
12m-rm seasonal anom: TRPAC Averaged temperature over the top 300m
0.6
sdv all = 0.206
s/n all = 2.028
1970
spread
= 0.101
1980
Time
1990
2000
Tropical Indian Ocean
12m-rm seasonal anom: TRATL Averaged temperature over the top 300m
12m-rm seasonal anom: TRIND Averaged temperature over the top 300m
0.4
0.4
ukdp
ukoi
cfcs2
cfas2
ecco50y
0.4
gfdl
soda
ecmfa
ecmfc
ukgs
ingv
mrieccoSIO
cfasa
mct2
mct3
eccoJPLa
eccoJPLc
eccoMIT
GMAO
ukdp
ukoi
cfcs2
cfas2
ecco50y
0.2
0.0
0.2
gfdl
soda
ecmfa
ecmfc
ukgs
ingv
mrieccoSIO
cfasa
mct2
mct3
eccoJPLa
eccoJPLc
eccoMIT
GMAO
0.2
•The North Pacific does
not show a warming trend,
but more of a rapid shift in
the early 90’s
ukdp
ukoi
cfcs2
cfas2
ecco50y
gfdl
soda
ecmfa
ecmfc
ukgs
ingv
mrieccoSIO
cfasa
mct2
mct3
eccoJPLa
eccoJPLc
eccoMIT
GMAO
0.0
-0.2
0.0
-0.2
-0.4
-0.2
-0.4
sdv ensm = 0.071
s/n ensm = 0.532
-0.4
1950
1960
sdv all = 0.108
s/n all = 0.803
1970
spread
1980
Time
= 0.134
1990
-0.6
2000
sdv ensm = 0.113
s/n ensm = 0.916
-0.8
1950
1960
sdv all = 0.144
s/n all = 1.172
spread
= 0.123
•Large uncertainty after
2000
1970
1980
Time
1990
sdv ensm = 0.078
s/n ensm = 0.674
-0.6
1950
1960
2000
Courtesy of Magdalena
•Phase/amplitude
of
decadal signal is poorly
sdv all = 0.131
s/n all = 1.137
1970
spread
1980
Time
= 0.115
1990
2000
Balmaseda
2
OceanObs09 Community White Paper by Xue et al. (2010)
(call for operational monitoring of climate signals)
Name
Method
& Forcings
In Situ
Data
Altimetry
Data
Resolution
Period
Vintage
Reference
EN3.v2a
Analysis
Correction
Scheme
No XBT
corrections
No
1°x 1°, 42 Levels
Monthly Temp.
1950present
2009
Ingleby and
Huddleston
(2007)
NODC
Objective
Analysis
No XBT
corrections
No
1°x 1°, 16 Levels,
0 to 700m
Seasonal Temp.
1955present
2010
Levitus et al.
(2009)
GODAS
3D-VAR
No XBT
corrections
NO (Yes in
real time)
1°x 1° (1/3° near Eq), 197940 Levels
present
Pentad, Monthly
2003
Behringer and
Xue (2004
ECMWF
(S3)
OI
No XBT
corrections
Yes
1°x1° (1/3° near Eq),
29 Levels
Daily, Monthly
1959present
2007
Balmaseda et
al. (2008)
JMA
3D-VAR
No XBT
corrections
Yes
1°x1° (1/3° near Eq),
50 Levels
Pentad, Monthly
1979present
2009
Usui et al.
(2006)
CFSR
3D-VAR
Partially
coupled
No XBT
corrections
No (Yes in
real time)
1/2°x 1/2° (1/4° near 1979Eq), 40 Levels
present
Daily, Pentad, Monthly
2010
Xue et al.
(2010)
GFDL
EnKF
Fully
coupled
XBT
corrections
Yes
1°x 1° (1/3° near Eq), 197050 Levels
present
Daily, Pentad, Monthly
2010
Zhang et al.
(2009)
GMAO
EnOI
Fully
coupled
XBT
corrections
No
1/2°x 1/2° (1/4° near 1980Eq), 40 Levels
present
Daily, Monthly
2011
Rienecker at al.
(2011)
MERCATOR
(PSY2G2)
KF-SEEK
No XBT
corrections
Yes
2°x 2° (1/2° near Eq), 197931 Levels
present
Daily, Pentad, Monthly
2007
Drévillon et al.
(2008)
BOM
(PEODAS)
EnKF
No XBT
corretions
No
2°x 1.5 ° (1/2° near
Eq.), 25 Levels
Daily, Monthly
2009
Yin et al.
(2010)
1980present
3
In Situ Observations
from Saha et al. (2010)
Pre-Altimetry
Altimetry
Argo
(1985-1992)
(1993-2002)
(2003-09)
4
Questions
•
How well is the mean HC300 analyzed by operational
ocean reanalysis (ORA)?
•
What are impacts of changes in the ocean observing
system on the quality of HC300 analysis?
•
How well does operational ORA capture interannual
variability, multi-decadal and long term variability in
HC300?
•
What are prospects for monitoring climate indices
using an ensemble of operational ORAs?
•
What are roles of HC300 on potential predictability of
ENSO, Indian Ocean Dipole and Atlantic Nino?
5
Mean Heat Content in 1985-2009
6
RMSD from EN3 in Different Ocean Basins
7
HC300 in Equatorial Pacific (2oS-2oN)
1993
1999
2003
8
HC300 in Equatorial Indian Ocean (2oS-2oN)
1997
2003
1997
9
HC300 in Equatorial Atlantic (2oS-2oN)
2005
2005
10
HC300 Anomaly Correlation with EN3
11
HC300 Anomaly Correlation with OI SST
12
Table 3. Anomaly correlation between HC300 and SST in 1982-2009 averaged in various ocean basins drawn as boxes in Fig. 8. Correlations less th
Anomaly Correlation between HC300 and SST
E. Pac
W. Pac.
S.E. Ind.
S.W. Ind.
E. Atl.
EN3
0.80
0.39
0.16
0.42
0.57
NODC
0.74
0.37
0.16
0.42
0.47
GODAS
0.78
0.39
0.25
0.41
0.46
ECMWF
0.78
0.41
0.32
0.48
0.58
JMA
0.77
0.38
0.36
0.51
0.45
CFSR
0.75
0.37
0.30
0.40
0.35
GFDL
0.76
0.38
0.24
0.45
0.60
GMAO
0.77
0.36
0.29
0.42
0.48
MERCATOR
0.78
0.41
0.39
0.47
0.56
BOM
0.79
0.39
0.34
0.45
0.47
mean
0.77
0.39
0.28
0.44
0.50
Spread/mean
5%
11%
29%
11%
18%
13
HC300 Anomaly Indices for ENSO, IOD and Atlantic Nino
ENSO
IOD
Atlantic Nino
14
Linear Trend of HC300 Anomaly in 1993-2009
15
HC300 Anomaly Indices for Multi-decadal Variability
1995
1999
2004
16
HC300 and HC300 Anomaly Average in 70oS-70oN
2003
El Chichon
Mt. Pinatubo
17
Impacts of HC300 on SST Anomaly
18
Role of HC300 for Predictability of ENSO
-Equatorial western Pacific
HC300a leads NINO3.4 by
10-12 months.
- The lead/lag relationship
between HC300a and
NINO3.4 is consistently
analyzed by all ORAs.
- NODC is too noisy near
the equator.
- The peak correlation
between HC300a and
NINO3.4 in CFSR is lower
than others.
19
Role of HC300 for Predictability of Atlantic Nino
-Equatorial eastern
Atlantic HC300a leads
Atlantic Nino by 4-6
months.
-Equatorial western
Atlantic HC300a leads
Atlantic Nino by 8-12
months.
-Differences in the
lead/lag correlation are
quite large.
20
Role of HC300 for Predictability of IOD
- Southeastern Indian
Ocean HC300a leads
IOD by 2 months.
- Southwestern Indian
Ocean HC300a leads
IOD by 8-12 months.
- Differences in the
lead/lag correlation are
quite large.
21
Summary
•
Consistency in mean HC300 is generally high south of 30oS except
near the Gulf Stream and Kuroshio-Oyashio Extension (KOE), in the
tropical Atlantic, and some regional seas such as Gulf of Mexico and
South China Sea.
•
Consistency, measured by root-mean-square differences from EN3,
tends to increase with time, particularly in the tropical Pacific, the
tropical Indian Ocean and extra-tropical southern oceans, which are
partly due to constraints from a dense observational network from
tropical mooring arrays and Argo floats.
•
Consistency in the equatorial Pacific HC300 increased significantly
after 1993 when the TAO mooring array was fully implemented.
•
Consistency in the equatorial Indian Ocean HC300 increased
significantly around 2003 when the two RAMA mooring lines were
implemented at 80.5o E and 90o E. All model-based HC300 are too
cold relative to EN3 in the eastern tropical Indian Ocean before
1997.
•
Consistency in the equatorial Atlantic HC300 is much lower than that
in the equatorial Pacific and Indian Ocean, but it improved
significantly after 2006.
22
Summary
•
HC300 anomalies (HC300a) associated with ENSO are highly
consistent among ORAs; HC300a associated with IOD are
moderately consistent, and model-based analyses are superior to in
situ-based analyses in the eastern pole of the IOD; HC300a
associated with the Atlantic zonal mode have considerable
uncertainties among ORAs, which are comparable to signals.
•
Large multi-decadal variability and long-term trends exist in HC300.
The consensus among ORAs suggests that the mean HC300 in 70oS70oN has brief cooling periods during early 1980s and 1992-1993
related to the volcanic eruptions of the El Chichon and Mt. Pinatubo,
and a short warming in 1985-1991, and then a continuous warming
in 1994-2003, followed by a persistence or weak cooling in 20042009.
•
Despite of many advances in ORAs in the past decade, uncertainties
in HC300 are still large near western boundary currents, in the
tropical Atlantic and extra-tropical southern oceans. To improve
HC300 analysis in those regions, additional advances, such as
improving surface fluxes, model physics, model resolution and data
assimilation schemes, will be needed in conjunction with
maintaining and enhancing ocean observing systems in those
regions.
23