planetwater

I would like to invite you to the following session at #AGU18:

• title: “Space-Time Data and Models” — click here to submit an abstract
• ID: H114
• co-convener: Laureline Josset

The problem of estimating a variable at unobserved locations and/or times is important for many areas of research, including geosciences, civil-/ environmental engineering, soil sciences, agriculture, ecology, forestry, meteorology / climatology, oceanography, health / epidemiology.

The amount of data gathered is increasing (e.g., advances in measurement technologies, remote sensing, or citizen science). Challenges remain related to the interplay between heterogeneous measurements and improvements in models that can make use of the various types of data. This session aims to bring contributions together that demonstrate how to improve datasets and maximise their use through measurement techniques, statistics, and modelling, e.g., via

• innovative ways to measure data in the environment;
• the incorporation of innovatively measured data into modelling (usefulness, relevant scale);
• the inclusion of as much information as available to improve prediction (secondary / heterogeneous data, data on different scales);
• the consideration of the variability in the quality of the measurements;

Please find a pdf about the session here.

(cross-posted from claus-haslauer.de)

Hi folks, here are some of the thoughts that came to my mind over the last few days.

AGU — looking back

The AGU fall meeting happened a couple of weeks ago now. However, it’s still vividly in my mind and there are still thoughts popping up:

• it was such a big meeting, so that it was impossible to see or hear everything. Hence it is a great thing for the people who attended the meeting, as well as for people who did not, that some of the lectures are available online. Here is a great example, the online version of of a presentation, the Bjerkens Lecture, given by Richard B. Alley from Penn State University. As it happens, the best live talk I have attended at the meeting was also by Richard B. Alley, when he talked about flying buttresses and ice shelves. The Bjerkens Lecture is on the role of CO2 in earth’s history. Here are a few of my thoughts:

  • for times when there are no more ice cores available, those earth scientists (that is the climate-earth-scientists as opposed to “us hydrogeologists”) need to do the same thing as we do — look for other sources of data that help them to infer what they were looking for in the first place. One example that Alley presents is that they look for the density of openings in ancient leafs. Leaves “have to decide” if they put many holes in their leaves, which allows them to take in a lot of CO2 which they need for breathing, but which also dries them out quicker – or if they put few holes in their leaves, allowing little CO2 to come in but at the same time allowing only little water to go out. If the atmosphere contains little CO2, plants need relatively more holes in their leaves. I think this is a great example of “complimentary independent data-sets“, a term coined by John Cherry. Call me a geek, but I do like this term!

  • Alley mentions snowball earth, and there is also a cool picture in his talk from Namibia, which can be found here

  

  Boulders dropped by icebergs into laminated marine sediment in late Precambrian time, Narachaampspos, Kaokoveld, Namibia. The chief proponent of the Snowball Earth hypothesis, Paul Hoffman, points to the transition to carbonate rocks which indicate the sudden termination of this frigid event. Photo M. J. Hambrey.

  • Alley mentions very briefly something along the lines that the mid-range models are right. Well, I don’t think that’s surprising. I would argue that the more important question is, if the extreme models get the extremes right…

• There are two other blog-posts related to AGU which I want to point out:

  • Brian Shiro wrote a nice agu-summary on his blog “astronaut for hire”

  • Dana MacKenzie wrote a nice post about the AGU’s “geoblogger meet-up” — there were some interesting and inspiring people, indeed!

Soil in the News

Two sites, “ScienceDaily” and “ScienceBlog” have the exact same story today, with exact the same heading: “Water hits and sticks: Findings challenge a century of assumptions about soil hydrology”. That sounds quite intriguing. Both articles stat that the research they write about is published on Nature Geoscience, but neither link to the paper. It is here. The “paper” is actually called in Nature Geoscience lingo a “letter”, and I am not sure what that implies.

Here is how I picture the process: it rains, some water enters the soil below the root zone, it continues it’s path towards the water table, some might flow laterally (towards a stream), some other part might be perched, and finally the rest makes it to the water table. On its way to the water table, it is commonly assumed, as the authors point out, that “water entering the soil as precipitation displaces the water that was present previously, pushing it deeper into the soil and eventually into the stream”, a concept referred to as “translatory flow”. Here is my first complaint, as stated above, I don’t think all the water below the root zone must go straight into a stream. But I agree with the (so far commonly used) concept of displacement.

The authors collected isotopic data, which suggests that “a pool of tightly bound water that is retained in the soil and used by trees does not participate in translatory flow, mix with mobile water or enter the stream.” And I think this is the key finding of this letter. Some water of the process I described above, might stay very close to the root zone.

This finding makes the authors suggest that their implications “are perhaps most profound for biogeochemical cycling and transport of nutrients to streams”. At the same time the authors concede that

“(t)his conceptual framework requires further testing to see if the underlying mechanisms are true, and if such separation of water resources holds for different climates and locations.”

I am wondering, how these two blog posts in ScienceDaily and ScienceBlog actually happened. Who wrote them? With what intentions?

More Water-Related News

• WaterWired has put up a great list of “Well-Worn Water Words” in two parts (part 1, part 2). Here is my favourite:

Water is the new oil because whisky is for drinking and water is for fighting, unless you are already in a water war, in which case you are probably already in water-power nexus from which only integrating science and policy will begin to address the fish versus farmer conflict defeating all efforts toward sustainability.

• Scott Long on NASW reports on a previously unknown toxin in treated water. This is intriguing, because during the process of trying to eliminate as many bad substances as possible, another and possible quite a few other bad substances are created. Even worse, probably not many people look for those “by-products”.

• Waterlogged points to a new documentary about the global water crisis, called “Flow”. Waterlooged links to two videos in which Maude Barlow (author of Blue Gold ) and Amy Goodman (of Democracy Now) http://waterblogged.info/2008/03/02/new-water-crisis-documentary-flow-for-the-love-of-water/

On thursday morning I sat into the “communicating climate change” session, which is not directly related with my work, but is timely, and relevant. It turned out that I saw some of the best talks of the conference so far in this session. As before I will post here some of my notes, again no guarantee for completeness.

M. Mann’s talk

• The scientific basis for climate change has been around for longer than many think, mostly since the early 19th century:
  • Joseph Fourier, 1827
  • John Tyndall
  • Arrhenius
  • some guy called “Guy Chanllender”, who I’ve never heard about, nor Wikipedia finds anything about… Do you know him?
• Jim Hansen has been one of the first people to try and validate a climate model – and he didn’t do poorly
• there is a thing called the “Luntz Memo“. It is a memo written by a politician called Luntz who outlines in this memo how to argue against climate change in the public. Similarly, there are other politicians who are against climate change, including Senator James Inhofe and Sara Palin. This is nothing new, but was interesting in this clearness. Palin recently established a thing called “Climate Gate” in which she called for president Obama to boycott Copenhagen. Not to confused with Watergate.

R. Alley’s talk

• to be a scientist is one of the greatest jobs available: you discover things that nobody knew before, you share, and you help. On the other hand, scientist argue like crazy every time. Which might be necessary to “keep shaking the info until it’s solid”. To non-scientists, this usually looks like scientists do nothing else other than arguing. And that’s not good!
• The National Research Council was established to “investigate, examine, experiment, and report upon any subject of science or art”. Later came similar institutions for health and engineering. Now, after the initial IPCC report, the US government asked the NRC, if the IPCC predictions might be ok. The NRC responded that yes, the IPCC predictions look good.
• Then he got into sea-level rise, the main topic of his talk
  • in 2001, sea level rise was predicted, excluding dynamics. In 2007, “scientists went like ‘Oh crap'” — sea-level rose faster than they expected. — “There’s the big gorilla out there that we don’t understand”
  • “it’s not hard to get 1m sea-level rise by 2100”
  • the underlying science: “all piles tend to spread, if you crank up the heat things melt, and if it snows it might accumulate”
  • Sara Das does cool research in Greenland
  • The Larsen B ice-shelf was one flying buttress for the ice of Greenland. Without a flying buttress, some ice might move up to 8x faster than with one. The less flying buttresses there are around Greenland, the “faster the whole thing goes”
  • melting goes up faster than increased snow fall

Ponds on the ice-surface of Greendland. Photo by Sara Das

Interesting Papers

• Regional Meteorological–Marine Reanalyses and Climate Change Projections by Weisse et al., 2009 in BAMS
• Geochemistry and the understanding of ground-water systems by Glynn and Plummer, Hydrogeology Journal 2005
• What indicators can capture runoff-relevant connectivity properties of the micro-topography at the plot scale? by Antoine et al., 2009 in AWR
• Zhu and Lin, 2009: preferential flow paths via EM in HESS
• Hydrodynamic Dispersion by Rose in Soil Science
• The original Pfannkuch, 1963 paper seems to be in french, not available online, but cited by many
• Berkovitz and Scher, 1995 in Water Resources Research

I’m sitting in Moscone West. As Apple aficionado, this is right where Apple’s Worldwide Developer Conference used to be! 😉

Moscone Center, San Francisco

Day 1 of 5 is almost over. I’ve been to a few talks, I’ve been to a few posters. I’ve never been to a conference of a comparable size, so I am a little overwhelmed. The online calendar was really helpful. Scientifically, what was interesting?

• I saw C. Meirovitz’s poster on modelling alluvial fans with TPROGS. He’s trying to use borehole-log data to model hydro-facies in space. Channels that deposited gravel up to bolder size form preferential flow paths, and the simulation of those continuous features is not a trivial task; however, it is important because those are the pathways critical for non-linear processes such as solute transport. Very much related to my own work!
• I have never spent much time learning about fractals, but the concept of “self similarity” popped up at least twice today. Once in F. Schwartz’s talk on modelling prairie potholes, where he uses tho model the size of potholes in simulation by using two parameters (length and water-hight, if I remember correctly), and once in S. Neuman’s talk.
• Using insane amounts of data seems to become quite standard.
• Why are people so crazy about linear regression? And why do people who call themselves scientists refer to what they’re doing as linear regression, if both of their axes are log-scale? Similarly, I’ve seen at least two people who plot some measurement against some measure of scale. For small scales there are a lot of measurements, for large scales there are few measurements. Their argumentation is that measurements on the larger scale result in an average measurement. I am not 100% sure on this. It might also be that there simply are not many measurements on a larger scale, temporal or spatial.
• I saw a map of accumulated daily precipitation intensities, that is accumulated at a given location over a year, then spatially interpolated. That seems like a neat idea. Probably also for temperatures.
• This is nothing new, but well presented presentations are just so much better. 🙂

Now I’m off to the “frontiers of geophysics” lecture!

Folks, I am getting ready for the AGU Fall conference, which starts tomorrow (Sunday) evening in San Francisco. I’ve never been to a scientific conference of that size, so I am very curious. I was browsing through the online database of talks and presentations, and it’s just mind-boggling.

Poster

My poster’s title is “Effects of Non-Gaussian Spatial Dependence of Hydraulic Conductivity on Hydrodynamic Macrodispersion”. Its ID is H43F-1093 and it will be presented on Thursday, Dec 17, starting at 1:40 PM in the Poster Hall (Moscone South). Come and drop by! It’s nice to meet blog-readers in person!

Copulas

The key method I am using are spatial copulas. I had set out to explain what this is on this blog here and here, but I have never gotten around to get really to what copulas are. I promise I will continue to write here about copulas as soon as I am back.

Geo-Bloggers

There is going to be a meeting of geo-bloggers on Wednesday! Some cool resources do exist already:

• a list online of who is registered
• a shared google.doc from @Boreholegroup of geo-bloggers who present their scientific work at AGU.
• a twitter list by @Allochthonous

I am looking forward to the show! 🙂

Folks, I’ll be at the American Geophysical Union’s (AGU) Fall meeting in San Francisco starting December 13th. TheAGU (twitter) had the awesome idea to put a webpage together that lists bloggers that participate at AGU. There will also be a meet-up including lunch. I’m very much looking forward to meet you fellow bloggers as well as professional writers out there!

AGU logo

Also, if you happen to be in San Francisco between Dec. 13th and 21st and if you would like to chat – let me know!

Folks,

the response to the regression line post was straight out phenomenal and mind-blowing. In the next sequel, we will look at some real data. I had this planned for today, but unfortunately preparing for the NUPUS conference, at which I will take part next week, takes longer than anticipated. I promise I will post on monday again.

However, I do have a suggestion for your weekend (if you’re not planning to climb up any mountains or if you are sick at home): read this!

I just found out that “the economist” has a sequel of classic debates, on various topics. The debate I’m suggesting for you to read is entitled “The value of H2O” — This house believes that water, as a scarce resource, should be priced according to its market value. Defending the motion is Mr Stephen J. Hoffmann, who recently published a book which is called just like this blog (more about this really soon). The arguments against the motion are represented by Dr Vandana Shiva.

Starting tomorrow, Monday, I will be attending the “Geostatistics 2008” conference. I am already in Santiago, the first time south of the equator. It’s December, and I had breakfast today on the patio. Wow. Yesterday I toured the city and had one of the best fish soups of my life. Today I went up to Cajon del Maipo, touched the Andes for the first time, enjoyed the fantastic scenery.

Now I am looking forward to a great conference, lots of new experiences and ideas. I will give a talk on tuesday afternoon around 4pm. The show is at the Sheraton Hotel in Santiago, if you’re in the area… 😉

Maybe I can even attract some visitors to this site!

On Friday I’m leaving for Southampton, UK. From Monday to Wednesday there’s the conference “geoEnv 2008“. I’m quite excited: There are many exciting speakers from the geostatistics community who I have never heard live let alone met. The conference seems to be organized really well. And I am going to give a talk on tuesday afternoon, entitled “Applications of Copulas in Geostatistics”. I would be really surprised if anybody who reads this here would actually be in Southampton, but if this should be the case, I sure would be happy to meet you, and buy you a beer!

It turns out that there is a dinner organized in the evening after my talk on restored classic british sailing ship.

Due to this conference, this blog here will likely be updated less frequently than usually. I hope you guys can understand!