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Monday, April 26, 2010

VERY PRELIMINARY April 2010 SST Anomaly Update

I’ve moved to WordPress.  This post can now be found at VERY PRELIMINARY April 2010 SST Anomaly Update
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The April 2010 SST data through the NOAA NOMADS website won’t be official until Monday April 10th. Refer to the schedule on the NOAA Optimum Interpolation Sea Surface Temperature Analysis Frequently Asked Questions webpage. However, the following are the preliminary Global and NINO3.4 SST anomalies for April 2010 presented by the NOMADS website today, Monday, April 26, 2010. I’ve also included the weekly data through April 21, 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 accelerated after the slowdown last month. They’ve dropped ~0.41 deg C over the past month.
http://i40.tinypic.com/dg3pcm.png
Monthly NINO3.4 SST Anomalies

Monthly Global SST anomalies, according to the preliminary data, increased 0.034 deg C since March.
http://i43.tinypic.com/11vllz8.png
Monthly Global SST Anomalies

The weekly NINO3.4 SST anomaly data, with the most recent value centered on April 21, 2010, shows a continued decline.
http://i39.tinypic.com/29v1c7b.png
Weekly NINO3.4 SST Anomalies

Weekly Global SST Anomalies are still elevated and have not yet begun their lagged drop in response to the decline in NINO3.4 SST anomalies.
http://i39.tinypic.com/oseal3.png
Weekly Global SST Anomalies

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

Monday, April 19, 2010

Mid-April 2010 SST Anomaly Update

I’ve moved to WordPress.  This post can now be found at Mid-April 2010 SST Anomaly Update
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NOTE: The weekly OI.v2 SST data is available in two periods through the NOAA NOMADS website, from November, 1981 through 1989, and from 1990 to present. I’ve been providing these mid-month updates with graphs that include the full term of the second batch of data. It’s really impossible to tell from those graphs what has transpired over the past few weeks due to the length of the dataset, so I’ve added shorter-term graphs, beginning in 2004, to make the wiggles visible.

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NINO3.4 SST anomalies for the week centered on April 14, 2010 show that central equatorial Pacific SST anomalies are continuing to decline. Presently they’re at 0.84 deg C, which is still well into El Nino temperature levels.
http://i41.tinypic.com/122khtu.png
NINO3.4 SST Anomalies
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http://i41.tinypic.com/24268nm.png
NINO3.4 SST Anomalies - Short-Term

Weekly Global SST anomalies are still elevated, near the peak levels for this El Nino. They are not showing any signs, yet, of dropping in response to the decline in central equatorial Pacific temperatures.
http://i40.tinypic.com/15y6u04.png
Global SST Anomalies
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http://i42.tinypic.com/30skcpx.png
Global SST Anomalies - Short-Term

SOURCE
OI.v2 SST anomaly data is available through the NOAA NOMADS system:
http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?lite

Friday, April 16, 2010

Is The Difference Between NINO3.4 SST Anomalies And The PDO A Function Of Sea Level Pressure?

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In Misunderstandings about the PDO – REVISED, I showed that the Pacific Decadal Oscillation (PDO) does not represent the Sea Surface Temperature (SST) anomalies of the North Pacific (North of 20N), and that the PDO is not detrended SST anomalies of the North Pacific like the Atlantic Multidecadal Oscillation (AMO), and that the PDO does not represent the difference between the North Pacific SST anomalies and Global temperature anomalies. I also provided links to Zhang et al (1997) “ENSO-like interdecadal variability: 1900-93”…
http://www.atmos.washington.edu/~david/zwb1997.pdf
…and Newman et al (2003) “ENSO-Forced Variability of the Pacific Decadal Oscillation”…
http://www.cdc.noaa.gov/people/gilbert.p.compo/Newmanetal2003.pdf
…both of which showed that the PDO lags ENSO. In fact, Newman et al state, “The PDO is dependent upon ENSO on all timescales.”

That earlier post was co-posted at WattsUpWithThat with the similar title of Misunderstandings about the Pacific Decadal Oscillation.

This post is not intended to resurrect the arguments presented in the previous post, but it will show a possible cause for the difference between NINO3.4 SST anomalies and the PDO.

THE DIFFERENCE BETWEEN THE PDO AND NINO3.4 SST ANOMALIES
Figure 1 is a comparison graph of monthly PDO Index Monthly Values from the JISAO PDO website and standardized NINO3.4 SST anomalies. I used standardized NINO3.4 SST anomalies in this post because the PDO data is standardized and I was going to subtract one from the other. (But there really was little visual difference in the results if the NINO3.4 SST anomalies were not standardized.) And both datasets have been smoothed with 13-month running-average filters to remove some of the noise. The variances between the two datasets lead to speculation and debate about which dataset drives the other (even though the papers linked above show the PDO lags ENSO).
http://i41.tinypic.com/34znfvr.png
Figure 1

The calculated difference between the two datasets (Standardized NINO3.4 SST anomalies MINUS PDO data) is shown in Figure 2.
http://i41.tinypic.com/spu920.png
Figure 2

The difference between the two datasets is noisy so I’ve smoothed it with an 85-month filter in Figure 3.
http://i40.tinypic.com/s66v6o.png
Figure 3

THE NORTH PACIFIC INDEX
The North Pacific (NP) Index is “the area-weighted sea level pressure over the region 30N-65N, 160E-140W, available since 1899. It was introduced in Trenberth and Hurrell (1994) “Decadal atmosphere-ocean variations in the Pacific”:
http://www.o3d.org/web/Trenberth_Hurrell_1994.pdf
Figure 4 illustrates a time-series graph of the North Pacific Index, smoothed with a 13-month filter. Even with the filter it’s a noisy dataset.
http://i43.tinypic.com/2lc2tl.png
Figure 4

For those noting the spikes and wondering if they correlate with ENSO, I’ve prepared Figure 5. NINO3.4 SST anomalies and the North Pacific Index are negatively correlated but poorly. There are times when the North Pacific Index falls (rises) during an El Nino (La Nina), and other times when it does not.
http://i43.tinypic.com/157yo34.png
Figure 5

Let’s compare the North Pacific Index to the data created by subtracting the PDO data from the NINO3.4 SST anomalies. Refer to Figure 6. While they do diverge from time to time, the curves do follow one another quite well as far back as the mid-1940s. Prior to then, they diverge significantly. But when one considers these datasets are based on reconstructions of data with periods when and areas where there were few measurements, the divergence is not surprising.
http://i43.tinypic.com/15xmqdi.png
Figure 6

THE SAME GRAPH WITHOUT STANDARDIZED NINO3.4 DATA
Earlier I noted that standardizing the NINO3.4 SST anomalies made little difference in this visual comparison. Figure 7 is the same as Figure 6, except that the NINO3.4 SST anomalies in Figure 7 have not been standardized.
http://i41.tinypic.com/dng9xz.png
Figure 7

Regarding the question asked in the title of this post, Is The Difference Between NINO3.4 SST Anomalies And The PDO A Function Of Sea Level Pressure?, the answer appears to be yes.

SOURCES
The HADISST NINO3.4 SST anomaly data is available through the KNMI Climate Explorer Observations webpage:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere

The North Pacific Index data is available through the KNMI Climate Explorer Climate Indices webpage (as is the HADISST NINO3.4 data):
http://climexp.knmi.nl/selectindex.cgi?someone@somewhere

The PDO data from JISAO is also available through the KNMI Climate Explorer Climate Indices webpage, but I used the data directly from the JISAO website for this post:
http://jisao.washington.edu/pdo/PDO.latest

Saturday, April 10, 2010

A Different Perspective Of The Rise In Global Temperature

I’ve moved to WordPress.  This post can now be found at A Different Perspective Of The Rise In Global Temperature
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Figure 1 is a time-series graph of Global Temperature Anomalies (land and sea surface temperature) and linear trend from January 1850 to February 2010. Also listed on the graph is the calculation of the rise in global temperature (0.624 deg C) based on the linear trend over the term of the data. The year-to-year variations from El Nino and La Nina events are visible, as are the multidecadal variations caused by the Atlantic Multidecadal Oscillation. And if you study the last 30+ years of the graph closely, you can note the upward shift in global temperatures in 1976 from what is called the Great Pacific Climate Shift, and you can make out the upward steps caused by the ENSO events of 1986/87/88 and 1997/98.
http://i44.tinypic.com/35a1ylw.png
Figure 1

The Hadley Centre’s HadCET Central England Temperature is included in the KNMI Climate Explorer webpage of Daily climate indices. Figures 2 and 3 show the daily high and low Central England Temperature from 2001 to 2009. Figure 2 presents the data in deg C, and for those who are more familiar with temperatures in deg F, I converted the data to that scale in Figure 3. The annual seasonal cycles are very apparent. Over this period, the highest temperature was 32.9 deg C (~91 deg F), and the lowest temperature was -7.3 deg C (~19 deg F), balmy by some standards. Note the red line.

THE WIDTH OF THE RED LINE EQUALS THE RISE IN GLOBAL TEMPERATURES (0.624 deg C or 1.123 deg F) FROM 1850 TO 2010 BASED ON THE LINEAR TREND IN FIGURE 1.
http://i43.tinypic.com/wc24y8.png
Figure 2
http://i39.tinypic.com/10naion.png
Figure 3

And yes, I got the idea for this post from an illustration used by Dr. Richard Lindzen in many of his presentations. A YouTube version of Dr. Lindzen’s November 17, 2009 lecture at Oberlin College follows.


YouTube Link:
http://www.youtube.com/watch?v=VwM_B4-5gaE

SOURCE

The global temperature anomaly data is available through the KNMI Climate Explorer:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere

Thursday, April 8, 2010

Converting txt Data Into Columns In EXCEL

I’ve moved to WordPress.  This post can now be found at Converting txt Data Into Columns In EXCEL
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You’ve made the decision to investigate climate data, or to verify a claim made by a blogger, or to check the graphs climate bloggers present in their posts. You want to make sure they’re not making incorrect claims or being creative with the data. So, for example, you go to the KNMI Climate Explorer Monthly observations webpage and select HADISST data. On the next page, you input -5 and 5 for latitudes and -170 and -120 for longitudes, which are the coordinates of the NINO3.4 region (5S-5N, 170W-120W) of the tropical Pacific, an ENSO index. Then, on the next page, you scroll down to the third graph “anomalies” and click on “Raw Data” above it. There, you’re presented with the webpage shown in Figure 1, with two columns of data in txt format: months and the monthly NINO3.4 SST anomalies from January 1870 to present.

http://i41.tinypic.com/x59stf.jpg
Figure 1

You copy and paste the data in TXT format into EXCEL, and you run into a stumbling block, Figure 2. Both of the columns of numbers appear in one column in EXCEL. You don’t know what to do, so, frustrated, you close the windows and forget about it.
http://i43.tinypic.com/2m4u2s5.jpg
Figure 2

Or you discover how simple converting the txt Data to Columns is in EXCEL, Figures 3 through 5. Your version of EXCEL may be different, but I believe the “Convert Text To Column Wizard” is present in other versions.
NOTE: The data often includes numbers in Scientific Notation (Example: 0.377E-02). Do not delete any part of the number. EXCEL understands Scientific Notation and will automatically convert it (Convert the example to 0.00377).
http://i42.tinypic.com/51x3px.jpg
Figure 3
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http://i41.tinypic.com/2dl966b.jpg
Figure 4
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http://i44.tinypic.com/vhqku9.jpg
Figure 5

Yup, it’s that simple.

Monday, April 5, 2010

March 2010 SST Anomaly Update

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

The map of Global OI.v2 SST anomalies for March 2010 downloaded from the NOMADS website is shown below. Note the pattern of warm SST anomalies over the Southern part of the North Atlantic and cool SST anomalies in the Gulf of Mexico. If the pattern persisted through the summer months (big IF), how would it impact the hurricane season?

http://i42.tinypic.com/rur969.png
March 2010 SST Anomalies Map (Global SST Anomaly = +0.301 deg C)
Note: I was advised via email that the NOAA corrected the February OI.v2 SST data. It represents an upward change of only ~0.005 deg C globally, but since it was a correction in areas with sea ice, I decided to check those as well. The February Arctic Ocean SST anomalies rose ~0.02 deg C and the Southern Ocean SST anomalies ~0.03 deg C with the corrections.

MONTHLY OVERVIEW

There was a minor rise (0.012 deg C) this month in Global SST anomalies. SST Anomalies in both the Southern and Northern Hemispheres rose approximately the same amount. El Nino conditions remain in the central tropical Pacific (Monthly NINO3.4 SST Anomaly = +1.14 deg C and Weekly NINO3.4 SST Anomaly = +0.97 deg C), but SST anomalies there are dropping. Monthly NINO3.4 SST anomalies dropped 0.10 in March. The North Atlantic, Indian Ocean and the East Indian-West Pacific Ocean datasets all show significant rises this month. They are partly offset by the drops in the Pacific and South Atlantic.
http://i40.tinypic.com/4rav48.png
Global
Monthly Change = +0.012 deg C
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http://i44.tinypic.com/24yvcrt.png
NINO3.4 SST Anomaly
Monthly Change = -0.104 deg C

EAST INDIAN-WEST PACIFIC


The SST anomalies in the East Indian and West Pacific continue their lagged rise in response to the El Nino. Will they also rise, noticeably, in response to the La Nina as they have in the past?

I’ve added this dataset in an attempt to draw attention to the upward step response. Using the 1986/87/88 and 1997/98 El Nino 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://i41.tinypic.com/wsabg2.png
East Indian-West Pacific (60S-65N, 80E-180)
Monthly Change = +0.084 deg C

Further information on the upward “step changes” that result from strong El Nino events, refer to my posts from a year ago 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 for the discussions of the processes that cause the rise, refer to 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

NOTE ABOUT THE DATA

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

MONTHLY INDIVIDUAL OCEAN AND HEMISPHERIC SST UPDATES
http://i42.tinypic.com/nn03rs.png
Northern Hemisphere
Monthly Change = +0.013 deg C
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http://i42.tinypic.com/2myrggz.png
Southern Hemisphere
Monthly Change = +0.011 deg C
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http://i40.tinypic.com/2mm6yw3.png
North Atlantic (0 to 75N, 78W to 10E)
Monthly Change = +0.120 deg C
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http://i41.tinypic.com/330679u.png
South Atlantic (0 to 60S, 70W to 20E)
Monthly Change = -0.007 deg C

Note: The 2009 upward shift in South Atlantic SST anomalies is becoming very obvious. I’ll have to work up a post about it. I have yet to see a paper that explains it.

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http://i42.tinypic.com/2eve0lk.png
North Pacific (0 to 65N, 100 to 270E, where 270E=90W)
Monthly Change = -0.058 Deg C
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http://i44.tinypic.com/2s180tw.png
South Pacific (0 to 60S, 145 to 290E, where 290E=70W)
Monthly Change = -0.033 deg C
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http://i40.tinypic.com/6i901z.png
Indian Ocean (30N to 60S, 20 to 145E)
Monthly Change = +0.082 deg C
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http://i40.tinypic.com/e002s4.png
Arctic Ocean (65 to 90N)
Monthly Change = -0.092 deg C
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http://i39.tinypic.com/dza246.png
Southern Ocean (60 to 90S)
Monthly Change = +0.120 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 +0.97 deg C. They’re working their way down.
http://i44.tinypic.com/2ll10ye.png
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

Friday, April 2, 2010

“Polar” Sea and Land Surface Temperatures (Not Anomalies)

’ve moved to WordPress.  This post can now be found at “Polar” Sea and Land Surface Temperatures (Not Anomalies)
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This post illustrates Arctic and Antarctic/Southern Ocean surface temperatures (not anomalies) using NCDC OI.v2 Sea Surface Temperature (SST) and CPC GHCN/CAMS t2m Land Surface Temperature (LST) data. The intent is simply to show the ranges of the annual variations in temperature and the relative magnitude of those temperature ranges in comparison graphs. In other words, these are reference graphs. I have not provided a detailed narrative for them.

The OI.v2 SST data begins in November 1981. The GHCN/CAMS t2m data is available as far back as January 1948, but I’ve started in January 1979 so that the comparison graphs of LST and SST have similar periods.

Polar is in quotes in the title because these datasets do not include areas with sea ice. Sea surface temperature does not measure sea ice temperature. And like other datasets the GHCN/CAMS t2m data only measures temperature on land—not sea ice. Refer to Figure 1. So there is a “gap” in the data presented in this post; keep that in mind. Figure 1 also shows complete land surface temperature coverage for the Antarctic. You’ll have to refer to Fan and Dool (2007) “A global monthly land surface air temperature analysis for 1948-present” for the methods used to infill data. Link to Fan and Dool (2007):ftp://ftp.cpc.ncep.noaa.gov/wd51yf/GHCN_CAMS/cpc_globalT.pdf
http://i41.tinypic.com/x41xch.png
Figure 1

Note: I’ve used the latitudes North of 65N for the Arctic and South of 60S for the Antarctic and the Southern Ocean.

POLAR SEA SURFACE TEMPERATURES (SST)

Figures 2 and 3 show SST for the Arctic and Southern Oceans. And the comparison, Figure 4, shows the range of Arctic Ocean SST far exceeds that of the Southern Ocean.
http://i42.tinypic.com/21on1up.png
Figure 2
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http://i42.tinypic.com/1zbb8mh.png
Figure 3
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http://i39.tinypic.com/nn4qc3.png
Figure 4

POLAR LAND SURFACE TEMPERATURES (LST)

Figures 5 and 6 illustrate LST for the Arctic and Antarctic. The comparison, Figure 7, again shows the variations in Arctic LST are much greater than in the Antarctic.
http://i40.tinypic.com/ay3akz.png
Figure 5
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http://i39.tinypic.com/htae69.png
Figure 6
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http://i43.tinypic.com/24w95vt.png
Figure 7

POLAR LAND VERSUS SEA SURFACE TEMPERATURES

The Arctic LST and SST are compared in Figure 8, the Antarctic SST and Southern Ocean SST are compared in Figure 9, and Figure 10 compares the four datasets. The variations in LST dwarf those of SST.
http://i41.tinypic.com/ip75aw.png
Figure 8
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http://i40.tinypic.com/10r8xt1.png
Figure 9
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http://i44.tinypic.com/24o25u0.png
Figure 10

SOURCES
The GHCN/CAMS t2m data is available through the KNMI Climate Explorer website:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere

OI.v2 SST data is available through the NOAA NOMADS website:
http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?lite=

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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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