56
votes
Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?
Water is a rather strange substance. With most substances, the solid phase is denser than is the liquid phase. This is not the case with water. Ice is less dense than liquid water. A side effect of ...
- 20.2k
53
votes
Accepted
Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?
Water melts at 0 °C (32 °F) but freezing is a more complicated affair. It is safe to say water gains the ability to freeze at 0 °C, but it can get much cooler before it actually does so resulting in ...
- 13.9k
53
votes
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How it's possible to measure temperature 2000 years ago with such precision?
How it's possible to measure temperature 2000 years ago?
Sans the technology used by Bill and Ted ("Bill and Ted's Excellent Adventure"), it obviously is not possible to directly measure ...
- 20.2k
41
votes
Why would it be drier indoors during the winter vs the summer?
The only physics you need to know is that if the temperature is higher the air† can hold more water vapour (the gaseous phase of water). Cool molecules don't have enough energy to free themselves from ...
- 10.7k
38
votes
Does human body temperature impact climate change?
Does human body temperature impact climate change? Directly? It's not even a blip. The Earth's population is 7.6 billion. With each person radiating about 80 watts (basal metabolism), that's about 600 ...
- 20.2k
38
votes
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I just read news that Antarctica had set a new record high temperature, above 18 °C. How can this be the case if it is currently winter there?
You just read the news too fast. WMO announced that, after evaluation by a committee, they have validated the 18.3°C temperature recorded in February (i.e., in summer) last year:
GENEVA, 1 July 2021 (...
- 5,614
31
votes
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What would be the temperature of earth if there was no atmosphere?
According to Wikipedia an approximate average surface temperature for a bare earth is 274.5 K. This scenario is quite reasonable in my opinion as stripping the atmosphere without changing much else ...
- 2,602
30
votes
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Why are mornings cooler than nights?
The Earth is always radiating heat to the space. But in the day the Sun delivers some heat. The net heat flux is then defined as the sum of those two factors. If the energy delivered by the Sun is ...
- 618
27
votes
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How to interpolate scattered data to a regular grid in Python?
It is straightforward to do so with numpy, scipy.interpolate.griddata, and matplotlib. Here ...
- 4,925
25
votes
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Is it possible for rivers to freeze completely and stop flowing?
I am interpreting your question as referring to rivers with flowing water freezing as as opposed to glaciers, which are already frozen.
Under current climatic conditions, small rivers can freeze ...
- 20.7k
24
votes
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Why was there a negative temperature anomaly between 1950 to 1980?
This phenomenon is known as global dimming.
It was due to the particles and aerosols mostly released by combustion of fossil fuels such as diesel. Those particles block the radiation from the sun, so ...
- 5,614
22
votes
Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?
Due to convection (the cold water sinks while the warm water rises), the entire pond needs to be brought to near-freezing temperatures before the surface can freeze. With only the top of the pond in ...
20
votes
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Did global warming cause the extreme cold 2013-14 winter in North America?
I bet you live on the eastern half of North America, which had a cold winter of 2013-2014, Europe and Alaska had a very warm winter, and China had its second warmest January.
Jennifer Francis of ...
- 2,095
19
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What was the highest temperature ever recorded on the surface of Earth?
The record the article is referring about seems to be the same as registered at Guiness World Records:
On 13 September 2012 the World Meteorological Organisation
disqualified the record for the ...
- 17k
18
votes
If the earth is a globe, what causes temperature differences across lines of latitude?
Polar regions are colder than equatorial ones for a simple reason - geometry.
More specifically, it is caused by the greater angle of the Sun's rays to the surface of the Earth. As you go farther ...
- 3,038
18
votes
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Does the US National Weather Service use Celsius or Fahrenheit?
NWS Temperature forecast or new forecast
From these URLs, it appears that the unit is Fahrenheit.
and if you click on this URL - Max/MinT
Is the maximum daytime or minimum overnight ...
- 6,267
17
votes
How do I explain why the Tibetan plateau is colder than lowlands at similar latitudes?
The answer is because the Earth is not a static system.
Due to the ideal gas law, air cools as it rises. This is referred to as the dry adiabatic lapse rate. However, you are curious why every ...
- 2,598
17
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July/August hottest months (northern hemisphere): because of continued warming or other effects?
The amount of surface heating from the sun is a function of time of year and latitude. You are aware of the dependence on the time of year with the sun over the equator at the equinoxes and ~ $\pm$23$...
- 13.9k
17
votes
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Could this study "totally dismantle" Global Warming claims?
There is several credibility problems with this work.
First, they mention after the title:
Abridged Research Report
but I cannot find any related full work from the authors on the matter. As a ...
- 2,623
16
votes
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Are cloudy nights warmer than nights without clouds?
Is there a correlation between temperature and cloud, during the night?
Very much so. It's called radiative cooling. Three factors come into play: cloudiness, relative humidity, and windiness. ...
- 20.2k
15
votes
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Where can I get archived hourly temperature data?
The authoritative sources for your data are:
ASOS: Automated Surface Observation Systems at airports, and
MADIS: the Meteorological Assimilation Data Ingest System, from NOAA
Those are collections ...
- 4,080
15
votes
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How accurate are climate proxies in giving us a clear picture of global average temperatures throughout Earth history?
Overall, any individual proxy is not a reliable indicator. It's the combination of multiple proxies that provides a clearer picture.
For example, tree ring growth has been correlated with ...
- 2,708
15
votes
How to reduce the atmospheric temperature artificially?
Ozone does not "filter" UV, it absorbs UV radiation (and undergoes some photo-chemistry reactions in the process). By absorbing those wavelengths it prevents them from reaching us at the surface, but ...
- 13.9k
15
votes
What happens to global temperature when we stop all the vehicles for a year?
Not much at first. The damage has already been done. Humanity has added at least 100 gigatonnes of carbon to the atmosphere since the start of the industrial age. Natural sequestration of that excess ...
- 20.2k
15
votes
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Why is the Ocean water on the west Coast so cold comparing to the East coast?
This is a good overview of ocean surface currents, which includes a schematic like this one:
In the mid-latitudes, you get gyre circulations that move poleward along the eastern coasts of continents (...
- 1,361
15
votes
Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?
The water in a pond is in contact with the ground and the ground is not even close to freezing even if the air temperature is 27° below freezing.
- 2,137
15
votes
Does the US National Weather Service use Celsius or Fahrenheit?
That device only shows Fahrenheit
I don't know about the full Weather Service, but that device only shows Fahrenheit measurements. You can see this in the user manual, in the appendix, page 18
- 259
15
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Is there a recent global gridded temperature dataset with 0.1 deg resolution?
The most important reanalysis datasets covering until present time (I'm excluding the others that stop some years before present time) currently available are:
ERA5 by ECWMF: 1979-present (soon 1950-...
- 1,258
14
votes
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Oscillations in the Keeling curve?
Photosynthesis increase in the northern hemisphere spring, especially in the Siberian Taiga, and carbon dioxide decrease in atmosphere. During autumn and winter, decomposition of plant material and ...
- 5,896
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