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Monday, June 28, 2010

PRELIMINARY June 2010 SST Anomaly Update

I’ve moved to WordPress.  This post can now be found at PRELIMINARY June 2010 SST Anomaly Update
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The June 2010 SST data through the NOAA NOMADS website won’t be official for another week, on Monday July 5th. Refer to the schedule on the NOAA Optimum Interpolation Sea Surface Temperature Analysis Frequently Asked Questions webpage. The following are the preliminary Global and NINO3.4 SST anomalies for June 2010 presented by the NOMADS website. I’ve also included the weekly data through June 23, 2010, but I’ve shortened the span of the weekly data, starting it in January 2004, so that the wiggles are visible.

Based on the preliminary data, monthly NINO3.4 SST anomalies are continuing to drop, and the drop has put them closer to the La Niña threshold.
http://i50.tinypic.com/vql2co.jpg
Preliminary Monthly NINO3.4 SST Anomalies

Monthly Global SST anomalies, according to the preliminary data, have stalled in their lagged decline, but as you will see with the weekly data, the uptick is temporary and normal.
http://i48.tinypic.com/2z7j5u1.jpg
Preliminary Monthly Global SST Anomalies

The weekly NINO3.4 SST anomaly data have dropped just below the -0.5 deg C threshold of a La Nina.
http://i48.tinypic.com/2qjgmrb.jpg
Weekly NINO3.4 SST Anomalies

Weekly Global SST Anomalies are declining but there was a minor uptick during the past few weeks.
http://i48.tinypic.com/33n7tzl.jpg
Weekly Global SST Anomalies

Thanks, Diane.

SOURCES
SST anomaly data is available through the NOAA NOMADS website:
http://nomad1.ncep.noaa.gov/cgi-bin/pdisp_sst.sh
or:
http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?lite=

Sunday, June 27, 2010

January To March 2010 NODC Ocean Heat Content (0-700m) Update And Comments

I’ve moved to WordPress.  This post can now be found at January To March 2010 NODC Ocean Heat Content (0-700m) Update And Comments
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The National Oceanographic Data Center (NODC) has recently updated its Ocean Heat Content (OHC) data for the depths of 0-700 meters. This dataset was released with the Levitus et al (2009) Paper. The update included data for the first quarter of 2010. There were no changes to earlier data.

Figures 1 and 2 are time-series graphs of the OHC data from January 1955 to March 2010 for the global oceans (Figure 1) and for the tropical Pacific (Figure 2). The 2009/10 El Niño did not have a major impact on the tropical Pacific OHC.

http://i45.tinypic.com/2u73syr.jpg
Figure 1 – Global OHC
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http://i46.tinypic.com/2ev6f7b.jpg
Figure 2 – Tropical Pacific OHC

Also illustrated are the OHC data broken down into hemispheres and into individual ocean basins, Figures 6 through 14. There weren’t any major rises or falls.

Before presenting those graphs, a few notes.

DISPARITY OF NORTH ATLANTIC OCEAN BASIN TREND

In the last update, OHC Linear Trends and Recent Update of NODC OHC (0-700 Meters) Data, the linear trends of the individual ocean basins from 1955 to 2009 were presented. I noted that since 1955 the linear trend of the North Atlantic OHC (0.205 GJ/meter^2/decade) was approximately 3 to 4 times higher than the linear trends of most of the other ocean basins.

Figure 3 illustrates the linear trends of the ocean basins since 1975. The data have been smoothed with a 13-month running-average filter. The year 1975 was chosen since it is about that time that the Atlantic Multidecadal Oscillation began its rise. 1975 is also approximately one year before the Pacific Climate Shift, which changed the frequency and magnitude of ENSO events. Since 1975, the North Atlantic OHC trend (0.323 GJ/meter^2/decade) was significantly higher than the linear trends of other ocean basins. The North Atlantic linear trend is approximately 1.75 times higher than the Arctic Ocean trend, but keep in mind that much of the Arctic Ocean is directly impacted by the North Atlantic. In fact, based on the coordinates used for those two datasets, they share data between 65N-75N and 78W-10E. At the other end of the spectrum, the North Atlantic OHC trend is almost 5 times the Indian Ocean OHC trend since 1975.
http://i49.tinypic.com/11wbm3a.jpg
Figure 3

NORTH ATLANTIC ALSO RESPONSIBLE FOR MUCH OF THE DROP IN GLOBAL OHC

Referring back to Figure 1, Global OHC has been declining since about 2005. It is quite obvious looking at the OHC data for the individual ocean basins, Figure 4, that the drops in the North Atlantic OHC and in the adjoining Arctic and South Atlantic datasets (that are directly influence by the North Atlantic) are the cause of the global decline. And as shown in Figure 3, those datasets have the highest trends since 1975.
http://i49.tinypic.com/5ebpua.jpg
Figure 4

BIG IFS

I’ll repeat a section from the past NODC OHC update. IF the multi-decade variations in North Atlantic OHC are similar in timing to the AMO, and IF the AMO did peak in 2005, and IF (lots of big IFs) the decline in North Atlantic OHC persists for another two plus decades, will global OHC continue to remain flat (or decline) for that long, too? Many of the other ocean basins are showing recent flattening or declines, so the North Atlantic is not alone. Regardless, a long-term decline in North Atlantic OHC (if one were to occur) would definitely not help long-term projections of a monotonous rise in OHC. And since the only variables that appear to cause significant rises in the other ocean basins are multiyear La Nina events and shifts in sea level pressure, a continued drop in North Atlantic OHC would have to be counteracted by one of those other factors.

There are significant differences between the North Atlantic OHC trends and those of the other basins, for the long-term periods when OHC is rising and for the recent short-term decline in OHC. These differences should call attention to the fact that factors other than anthropogenic greenhouse gases dominated the rise in Global Ocean Heat Content since 1955.

The following are links to earlier posts that illustrate and discuss how natural variables (including ENSO events and changes in sea level pressure as represented by the North Atlantic Oscillation and North Pacific Index) are responsible for most of the rise in OHC since 1955:
ENSO Dominates NODC Ocean Heat Content (0-700 Meters) Data,
AND
North Atlantic Ocean Heat Content (0-700 Meters) Is Governed By Natural Variables,
AND
North Pacific Ocean Heat Content Shift In The Late 1980s

COVERAGE OF SUBSURFACE TEMPERATURE READINGS

Like Sea and Land Surface Temperature datasets, subsurface ocean temperature data used in OHC data are incomplete in early years. How incomplete? Harrison and Carson (2007) in “Is the World Ocean Warming? Upper-Ocean Temperature Trends: 1950–2000” presented the number of temperature readings at various depths, from 100 meters to 2000 meters, contained in the World Ocean Database (2001). This is the database used by Levitus et al for their OHC data. Link to Harrison and Carson (2007):
http://journals.ametsoc.org/doi/pdf/10.1175/JPO3005.1

Figure 5 is Harrison and Carson’s Figure 1. I’ve added the depths in red to simplify viewing. The numbers of temperature readings are shown by the color scale at right, with the light blue and “warmer” colors representing readings of 100 to 150 and more. The vast majority of the data, where there are readings, are in the darker cells, which show fewer readings. Those are the areas with 10 to 100 readings. Note that the numbers of readings are not annual or decadal. They are the total number of readings for the period of 1950 to 2000.
http://i45.tinypic.com/ne83d.jpg
Figure 5

Note: Harrison and Carson (2007) provides an interesting perspective on subsurface temperature data and trends at different depths. It is worth reading.

HEMISPHERIC AND INDIVIDUAL BASIN OHC UPDATE THROUGH DECEMBER 2009

For those who enjoy information overload, the following are time-series graphs of OHC data (0-700 meters) for the hemispheres and the individual ocean basins, without commentary.
http://i50.tinypic.com/1zpmgqu.jpg
Figure 6 - Northern Hemisphere OHC
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http://i46.tinypic.com/53a9tl.jpg
Figure 7 - Southern Hemisphere OHC
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http://i48.tinypic.com/wqsemr.jpg
Figure 8 - North Atlantic OHC
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http://i50.tinypic.com/a6qvd.jpg
Figure 9 - South Atlantic OHC
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http://i47.tinypic.com/2yy4mwx.jpg
Figure 10 - North Pacific
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http://i47.tinypic.com/11sid4w.jpg
Figure 11 - South Pacific
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http://i45.tinypic.com/axkynr.jpg
Figure 12 - Indian Ocean
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http://i45.tinypic.com/28iahe9.jpg
Figure 13 - Arctic Ocean
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http://i47.tinypic.com/uxwzq.jpg
Figure 14 - Southern Ocean

SOURCE

NODC OHC data is available through the KNMI Climate Explorer website. Many thanks to Dr. Geert Jan van Oldenborgh:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere

Thursday, June 10, 2010

La Niña Is Not The Opposite Of El Niño – The Videos

I’ve moved to WordPress.  This post can now be found at La Niña Is Not The Opposite Of El Niño – The Videos
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Weather noise and seasonal variability have stifled my previous attempts to animate noisy datasets like TLT anomalies. That noise made it difficult, at best, to determine what is taking place. A short example of a .gif animation of monthly TLT anomaly maps is shown in Figure 1.

http://i46.tinypic.com/2zqznnn.jpg
Figure 1 – Sample Animation – Not Used In Video

Recently, I began animating maps that represent 12-month averages of “noisy” datasets with good results. The weather noise and seasonal variations are gone, for the most part. The 12-month-averaged TLT anomaly maps present a much “smoother” animation, as shown in the .gif sample, Figure 2.
http://i48.tinypic.com/2gt6slz.jpg
Figure 2 – Sample Of Animation Used In Video

In the video, I liken the effect to smoothing the data in a time-series graph with a 12-month filter, Figure 3.
http://i48.tinypic.com/160wk1w.jpg
Figure 3 – Smoothed Time-Series Graph

VIDEO DESCRIPTION
The following 2-part video series provides detailed descriptions, time-series graphs, and animations of the processes that take place during El Niño and La Niña events. It uses TLT, SST, Total Cloud Amount, Sea Level, and Downward Shortwave Radiation anomalies to help illustrate the significant differences between the 1997/98 El Niño and the 1998/99/00/01 La Niña.

The videos also help illustrate why the effects of ENSO cannot be removed from the global surface temperature record by simply subtracting scaled and lagged NINO3.4 SST anomalies (or another ENSO index) from global temperature anomalies. There are significant residuals that contribute to global temperature anomaly trends, and these residuals are not accounted for with the simple methods used in climate studies such as Thompson et al (2009). Link (with paywall) to Thompson et al (2009):
http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI3089.1

I’ve also included animations that compare global SST anomalies with the other datasets. A sample frame that compares SST and TLT anomalies is shown in Figure 4. To indicate the timing of the maps as they proceed from El Niño to La Niña, many of the animations also include time-series graphs that fill in as time progresses.
http://i49.tinypic.com/2yl22bk.jpg
Figure 4 – Sample Frame From Animation Of Two Datasets

THE VIDEOS
Please view the animations full screen and, if possible, in high definition.

Part 1


YouTube Link
http://www.youtube.com/watch?v=Et3wjKKCy5o
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Part 2


YouTube Link
http://www.youtube.com/watch?v=A6bmb8hi6u0

SOURCES AND DATASETS
The maps were created using the map-making feature of the KNMI Climate Explorer, which was also used for the data in the time-series graphs.
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere

The primary SST and SST anomaly data used in the animations and graphs are NOAA/Reynolds Optimum Interpolation (OI.v2) SST.
http://www.emc.ncep.noaa.gov/research/cmb/sst_analysis/

For the comparison to tropical Pacific Ocean Heat Content, a longer-term SST dataset was required, and for that graph, I used Kaplan/Reynolds (OI.v2) NINO3.4 SST anomalies from the Monthly climate indices webpage of the KNMI Climate Explorer. Link to Kaplan overview:
http://www.cgd.ucar.edu/cas/guide/Data/kaplan_sst.html

The other datasets used in the videos are also available through the KNMI Climate Explorer and they include:
1. International Satellite Cloud Climatology Project (ISCCP) Total Cloud Amount data. Link:
http://isccp.giss.nasa.gov/projects/flux.html

2. CAMS-OPI [Climate Anomaly Monitoring System ("CAMS") and OLR Precipitation Index ("OPI")] precipitation data. Link:
http://www.cpc.noaa.gov/products/global_precip/html/wpage.cams_opi.html

3. RSS MSU Lower Troposphere Temperature (TLT) anomalies. Link:
http://www.remss.com/msu/msu_data_description.html

4. CLS (AVISO) Sea Level anomalies. Link:
http://www.aviso.oceanobs.com/en/news/ocean-indicators/mean-sea-level/

5. NCEP/DOE Reanalysis-2 Surface Downward Shortwave Radiation Flux (dswrfsfc) anomalies. Link:
http://www.cpc.ncep.noaa.gov/products/wesley/reanalysis2/kana/reanl2-1.htm

There is also an animation of the Equatorial Subsurface Temperature Cross-sections that are available through the ECMWF website:
http://www.ecmwf.int/products/forecasts/d/charts/ocean/reanalysis/xzmaps/Monthly!monthly!201004!Full%20field!Temperature!/

The Trade Wind Index (5S-5N, 135W-180) Anomaly data is available through the NOAA CPC website. Scroll down to the second grouping for the anomaly data:
http://www.cpc.noaa.gov/data/indices/wpac850
FURTHER DISCUSSIONS

The first detailed posts on the multiyear aftereffects of El Nino events are:
Can El Nino Events Explain All of the Global Warming Since 1976? – Part 1
And:
Can El Nino Events Explain All of the Global Warming Since 1976? – Part 2
And:
Supplement To “Can El Nino Events Explain All Of The Warming Since 1976?”
And:
Supplement 2 To “Can El Nino Events Explain All Of The Warming Since 1976?”

The impacts of these El Nino events on the North Atlantic are discussed in:
There Are Also El Nino-Induced Step Changes In The North Atlantic
And:
Atlantic Meridional Overturning Circulation Data

The Lower Troposphere Temperature (TLT) anomaly responses are discussed in:
RSS MSU TLT Time-Latitude Plots... Show Climate Responses That Cannot Be Easily Illustrated With Time-Series Graphs Alone
And:
El Ninos Create Step Changes in TLT of the Northern Hemisphere Mid Latitudes

The misrepresentation of ENSO in climate studies are discussed in the following (The discussions are similar but there are differences in the presentation):
Climate Studies Misrepresent The Effects Of El Nino And La Nina Events
And:
The Relationship Between ENSO And Global Surface Temperature Is Not Linear
And:
Multiple Wrongs Don’t Make A Right, Especially When It Comes To Determining The Impacts Of ENSO
And:
Regression Analyses Do Not Capture The Multiyear Aftereffects Of Significant El Nino Events.”

Posts related to the effects of ENSO on Ocean Heat Content are here:
ENSO Dominates NODC Ocean Heat Content (0-700 Meters) Data
And:
North Atlantic Ocean Heat Content (0-700 Meters) Is Governed By Natural Variables
And:
North Pacific Ocean Heat Content Shift In The Late 1980s

Detailed technical discussions can be found here:
More Detail On The Multiyear Aftereffects Of ENSO – Part 1 – El Nino Events Warm The Oceans
And:
More Detail On The Multiyear Aftereffects Of ENSO - Part 2 – La Nina Events Recharge The Heat Released By El Nino Events AND...During Major Traditional ENSO Events, Warm Water Is Redistributed Via Ocean Currents.
And:
More Detail On The Multiyear Aftereffects Of ENSO - Part 3 – East Indian & West Pacific Oceans Can Warm In Response To Both El Nino & La Nina Events

Monday, June 7, 2010

May 2010 SST Anomaly Update

I’ve moved to WordPress.  This post can now be found at May 2010 SST Anomaly Update
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MONTHLY SST ANOMALY MAP

The map of Global OI.v2 SST anomalies for May 2010 downloaded from the NOMADS website is shown below. The central equatorial Pacific SST anomalies have decreased considerably since their peak in December and are now below zero. SST anomalies in most oceans basins are now dropping in response.


http://i49.tinypic.com/15oxh01.jpg
May 2010 SST Anomalies Map (Global SST Anomaly = +0.25 deg C)

MONTHLY OVERVIEW

NINO3.4 SST anomalies have dropped into ENSO-neutral conditions. The central tropical Pacific (Monthly NINO3.4) SST Anomaly is -0.09 deg C. Weekly data has fallen well into ENSO-neutral ranges (-0.32 deg C) and are approaching the threshold of a La Niña.

Global SST anomalies dropped 0.066 deg C during May. The decline in the Southern Hemisphere (-0.081 deg C) exceeded the drop in the Northern Hemisphere (-0.046 deg C). SST anomalies dropped in all ocean basins except for the Arctic.
http://i47.tinypic.com/29o3n7q.jpg
Global
Monthly Change = -0.066 deg C
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http://i48.tinypic.com/nbc945.jpg
NINO3.4 SST Anomaly
Monthly Change = -0.77 deg C

EAST INDIAN-WEST PACIFIC

The SST anomalies in the East Indian and West Pacific continue their decrease also. Will they rise, noticeably, in response to a La Niña as they have in the past?

I’ve added this dataset in an attempt to draw attention to what appears to be the upward step responses. Using the 1986/87/88 and 1997/98 El Niño events as references, East Indian-West Pacific SST Anomalies peak about 7 to 9 months after the peak of the NINO3.4 SST anomalies, so we shouldn’t expect any visible sign of a step change for almost 18 to 24 months. We’ll just have to watch and see.
http://i49.tinypic.com/28i511j.jpg
East Indian-West Pacific (60S-65N, 80E-180)
Monthly Change = -0.032 deg C

Further information on the upward “step changes” that result from strong El Niño events, refer to my posts from a year ago Can El Niño Events Explain All of the Global Warming Since 1976? – Part 1 and Can El Niño Events Explain All of the Global Warming Since 1976? – Part 2

And for the discussions of the processes that cause the rise, refer to More Detail On The Multiyear Aftereffects Of ENSO - Part 2 – La Niña Events Recharge The Heat Released By El Niño Events AND...During Major Traditional ENSO Events, Warm Water Is Redistributed Via Ocean Currents -AND- More Detail On The Multiyear Aftereffects Of ENSO - Part 3 – East Indian & West Pacific Oceans Can Warm In Response To Both El Niño & La Niña Events

NOTE ABOUT THE DATA

The MONTHLY graphs illustrate raw monthly OI.v2 SST anomaly data from November 1981 to May 2009.

MONTHLY INDIVIDUAL OCEAN AND HEMISPHERIC SST UPDATES
http://i50.tinypic.com/2wh3wia.jpg
Northern Hemisphere
Monthly Change = -0.046 deg C
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http://i50.tinypic.com/xb04mf.jpg
Southern Hemisphere
Monthly Change = -0.081 deg C
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http://i49.tinypic.com/e862s9.jpg
North Atlantic (0 to 75N, 78W to 10E)
Monthly Change = -0.058 deg C
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http://i46.tinypic.com/aw93ee.jpg
South Atlantic (0 to 60S, 70W to 20E)
Monthly Change = -0.099 deg C

Note: I discussed the upward shift in the South Atlantic SST anomalies in the post The 2009/10 Warming Of The South Atlantic.

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http://i45.tinypic.com/jiovhx.jpg
North Pacific (0 to 65N, 100 to 270E, where 270E=90W)
Monthly Change = -0.059 Deg C
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http://i46.tinypic.com/29qjjg2.jpg
South Pacific (0 to 60S, 145 to 290E, where 290E=70W)
Monthly Change = -0.081 deg C
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http://i49.tinypic.com/6jmslv.jpg
Indian Ocean (30N to 60S, 20 to 145E)
Monthly Change = -0.074 deg C
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http://i47.tinypic.com/3462p1u.jpg
Arctic Ocean (65 to 90N)
Monthly Change = +0.039 deg C
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http://i45.tinypic.com/2i7nz1v.jpg
Southern Ocean (60 to 90S)
Monthly Change = -0.089 deg C

WEEKLY NINO3.4 SST ANOMALIES

The weekly NINO3.4 SST anomaly data illustrate OI.v2 data centered on Wednesdays. The latest weekly NINO3.4 SST anomalies are -0.35 deg C. And NOAA has posted a La Niña watch.
http://www.noaawatch.gov/headlines/enso.php
http://i46.tinypic.com/4ibi9s.jpg
Weekly NINO3.4 (5S-5N, 170W-120W)

SOURCE

The Optimally Interpolated Sea Surface Temperature Data (OISST) are available through the NOAA National Operational Model Archive & Distribution System (NOMADS).
http://nomad1.ncep.noaa.gov/cgi-bin/pdisp_sst.sh
or
http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh

Wednesday, June 2, 2010

PRELIMINARY May 2010 SST Anomaly Update

I’ve moved to WordPress.  This post can now be found at PRELIMINARY May 2010 SST Anomaly Update
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UPDATE: Corrected the .gif animation at the end of the post. Thanks, Anonymous
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The May 2010 SST data through the NOAA NOMADS website won’t be official until Monday June 7th. Refer to the schedule on the NOAA Optimum Interpolation Sea Surface Temperature Analysis Frequently Asked Questions webpage. The following are the preliminary Global and NINO3.4 SST anomalies for May 2010 presented by the NOMADS website. I’ve also included the weekly data through May 26, 2010, but I’ve shortened the span of the weekly data, starting it in January 2004, so that the wiggles are visible.

Based on the preliminary data, monthly NINO3.4 SST anomalies are continuing to decline. They dropped significantly last month, approximately 0.72 deg C.

http://i45.tinypic.com/2h2p3xy.jpg
Monthly NINO3.4 SST Anomalies

Monthly Global SST anomalies, according to the preliminary data, are now dropping in a lagged response to the change in the tropical Pacific.
http://i49.tinypic.com/ezrgpx.jpg
Monthly Global SST Anomalies

The weekly NINO3.4 SST anomaly data are firmly below zero, but they’ve stalled over the past week.
http://i50.tinypic.com/2mpddlx.jpg
Weekly NINO3.4 SST Anomalies

Weekly Global SST Anomalies are still elevated but continue their lagged drop in response to the decline in NINO3.4 SST anomalies.
http://i50.tinypic.com/2a9sn44.jpg
Weekly Global SST Anomalies

HOW LOW WILL NINO3.4 SST ANOMALIES GO THIS YEAR?

The following is a gif animation comparing the equatorial subsurface temperature anomalies for June 1, 2010 to June 1, 2007, as NINO 3.4 SST anomalies were working their way down toward the 2007/08 La Niña. The negative subsurface anomalies in the equatorial Pacific this year appear more significant than three years ago.
http://i48.tinypic.com/iw29fm.jpg
Equatorial Subsurface Temperature Anomalies June 1, 2007 & 2010

SOURCES
SST anomaly data is available through the NOAA NOMADS website:
http://nomad1.ncep.noaa.gov/cgi-bin/pdisp_sst.sh

Daily and Monthly equatorial subsurface temperature anomaly graphics are available through the ECMWF website:
http://www.ecmwf.int/products/forecasts/d/charts/ocean/real_time/xzmaps/

Donations

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Comment Policy, SST Posts, and Notes

Comments that are political in nature or that have nothing to do with the post will be deleted.
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The Smith and Reynolds SST Posts DOES NOT LIST ALL SST POSTS. I stopped using ERSST.v2 data for SST when NOAA deleted it from NOMADS early in 2009.

Please use the search feature in the upper left-hand corner of the page for posts on specific subjects.
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NOTE: I’ve discovered that some of the links to older posts provide blank pages. While it’s possible to access that post by scrolling through the history, that’s time consuming. There’s a quick fix for the problem, so if you run into an absent post, please advise me. Thanks.
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If you use the graphs, please cite or link to the address of the blog post or this website.