Can El Nino Events Explain All of the Global Warming Since 1976? – Part 1

11 01 2009

Can El Nino Events Explain All of the Global Warming Since 1976? – Part 1

A guest post by Bob Tisdale

UPDATE 1 (January 12, 2009):

In my extremely brief description of an El Nino event, I wrote, “…and a subsurface oceanic temperature boundary layer called the thermocline pushes the warm subsurface water to the surface.” My oversimplification may be misleading, and while it does not undermine the intent of this post, a better explanation is available in the following video from NASA Scientific Visualization Studio video titled “Visualizing El Nino”: http://svs.gsfc.nasa.gov/vis/a000000/a000200/a000287/a000287.mpg

If I rewrite that sentence in the future, it would read something to the effect, “During El Nino events, natural changes in atmospheric and oceanic conditions cause the warm water that was ‘contained’ by the Pacific Warm Pool to shift east along the equator. The warm subsurface water rises to the surface.”

h/t Gary for noting the poor wording.

NOTE: For those who are new to the subjects of El Nino events and sea surface temperatures, I’ve tried to make the following discussion as non-technical as possible without overlooking too many aspects critical to the discussion. It includes detailed descriptions of many of the processes that take place before, during, and after El Nino events. The period after an El Nino event is often neglected, but it holds the oceanic responses that are the most significant over multiyear periods.

INTRODUCTION

Two things have always stood out for me in a graph of Global Sea Surface Temperature (SST). The first was the Dip and Rebound in the ERSST.v2 version of the Extended Reconstructed SST data from the 1800s to the 1940s. The link above discussed it in detail.

In Figure 1, I’ve boxed SST anomaly data for the period from 1854 to 1976 to indicate that, other than the dip and rebound and the temporary rise in the early 1940s caused by a multiyear El Nino, there really wasn’t a rise of any note in SST between the late 1800s and the period from the mid-1940s to mid-1970s. The ERSST.v2 data used in this post illustrates little to no change in SST anomalies from the one period (late 1800s) to the other (mid-1940s to mid-1970s).
http://i42.tinypic.com/2ibc87o.jpg
Figure 1 Read the rest of this entry »


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Categories : ENSO, Science, climate data

Mauna Loa CO2 record posts smallest yearly gain in its history – maybe

11 01 2009

UPDATE: I received a reply tonight from Pieter Tans, who is the manager for the MLO data, it is another error in presenting the data, similar to what happened with GISS in October, a monthly data value was carried over. In this case, November to December.  – Anthony

From: “Pieter Tans” <Pieter.Tans@xxxxx.xxx>
Sent: Sunday, January 11, 2009 7:24 PM
To: “Anthony Watts ” <awatts@xxxxx.xxx>
Subject: Re: Questions on currently posted 2008 MLO data

> Anthony,
>
> The posted December figure is an error. It will probably be fixed
> tomorrow.  The error does not appear on my computer.  Our web site is
> run by a separate server dedicated to communicate outside the firewall.
> At this moment I don’t know why it repeated the November value for December.
>
> Sorry about this mishap.
>
> Pieter Tans

The year end CO2 data for the Mauna Loa Observatory is out, and it shows that the trend of Co2 increase has slowed. This year saw the lowest increase in the annual mean growth rate ever in the Mauna Loa Co2 Record:  0.24 parts per million.

Whether this is real, a data error, or something else remains to be seen.  As we’ve learned previously, the Mauna Loa record is not infallible and can be adjusted post facto. To MLO’s credit, they have been responsive to queries from myself and others, and have pledged to make improvements to the process. They now have a change log, but there is no mention of the December 2008 data in it.

Here is the graph recently posted by MLO. Notice the two dips in 2008.

The blue line represents the mean value, while the red line is the monthly values. Note that the red line shows seasonal variance related to earth’s own processes that emit and absorb CO2. In the case of the 2008 value of 0.24 ppm/yr it comes on the heels of 2007’s strong year of 2.14 ppm/yr which by itself isn’t that remarkable, being only the seventh highest year in the record. Read the rest of this entry »


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Categories : Carbon dioxide, Science