Global Warming - Icecore Data
non-Ice Boreholes
With all the hype, you would think that ice cores and tree rings are the only
temperature proxies.
Well,
NOAA provides borehole data from non-ice sources.
There is a great interactive map - just click on the indicated site
and then you can see a plot of the data (or download it, your choice).
The plots show very clearly that the 1600's were warmer than today in some areas
and colder than today in others.
If you want to see the coral data, you will have to plot it yourself.
(Excel will do it - copy, past, break data into columns, plot.)
Looking at various data, some of it supports my point of view .. and some dose not.
None of it (in the small sample I have looked at) supports the climate change activists.
In all cases, the borehole data I have seen disagrees with the tree ring data
used to support the IPCC consensus.
Some plots
20,000 Year Borehole Surface Temperature Reconstructions
(HPS08)
is one of the first non-ice core plots that I made -
it absolutely supports the global extent of the Little Ice Age.
(Other borehole reconstructions do not.)
The data indicates 3 different values of steady state heat flux
and 3 different values of thermal diffusivity.
Each series (there are nine) is the result of one of the possible combinations.
I like this data set for a number of reasons
- It shows how different models using the same data can produce different results
- It clearly shows the mid-Holocene warm episode,
the Medieval Warm Period (MWP), and the Little Ice Age (LIA),
- It shows that we are currently no where near as hot as previous recent values
That said, I have some serious problems with this data
- The Younger Dryas is not shown
- The Roman Warm Period is not shown, in fact, many records indicate that at 70 AD
it was warmer than today
- The 20th century uptick is caused by adding "official" temperatures
and are not from the model (which explains the obvious discontinuity)
Discussion
The dataset was created by piecing together 3 separate datasets.
| Time Period
| Depth | Report | Comment
|
|---|
| 20th century
| surface to 100 meters
| CRU
| "Measured" air temperatures - actually, the results of a model
|
| 16th through 19th centuries
| 100 to 400 meters
| HPS00
| "actual temperature measurements at 10 meter intervals"
HPS00 is a "letter" .. not a "paper". The depths reported in HPS00 (150 to 600 m)
do not agree with the depths that HPS08 says were used in HPS00.
|
| The rest
| 300 to 2,000 meters
| HPS97
| "heat flux measurements aggregated in 50-meter depth intervals",
integrated to attempt an recover the original temperature measurements
|
This explains why details before the 1500's, like the Younger Dryas and the
Roman Warm Period, are not resolved. It also brings into question
the calibration of the three datasets with respect to one another.
(Yes, I can see the "overlap", and calibration gets almost a full paragraph
in the main paper, but I want more!)
It is unfortunate that they do not use actual temperature measurements from
the surface to the full depth.
To quote a quote
"We excluded data with representative depths less than 100 m ...
[because] ... the uppermost 100 meters is the depth range most
susceptible to non-climatic perturbations ..."
|
If this is true, then the entire reconstruction is completely bogus.
Basically, if the top 100 meters of the column does not represent the climate,
then NONE of the column represents the climate.
Where do these people think that the temperature anomalies at 200 meters come from?
Were these changes able to magically appear without propagating down from the surface?
Based on this "quote of a quote", I now want to see the data they have omitted.
I suspect that it does not agree with the "official" story about the climate and current
temperatures. But, without actually seeing what they are (so obviously) hiding,
it is hard to know for sure.
In addition, there is no discussion on how heat flows differently in different rock types.
There is no way that granite, limestone, and shale will produce the same
diffusion profiles. Yet .. this is not even mentioned.
However, these questions are covered in
Climate Reconstruction from Subsurface Temperatures (2000).
Basically, the high frequency signal (seen near the surface) encodes data from many sources,
but the low frequency signal that finally propagates through the surface layer
contains only the long term climate signal.
(At least, that is the theory.)
This paper is an excellent introduction to the issues.
In summary, I consider the provided data to be interesting, but in serious
need of additional review.
(This would make a great school project.)
Terminology
In the papers, and, in fact, anytime borehole temperature reconstructions are discussed,
you will see the term inversion.
This refers to the mathematical technique used to solve certain matrix equations.
Example, from
HPS08
|
The temporal length of a reconstruction
derived through inversion of a borehole temperature profile
is limited in part by the depth of the borehole temperature
profile and the noise level of the borehole data.
|
Author:
Robert Clemenzi