Guest essay by Rud Istvan
The abstract of a new Science paper by JPL’s Reager based on GRACE claims that AGW caused more landfall precipitation from 2002 to 2014, that ~3200 gigatons (cubic kilometers) was retained as groundwater, and that this slowed annual sea level rise by ~0.71mm/year. The paper is paywalled, but the phys.org report on it provides a key figure from Reager/JPL:
It is apparent from this JPL figure that the two basins with the most groundwater accumulation (dark blues) are the Amazon and the Congo. Unfortunately for JPL and for GRACE, those accumulations of ground water are physically impossible.
The Amazon basin drains to the sea via its river system, the largest in the world. Low elevations are covered by 5.5E+6km2 of relatively flat rainforest (blue on the following map) comprising [5.5/7.7] 71% of the entire basin. Manaus (red star) is 1500 km inland from the Atlantic, yet only 69 meters above sea level. The Amazon is navigable by ocean going cargo ships from the Atlantic all the way to Manaus. It will drain.
The Amazon has ITCZ determined wet/dry seasons. ‘Dry’ season June to October groundwater levels are about at local river levels. (Rainfall during the five-month Manaus ‘dry’ season (left image below) is ‘only’ about 80mm/month.) Most of the Amazon rainforest is at or just slightly above that ‘low’ river level. And it inundates during annual ‘wet’ seasons since already nearly saturated (right image). The rivers are slow moving, but wet season rainwater still drains to the sea by the next ‘dry’ season. There is no ability for the Amazon basin to retain extra ground water for years as JPL claims; it is already saturated.
The Congo River basin is the world’s second largest. The Congo has substantially more elevation change (scale in meters), so perhaps more potential ability to retain rainfall in unsaturated soils than the flat, saturated Amazon basin.
Central Africa has an ITCZ determined ‘wet’ season from October to March. Even at the beginning of the Congo wet season, almost half the basin soils are nearly or fully saturated. The rest of the basin saturates; then additional rainfall drains more rapidly to the sea than in the Amazon. Extra Congo basin water cannot be retained either, let alone accumulate hundreds of cubic kilometers over several years as JPL claims.
JPL scientists need remedial education in geography, geology, and hydrology before publishing such nonsense in Science. Ground truthing GRACE is not hard in this case based on their map. Another failure of climate science and peer review.
This quick post was easily excerpted from essay PseudoPrecision (concerning SLR) in my ebook Blowing Smoke.
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Rud: Looking at the map, it looks like the increase in mass is mostly north of the Amazon basin in Venezuela and mostly south of the Congo River basin in Angola and Zambia. However, the resolution of the map makes it difficult to tell and the abstract and press releases don’t appear to say. Do you have any direct information saying that ground water has disappeared from either of these two river basins?
We also need to remember that these maps represent the change for 2002 to 2014. If an area was suffering from a drought in 2002 (or possibly earlier in this period if multi-year averages were used) and returned to normal in 2014, its mass would increase. The Amazon has suffered from highly publicized droughts in recent years, but those were in 2005 and 2010.
The current drought in California and the recently-ended drought in Texas are apparent on their map.
Frank
What you say should not affect sea level very much, and only temporary. The great offset they are talking about is not very trustworthy, it seems to me.
The great offset they talking about may or may not be very trustworthy. Rud created doubt about two key features in the map – but his rational could involve an incorrect (but neighboring) geographic area. He should – but probably won’t – address this issue.
I’m not aware that I made any statements above that require correction, I don’t need to make any statements about the slow rate of current sea level rise. However, scientists are trying to prove that they quantitatively understand the causes of current sea level rise, mostly thermal expansion and melting. These changes are relatively small right now, so they need to account for even smaller changes like ground water depletion, changes in surface reservoirs and glacial isostatic rebound, If sea level rises more than a meter by the end of the century, these trivial changes will actually be trivial. Today, they help increase confidence that we can accurately model the changes have occurred recently.
IMO, we have not seen any evidence for the massive acceleration of SLR that is needed to cause 1 m of SLR by the end of the century: an acceleration of 25 mm/decade/decade (1 inch/decade/decade) if constant. This article is talking about a correction of 7 mm/decade. Yes, that is potentially important today. Hopefully Rud will reply, so that we know whether this post is one of many at WUWT that can’t survive 5 minutes of skeptical scrutiny.
Frank, late reply as I just returned to this near dead thread for a different reason having to do,with Mosher. I posted a map of the Amazon, by type of ecosystem, overlaying Manaus to give elevation. You apparently did not comprehend it. Your geography assertion is just wrong, as is self evident from the post itself, so I thought no reply was necessary. You just changed my mind.
I’ve always wondered about GRACE as I worked on the thrusters for the GOCE mission. As far as I know GRACE measure the longer wavelength changes in the gravity field whereas GOCE measures to a spatial resolution of around 100 km2.
GOCE is good for ocean circulation and even atmospheric disturbances whereas GRACE picks up more long term changes or so I believe. I think that’s why it used for natural processes as well. I often heard people mention this during mission development.
And following my current philosophy in dealing with these things…ask the simple questions first…
1. How do we know that GRACE is really accurately measuring what it is intended to measure? What is it being calibrated against? Or is this just a simple mathematical relationship that we have to assume is true?
2. How do we know that when GRACE says X and the scientists working with the data interpret X and being Y, that this is correct? What direct measurement is it being calibrated against that we can feel confident is accurate?
Correction
2. How do we know that when GRACE says X and the scientists working with the data interpret X as being Y, that this is correct? What direct measurement is it being calibrated against that we can feel confident is accurate?
PS. I’m not real clear on what you are asking. Nor have I spent years of my life working with GRACE. So I’m no expert. But what GRACE measures is the distance between two “identical” satellites in the same orbit with one traveling 220 km (about 2 min in time) behind the other. That distance can be measured with great precision and conceptually it really doesn’t vary a lot due to anything other than small variations in gravity. I’m sure there are quality checks, and a bunch of adjustments to deal with imperfections in the real world, but it’s not clear what would need calibration. … Maybe frequency counters for the measurement link or some such, but that’d probably be pretty straightforward.
While I cannot run the calculations on such things, I can understand the concept of two satellites chasing each other around the Earth. As the lead satellite enters a stronger gravitational field, I would think it would naturally accelerate and increase the distance until the lead satellite leaves the field and slows down.
Ok…so the gravity changed. Now, how do you turn that into a high probability answer to what caused it? These secondary measurements of the effects of other phenomenon leave a LOT of room for speculative analysis.
Proud Skeptic: Good questions about the calibration of GRACE. Initially skeptical websites reported significant controversies about the best way to process the raw data from GRACE. Lately there has been silence of this subject. I think there are large changes in mass occurring that could be used to estimate the accuracy of GRACE, but I don’t know if anyone wants to do so: 1) ENSO raises and lowers sea level in the Western and Eastern Pacific by up to 0.5 m. 2) Glacial isostatic rebound is 15+mm/year (1) in northeastern Canada. 3) The Aral Sea is disappearing. 4) Depletion of the Ogallala Aquifer (one of the largest in the world is currently being carefully monitored (by thousand of wells). It would be interesting to see a comparison of GRACE with more traditional measures of these changes. Of course, I’m not sure that the GRACE scientists are interested in performing such comparisons when they can be creating headlines with discoveries that increase society’s fears about change. Fear, not quality science, creates the impact that allows your work to appear in Science and Nature.
Thanks. I am an engineer and not a scientist but I have studied and have begun to understand the fundamentals of climate change. After years of reading, I am starting to get a sense of some of the fundamental problems with the basic science. We seem to be arguing step 43 without having proved step one to the degree necessary.
How teachers are getting it wrong on climate change
https://www.washingtonpost.com/news/energy-environment/wp/2016/02/11/how-teachers-are-getting-it-wrong-on-climate-change/
A major new survey of U.S. middle school and high school science teachers has found that across the country, a majority are teaching about climate change in their classrooms — but a significant percentage are also including incorrect ideas, such as the notion that today’s warming of the globe is a “natural” process.
[More than 5 million people will die from a frightening cause: Breathing]
The study, published in Science Thursday by Eric Plutzer of Penn State University and a number of collaborators from Wright State University and the National Center for Science Education — which supports the teaching of evolution and climate change in schools — consisted of a mail survey of 1,500 teachers nationwide. They included both middle school science teachers and also high school biology, chemistry, physics and Earth sciences teachers, since it wasn’t entirely clear which classes might cover the subject (unlike evolution, which clearly belongs in biology class, climate change stretches across many disciplines)…
==============
These folks must be DNC super delegates. /s
You’re a few days behind here !
http://wattsupwiththat.com/2016/02/11/shock-study-some-school-students-are-still-taught-about-climatic-natural-variation/
Remember that GRACE is looking for gravity variations & gravity variations are driven by density variations. I think Rud makes good point that in a saturated basin that addition rainfall is unlikely to cause a density variation that would drive an anomaly .
On the other hand, this could easily represent subsidence & sedimentation in the Amazon & Congo basins (i.e. water being displaced by sediment, with small scale accommodation driven by basin subsidence). This would give a positive delta in density (sediments being more dense than water) and could lead to the observed anomaly.
Elsewhere, the idea of increased ground water anomalies isn’t implausible but does need to be tied to observed precipitation & see if that makes sense.
Interesting in that this would be a “negative feedback” to AGW driven Sea level rise …
Preparing for another hiatus….please not again….please not another “fighting” over “hiatus or not hiatus”….or the pain of going through 1001 excuses why there is a Sea level rise hiatus in a “certain” and “indisputable” AGW era, or the pain of “fighting” whether that is going a be catastrophic or not.
Gosh this really becoming insane…………. 🙂
cheers
I prescribe tequila
“There is no ability for the Amazon basin to retain extra ground water for years as JPL claims; it is already saturated.”
So, an already “saturated floodplain” that doesn’t have the ability to retain extra groundwater. I like the concept. The next time some tries to tell you that doing something that creates an impervious area increase of maybe 0.1% within a drainage basin, or even a floodplain, will create disastrous flooding because we lose the ability to retain water, please remember this concept.
Each basin is obviously different and will react differently. An additional 20% impervious area within the “flash flood” basin or associated flood plain will make no measurable difference. Impervious area added to the Amazon basin type of flooding will not be significant. The types of flooding that range/exist in between the two stated extremes may (or may not) be impacted by impervious area,
But in any event it would be nice if people would remember the above concept is valid even if they don’t like development.
Hang on – just a moment ago it was the parched earth soaking up rainwater – now its just the large volume of rain that rained, not the ground ‘s parchedness. Hard to keep up with the frenetic pace of hair-brained hypothesis-de-jour desperate apologies for AGW dissonating with the real world.
It calls to mind a busy roomful of middle aged ladyfolk industriously writing copy for pornography magazines. Pure fiction aimed for exciting effect and making easy money.
Rud , thank you for another interesting posting . If you look carefully at the Reager/JPL map you provided , the Amazon basin is indeed blue , but the Congo basin is not blue . The blue in Central-Southern Africa of that map is in the highlands of Angola/Zambia . Your rainfall map of the Congo basin does show the Congo basin north of Reager’s blue area . I am not sure if this makes any difference to your argument though ……..
A skeptical attitude toward climate-change claims is healthy; simplistic proofs of “physical impossibility” are not. Groundwater storage is by no means solely a matter of river drainage rates, as assumed here. Nor is the deep-blue area in the first figure within the Congo Basin. It lies primarily in Angola and Zambia, which are drained by other rivers. Sea level rise is an enormously complex process, which remains largely enigmatic even in the face of expert explanations, let alone those of geophysical novices.
i never have taken the GRACE/conclusions analysis seriously.
GRACE measures gravitational anomalies, but doesn’t point to a cause of these changes. There are even changes in gravitational fields due to natural changes (so not all changes are due to a mass gain or mass loss. the best one is where GRACE pointed out that the antarctic was losing ice, while recent studies proved this wrong and that the antarctic as a whole was gaining ice.
That made me to the conclusion that how the data from GRACE is interpreted is “guess science” based on what they think is causing these anomalies, based on an incomplete set of facts.
There is no ability for the Amazon basin to retain extra ground water for years as JPL claims; it is already saturated.
Your essay would be enhanced if you could supply evidence/citations in support of those assertions. The fact that you can observe water flowing along the surface does not imply that soaking into deeper and deeper layers has ended.
MM, you make a good point. There was a simple answer (a figure) in the original essay that I omitted when hurridly throwing this post together so AW could get it reasonably close to the original post. My apologies, as inclusion would have resolved your quite proper comment.
The rainfall at Manaus over the last 100 years averages about 2300mm/year. Yup, 2.3 meters per year, for a hundred years. There is literally no way a recent increase could have increased soil saturation as depicted, under the observed rainfall conditions. The bathtub was already full.
If it’s raining more, doesn’t that imply more clouds, and aren’t clouds a strong negative feedback?
Is this the equivalent of having a bet both ways again? AGW causes sea level to rise faster than under normal conditions, but it also causes sea level to rise less fast than would be expected under the influence of AGW. In other words, what we’re observing is sea level rise under normal conditions? The entire catastrophic climate change camp has tied itself in knots trying to maintain the scam and yet conform with observations.
Soil water content increases by CO2:
‘The analysis also showed that elevated carbon dioxide significantly enhanced soil water levels in drylands more so than it did in non-drylands, with soil water content increasing by 9 percent in non-drylands compared to 17 percent in drylands, Wang said. Determining the mechanisms of stronger soil water responses in drylands will require further investigation.’
Source: http://wattsupwiththat.com/2016/02/16/study-increased-carbon-dioxide-is-greening-deserts-globally/
hum …
what are we talking about ?
0.71 mm/year during 13 years, that’s 10 mm of water over 360 E+6 km²
let’s suppose that amazon and congo basin soak 10% of that : 360 E+6 km²mm
Since they sum around 9 E+6km², that’s 45 mm of water. Impossible ? not so. it’s less than a couple of week of rain during “dry” season, a few days during “wet”. draining just have to take not much longer, and that’s it