Nile floods – is the sun guilty?

Guest post by Mike Jonas

9 Sep 2020

News today is that the highest floods in over a century are threatening Sudan’s ancient pyramids (not to be confused with Egypt’s pyramids):

The authorities in Sudan are trying to protect the country’s ancient pyramids from flooding as heavy rains have caused the nearby River Nile to reach record-breaking levels.

https://www.bbc.com/news/world-africa-54070697

Now I do understand that one flood does not a cycle make, but the news immediately made me think of the NASA report of 2007 that found a link between the Nile water level and solar activity:

NASA Finds Sun-Climate Connection in Old Nile Records

03.19.07

Long-term climate records are a key to understanding how Earth’s climate changed in the past and how it may change in the future.

[..]

Now, however, a group of NASA and university scientists has found a convincing link between long-term solar and climate variability in a unique and unexpected source: directly measured ancient water level records of the Nile, Earth’s longest river.

[..]

“Since the time of the pharaohs, the water levels of the Nile were accurately measured, since they were critically important for agriculture and the preservation of temples in Egypt,” she [Joan Feynman of NASA’s Jet Propulsion Laboratory] said. “These records are highly accurate and were obtained directly, making them a rare and unique resource for climatologists to peer back in time.”

A similarly accurate record exists for auroral activity during the same time period in northern Europe and the Far East.

[..]

The researchers found some clear links between the sun’s activity and climate variations. The Nile water levels and aurora records had two somewhat regularly occurring variations in common – one with a period of about 88 years and the second with a period of about 200 years.

[..]

So what causes these cyclical links between solar variability and the Nile? The authors suggest that variations in the sun’s ultraviolet energy cause adjustments in a climate pattern called the Northern Annular Mode, which affects climate in the atmosphere of the Northern Hemisphere during the winter. At sea level, this mode becomes the North Atlantic Oscillation, a large-scale seesaw in atmospheric mass that affects how air circulates over the Atlantic Ocean. During periods of high solar activity, the North Atlantic Oscillation’s influence extends to the Indian Ocean. These adjustments may affect the distribution of air temperatures, which subsequently influence air circulation and rainfall at the Nile River’s sources in eastern equatorial Africa. When solar activity is high, conditions are drier, and when it is low, conditions are wetter. [My bold]

https://www.nasa.gov/vision/earth/lookingatearth/nilef-20070319.html

From the WUWT solar reference page, it does indeed appear that solar activity has been heading lower for a while, though the data appears to be not quite up-to-date:

So the question is: Are the unusually high Nile Floods caused by this lower level of solar activity?

To try to answer the question, I plotted rainfall for Sudan:

[Annual precipitation anomaly 1979-2019, requested lat 10N-20N lon 25E-35E, from NOAA. Hopefully I have accessed and charted the data correctly. I couldn’t find a longer record.]

Well, it doesn’t look much like a cycle to me, but then 40 years would not be long enough for one to show up. However, it does look like there was a big step-change from 2013 to 2014. Any ideas on what could have caused that? Could it have been because of a change in solar activity?

The IPCC has not managed to shed much light on this issue. Their latest Africa Report shows that the third IPCC assessment report predicted “Threats of desertification and droughts to the economy of the continent“, but the fourth report predicted “Potential impacts of extreme weather events (droughts and floods)“. The fifth report said “A continued warming in the Indian-Pacific warm pool has been shown to contribute to more frequent East African droughts over the past 30 years during the spring and summer seasons. It is unclear whether these changes are due to anthropogenic influences or multi-decadal natural variability.” but then (maybe just as the 2014 rains were starting?) they went on to say that “Projected increases in heavy precipitation over the region have been reported with high certainty [..]”. Looks like the IPCC were hedging their bets when the climate wasn’t following their script. Africa Renewal didn’t worry too much about the hedging. A few years later, under the scary heading Global warming: severe consequences for Africa, they reported that “Every bit of additional warming adds greater risks for Africa in the form of greater droughts, more heat waves and more potential crop failures.“.

My guess is that the 2013-14 step-change is fortuitous, and that it is a part of a cycle that would normally have taken several years but this time happened to occur very sharply. The cycle itself is more likely to be driven by the Indian ocean (or maybe the Atlantic) than solar activity. Ocean cycles would have a more obvious effect than solar activity on precipitation in places like Sudan over decade+ timescales, but solar activity would show up on century+ timescales. Also that the combination of ocean and solar cycles would be significant. But that’s only a guess.

49 thoughts on “Nile floods – is the sun guilty?

  1. There seems to be considerable auto correlation (year-to-year trend carry over) in the data. But where is the hypothetical 2008 precipitation peak that would match the 2008 solar minimum?

    It’ll be interesting to see what Willis has to say about this. (Non-) Correlation of sunspot cycles with just about everything is one of his fortes. He did an analysis of Nilometer (a very lengthy record of Nile River level prior to the first dam at Aswan) a number of years ago.

    I’ll check back later today after the West Coast has had a chance to wake up and have a morning cup of coffee.

    • The paper refers to ~88- and ~200-year cycles in solar activity relating to Nile levels, not the ~11-year cycle. The link posted by Walter J Horsting here identified a 21-year cycle. I found some of that paper unconvincing (they were IMHO too keen to see data as matching their hypothesis), but the authors were clearly convinced, with statements like:
      Although not included in the model, the synchronous linkage with sunspot activity is beyond all doubt.
      In November 2005, during the then drought, Alexander (2005c) issued the first of four flood alerts based on the [Alexander prediction model]. [..] Three months later large regions of the African subcontinent were wetter and greener than at any time in human memory.
      The commencements of the periods are readily identified and predictable. They are characterised by sudden reversals from sequences of years with low rainfall (droughts) to sequences of years with wide- spread rainfall and floods.
      sudden reversals from low flow sequences to high flow sequences [..] identified the commencement of the 21-year periods. Note that these are not exactly 21 years apart.
      An important characteristic is that the most extreme conditions occur at the beginning of the periods (floods) and at the end of the periods (droughts) with sudden reversals from droughts to floods that identify the beginning of the periods.
      The commencement dates they referrred to are “years beginning Oct 1912, 1933, 1954, 1974, 1995“. That suggests that the 2013-2014 step-change that I noted is two years early (1995+21 = 2016).

      As Walter J Horsting notes, the paper refers to “sun cycles driven by the large gas planets“. The papers by Ken McCracken, Jose Abreu, Jurg Beer, and others may be of interest. eg:
      https://www.aanda.org/articles/aa/abs/2012/12/aa19997-12/aa19997-12.html – Is there a planetary influence on solar activity?
      https://link.springer.com/article/10.1007/s11207-014-0510-1 – Evidence for Planetary Forcing of the Cosmic Ray Intensity and Solar Activity Throughout the Past 9400 Years

  2. Cmon
    The Nile River is made up of many complex basins or catchments totaling more tham 3 million sq km.
    These basins have their own unique climates.
    Just consider the blue Nile catchment ( Ethiopian highlands)is about 350,000 sq km but contributes 80% of the water.
    There is insufficient historical weather stations in these basins.
    Making links of downstream flow to CO2 is not possible.

    • I was going to mention this too. Ethiopia has completed the GERD (Great Ethiopian Renaissance Dam) in western Ethiopia just before the Sudan border. The Blue Nile is fed by lake Tana (I have been there, it’s really nice). It has taken Ethiopia about 10 years to complete and now the lake behind the dam is being filled. It will cover an area the size of Greater London IIRC and will take between 5 to 15 years to fill to capacity. It’s going to be interesting to see what happens downstream.

  3. Are the unusually high Nile Floods caused by this lower level of solar activity?

    You posed the wrong question Mike. If you have bothered checking the original article:
    Ruzmaikin, A., Feynman, J., & Yung, Y. L. (2006). Is solar variability reflected in the Nile River?. Journal of Geophysical Research: Atmospheres, 111(D21).
    You would have seen that what responds to solar activity is Nile low-water anomalies, not high-water anomalies.

    “The water of the Nile …, is supplied predominantly by the Blue Nile … whose main source is Lake Tana in Ethiopia, and by the White Nile whose main source is Lake Victoria …. The Blue Nile source accounts for about 90% of the levels in times of floods. …. In contrast, the White Nile is critically responsible (at about 83%) for maintaining the Nile flow during the low-water levels in the dry (October-April) period [Hurst, 1952]. The low water levels show a rich low-frequency variability, which is rooted in the variability of Lake Victoria. …. Low-frequency variations were suggested as possibly related to solar forcing [Hameed, 1984; Loutre et al., 1992].”

    So by looking at times of floods you are not looking at solar effects on climate.

    • If you look for a correlation with a solar variability, you have many options: Look for water flow anomalies, for high water anomalies, for low water anomalies, for water temperature anomalies, for low water temperature anomalies, … Sooner or later you will find a correlation that “confirms” your predefined conclusion.

      • It is not a question of finding a correlation. It is well known that pressure gradients during winter months in the Northern Hemisphere respond to solar activity. So when you look at phenomena that depends on those pressure gradients you usually find a solar effect:

        – The winter polar vortex is strong and well organized when solar activity is high and weak and disorganized when solar activity is low.

        Here you have the evidence:
        https://i.imgur.com/CvkEnS5.png

        – The winter Polar Jet Stream is near circular when solar activity is high and meandering when solar activity is low.

        – North Atlantic winter blocking is more frequent when solar activity is low.

        – European winter storm tracks have a more northerly path when solar activity is high and more southerly path when solar activity is low. This has a strong effect on precipitations.

        There are literally hundreds of articles dealing with this, and the thing is that all that phenomena are highly related. The problem is that it is multifactorial, so separating the effects is not easy. Things know to participate are: ENSO, QBO, Solar activity, and Autumn Eurasian snow cover. It is also very much affected by tropical eruptions.
        Take a look at this diagram from a paper by Roy Indra:
        https://i.imgur.com/7YvSeik.png

        This is a lot more than just looking at correlations, but correlations obviously do appear in related phenomena, like Lake Victoria levels that determine Nile low-water anomalies, that depend on winter (dry season) atmospheric pressure gradients in the Northern Hemisphere.

        This is all well known by researchers. They just don’t know how to put it in models as they don’t know enough to work out the equations and quantifications. Some of these things show up weakly in reanalysis but models have a hard time reproducing some phenomena, like the QBO, that are essential to the processes.

  4. A colder world will increase desert and shorten the growing season.
    A warmer world will increase rain and lengthen the growing season.
    True or false?

    • It depends where in the world you are. A colder world would mean reduced evaporation in some desert areas, so the same or even less rain could be more effective. Large parts of semi-arid inland Australia were wetter during the ice ages, due to a combination of glaciers in the mountains providing spring runoff to rivers, and lower local evaporation. As a result, many now permanently dry lakes were full. If those cooler conditions even partly returned, it would be possible to grow some crops in areas now too dry. A warming climate is likely to reduce the cropping area in drier regions, though we’ll be able to grow more wine grape varieties in Tasmania! And things will improve in Siberia.

    • The assumption that warming makes for more rain is not a given, as the circulation patterns are also affected. Remember, cold air can contain less water and thus likely to not carry water as far as warm air, so rain patterns change. The apocalyptic movie of a wall to wall dust planet is impossible unless we find away to get rid of our oceans.

  5. A test for these kinds of relationships between time series field data requires the iid assumption – “independent and identically distributed”. Nile river flow and long term precipitation and temperature data are known to violate these assumptions in the form of what is called “Hurst Persistence”. This phenomenon of nature was first reported by Edwin Hurst in the 1950s from these very same Nile River data.

    Briefly, Hurst Persistence implies that that the Nile River data are not iid because both increases and decreases persist. Persistence means that increases are more likely to be followed by increases and decreases are more likely to be followed by decreases. Time series of this nature are chaotic and not iid and therefore regression and correlation analyses do not yield results that have a useful interpretation because Hurst Persistence violates the required assumptions about the time series.
    CITATION: Hurst, H.E. (1951). “Long-term storage capacity of reservoirs”. Transactions of American Society of Civil Engineers

    Hurst persistence examples

    https://tambonthongchai.com/2019/02/26/a-chaotic-solar-cycle/

    https://tambonthongchai.com/2020/05/24/wbm1996-a-chaos-model-of-glaciation-cycles/

    https://tambonthongchai.com/2018/05/25/nonlinear-dynamics-is-climate-chaotic/

    https://tambonthongchai.com/2019/07/16/antarctica-slr/

    https://tambonthongchai.com/2020/08/05/wbm2001-fractal-structure-of-capital-markets/

    I have more if anyone is interested.

      • How is this spam? Chaamjamal’s posts and links are on topic. The site does not feature advertising or evidence of a for-profit model of wikipedia.org et al. It follows the mode of other comments where propriety warrants inclusion of bulk information or cross-referencing with preexisting information through out-of-band storage (e.g. youtube.com, eurakalert.org). It does not appear to draw viewers and commenters away from the original source, where the conversation persists intact.

        • I agree with n.n. I don’t think Chaamjamal should be discouraged from posting.

          If she is posting too many links in a post that requires the moderators to spend extra time dealing with it, then that’s another matter but that should be specified.

          Chaamjamal’s post are always informative and on point, and do not appear to be self-serving. She has to store her thoughts on subjects somewhere.

      • Anthony, Chaamjamal is a very fine statistician. One link of his is worth about 50 unreferenced opinions from your readers. Besides which, his work invariably shows that the 97% consensus is wrong. I for one enjoy following out his links. You are censoring comment in exactly the way the 97% attempts to censor all skeptical comments.

        • I understand Anthony. It is not strictly spam, but if he includes more than 3 links in everyone of his comments it means everyone of his comments has to be rescued from the filter by someone, and that is work. And if everyone of his links is to his place it means he is advertising his place here while generating work.

          I think Chamjamaal needs to exert some self-control. He is not being censored for content but being told that his manners are not adequate netiquete.

          • But let us thank Chamjamaal for drawing attention to Hurst, who first drew discovered “memory” in time series from the records of the eleven hundred year old Nilometer on Roda island and from his own observations not only of the Nile but of other rivers and lake sediments.

            Mandelbrot gave credit to Hurst when he devised fractal theory. So, in a way, Hurst was if not one of the fathers, at least one of the ancestors of chaos theory, which so many “climate scientists” do not seem to understand. They do not seem to understand history and geography either. The Nile has always flooded despite, and more recently because of, man”s attempting to control its flows with dams and canals.

  6. Hubris is often astronomical. I’m old enough to recall when NASA said the cooling that began in the 1940’s shows no end in sight. But when multiple cycles, some known and some not, combine to produce a propensity for some effect, it’s complicated and stochastic, maybe chaotic. Keep searching for those simple relationships though.

  7. I think it’s more likely that precipitation is in quadrature with the solar cycle.
    Instead of
    “When the sun is active, it’s dryer, and when it’s quiet it’s wetter”
    substitute
    “When solar activity is rising, it’s dryer, and when it’s falling it’s wetter.”

  8. The actual solar impact happens through net solar insolation i.e. shortwave radiation. There has been a clear increase of shortwave radiation since 2014, which has caused about 0.4 C degrees global temperature increase. It seems to correlate with the annual precipitation amounts in Sudan pretty well:

    https://www.climatexam.com/post/temperature-increase-since-2016-is-not-anthropogenic

    I am sorry to use this link but it seems to be the only way to show images on the present WUWT page comments.

  9. Gosh, let me see, NO. One of the few things pretty much everyone kniws is the the ancient Egyptians relied on the Nile floods for their civilization. That goes back as far as recorded history and we can confidently extend that to all history.

  10. Unprecedented rise in water levels of Lake Victoria

    In the recent months, Lake Victoria has experienced rising water levels that have caused significant flooding impacts on the Lake Shoreline communities in Kenya, Tanzania and Uganda as well as downstream communities near Lake Kyoga and Lake Albert. Based on analysis using the CHIRPS v2.0 dataset, the rainfall in Lake Victoria exhibited above average rainfall since May 2019. A considerable increase in rainfall in 2019 was experienced in October by 79%, in November by 56%, and in December by 74% compared to the long term average. Observed rainfall in 2020 increased in January by 83%, in February by 25%, in March by 43%, and in April by 33% compared to the long term average. However May rainfall was less than the long term average (Fig. 2).

    The cause of these major increases in rainfall in Lake Victoria Sub-basin was due to a positive Indian Ocean Dipole (IOD) phase [5,6,7] caused by warmer sea temperatures in the western Indian Ocean region, with the opposite in the east (Fig. 3). This resulted in the higher-than-average rainfall and floods in eastern Africa. The positive IOD occurs when the westerly wind weakens and the easterly wind forms and allows warm water to shift towards Africa. The 2019 IOD was the most extreme event over the past 40 years [8].

    https://nilebasin.org/new-and-events/307-unprecedented-rise-in-water-levels-of-lake-victoria

    The IOD is known also as the Indian Niño and is responsible for precipitation patterns in the area.
    https://en.wikipedia.org/wiki/Indian_Ocean_Dipole

    Climate is a very complex stuff. No simple answers. It is very likely that solar activity affects Nile levels, but if it does so it is one of several factors.

    • Javier, hi
      During a discussion not of the sunspot but the Hale cycle effect on climate events with engineer Will Alexander professor emeritus of Pretoria University (SA) in March of 2007 he forwarded link to his article:
      “Causal linkages between solar activity and climatic responses”
      at: http://planet.uwc.ac.za/nisl/aiacc/Course_documents/Causal%20linkages.pdf
      “Abstract: Statistically significant 21-year periodicity is present concurrently in South African
      annual rainfall, river flow, flood peak maxima, groundwater levels, lake levels and the
      Southern Oscillation Index. This is directly related to the double sunspot cycle.”

  11. In the mid 1970s, astronomer Barbara Bell published articles about climate change influencing floods on the Nile.
    Right back to ancient times.
    There were cyclical changes inducing long periods of improving floods, food production and population growth.
    Then the opposite, and one feature was that with low production the governing classes lived well and ordinary folk did not.
    As Bell reviewed the history she pointed out that the palace guards were not of the governing classes, but of the people.
    When push came to shove the palace guards laid down their spears as a benign popular uprising overwhelmed authoritarian government.
    These happened a few times and have been called dynastic change.
    With this history in mind, it was fascinating to watch similar popular uprisings develop in East Germany in the late 1980s.
    The key to the uprising was not so much Gorbachev and Reagan. It was that the border guards laid down their machine guns and East Germans went cross-border shopping.
    The dictator Honecker had to change the laws requiring him to murder Germans for going from one part of Germany to another.
    A magic time.
    And it could happen in America on this recession.
    And what is equivalent to the “palace” or “border” guards?
    The media.
    Which believe it or not, could lay down their “arms”.

  12. t is possible, even likely that the ancient Egyptians knew of solar cycles and may have regularly observed sun for sunspot cycles. Few years ago I came across this illustration:
    http://www.vukcevic.co.uk/Egypt.jpg
    It appears that the sphinx is holding an object while looking directly at the sun with a trail of ‘blemishes’ just south of equator, perhaps using a piece of coloured glass (the earliest known man made glass dates back to around 3500 BC, with finds in Egypt and Mesopotamia). Two tablets directly in the eye line may be related to records or a method of observation.
    Ancient Egyptians initially worshiped sun-god RA, but during reign of Akhenaten (1353–1336 BC) they switched over to the sun-disc god Aten. (Google ‘Aten’ and ‘Akhenaten ‘

    • There was also volcanic glass that was found in King Tut’s tomb along with a sword that had been made from a meteorite that was almost entirely made of pure iron, well before the iron age. Akhenaten was born about 1380 BC and King Tut was born just a little later around 1341 BC.

      It is also possible that either Akhenaten or vice versus, the ancient Israelites, that this was the time of the advance of Monotheism, and that while the Egyptians returned to RA after Akhenaten, the Israelites went on to form the basis for the 3 modern Abrahamic religions, which stemmed from the ancient Hebrews and their version of monotheistic faith, which also incorporates the older flood myth from Gilgamesh in the Fertile Crescent. Did the ancient Hebrews (Moses) influence Akhenaten or was it the other way around?

  13. Some time ago, there was an interesting study about the influence of the solar cycle on the position of the jet streams (and accompanying rain patterns). As many non-CO2 related subjects are of less interest, I didn’t find it back…
    The main points were: active sun = more UV = more ozone in the lower stratosphere of the tropics = higher temperatures at that heighth = larger temperature difference between equator and poles at that height = jet streams more poleward and polar vortex both firmly on their position.
    Low solar activity = jet streams more equatorward and more meandering.

    Several articles did link the solar cycle on rainfall of different rivers, (be it together with other natural cycles like the oceanic NAO (Atlantic) and PDO (Pacific). I could only recover a few:
    Portugal:
    https://www.researchgate.net/publication/248814610_Learning_with_solar_activity_influence_on_Portugal's_rainfall_A_stochastic_overview
    St. Lawrence and Nile:
    https://www.researchgate.net/publication/292000195_Variance_contribution_of_luni-solar_and_solar_cycle_signals_in_the_St_Lawrence_and_Nile_River_records
    And discovered a recent one for many European rivers:
    https://www.sciencedirect.com/science/article/abs/pii/S1364682618305273?dgcid=author
    But there were many more: from the Mississippi, rivers in South Africa and South America,…

    Interesting was the fact that in our normally wet country, the dryest years were all (with one exception) at solar minima (figures from 1833 on), when the jet stream’s position is more over the Mediterranean countries.

  14. I’m curious how global warming, sorry, “climate change” has caused a disruptive amount of snow to fall in South Africa over the last few months.

    A Google search shows several heavy snowstorms on the West Cape, which has a Mediterranean climate.

    https://tinyurl.com/y5vwtp3b

    Im also wondering how 2020, which was reported as on track for the hottest year EVER, has record cold and Labor Day snow out West.

    Two feet of snow falling in the Rockies last weekend doesn’t seem to jibe with any of the many climate change narratives….

    https://www.google.com/amp/s/amp.cnn.com/cnn/2020/09/06/weather/holiday-weekend-weather-forecast-record-heat-cold-snap-snow/index.html?espv=1

  15. Note the extra precipitation in around the equator:

    https://www.aljazeera.com/news/2020/08/kenya-rift-valley-lakes-crisis-200826191324986.html

    https://www.world-grain.com/articles/13193-indonesia-seeing-more-rainfall

    https://www.bbc.com/news/world-africa-54070697

    https://www.dw.com/en/dr-congo-more-than-50-killed-in-gold-mine-collapse/a-54905575

    As a result of this, drought times + accompanying wild fires on the higher latitudes, namely e.g. California, Portugal, Australia and Siberia.

    I am afraid more is yet to come… (click on my name to read my report)

  16. “Ocean cycles would have a more obvious effect than solar activity on precipitation in places like Sudan over decade+ timescales, but solar activity would show up on century+ timescales.”

    Ocean phases respond to North Atlantic Oscillation anomalies which are driven at the noise level by daily-weekly scale variability of the solar wind. With extreme events the short term solar influence on the NAO easily dominates, like in 1540, the greatest recorded drought year in Ethiopia, and also an extreme heatwave in Europe. 2019 and 2020 have seen an increase in negative NAO conditions giving a wetter signal. Much of the weekly NAO variability would not even exist without its discrete solar forcing.

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