Kenyan lake levels and drought solar linkage, Potsdam study, curious silence

Posted: January 28, 2014 by tchannon in climate, Natural Variation, ozone

The effects of solar irradiation changes on the migration of the Congo Air Boundary and water levels of paleo-Lake Suguta, Northern Kenya Rift, during the African Humid Period (15 ka – 5 ka BP),

Annett Junginger, Sybille Roller, Lydia A. Olaka, Martin H. Trauth,

Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 396, 15 February 2014, Pages 1-16, ISSN 0031-0182, http://dx.doi.org/10.1016/j.palaeo.2013.12.007.

(http://www.sciencedirect.com/science/article/pii/S0031018213005373)

Abstract: [first sentence from long A.]

The water-level record from the 300m deep paleo-lake Suguta (Northern Kenya Rift) during the African Humid Period (AHP, 15-5ka BP) helps to explain decadal to centennial intensity variations in the West African Monsoon (WAM) and the Indian Summer Monsoon (ISM).

h/t to Die kalte Sonne article here http://diekaltesonne.de/?p=16256
(German site has translator link top right)

The previous article http://diekaltesonne.de/?p=16239 highlights the same issue of the same journal “The suspicion hardens: controlled changes in the Indian monsoon significantly by variations in solar activity”

Who said Germans have no sense of humour?
“It must have been the man with his excessive CO 2 emissions well who has scared away the rain. ”

They link to a variety of other content, mostly in German but also to a prior work, this

SOLAR RADIATIVE VARIABILITY FORCING OF CLIMATE CHANGE ON SEASONAL TO DECADAL SCALES IN KENYA

JARED OCHIENG’ HERA NDEDA

DOCTOR OF PHYLOSOPHY (Physics)

JOMO KENYATTA UNIVERSITY OF AGRICULTURE AND TECHNOLOGY

2008

link to PDF at above university, Kenya

I add independent of the above that there are many works about variations in the general region showing many relationships such as to ENSO and so on. This is also close to the river Nile headwaters, studies there too including the longest instrument record in the world, 663 years. (Nileometer, flood levels)

Image

Post by Tim

Comments
  1. A C Osborn says:

    Their conclusions must be wrong, because Leif & Willis say so.

  2. Nile flood levels are interesting but because the Blue Nile and While Nile both contribute to floods and because the two sources have different climate regimes, it is difficult to conclude anything from the nilometer alone.

    I made that mistake in a paper and had to post a retraction.

    Now the East African rift lakes are a different matter. Recent drilling of these lake show that there was substantial drawdown of the lakes during periods of advance of the continental glaciation but that the lakes are so deep that freshwater would have been available and accessible when most water other African lakes dried up and rivers stopped flowing.

    The East African lakes are good candidates for human refuges during century and millennium long droughts that would have characterized glacial maxima.

    .But for these lakes, it is unlikely that the genus Homo could have survived the Pleistocene glaciations. Thus these lakes will someday be recognized as the cradle of humanity.

  3. tallbloke says:

    Chris M: Millennium long droughts, a sobering thought. How well evidenced are they in paleo-proxies?

  4. tchannon says:

    Yes I gather the area is of extreme importance in our evolution, at leasts insofaras our present state of knowledge. Discoveries seem to turn up with overturn past wisdom.

    The Nile problem is indeed interesting. The flood data is the origin of Hurst’s work, an overturn of statistical math which is barely accepted even today.
    When the idea was tried on other rivers, at least where long enough data was available, most but not all produced much the same answer. The difference between the two is I gather about catchment areas, ranging single through many. One apparently which doesn’t is the Rhine and that has something like 5 distinct catchments.
    Fascinating topic.

  5. Andrew McRae says:

    Tangentially related on topic of periodicity analysis of climatic phenomena…
    “Australian tropical cyclone activity lower than at any time over the past 550–1,500 years.”
    Interesting diagram Fig 3: http://www.nature.com/nature/journal/v505/n7485/fig_tab/nature12882_F3.html
    Looks like a 64 year cycle, and if you squint you might even convince yourself that the length of that cycle is itself varying sinusoidally between 60 and 80 years over a 1200 year time frame.

    Not that I am suggesting that anyone at Nature had allowed an exercise in pattern recognition of climate-related cyclic phenomena to be published, because as we know that is strictly forbidden. 😉

  6. tallbloke says:

    Andrew M: Thanks for that interesting plot, I wasn’t aware of such a long proxy record of cyclone activity in Australia. It would be great if we could run that through the software Tim Channon wrote which finds underlying cycles as in this post:
    https://tallbloke.wordpress.com/2014/01/29/julia-slingo-says-it-sir-mark-walport-needs-to-think-about-it/2011/02/21/tallbloke-and-tim-channon-a-cycles-analysis-approach-to-predicting-solar-activity/

    I’ll write a polite letter to the authors to see if they’d be willing to share.

  7. Andrew McRae says:

    TB, save yourself an email, they seem to have actually made the data available already on Nature, just check the Supplementary Information section of the parent page.
    http://www.nature.com/nature/journal/v505/n7485/extref/nature12882-s1.xls
    When I plug that XLS data into the wavelet analyser it generates a periodogram superficially very similar to what they published, though their picture has a higher power level resolution.
    So it looks like that is the same data they used.

    Publicly archived data. Almost smells like open science?

  8. tallbloke says:

    Andrew M: Great, I’ll see if we can interest Tim in processing it.
    I’m collating a sources page for our own work. More soon.

  9. tchannon says:

    The Nature paper de-natured might be the subject of an article, needs a lampoon.

    Noise.