By 'local water level' were you talking about a specific area? Or everywhere in the world? There are many instrumentation differences, methodology of measurement differences, and so on, if you are talking global. On the other hand, if you were talking about the SF bay area and some specific team and time frame, I think you'd probably get the data.
Here in Portland, we have a NOAA weather office, for example. They do things like read temperatures, monitor rain precipitation, snow precipitation, wind speed and direction, and the usual lot of your basic measurements. Some of the data is intermittent -- snow fall has ceased to be measured, about 10 years ago, and monitoring wasn't begun until perhaps the 1950's. Some of it is continuous, like temperature, going back a ways. However, the locations of the measurement, the type of measuring instrument, the frequency and timing of those measurements, and the calibration methods used have changed over the years. Even though there is some digesting of the data before it makes it into their SF6 preliminary product, it's still not reliable and certainly not usable as a continuous dataset without a lot of specific information to help.
Much of that information isn't even available on the web. Even the more recent data only goes back 5 years -- by policy, after this late Bush took office and had key staff in Washington DC _order_ (I've read the order, personally) the datasets curtailed on the web. They do have data going back further and, upon request, sent me much of it. However, to make use of that data as well as other data that still remained only in paper records, I has to personally visit the office and take days of time going through stacks of old papers and copy out calibration standards and references and methodology.
And that is just one process variable for one site.
So what exactly were you asking for?
Mostly, I wanted to point out the effort required to fuse even just a couple of data sets. My above comments give you even more about it.
By the way, 1.12mm/year represents perhaps (in my opinion) the single largest source of rise, right now, except perhaps thermal expansion. In other words, mountain glacier loss is pronounced and not to be set aside or laughed at. Broadly speaking, it's important and widespread.
Well, the report I cited provides all you need to know. From there, you can realize the assumptions and know at least some of what else may need to be examined further. You know the data sets, broadly speaking, and can track those down (or ask for more details.) You know the results and methods and probably could get very close to replication, if you put in the work he did. What else should have been included?
Depends. If the subject were far, far more complex and the question illustrating much, much further to go in terms of education... you might. I think I definitely would brush them off, because I frankly care about my time, unless they somehow showed me the were serious enough to work hard for their own opinion. If someone is serious and can show it, I usually agree with you. I love it when people want to know things and are willing to put in the sweat to get there. But there are so many people out there who aren't.
And in climate science, it's is _so_ politicized and there is _so_ much money there for those willing to do little other than confuse and waste others' time, that you really _do_ need to be a little careful. Even the late Bush administration actively worked hard to "make this political." I only wish the world were different. But it isn't. Still, many scientists are generous people and a lot of them will give away their time even when the questioners msy only be asking to be annoying and will never do anything with the effort granted them.
Best foot forward is to show you have put in some time, first, and know just a little bit about what they've done and are currently interested in. Just as that would be a best foot forward with you. For example, I know that you look for other than boutique parts and often have a cost/space issue and sometimes deal with controlling RF power levels fewer have to. If I were writing to you for information, it might go just a little further perhaps that I was at least aware of some of your own concerns and could couch my request in a way that presents well.
It's just good practice.
I think you know what I mean, though. They might be asking also for a lot of work on your part in the request. (Presumed here, because when you ask a scientist for 'sea level data' you probably are asking for an hour or two of their time, if for no other reason than to explain to you the caveats of it.)
And yes, taking your point it would be nice if scientists would ask you for more about what you plan to do or what problem you are trying to solve, so they can better advise you even if they don't plan themselves to provide everything. Often, they can refer you to someone else, or a good book on the subject.
Yes, it can. Which stations? How long of a period? Did the instrumentation change? If so, when and when and when? Did the locations change, too? If so, what are the calibration differences? How were they determined and with what precision and variances, based on methods used? What methods were used? Have there also been changes in the land mass, itself, based upon satellite observation or other geologic information that confounds the measurements in the interim? Etc. I'm only just getting started.
Yes, I agree.
Read my above comments. It's not 'that easy,' except to someone who hasn't ever done this. But of course, to those ignorant of the details everything seems 'easy.' Boy did I learn that digging my own foundations and perimeter wall cement forms! Just the very idea of 'digging a level base' seems easy enough to conceive. Until you go there and dig it out. Not the work, but what you find. I found biotic material here going twice as deep as I wanted to dig, in one corner of the area. And NONE of the books told me how to deal with it
-- except to say that the foundation needs to based upon inert ground. So I knew I had a problem. It took me days to work out the answers and remove all of the 'bad' material leaving cavities, develop engineered fill on my own, learn how to tamp it down properly and bring the cavities back up, and move earth around the area to bring a more uniform appearance. Damn! I just wanted a level foundation.
Reality impinges.
Nothing is easy. Especially this stuff.
I think I have every right to control _my_ time. Sometimes, I think the effort is worth it and, since I generally agree with your approach, I often try. But in the end, _I_ decide when and where I am willing. Sometimes, I've got other things going on (like my daughter) that require my time and it's just a bad time that the request comes in. So I brush them off. I usually try and send them somewhere slightly useful and spend _some_ time, even then. But if the number of requests were high, perhaps, and my personal circumstances very demanding at the time... I might not respond at all. If the questioner is serious, they will either write in a few months or else they will find someone else. I don't owe anyone my time, though.
Great.
Show me what you know about getting 'sea level data.' What instrumentation is used, Joerg? Where and over what periods of time? What areas are markedly different in their methods? How have methods changed over time? How are they calibrated? How do you calibrate the differences in means and methods against each other (how do you match up measurements from one method with another, even in the same area?) How have positions of instrumentation changed and why? How does land level changes affect results? Which satellites and instruments aboard are also used in all this? How are they used? What processing is required merely to get a measurement out of satellite based equipment that can be used, in the first place? How long have they been in space? Etc.
What work have you really done, here? Seriously. What puts you in the position of being able to come to your own opinion on any of it?
Where are your callouses? Show me.
Jon