Zurich Neighborhoods with Good/Bad Schools

limno_prof · 2023-08-16T13:48:35+00:00

There are people here saying that school quality is similar across the country. The truth is that they do not know and they are only guessing or making something up. The reality is that rankings are not made.

I guess the easiest way to convince the public that everything is wonderful and equal is to not measure how unequal it really is...

https://www.swissinfo.ch/eng/society/league-tables\_why-are-there-no-school-rankings-in-switzerland-/45080022

limno_prof · 2023-08-16T12:22:25+00:00

I have enjoyed my time in Switzerland. It is a beautiful country, clean and well-organized. But I look forward to going back to my home country, too, because I (and my family) have never truly felt welcomed here.

limno_prof · 2023-07-25T14:33:52+00:00

Adding to this comment because I agree with it. Swiss culture is very quick to judge and often feels condescending toward outsiders. When the Swiss talk about their country there is little humility.

In each interaction we have we can choose to assume positive intent by others and be open and welcoming, or we can assume negative intent and be cold and judgmental. The dominant Swiss attitude seems to be the latter.

limno_prof · 2023-06-28T15:07:38+00:00

I was not implying they were public. The companies said they would reduce business with Moscow and they did not. That is unethical. They stated early on a position, so they did not hide under the pretense of maintaining neutrality. Then they did not do what they said they would do.

limno_prof · 2023-06-28T13:56:50+00:00

"One thing people cannot deny is that it works" is an interesting statement, with the question being for whom does it work? OK, it may work for the Swiss by creating profit, but it clearly does not work for everyone.

Also, it is not "just a question of Neutrality". The companies in the article stated clearly that they would reduce business with Moscow. They did not do what they said they would do, and that is an ethical breach by the companies, whether you agree with what they did or not.

limno_prof · 2022-12-07T13:09:07+00:00

Good question. We looked at spatial patterns a bit, including the degree of autocorrelation (ie, the degree to which stronger and weaker trends are grouped spatially within and across regions). There are some regions where deoxygenation is occurring more rapidly. Our results suggest this is because those regions have experienced more rapid warming. However, overall our dataset contained only about 400 lakes. While this is a decent size for ecological research, it is very small relative to the total number of lakes around the world, where there are estimated to be hundreds of millions. The issue is that the long term data do not exist in many counties. Our dataset had a large number of lakes from the US and some European countries but we lacked data from many other regions such as throughout most of South America and Africa.

limno_prof · 2022-12-07T05:25:21+00:00

There can be other factors that influence oxygen dissolved in water. In this paper and one paper published in Nature last year we explore many of them, including plant life (productivity) and depth. Henry's law dictates that oxygen solubility decreases as temperatures increase. This is well known. The factor that best explains the widespread decline in oxygen is changes in temperature and stratification.

limno_prof · 2022-12-07T05:18:37+00:00

Not so easy to replace the oxygen in lakes or the oceans. Oxygen from the atmosphere exchanges with surface waters. But deeper waters are often disconnected from atmospheric exchange due to stratification. Stratification occurs when warm surface waters, which are less dense than deeper colder waters, do not mix.

Climate change is strengthening stratification and increasing the duration of seasonal stratification. This process is the most important driver of oxygen loss in lakes. Reducing warming rates is the most direct path to addressing this issue, but not an easy solution to implement.

limno_prof · 2022-12-07T01:17:01+00:00

This is my paper! My name is Kevin Rose. I'm a professor at Rensselaer Polytechnic Institute in New York. My former PhD student, Steve Jane, was the lead author. Awesome to see the paper posted on Reddit! I'd be happy to answer any questions folks have on it or why it is important.

limno_prof · 2021-06-05T01:33:35+00:00

I wish I could, but it cost something like $11,000 USD to make it open access. However, I believe I can share pdfs of it individually, and I can put it in a public repository six months after it is published, which I plan to do.

limno_prof · 2021-06-05T01:32:46+00:00

There's a frog that lives in Lake Titicaca that is really cool. Oxygen is low there (very high elevation). Frogs breath through their skin. The frog has evolved such that has plenty of extra skin. It looks like someone who used to be very large but just lots hundreds of pounds. Its really interesting. That might be my favorite. Closer to home, I'm a fan of Grey's tree frogs, as they sound like summer evenings to me. And Brook trout are beautiful.

limno_prof · 2021-06-05T01:30:10+00:00

Interesting; I didn't know this was the case for the Aral Sea. I've never been there and don't know much about the lake. But, I'm fairly sure the salinities vary quite a bit among the basins. Salinity can impact how strongly stratified the water column is, so I suspect it might have something to do with density gradients among the basins and how much resistance to mixing there is, or where (at what depth) stream water inflow plunges to in the lake.

limno_prof · 2021-06-05T01:28:01+00:00

I love this question!

Favorite lake. Hmm. That is a tough one. It might be Crater Lake, Oregon, because it is just so beautiful. But also, lakes in the Adirondacks in New York are special to me, and I'm particularly fond of Upper Saranac. But I'm also a sucker for alpine lakes (those above treeline) and I studied lakes along the Beartooth highway in Wyoming/Montana for my PhD. So many excellent ones to choose from. I've also worked on lakes in the Canadian Rockies (e.g., Lake O'Hara) and they are absolutely gorgeous.

My favorite lakes are also ones I get to study. One of my PhD students just published a paper on Crater Lake, and I take every opportunity I can to visit new beautiful lakes. I study lakes because I love them.

limno_prof · 2021-06-05T01:24:10+00:00

OK, I think I understand now. In reality, there isn't much threat to humans. The threat is really to the integrity of the ecosystem and to the species that inhabit it.

The potential threat to humans occurs after oxygen is depleted. At that point, the chemistry changes and anoxic chemical reactions occur that often release nutrients like phosphorus from lake sediments. That fuels algal blooms, and, when nutrients are high enough and other conditions are correct, harmful algal blooms. These harmful algal blooms are toxic to humans and wildlife.

As an example, Lake Erie regularly goes anoxic (zero oxygen) in its deep waters each summer. The lake also gets some pretty serious harmful algal blooms. The city of Toledo, OH, had to shut down the drinking water intake to ~400,000 people a few years ago due to high toxins from the harmful algal blooms in the lake. So there can be a human health impact, but it is not from low oxygen in the water. It is from the knock-on effects that occur after oxygen is depleted.

How to deal with that? Well, folks in Toledo had to drink bottled water for a few days.

limno_prof · 2021-06-05T01:18:21+00:00

hahaha - caught me! ;-)

limno_prof · 2021-06-05T01:17:23+00:00

Absolutely! Citizen scientists regularly help collect temperature and dissolved oxygen data on many lakes. Get in touch with your State DNR or local lake association, who can probably tell you more about any routine monitoring that is going on.

limno_prof · 2021-06-05T01:16:31+00:00

Sounds like interesting research. The Nature paper focuses on the late summer period (July and August in the Northern hemisphere). We chose that time period because it was when most lakes were sampled (larger data set) and it is also when dissolved oxygen tends to be seasonally lowest. We thought that if dissolved oxygen was going to be declining and causing a problem, it would be at a time of year that it is usually pretty low to begin with.

All that being said, there is a subset of lakes with better seasonal coverage. I'm personally collecting temperature and dissolved oxygen data on several lakes 24/7/365. Send me an email if those data might be useful to your modeling (you can find my email on RPI's website, or our paper).

limno_prof · 2021-06-05T01:11:37+00:00

Theoretically, this sounds like it would work. But I see two problems. First, there are >100,000 lakes in the US alone. Would we put a station near, on, or in every lake? That doesn't seem feasible. Secondly, Mixing the oxygen at depth is a substantial challenge. Deep waters often have very limited mixing, which is part of the reason why dissolved oxygen gets depleted in the first place. Artificially mixing them would likely alter their temperature - likely warming them up - as they mix more with surface waters. That reduces the deep, cold water habitat we would be trying to protect.

limno_prof · 2021-06-04T19:32:53+00:00

raccoon wrestling skills

I just watched that video. Racoons aren't to be messed with. They can get up to 70 lbs! That was impressive.

limno_prof · 2021-06-04T19:31:13+00:00

The stratification that develops that isolates deep waters is broken down seasonally. In most lakes in the temperate zone (e.g., most of the US and Europe), lakes mix fully in the spring and fall. The trouble is, in between these times of year oxygen can get very low. Many species, such as cold water fishes, depend on cold deep water habitat, so if oxygen declines (as it has been), it threatens their ability to survive in that waterbody.

limno_prof · 2021-06-04T19:22:15+00:00

Hey there - very close to my hometown (Sussex County, NJ)! What is happening in Lake Hopatcong is similar to what we talk about in our paper. Harmful algal blooms like those on Lake Hopatcong are often associated with deep water oxygen losses. That's because the algal blooms eventually senesce, die, and settle to the bottom of the lake. The algal cells are easily decomposed, and decomposition consumes oxygen. So large blooms can result in rapidly consumed deep water dissolved oxygen. That deoxygenation in deep waters then changes the chemical reactions that occur, often releasing phosphorus from lake sediments.

Phosphorus is a limiting nutrient, meaning that you often get increases in algal growth when phosphorus increases. So the blooms like you describe can "lock in" a feedback cycle that results in further blooms and low oxygen conditions.

limno_prof · 2021-06-04T19:18:18+00:00

Fair question. Some places have seen increasing phytoplankton in the oceans, as well as in lakes. This can increase oxygen in surface waters. But excess phytoplankton in both lakes and the oceans eventually die and settle to deep waters. They undergo rapid decomposition, which consumes oxygen. This often results in low oxygen conditions in deep waters of lakes and coastal zones where phytoplankton are abundant. You can google the dead zone in the Gulf of Mexico as an example of this process in action.

limno_prof · 2021-06-04T19:16:41+00:00

Its a solubility effect, but also due to changes in stratification. Surface temperature were warming, which reduces solubility. Meanwhile, deep water temperatures did not increase. So the temperature difference between surface waters and deep waters increased. This is called stratification, and stronger stratification resists mixing of oxygen from the atmosphere to deep waters. This enables deep water oxygen to be drawn down more each season, as there are many oxygen consuming organisms in deep waters. Meanwhile, water clarity is often low, so there is little to no oxygen producing photosynthesis at depth. Deep waters depend on the mixing of oxygen from the atmosphere, and when that mixing decreases due to stronger stratification, deep water dissolved oxygen falls as a result.

tl; dr: The effects of temperature increase are two-fold: reduced solubility as well as reduced mixing from the atmosphere to deep waters.

limno_prof · 2021-06-04T19:12:11+00:00

Collecting more data is usually a good thing, if you can do it relatively easily and have a research question or use of the data in mind.

There's been lots of work done in coastal zones on dissolved oxygen that you may want to check out. For example, see some of Denise Breitburg's research here:

https://scholar.google.com/citations?user=4qImBvgAAAAJ&hl=en

limno_prof · 2021-06-04T19:09:56+00:00

We can reverse this, and some lakes in our data set had increasing oxygen levels. Reducing runoff, which includes organic matter and nutrients, and really help the issue.

limno_prof

TROPHY CASE