Wikipedia:Reference desk/Archives/Science/2023 February 4

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February 4

Global warming causing cold wave

I have seen that some areas are facing record cold wave, and most places also face record heat wave during summer. Antarctica glaciers are melting, some areas don't have snowfall like 1960s. Then how global warming is causing extreme cold in some areas?

I understand how rising temperatures can increase cloud burst, cyclones, tornadoes, storms, floods, but this cold wave due to global warming is confusing. PringalDer (talk) 06:28, 4 February 2023 (UTC)

Changing wind patterns. In general, it gets warmer, but there are a few areas where in winter winds from high latitudes get more common. For example, in some central and eastern parts of North America, winds from the Arctic get more common in winter, leading to extreme cold outbreaks. These winds change because of regional changes in air pressure, which in turn result from changes in temperature at high latitudes. PiusImpavidus (talk) 11:00, 4 February 2023 (UTC)

See this BBC article: "Climate change: Arctic warming linked to colder winters", and this Science article: "Linking Arctic variability and change with extreme winter weather in the United States".  --Lambiam 11:38, 4 February 2023 (UTC)

The article Effects of climate change#Heat waves and temperature extremes has some more references. Mike Turnbull (talk) 12:05, 4 February 2023 (UTC)

A lot of it is due to the Jet stream wiggling more violently so it goes up and down more. See yhe first picture in that article for how it goes up and down. When it comes down the area behind can get very cold. NadVolum (talk) 16:04, 4 February 2023 (UTC)

Global warming cooling was a recognised descriptive issue ages ago,that's why we now call it climate change, and there are a group of people whose intent is to attribute every bit of weather to it. https://climateattribution.org/ Greglocock (talk) 21:37, 4 February 2023 (UTC)

I provided computer support to climate scientists in Australia 40 years ago. Right back then they said humans were causing global warming, leading to climate change, which would include more extreme weather events, both hot and cold. You are not the first person I have recently seen say "we now call it climate change". I don't understand the "now". It's been called that or 40 years!!!! HiLo48 (talk) 05:58, 7 February 2023 (UTC)

Recentism. ←Baseball Bugs ^{What's up, Doc?} carrots→ 12:37, 7 February 2023 (UTC)

You do realize that a change to the climate would necessarily mean impacts on the majority of weather events, you know, since the climate is made of the collection of individual weather events taken together as trends. In fact, the surprising thing would be if we could only attribute a small minority of extreme cases to climate change, since they would, by definition, be outliers and not constitute the trend. A far smaller group of people don't seem to understand this, and expect the opposite (or likely just are trying to find other ways to basically deny anthropogenic impacts upon, and changing, climate exists). --OuroborosCobra (talk) 22:53, 4 February 2023 (UTC)

There is definitely some rhetoric of "now it’s climate change instead of global warming, seems like those scientists schmucks aren’t really sure after all, lol" from the climate-denier crowd, but I have met reasonable people who thought that "well, a couple of small changes here or there ain’t such a big problem". That reasoning is faulty on two counts.

The first one is that even if you, personally can move to a climate that is 5°C hotter or colder without much disruption, agriculture is much pickier about stuff such as temperature and irrigation than the modern supermarket-supplied human is.

The second one is that local variations can still be tremendously disruptive. For instance, consider the islands of Sicily (millions of inhabitants, very suitable for agriculture since ancient times) and Somerset Island (Nunavut) (a desert island north of the Arctic circle). Imagine that the climate characteristics of those islands swap "suddenly" (within a hundred years). You are given unlimited political power to solve the issue as you see fit (nobody will complain), scientists manage to give you an incredibly-accurate timeline, and somehow the fauna and flora swap along all on their own without mass extinction (aka: the easy peasy scenario). Even if you deport millions of people across the globe (which is an ethically dubious proposition), you must leave behind a large amount of existing urban infrastructure and change major trading routes: climate change caused you to forfeit the cost of one Sicily worth or roads, buildings etc. Tigraan^{Click here for my talk page ("private" contact)} 16:04, 7 February 2023 (UTC)

Voltage multiplier for rectified flyback transformer?

I have a flyback transformer with built-in diode. Since the output is pulsed, I thought I could use a voltage multiplier to increase the voltage. However, after looking at the Villard or Cockcroft–Walton circuit, I doubt it can work, since the rectifier diode will make the source an open circuit when the voltage drops. Am I right in thinking that multiplying the voltage (using only capacitors and diodes) is simply impossible? Prevalence 22:55, 4 February 2023 (UTC)

From Flyback transformer: "The pulse train coming from the flyback transformer windings is converted to direct current by a simple half wave rectifier. There is no point in using a full wave design as there are no corresponding pulses of opposite polarity. One turn of a winding often produces pulses of several volts. In older television designs, the transformer produced the required high voltage for the CRT accelerating voltage directly with the output rectified by a simple rectifier. In more modern designs, the rectifier is replaced by a voltage multiplier." So it is both possible and routine. Philvoids (talk) 00:51, 5 February 2023 (UTC)

For the flyback they used a flyback transformer though as it could produce the big current with the nice sawtooth shape needed for the coils in an old TV. Is this to drive an old CRT? NadVolum (talk) 01:03, 5 February 2023 (UTC)

The flyback comes from an old CRT tv. I want to use it to generate high voltage for some experiments, preferably 50kV or more. Prevalence 02:20, 5 February 2023 (UTC)

I know the diode can be replaced by a multiplier. But I can't remove the diode, since it is inside the housing, and the whole thing is potted. The question is, is it possible to add a multiplier after the diode. Prevalence 01:46, 5 February 2023 (UTC)

I think the diode forms the first stage of the voltage multiplier. The usual anode voltage for 20 to 26 inch colour CRT's was 25kV and I would never come near that potential except with a special long-reach high voltage probe. Please tell someone what your "experiments" will be. Philvoids (talk) 18:16, 5 February 2023 (UTC)

If you want to produce really high voltages you're better off with the diodes and capacitors. The transformer might break down with flashing between coils. Also I think you're less likely to klll yourself with the voltage multiplier. NadVolum (talk) 11:13, 5 February 2023 (UTC)

I found a solution: the Cockcroft-Walton multiplier will work when a "pull-up" resistor is added, connecting the output of the flyback (+ diode) and the ground. That way, the capacitor at the input of the multiplier will be pulled to ground when the output of the flyback is zero. I ran simulations in Qucs, with good results, so I'm pretty sure it will work (haven't tested it yet, I'm waiting for the HV diodes I ordered). Prevalence 21:01, 5 February 2023 (UTC)