Tropical Warming Events in the Indian Ocean

September 18, 2008

Due to a lack of material on the internet concerning how El Nino and La Nina events manifest themselves in the Indian Ocean, I extracted data from the NOAA site mentioned in my previous post.  I broke up the tropical Indian Ocean into 9 blocks in order to find where the signal from a El Nino or La Nina first appears.

Listed below are the regions used.

  Lat Long
Region 1 4 to 12 52 to 66
Region 2 -4 to 4 52 to 66
Region 3 -12 to -4 52 to 66
Region 4 4 to 12 66 to 80
Region 5 -4 to 4 66 to 80
Region 6 -12 to -4 66 to 80
Region 7 4 to 12 80 to 94
Region 8 -4 to 4 80 to 94
Region 9 -12 to -4 80 to 94

 I extracted data for each of these regions, graphed them, and found that the Western Indian Ocean was the first to react to the 1997/1998 El Nino event, followed by the Central Indian Ocean, and finally the Eastern Indian Ocean.  The region reacted simulataneously, regardless of latitude, although latitude did effect the intensity of the variations in sea surface temperature.

Below is a graph of the Western, Central, and Eastern reaction to the El Nino.

And here’s a graph of the Western Indian Ocean at different Latitudes.

And just to show that this isn’t unique to the 1997/1998 El Nino:

So, after this discovery, I went back to compare my Indian Ocean record in the last post with this new Western Indian Ocean record.  Remember that I wasn’t looking for an accurate description of an El Nino/La Nina event; I was looking for the region that first expressed an event, which turned out to be the Western Indian Ocean.

Because this analysis is so dependent on determining the exact time that the El Nino starts, I decided to forgo the 12-point mean smoothing that the website offered and that I had been using.  Instead, to rid the dataset of the influence of seasons, I calculated each month as anomoly from the average temperature of that same month from 1978 through 2007. 

So, when I went to compare my new Western Indian Ocean dataset to my old, smoothed Indian Ocean dataset, I was surprised to find that my old dataset actually responded to the El Nino first.  Out of curiosity, I applied my new data handing technique to the Pacific temperature box that I used in my previous post, and found that my smoothed Pacific preceded my new Pacific, too.

The new, un-smoothed data shows a much smaller lag-time (perhaps only a month) than the old, smoothed data.  This may mean that the apparent inconsistent lag time between the Atlantic and Pacific Nino is an artifact of smoothing rather than an actual phenomena.  I’ll need to revise my last post to use the un-smoothed data.

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Global Tropical Response to ENSO Events

September 17, 2008

UPDATE (10/06): As I have written in more recent posts, this analysis is flawed.  In fact, as I have begun to understand cirrus cloud behavior in the tropics better, I’m beginning to find this analysis unnecessary.  Soon, I will make a post that will hopefully conclude my studies on cirrus cloud in the tropics.

A component of Erl Happ’s theory of climate change, which I will eventually post on, is that El Nino and La Nino events are not internal oscillations.  He claims that these tropical warming events are caused by changes in tropical albedo, which is caused by a change in 200 hPa cirrus cloud cover, which itself is caused by changes in solar activity.

So if tropical warming events are due to an increase in the amount of UV radiation reaching the tropics, then the tropics should respond globally – not just in the Pacific.

Using regions defined as the first place that ENSO events become apparent in the Pacific, Atlantic, and Indian Oceans, I retreived Sea Surface Temperature (SST) for each of the oceans. (Source: http://nomads.ncdc.noaa.gov/.  See this post for instructions.)

Indian Ocean: Lattitude: (-5, 5) Longitude: (60, 94)

Atlantic Ocean: Latitude (-5, 3) Longitude: (-15, 5.5)

Pacific Ocean: Lattitude (-5, 5) Longitude: (-132, -82)

Once again, these are not the entire areas where El Nino/La Nina events occur in the tropics, nor are they the entire areas where heating from a decrease in tropical albedo should occur.  These are the regions that the El Nino/La Nina signal first becomes apparent in each ocean.  The point of this is not to accurately describe the tropical warming events, but to determine when they each begin.

Here is a graph of each of these regions from Jan 1978 to Aug 2007.

To more clearly see the different response times in the oceans, here is a graph of the 1997/1998 El Nino event as exhibited in the three oceanic regions that show the first response to an El Nino/La Nina event.

For this tropical warming event, the Atlantic saw a 7-month lag behind the Pacific, and the Indian Ocean saw an 8-month lag behind the Pacific.

This large lag between the Indian and the Pacific ocean appears to hold relatively well during the period 1978-2007.  However, the lag between the Atlantic and the Pacific is less clear.  In fact, since 2000 it seems that changes in the Atlantic have preceded changes in the Pacific, though the Atlantic seems to have missed the past year’s large La Nina. 

In 1982, the largest recent El Nino event occured, though its effects on temperatures were dampened by the eruption of El Chichon that same year.  In this case, the Indian Ocean saw about the same lag, though the Atlantic Ocean lagged by almost two years!

So what does this mean?  Seemingly, the Indian Ocean exhibits warming with a consistent lag time (regardless of the intensity of the El Nino/La Nina).  Does this suggest that warming in the Indian Ocean is only caused by warming in the Pacific?  Or is it still possible that changes in albedo are also impacting the sea surface temperature in the Indian Ocean, and that it merely takes longer for this warming to express itself than in the Pacific?  If so, why would this be the case?

It also seems that Atlantic Nino events do not consisently lag behind Pacific Nino events.  For smaller events, Atlantic warming might actually precede the Pacific warming.  And even if small events in the Atlantic do not actually precede small events in the Pacific, they do not lag behind.  But for larger events (like the 1982/3 El Nino, the 1997/8 El Nino, and the 2007/8 La Nina), they lag up to two years behind the Pacific.  If the Atlantic Nino is actually preceding the Pacific Nino for small events, then conventional wisdom about the cause of El Nino/La Nina events is wrong, and Erl Happ’s theory stands a chance.  Yet, with such large independent oceanic variation, it is difficult to actually say if this is actually the case.

I’ve emailed Erl Happ to give him a chance to respond to my findings.  After that I’ll post a link to our discussion on the CA forum dedicated to this subject.

Data Collection: Oscillations

September 10, 2008

I’ve spent a lot of time tracking down and graphing this data.  It’s part of my attempt to make a record of all terrestrial climate data since 1900.

Below are oscillations that I managed to find on a very long time scale.

(D’Arrigo, R., et al. 2005. Pacific Decadal Oscillation Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2005-020. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: D’Arrigo, R., R. Villalba, and G. Wiles. 2001. Tree-ring estimates of Pacific decadal climate variability. Climate Dynamics, Volume 18, Numbers 3-4, pp. 219-224, December 2001. )

Since 1900…

Since 1950…

Since 1998…

More Adventures in the Arctic Oscillation

September 9, 2008

The data that I have been using is the work of Dave Thompson, and is being used by the Joint Institute for the Study of the Atmosphere and Ocean (JISAO) between the University of Washigton and NOAA.  Unfortunately, the data ends six months in to 2003.  NOAA, though, separately maintains AO data that begins in 1950 and has continued through th first four months of 2008.  For some reason, the JISAO datset lags NOAA by exactly one year, but once that is adjusted for, the two datasets fit nearly perfectly.

The large jump in the JISAO index in 2003 is not apparent at all in the NOAA dataset.  In the JISAO index, 2003 contains only six months, and although the first six months of NOAA don’t match up to JISAO, it may be that the massive monthly variability (see previous post) has effected JISAO data due to a lack of datapoints in 2003.

For this same reason, I left out 2008 from the NOAA dataset.  Altough, at this point in the year, it is trending upward.

So here is the combined record of JISAO (1900-2002) and NOAA (2003-2007).  I’ve also included a polynomial in the graph to highlight the difference between the trends in this graph and the trends in the graph presented on the JISAO site that I’ve been discussing.

And here’s the graph presented on the JISAO site once more, for comparison.

More on the AO

September 9, 2008

If you’re researching the Arctic Oscillation, you’re bound to come upon this site: http://jisao.washington.edu/ao/.

The first graphic presented on the website is the one I posted in my previous post. 

Along with it, the description: “Fluctuations in the AO can be seen in the time series of SLP anomalies for the North Pole”.  SLP stands for sea level pressure.  The paper referenced for the graph is listed as “Hodges, G., 2000. The new cold war. Stalking arctic climate change by submarine. National Geographic, March, 30-41.”  Athough I could not gain access to the article, the abstract reads, “In an attempt to better understand changing climate conditions in the Arctic, where water temperatures are rising and ice cover is both thinning and receding, the American navy has made nuclear submarines available to scientists to help them conduct their research in this inhospitable and remote environment.”  I’ve never seen data (or in this case “screw the data, we’re makin’ a graph!”) taken from a National Geographic article, and I am very suspicious.

The graph appears to show a steep trend towards lower-than-normal SLP over the past few decades.  Before then, there doesn’t appear to be much variance.  (In fact, if you look closely, you can see MBH98 with the Medieval Warm Period just below “normal” in the 1920s and with the mid-century global cooling scare in the middle of the 1990s.)  No comment is made about why the Arctic Oscillation looks more like a hockey stick than an oscillation.  The intention of the original author was to illustrate the effect of climate change on the Arctic, and perhaps that was also the intention of its use on the site. 

Alone, this situation of using a graph from a National Geographic article, implying that the Arctic Oscillation is being significantly altered by climate change without ever directly stating it, would be confusing.  But once you throw in the fact that the site then provides monthly data from David Thompson that does not seem to match up to the Hodges 2000 data, things get fishy.  Why did they show Hodges data, but not Thompson’s?  Thompson’s data, graphed both with monthly anomolies and yearly averages, is shown below:

Less impressive, right?  The link to Thompson’s website is broken, but I found it here.  And the data supplied by the JISAO site should exist somewhere in here.

So, I have a few questions.

Why is Hodge’s data being used at all?  National Geographic?  How was it smoothed?  Why do they use his graph, without access to his data or his ascetic massaging of the data, when they have the raw data of Thompson on the same website?  Why did they decide to use Hodge’s data over Thompson’s data?  Should they not have provided an explanation or used both?

I doubt it’s intentional manipulation to prove a point; it’s just reflective of an attitude indifferent to accuracy.

Arctic Oscillation and AGW

September 8, 2008

There are many projected effects of an increase in GHG content under the assumption of a high climate sensitivity.  One of which is a cooling lower stratosphere, a topic that I addressed in a recent post.  Today, I ran into this we-knew-it-would-happen-all-along after-the-fact claim projection of climate models – an altered Arctic Oscillation with higher atmospheric pressure over the North Pole.

The claim is awkwardly outlined here at a University of Washington site: http://www.washington.edu/newsroom/news/1999archive/12-99archive/k121699.html.

The graph below is of atmospheric pressure over the North Pole, an indicator of the Arctic Oscillation.  It is taken from from Hodges (2000).

 

My first reaction is how in the world do we know atmospheric pressure over the North Pole in 1900?  I’ll have better informed comments on the issue soon.

Arctic Warming

September 8, 2008

For a long time I ridiculed the idea of “global warming” as innacurate, because it implies a single warming trend with a single cause.  It made more sense, to me, that global temperature was more of a patchwork of regional oceanic/atmospheric phenomena.  And, to a certain extent, that is true.  Land use has been shown to have dramatic effects on regional climate, as documented by Roger Pielke Sr.   And it is also true that policymakers should pay more attention to regional climate behavior rather than the global average.  Yet, it appears that the entire Earth is experiencing the same temperature fluctuations, though varying in intensity with lattitude.  From Erl Happ’s paper, “The Solar Signal in the Troposphere,” (who’s theory I will be writing about soon):

“The energy that is absorbed in the tropics and in particular the energy that is absorbed by the oceans of the southern hemisphere fluctuates from year to year. The change in this input to the Earths energy budget has knock on effects in terms of temperature change at high latitudes where there is an energy deficit. At latitudes greater than 40° outgoing radiation exceeds incoming insolation. The difference is made up to a variable extent by the transfer of energy from the tropics. It is at these relatively high latitudes that the greatest fluctuation in sea surface and atmospheric temperature occurs.”

Trends in the Southern Hemisphere, the Northern Hemisphere, and the Arctic are all exactly the same; they merely exhibit different factors of intensity.  To demonstrate this, I have graphed the Global temperature anomoly against the Arctic temperature anomoly as recorded by sattelite data at the University of Alabama at Huntsville.  I adjusted the Arctic temperature record, dividing each year’s anomoly by 3.4.  By doing this, I am essentially saying that the Arctic temperature trend (in the lower troposphere) amounts to 3.4 times the global trend.

As you can see, Arctic and global temperatures follow eachother very well once adjusted for high-lattitude trend enhancement, aside from the 1998 El Nino.  This seems to imply that oceanic oscilations (aside from ENSO) are either synchronized or have a minimal effect on regional temperatures.  It also would imply that claims that soot has caused Arctic warming (“. . . such dark carbon triggers melting, and may be responsible for as much as 94 percent of Arctic warming.”) are probably innacurate as the Arctic warming trend has exhibited the same ups and downs as the global warming trend.

In conclusion, it seems that something global in nature has been causing global warming.  Perhaps it is synchronized oceanic cycles, perhaps it is changes in solar interaction with the atmosphere, or perhaps it’s something completely unexpected.

 

Stratospheric cooling?

August 27, 2008

One consequence of Earth undergoing greenhouse-caused warming would be a cooling stratosphere.  It i often claimed that the stratosphere, specifically the lower stratosphere, has in fact been cooling, thus confirming the enhanced greenhouse effect hypothesis.  Skeptics refute this claim in two ways: the cooling was caused by ozone depletion; and the cooling has now stopped.

Proponents of the Enhanced Greenhouse Effect theory suggest that the observed stratospheric cooling has been the product of both ozone depletion and a more intense greenhouse effect.

I recognize that the fact that the stratosphere hasn’t cooled for 13 years is an important point to make, especially considering the fact that month-to-month variation in stratospheric temperatures is small and thus trends are easy to extract.  Yet, I’ve never heard the point made that the only time the stratosphere seemed to cool was right after volcanic stratospheric warming episodes.  I’ve used paint to illustrate my point:

During the volcanic eruptions of El Chichon and Mt. Pinatubo, stratospheric temperature jumped and surface temperature fell.  Yet, instead of stratospheric temperatures returning to normal, they appear to have dropped significantly lower than they were before the eruption.  I’m not proposing any physical mechanism that could explain this, nor am I fully backing the idea that the volcanic eruptions caused the observed coooling.  I just thought it was worth noting.

UPDATE

I finally found a graph of global ozone levels (rather than Antarctic ozone levels or the size of the Antarctic ozone hole).  I’ve posted it below.

With this graph (data from here) as context, the trends in lower stratospheric temperature make sense, as caused (at least in part) by changes in ozone.  The graph appears to show diminishing ozone, with either an 11-year solar cycle!!!! or more likely the effects of bromine and chlorine released into the stratosphere by the especially intense eruptions of El Chichon and Mt. Pinatubo.

Predicted Tropospheric Warming Fails to Occur

August 27, 2008

Edward Linacre and Bart Geerts wrote here,

“With regard to the upper troposphere, radiosonde and MSU data do not show any warming trend either. Critics of ‘global warming’ (6) interpret the observed absence of upper-tropospheric warming as evidence that climate models are flawed: GCMs forced by a doubled CO2 concentration show strong warming in the upper troposphere. They argue that the observed lack of warming (or slight cooling) is an indication of a negative water-vapour feedback. However, the results of Hansen et al (5), obtained with a model that has a strong positive water-vapour feedback and is driven by measured radiative forcings, are consistent with observed temperature change and indicate that ozone depletion has reduced tropopause warming. If this interpretation is correct, during the next 5-10 years, as ozone-depletion levels out and perhaps reverses, warming of the upper troposphere by well-mixed greenhouse gases should become apparent. The model results indicate good agreement with the observed strong cooling in the lower stratosphere (see MSU data above), which is a result of the greenhouse gas accumulation and, secondarily, of the decrease in stratospheric ozone.” 

Here’s the catch; they wrote that in 1998.

So, it’s been 10 years and we have a chance to falsify their claims.  I don’t have upper tropospheric temperature data, but if mid-tropospheric temperatures aren’t increasing, then we shouldn’t expect upper-tropospheric temperatures to be increasing either.

No warming since 1979, and no warming over the past ten years.

And where we’d really expect to see the warming – in the tropical mid-troposphere:

What’s left when you take out ENSO?

August 27, 2008

Here’s my own temperature record without ENSO (El Nino & La Nina).  I know that this is done by NASA, but I don’t know where to find the data, nor would I completely trust the data if I did.  I could explain how I did it, and if anyone wants to know (apparently there were 21 of you today), make a comment, and I’ll post an explanation.

Here’s what you get when you subtract ENSO from hemispheric lower tropospheric temperature from UAH.  This is NOT a removal of ENSO, because the effect of ENSO lasts beyond the initial event.  Instead this is an indication of what needs to be explained, and ENSO might provide the solution (or part of it).

ENSO and volcanoes are the two largest phenomena that impact global temperatures on short timescales.  I had no real way to take the effect of volcanoes out, though you can use the following graph of lower stratospheric temperatures to see when volcanoes effected temperature (as shown by large stratospheric warming events).

David Stockwell has posted on the theory (not endorsed) that surface temperatures are determined by temperatures in the stratosphere, and that an inverse correlation between surface temperatures and lower stratospheric temperatures is implied by Miskolszi’s semi-transparent model.  He posted a graph comparing the two temperature trends over the past several decades.  While I only have access to lower stratospheric data, it still might be informative to do the same comparison shown on his post with the effects of ENSO removed.