How long could a steel artifact last? Would man-made steel artifacts be able to be preserved like fossils for millions of years, or would corrosion make them dissipate? What about metals such as aluminum that don't corrode as easily?

The short answer is no.

Most metals do not fossilize well, they are too reactive/water soluble. Metals are usually what is doing the fossilizing, dissolved metal in groundwater is being attracted to the electrical properties of organic material and filling in or swapping places with a porous material. You might have a stain left or some of the shape as a natural casting, but not material preserved. The exception might be in amber, but it could also be really bad: amber preservation is tricky chemistry, so I am not comfortable saying yes or no. Metal objects have good short term preservation but horrid long term preservation. there are some low reactivity metals that might survive like gold, but not as fossils. But even gold is water soluble over millions of years, so even that would require some unusual conditions.

It all depends on the conditions of fossilisation and the type of steel. Human flesh doesn't usually last long, but the Ice Man found cryogenically preserved in the Austrian Alps had been there for 5,000 years and would have been there for another few thousand if he hadn't been removed. Dinosaur proteins and DNA much older than that have been found.

Iron doesn't last long in damp conditions unless it is alloyed with another metal. The best stainless steel artefacts could fossilise under the right, non-acidic conditions. Copper, silver, gold, platinum and several other metals have been found fossilised in their pure, metallic state, so it follows that artefacts made of these metals could fossilise. Iron-nickel fragments of the famous Barringer meteorite in Arizona have been fossilised under the crater for at least 50,000 years and will probably (apart from the bits that have been removed) stay there for millions of years longer in an almost pristine state.

Aluminium may not corrode as readily as iron, but it does corrode. Nevertheless, aluminium artefacts might fossilise under the right dry, non-acidic conditions, as there are plenty of even more remarkable examples of fossilisation known to science..


If rocks are stones, what type of rock are gallstones? From Wikipedia:

  Rock or stone is a natural substance, a solid aggregate of one or more minerals or mineraloids. For example, granite, a common rock, is a combination of the minerals quartz, feldspar, and biotite. The Earth's outer solid layer, the lithosphere, is made of rock.

From Wikipedia page about gallstones:

  A gallstone is a stone formed within the gallbladder out of bile components

So if rocks are stones, what type of rock are gallstones?

Igneous rock is formed through the cooling and solidification of magma or lava.
Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of that material at the Earth's surface and within bodies of water.
Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism

Gallstones don't fit into any of these categories so what type of rock is it?

The nature of this question is more about biological chemistry than it is about earth science. This is because gall stones have nothing to do with geology, but chemical processes in the body.

Consequently, it would be inappropriate to apply geological classifications, such as igneous, sedimentary or metamorphic, to gall stones.

Due to the way gall stones are formed - layers of bile coating a nucleus - they could be describes as being concretions.

"Metamorphic rocks arise from the transformation of existing rock types"
"a natural substance, a solid aggregate of one or more minerals or mineraloids."

Looks like Metamorphic wins.


Why was the sky SO yellow? Today, I was coming back from music school, and it was raining heavily. An hour after I came back, the sun started coming out from one side, and the sky wa very brighr yellow. The lighting effects that came through all my windows were spectacular.

Here are some images:

I appreciate any explanation how phenomenon like this can occur and why.

In this case I'd say it's a combination of Rayleigh scattering,
Mie scattering and the angle of the sun.

Rayleigh scattering is related to the chemical composition of the atmosphere and occurs when the particles causing the scattering are smaller in size than the wavelengths of radiation in contact with them (this is why the sky appears blue most of the time). The yellow sky in this question is likely mostly owing to Mie scattering. Mie scattering is caused by pollen, dust, smoke, water droplets(the most likely culprit in this case), and other particles in the lower portion of the atmosphere. It occurs when the particles causing the scattering are larger than the wavelengths of radiation in contact with them. The angle of the sun and Raleigh scattering may also be at play, when the sun is low in the sky sunlight passes through more air than when the sun is higher in the sky. More atmosphere means more molecules to scatter the violet and blue light away from your eyes. If the path is long enough, all of the blue and violet light scatters out of your line of sight. The other colors continue on their way to your eyes. This is why sunsets are often yellow, orange, and red.

It's a concept called rayleigh scattering. Shorter wavelengths are scattered more and longer ones are scattered less. This explains why the sky is blue. Sometimes, after a storm passes, the yellow/orange tint is a result of that reyleigh scattering.


Prevailing Winds: Is the speed relevant? The Wikipedia entry for prevailing winds notes (in my understanding) that the prevailing wind direction is determined solely by the mode of the directions. They note another qualifier called 'dominant wind' which should give the direction of the strongest wind.

However, it feels a bit counter-intuitive that if we had (an example) over 8h a wind from the east at 2m/s and after that a 10m/s wind from the north for 4h, that the prevailing wind direction would still be east.

Based on the above example, would the prevailing wind direction be east?

Is the term 'dominant wind' (with a northerly direction) used in common meteorology, and would that be (in the above example) northerly?

Part of the complication goes to two separate definitions for the word:

prevailing:

  To be frequent (Miriam-Webster)

The most frequent, the most occurring wind direction in your example, even if weak, is east.  So that would be the prevailing wind, as that's the definition we generally use in meteorology.

So don't think of it as

  Having superior power or influence (Dictionary.com)

as indeed, that'd become a bit more subjective of a concept.

Sometimes you may hear about the average direction (which would be east-northeast in your example).  So perhaps that's more what you're wishing for?  Of course if you have an east wind for half the day and a west wind for half the day, the average wind direction would be either north or south.  Or, if instead of treating direction and speed differently, you took the vector average... you'd have a mean windspeed of nothing!

Looks like this MathSE question fairly discusses some of the benefits and troubles with different methods of summarizing wind direction... which line up closely with the more general disparities of each of mean, median, and mode.

Alternatively, wind roses can be much more informative and enticing.  They give both an indication of the directions (by the length of the bars in each direction) and the intensity (color coded).  You can find things, such as: in Colorado Springs in May (as shown below), winds aren't from the southwest very often... but when they are, they tend to be fairly strong (whereas when winds are from about east, as is more common, they're typically quite light):

Looks like you can make some pretty snazzy/customizable recent wind rose plots of locations around the world at the Iowa Environmental Mesonet site.

But the take home is: in meteorology we typically define prevailing wind as simply the most common direction, with no consideration of the speed distribution.

Prevailing Wind is predominantly related to the most common wind direction and how long in a period of time the wind is blowing in this direction.


What sort of a plate is the Sunda plate? I have read that the islands of Sumatra & Java have resulted from the subduction of oceanic crust of the Indo-Australian plate beneath the Sunda plate. I want to know whether this boundary is ocean-ocean convergence or ocean-continent convergence.

Are islands of Sumatra and Java like Mariana Islands which result from the subduction of the oceanic Pacific Plate beneath the oceanic Mariana plate? Or are they like the Andean volcanic continental Arc which results from the subduction of the oceanic Nazca plate beneath the South American plate.

Well, in short, it's mainly continental, (oceanic-continental convergence).
But in regards to the "type of plate" that the Sunda plate is, is minor plate or tertiary plate. Meaning it's not very big etc. Because 1 tectonic plate can have both oceanic or continental crust. Tectonic plate and crust are slightly different concepts. So, The Sunda plate is mainly comprised of continental crust. There might be a bit of oceanic crust, but less.
Map of oceanic crust on earth: https://www.ngdc.noaa.gov/mgg/ocean_age/data/2008/ngdc-generated_images/whole_world/2008_age_of_oceans_plates.jpg

The convergence of the Indo-Australian plate with the Sunda plate is an oceanic-continental convergence. The Sunda plate carries some major land masses: much of SE Asia including half of Vietnam, and Borneo (which is itself three times the size of Great Britain).

The islands of Sumatra and Java are part of what is known as the Malay Archipelago, though they belong to Indonesia, as do the Lesser Sundas to the south. They are part of the original land mass of the Sunda Plate and were once connected before sea level rise separated them. They have numerous volcanoes caused by the subducting Indo-Australian plate. Arguably, these volcanoes are gradually making them larger, which also applies to the Lesser Sundas to the south. In 1815 Tambora, on the island of Sumbawa, was the site of the largest volcanic eruption in recorded history. An even larger eruption occurred at Lake Toba on Sumatra, some 75,000 years ago.


Why does the salt in the oceans not sink to the bottom? This is something that just occurred to me. If heavier elements sink, then how can the entire ocean be salty? Shouldn't the 'salt', because of its density, all sink to the bottom of the ocean? In theory, only the deepest parts of the ocean should be salty, while the top of the ocean is not. Yet, the only water in the world that isn't salty comes from rain and rivers. How can this be?

When dissolved in water, salt breaks up into sodium and chlorine ions, which combine with water molecules so they cannot easily sink. However, there is a tendency for streams of fresh water to float on salt water and rise to the top. This caused problems for British submarines in the Dardanelles Straits during WW1. Moving from almost fresh water to the denser salt water, they suddenly became more buoyant and rose involuntarily to the surface, making them visible to Turkish gunners on the shore. There are also parts of the ocean where there are pools of very salty water lying on the bottom in such a way as to clearly show the pool to any diver who happens to see it, as though it were a pool on land, so in some circumstances very salty water can sink.

Actually it does. But the thermo-haline cycle of cold water and upwelling mixes that water around. In stagnant stand, the salt will accumulate on the bottom. But ocean currents and the rise and fall of varying temperature water flushes that salt and moves it around.


Observations of sea ice typology in the Arctic What are the main datasets characterizing sea ice typology, thickness, density, "passability", presence of pressure ridges in the Arctic?

Is it something that can be detected from the air or a space satellite, or from a surface station only?

How extensive is our coverage of ice conditions in the Arctic?

Concerning datasets, there are several, depends on Your final purpose.
One of the simplest is output from OSI-SAF, which has info about Sea Ice edge, concentration, type, emissivity and drift. It is derived mostly from polar orbiting meteorological satellites, I guess.
More detailed info can be found on Univ of Illinois pages
Visual images from  MODIS satellitescan be handy
But, most detailed info about sea ice conditions can be derived with radar satellites, with commercial options like radarsat being available. From free sources, data from Sentinel-1 is available since late 2014.
So the best info is available from satellites, in-situ measurements do not cover most of the area.
Our knowledge of Arctic sea ice is pretty good IMO, at least since 1979 when satellites started to measure the extent. Understanding the age of sea ice is a bit more tricky, as it can be up to ten, maybe even few more years
old.

What do you mean by "datasets"? Are you simply asking about the sources of research/information regarding polar ice?

I worked on a bowhead whale study in the Arctic Ocean for a couple seasons. One of the guys running the project was a retired U.S. naval officer. I remember him commenting on the research done by Germans - WWII era Germans, to be precise. As near as I can recall, he suggested that the Nazis were responsible for the bulk of the early knowledge. Then again, he may have been referring more to underwater acoustics than to the actual ice conditions.

Native peoples have long had extensive knowledge of polar ice conditions, of course. There was a guy who was born in Greenland but educated in Denmark who became one of the most famous explorers. I believe he wrote a book(s) that was considered he Bible of all things Arctic. I think the person I'm thinking of is Knud Rasmussen, though I haven't actually read his book and can't remember the title offhand. But I suspect you could find a lot of general information about polar ice there.

EDIT: Sorry, wrong guy (though his works might still be worth examining). I was thinking of Vilhjalmur Stefansson's book "The Friendly Arctic." I believe it was long considered the Bible of everything Arctic.


Impossible or improbable? Hurricane crossing the equator No known hurricane has ever crossed the equator.  Hurricanes require the Coriolis force to develop and generally form at least 5° away from the equator since the Coriolis force is zero there.

Are the physics of the earth and tropical systems such that it is impossible for a hurricane to cross the equator after forming, or are the forces working against this occurring so strong that an equator crossing hurricane is an exceedingly rare event we may not witness in 1000+ years?

Improbable.

It is well known that the Coriolis force is needed to form a hurricane, and the figure of 5oN/S as the minimum for formation is widely publicized. You can also find record of tropical storm formation near India as far south as 1.4oN.

The problem of crossing the Equator isn't one of hurricane formation though, it is one of hurricane motion.  Due to Coriolis, a hurricane initially moving parallel to the Equator will start gaining a poleward component to its motion, thus moving it away from the Equator.  But, because this is due to Coriolis, if you could get a storm close enough to the Equator, this effect would not be as strong.  This would be an improbable track, but I'm not willing to call it impossible.  We haven't had satellites all that long, and all we can really say is that it hasn't happened since we've been watching.

If a storm did cross the equator though, what would it do?  Nothing at first, but as it moved further into the opposite hemisphere, Coriolis would be working against the storm and it would spin down, become disorganized and cease to be a hurricane, probably becoming a remnant low.

A tropical disturbance has crossed the equator.  One such disturbance occurred June 27, 2008 in the Atlantic basin (south to north) that retained its clockwise motion for some time:

Here is an archived comment on NASA’s Earth Observatory website, regarding an estimated once in 100-400 years equatorial cyclone – typhoon Varmei in December 2001.

https://earthobservatory.nasa.gov/images/3441/a-rare-cyclone-on-the-equator


Can anyone help me identify these rocks please? I apologize for any errors in my pictures or writing. My first post.

[

The first two images look like banded calcite to me.  The rock appears to have distinct cleavages, no clearly conchoidal fractures, and a slightly waxy luster on the weathered surfaces.  Sometimes this type of rock goes under the term onyx but traditionally onyx is a type of chalcedony.  If it is banded calcite a typical knife will easily scratch the surface, additionally it would fizz with some muriatic acid (or dilute HCl).  If it is type of chalcedony, then knife will have a harder time scratching the surface an may not if the knife is on the soft side.  Also the acid will not react with the stone.

Jan Doggen's suggestion will help you get better results for the other stones.

Quarts and most of all agate. Where did you find them? That was just my guess.


How does agriculture release so much greenhouse gas? I recently came over some numbers of GHGs released per energy in food produced, and the result is pretty flooring. I can see how animal-based food production is quite inefficient so let's ignore that for now and just look at plants.

For example rice releases 2 kg carbon =  7.6 kg CO2-equivalents per 1000 kcal. This would actually mean that it is more environmentally friendly to drive a car 10 km than to bike 10 km on a rice-based diet, because biking burns around 300 kcal = ~2.28 kg CO2e, while a normal compact car burns 0.5 liters of gasoline = ~1.9  kg CO2e. Are my numbers wrong? If not, how can this be?

There are several contributing factors,

livestock, Livestock is easy animals produce co2 but their methane is a bigger problem, methane is a better greenhouse gas than the co2 that the feed plants took in.   Livestock waste is also a problem , people do not realize how much waste modern factory farms produce, specially when stored as a liquid is it produces all the problems of rice production with addition release of methane from the waste itself.
transportation, transportation of ag products to market are almost all petroleum based. Depending on the source this may or may not be included in agricultural emissions.
Landuse, changing land, especially things like draining wetlands and burning forest for farmland are big contributors, Wetlands in particular produce huge amounts of co2 and keep doing so for decades if not centuries, all the organics built up in wetland start oxidizing when drained, this is basically the same as burning petroleum without actually getting any usable energy out of it.
Fertilizer produces a plethora of problems, and could justify an question all its own.
Rice, rice production has been called out as particularly problematic.  You would think this would produce the opposite effect to draining wetland but it is actually worse. Bacteria in flooded soil produces methane instead of co2 and as I said methane is better greenhouse gas, too top it off rice fields are supplied with enough nutrients to keep the bacteria producing way above normal wetland levels and keep it from being trapped the way carbon in mostly anaerobic wetlands will be.

Source

If you want to exclude animals, better to say why does arable farming release so much greenhouse gas. I have heard the argument about rice fields before, and it may well be true, but you have to remember that arable farming is almost carbon neutral. It removes CO2 from the air and gives it back in the ways you mention. You could even have tractors powered by biofuel, and some tractors already are. There is a very small downside, which is that plants, rice fields in particular, return a small amount of the carbon in the form of methane, which is a more potent greenhouse gas. Whatever the arguments against arable, it is more environment friendly than livestock. One thing you are never going to do is persuade people to give up eating. You aren't even going to persuade many to give up eating rice. With regard to livestock farming, its effect is not as damaging as some people allege, because you need to remember that the Earth has always had vast herds of herbivores releasing methane, it's just that the previous herds of bison etc have now largely been replaced by cattle.


How does one create petroleum/crude oil for future generations? I am a geological novice so maybe this is a wrong question. But the idea is to create a thought experiment. How does one "create" petroleum or crude oil for future generations? Is it enough to bury a lot of trees underneath the earth at great depths and eventually thousands (maybe hundreds of thousands years) later crude oil is formed?

Geological processes are just too slow. Although, given how quickly we are pumping greenhouse gases into the atmosphere, humanity may well (in a generation or two) be growing biological material as fast as possible and throwing it into deep holes in the ground, which will give another fossil-fuel resource in a few million years. But we'll be doing that just to sequester carbon dioxide from out of the atmosphere, not to invest in future hydrocarbon supplies.

Hydrocarbons are useful because they have very high energy density: the energy stored per unit weight and unit volume is extremely high. Furthermore, that energy can be harnessed with very primitive technology - just burn it. Because we've been relying on them for nearly two centuries now, we've got very good at safely transporting them globally, and safely storing them in a form ready for immediate use.

So, hydrocarbons have two uses: one, they act as storage, as a time-buffer for time-sensitive energy demands such as electricity consumption. And two, their energy density makes them very suitable for powering transport on irregular or changeable routes.

However, as a means of energy storage, they're not very efficient: even the best CCGT gas-powered electricity generators are only 60% efficient; and internal combustion engines tend to give an efficiency of about 20-25%, tank-to-wheel. And that's without the losses involved in creating the hydrocarbons in the first place

So whether hydrocarbons have a future as a source of energy is very dubious, because for almost all applications, we now have superior options.

And the future for fossil hydrocarbons must, for the sake of human civilisation, be short and quickly-tapering, because of the risk of catastrophic global warming.

For some transport applications, the energy density is still a winning attribute of hydrocarbons: most notably, powered flight for freight and travel.

We already have two routes to non-fossil hydrocarbons: biological sources, and direct chemical synthesis. Each involves capturing atmospheric CO2, and combining with water, to generate a blend of hydrocarbons.

Now, we already have means of creating hydrocarbons suitable for flight (e.g. Jet-A and Jet-A1 fuels). And there are already demonstration plants that have closed-loop generation of synthetic hydrocarbons, for use in electricity-grid-balancing, by using surplus electricity to synthesise methane, which is then burnt in gas turbines when required. Similarly, Tony Marmont's team have been synthesising petrol (gasoline) from air, water, and electricity.

However, none of those things mean that hydrocarbons necessarily have much of a future, beyond plastics production. Because hydrocarbon-powered aviation has a lot of environmental problems beyond just CO2 emissions, in particular it makes other contributions to exacerbating global warming. And there are lots of options for energy storage within the electricity supply chain.

Short answer: Yes, kinda.

Long answer: the processes that govern the creation of oil as you are calling it take a couple hundred million years to happen. So in a human timeframe there is way to 'create' more oil, but if you got a time machine and you bury a couple hundred thousand bodies in a place you will find oil in say 100 million years!

However we can create biofuel from other sources like algea, or corn. As for plastics, they can also be synthetically produced. (by this i mean no oil required.)


What are the fields in Petrel's IESX seismic horizon file? I have a text file containing 23 seismic horizons from Petrel, Schlumberger's seismic earth interpretation and modelling tool, using the 2D IESX format. Here are the first few rows:

PROFILE Fault to seafloor    TYPE 1  5 By Petrel 2014.2 (64-bit)                2d_ci7m_gf.ifdf  m  ms
SNAPPING PARAMETERS 5     2 2
  4.19846879E+05  4.66812161E+06  1 14  2742.85   5460.00  16382.00 4262               2 276-109::normTOv
  4.19840089E+05  4.66813210E+06  1 14  2756.25   5461.00  16383.00 4263               2 276-109::normTOv
  4.19833299E+05  4.66814259E+06  1 14  2769.65   5461.00  16384.00 4264               2 276-109::normTOv
  4.19826509E+05  4.66815308E+06  1 14  2783.05   5461.00  16385.00 4265               2 276-109::normTOv
  4.19819720E+05  4.66816357E+06  1 14  2733.93   5462.00  16386.00 4266               2 276-109::normTOv
  4.19812930E+05  4.66817406E+06  1 14  2809.85   5462.00  16387.00 4267               2 276-109::normTOv
...

Each horizon starts with two similar header rows. I'm not too worried about those (but it would be nice to know about them too). I'm more interested in the (400,000 or so) data rows. Here's what I surmise so far:

(float) — x location
(float) — y location
[1-9] (int) — seems to change with each interpreted segment of horizon
14 — no idea
(float) — two-way time
(float) — no idea
(float) — no idea
(int) — CDP or trace number
2 — no idea
(str) — line::dataset

I have look at the application's documentation, to no avail. Does anyone know what the fields are?

X-coordinate
Y-coordinate
Segment number
Symbol code
Two-way time (ms)
Shot-point number
CDP number
Trace number
Line type (2=2D, I=inline, X=crossline)
2D line name or 3D survey name

The format allows for a column between 8 and 9, for amplitude value — not present in this example.

This is a formatted layout to specific columns. So there is the potential for fields to butt against each other with no spaces between.

The top 2 lines define the horizon name (after PROFILE) and various picking parameters you shouldn't need.

This answer comes from Tom Cox (geoscientist at Schlumberger).

Here is the official file

fdf_name="2d_ci7m_gf.ifdf";
fdf_description="2D Card Image 7 multi-horizon export (XY in meters)";
data_struct=header_data;
header_length=by_header;
sort_order=by_horizon;
num_header_cards=2;
begin_of_header_on=false;
end_of_header_on=false;
begin_of_data_on=false;
end_of_data_on=true;
end_of_data="EOD";
end_of_data_scol=1;
end_of_data_ecol=4;
end_of_data_pos=after_last_card;
profile_label_on=true;
profile_label="PROFILE";
profile_label_scol=1;
profile_label_ecol=7;
profile_label_cnum=1;
profile_name_on=true;
profile_name_scol=9;
profile_name_ecol=28;
profile_name_cnum=1;
profile_description_on=true;
profile_description_scol=40;
profile_description_ecol=79;
profile_description_cnum=1;
type_label_on=true;
type_label="TYPE";
type_label_scol=30;
type_label_ecol=33;
type_label_cnum=1;
profile_type_on=true;
profile_type_scol=35;
profile_type_ecol=35;
profile_type_cnum=1;
posting_color_on=true;
posting_color_scol=37;
posting_color_ecol=38;
posting_color_cnum=1;
contact_symbol_on=false;
line_label_on=false;
line_name_on=false;
line_number_on=false;
line_type_on=false;
survey_name_on=false;
snap_label_on=true;
snap_label="SNAPPING PARAMETERS";
snap_label_scol=1;
snap_label_ecol=19;
snap_label_cnum=2;
snap_position_on=true;
snap_position_scol=21;
snap_position_ecol=21;
snap_position_cnum=2;
snap_window_on=true;
snap_window_scol=23;
snap_window_ecol=27;
snap_window_cnum=2;
event_picked_on=true;
event_picked_scol=29;
event_picked_ecol=29;
event_picked_cnum=2;
format_file_name_on=true;
format_file_name_scol=81;
format_file_name_ecol=96;
format_file_name_cnum=1;
xy_units_on=true;
xy_units_scol=98;
xy_units_ecol=99;
xy_units_cnum=1;
z_units_on=true;
z_units_scol=101;
z_units_ecol=102;
z_units_cnum=1;
x_coordinate_on=true;
x_coordinate_scol=1;
x_coordinate_ecol=16;
x_coordinate_units=meter;
x_coordinate_type=exponent;
x_coordinate_decimal=8;
y_coordinate_on=true;
y_coordinate_scol=17;
y_coordinate_ecol=32;
y_coordinate_units=meter;
y_coordinate_type=exponent;
y_coordinate_decimal=8;
latitude_on=false;
longitude_on=false;
time_on=true;
time_scol=39;
time_ecol=47;
time_units=mili_second;
time_type=floating_points;
time_decimal=2;
seismic_trace_number_on=true;
seismic_trace_number_scol=68;
seismic_trace_number_ecol=72;
seismic_trace_number_type=integer;
seismic_trace_number_decimal=0;
shot_point_number_on=true;
shot_point_number_scol=48;
shot_point_number_ecol=57;
shot_point_number_type=floating_points;
shot_point_number_decimal=2;
cdp_on=true;
cdp_scol=58;
cdp_ecol=67;
cdp_type=floating_points;
cdp_decimal=2;
amplitude_on=true;
amplitude_scol=73;
amplitude_ecol=86;
amplitude_type=exponent;
amplitude_decimal=7;
attribute_1_on=false;
attribute_2_on=false;
attribute_3_on=false;
dat_profile_name_on=false;
dat_profile_type_on=false;
dat_line_name_on=true;
dat_line_name_scol=90;
dat_line_name_ecol=131;
dat_line_number_on=false;
dat_line_type_on=true;
dat_line_type_scol=88;
dat_line_type_ecol=89;
dat_survey_name_on=false;
dat_contact_symbol_on=true;
dat_contact_symbol_scol=36;
dat_contact_symbol_ecol=38;
dat_segment_id_on=true;
dat_segment_id_scol=33;
dat_segment_id_ecol=35;
dat_horizon_name_on=false;
dat_fault_name_on=true;
dat_fault_name_scol=132;
dat_fault_name_ecol=151;


Global warming - why doesn´t mankind collect heat (thermal energy) and turn it into electricity or send it to space? Why doesnt mankind "collect" thermal energy (there has to be some way: thermal couplings, detour over chemical energy, whatever) and after it has been concentrated at one point, turn it to electrical energy (like steam turbines do) or at least radiate it to space?

Your middle school physics perhaps hasn't gotten to thermodynamics yet. The three laws of which can be summarized as 1) You can't win; 2) You can't even break even; 3) You can't leave the game.

The crucial point here is that heat engines don't actually work on heat, they work on temperature differences.  So you can't really "collect" heat and turn it into other forms of energy, because you need a colder place to transfer the heat to in order to convert the heat to say electricity.  Which is why power plants are usually situated by oceans, lakes, or rivers, in order to use the water as the cold side of the generator.  (And ones that aren't have large cooling towers, in order to use the air.)

When you do move heat around, say with the heat pumps used for home heating and cooling, you're always using some extra energy to "pump" the heat from one place or another.  If you're heating, you move some heat from the ground outside to your house, but the net result is that the system of ground+house gets a bit warmer, because the electricity used for the pump becomes heat.

WRT sending the heat back into space, that's actually the cause of global warming.  Atmospheric CO2 acts as an insulating blanket, preventing some of the sun's heat from being radiated back out into space.  By increasing the amount of CO2 in the atmosphere, we've increased the thickness of the blanket, so the Earth gets warmer.

Mankind does collect natural sources of heat and turn it into useful energy: heat pumps, solar arrays, geothermal etc, but it would be impossible to reduce global warming in this way. Most of the heat collected for useful purposes is in any case given back to the atmosphere when the energy is used. If you think about it, even wind farms are collecting solar energy, because it is the sun's heat which drives the winds. When the energy is used, it is re-converted into heat. As a physics student you should know this.


Trends in atmospheric CO2 I plotted the atmospheric CO2-concentrations to see trends and wondered especially about the phase around 1600 in the plot which I find very interesting. Etienne Godin already told me some facts in the comments of another thread, but I'm curious about more details, since I'm a newbie in this area.

source: https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/frank2010/smoothedco2.txt

Where I plotted the column ALL_50_full.

What do you say?

Since CO2 concentration is responsible of temperature, that trend is related to the little ice age, where Earth cooled a little. Wikipedia article describes several possible causes for that, one of the is the answer of Keith, but others might be orbital cycles, solar activity, volcanic activity and ocean circulation.
Also is possible that is just a cycle that repeats itself each 1000 or 1500 years.

One theory:
European Genocide of Indigenous Peoples in the Americas Cooled Earth’s Climate

  The mass deaths of Indigenous American peoples 500 years ago—caused by disease and violence spread by European colonizers—was so extreme that it cooled Earth’s climate, according to a new study in Quaternary Science Reviews.
  Led by Alexander Koch, a graduate student in geography at University College London, the authors said that a period of global cooling that lasted from the 16th to 19th centuries was partly caused by epidemics and warfare that killed 90 percent of the Indigenous population in just 100 years.
  The devastating loss, known as the Great Dying, left 56 million hectares of farmland unattended, enabling forests and other vegetation to grow over agricultural terrains. The rewilded landscapes drank in much more carbon dioxide than the preceding farms, which reduced levels of the greenhouse gas in the atmosphere by 7-10 parts per million.

Original research this article references:
Earth system impacts of the European arrival and Great Dying in the Americas after 1492


Where on Earth does the atmosphere have the most $O_2$ concentration? Is there a map that shows the average oxygen concentration in the atmosphere? Seems to me that it would be where the most plants are but I wonder if population and industry make a difference in oxygen levels in a given area?

You may find bigger O2 levels at the upper layer of rich oceans -biologically talking-. There is Henry's Law, an equilibrium between gas pressures/concentrations of the ocean and the atmosphere, so you might find it at the contact between an ocean bacterial rich system and the atmosphere, but maybe on arboreal forests at light.

I have no data about O2 levels at both suggestions, atmosphere/ocean contact at a rich ocean system & a very rich arboreal forest on hot season. Just a caution for a possibly answer from a botanic. There may be maps about O2 levels at ocean surface but that at NASA and so and I am a student with no access to Science papers Muze and don't know how to get them. For arboreal system they can give you absolute maximum O2 levels registered, and then comparison.

The maximum level will happen at a certain time, and even I think satellites can measure gas levels the layer to search is about 1mm or so. maybe doing a comparison between highest O2 levels measured at the interface of a rich estuary or so and a tropical forest coming from local studies we find a non exactly answer but giving the environment where to find it and an approximate concentration.

There are those ozone/O3 layers with a very high concentration at industry zones,but i guess you ask for O2 gas. There are also hyperbolic conditions,eg at a Erlenmeyer flask of a lab, but I guess you are asking for levels on Earth's Atmosphere sensu stricto at a relative big atmosphere's surface/volume. I think others will appreciate more the question if you write eg "higher O2 concentration measured on an Earth's Atmosphere area despite labs or natural micro-layers" or something like that if that's you want to mean. Also sensu stricto more oxygen no matches with saturation (saturation is function of Temperature and Pressure).


Is it natural for clouds to flow near the surface? A week ago, I have seen something that I have never seen before, Nah it's not a flying dragon, but clouds that were flowing so near my roof (about 5-6 meters above my roof). These are the pictures, I have taken

Some of the clouds were passing just above the tree. I just want to know if this is a natural scene that occurs very often. What's the reason for clouds to flow so close to the surface?

I suppose that it had been raining before. The water had gone to the soil, but the moment you took that picture, it was already evaporating. The air was filling with such water coming from the soil, but air can hold only a limited quantity of gas water, so no more water could be in the form of gas (at so called "point of saturation"). Thus, it changed its state of matter from gas to liquid. But as we all now, liquid water can be seen (the "gas" above the boiling water that we can see is actually liquid water that rapidly cools down). Also, clouds are just such liquid water caught in the air, thus a cloud formed.
The near surface clouds can also form near the sea, with orographic clouds, or on a front, but such near surface clouds are more similar to fog (actually they are fog).


Did climate cool down when underground hydrocarbons stocks formed? As far as I understand, the dominant theory of modern climate change says that recent warming is mainly caused by the massive burning of hydrocarbons that used to be stored in solid form mostly underground as petroleum, coal, etc.

This suggests that the reverse process should contribute to a cooling of the climate (or to a slowed down warming if other processes are at play at the same time).

In particular, a cooling should have occurred throughout the period when the stocks of underground hydrocarbons were formed by the "pilling" of organic remains.

My questions:

Is this roughly what climate theory would predict or am I omitting some things?
Was such an effect observed during the formation of the underground stocks of hydrocarbons?
Can this reasoning be extended to say that a world where no solid hydrocarbons are burnt and the concentration of atmospheric hydrocarbons keeps falling (as it is captured by organism and transformed into solid hydrocarbons) would experience a continuous (if slow) cooling? Or are there some non-linearities by which the stock of solid hydrocarbons would "max out" or the effect of removing carbon from the atmosphere fade away?

Possibly

One thing you have to understand is that natural carbon sequestration via the formation of fossil fuel is VERY slow, it can take millions of years to build up the coal we burn in a day. In addition, one of the more dominant effects on the climate is solar radiance and continental position which changes over such long stretches of time, making matching such slow changes to carbon with climate change more difficult. Continent position also affects carbon sequestration and CO2 concentration directly making it even more confusing. Things like seaways and deserts can have huge effects on CO2.

The real problem is matching coal formation to changes in CO2 concentration.
Most coal comes from the carboniferous and the Permian time periods (along with the evolution of land plants that make it), the carboniferous saw severe cooling and severe drops in CO2. How much of this is CO2 lost to coal versus how much is just the formation of forests and other terrestrial ecosystems combined with changes in contingent positions is still up for debate.

The Permian however saw severe warming near its end and a rapid rise in CO2 at the same time, but most of it was relatively stable and unchanging both in CO2 and temp. It also included one of the largest volcanic events in earth's history, and again changing tectonic position. So although the link between CO2 and temperature is really well established we can't even say for sure such slow coal formation actually reduces atmospheric CO2 concentrations.

source

Compare CO2 above to temp (red line) below. Note that just three variables together predict temprature amazing well.

source

At the instant any atom of carbon is taken out of the atmosphere by a plant or animal and incorporated into its structure then that atom is "off the list" as it were with respect to having an effect in the atmosphere. Once in the animal/plant it may be there for eons until it becomes oil, coal,or whatever.
So it is not the ultra slow conversion of organic matter to hydrocarbons that is relevant but the amount taken up by living matter on a daily basis which is sequestered into its structure.

Looking at the historical record we would therefore need to think about the amount of animal and plant activity on the planet and, to some extent, its type. This is quite difficult as we only have proxy records. however as we know that CO2 is effectively plant food it seems reasonable to assume that if the proxy record shows high levels of atmospheric CO2 we might expect that fairly quickly, a few year/decade timescale, that plant life on earth would respond quickly and become very lush indeed.

This is of course only one factor with respect to CO2. Past volcanic activity is likely to also be relevant.


In winter, is pond water warmer with or without a fountain? I have goldfish I know that goldfish can hibernate but I'd like to keep the water warmer for them.  Is moving water colder or warmer than still water?  The water shoots out of "pipes" about 3" above the water's surface.

Thank you for your comments, I have disconnected the water pumps that shoots water into the air.

In nature, fish survive in ponds due to a lack of turnabout of water.

(Fresh) Water has its highest density at 4°C, meaning both warmer and colder water float on top of 4°C water. Wind may push surface water to the bottom, slightly lowering the temperature at the bottom of the pond. Still, once the surface starts to freeze, this proccess is discontinued, creating a temperature-gradient with the relatively warm 4°C water at the bottom - until spring. Thus fish don't freeze to death.

Meaning, leaving your fountain running is a rather bad idea.

As to the issue of possible lack of  oxygen - I can't answer that reliably.

In winter the only use of the fountain is decoration ; as commented it will cool the water. As cold water has a higher oxygen content , there is no need for the aeration value of a fountain or moving water. I am sure what goldfish and koi do in the winter is not hibernation, they just slow down. At 50 F they will eat a little . I have tropicals with the koi so I keep the pond as warm as possible , which turns out to be above 50F for my location.


Is the ocean guaranteed to warm in a warming climate, regardless of whether it absorbs LW radiation? More specifically, I've seen some discussion of this article:

http://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/

which claims that the observed ocean warming is explained by the ocean skin absorbing long-wavelength radiation. What I am asking is: is this mechanism necessary for ocean warming to occur? My naive understanding was that our increasing the magnitude of the greenhouse effect meant that there was less radiation escapting to space, and therefore the average temperature of the entire ocean+earth+atmosphere system will increase until it reaches a new equilibrium, where outgoing radiation again equals incoming. Is this correct? And if it is, does it not imply that the ocean must also get warmer, simply because it is a thermally coupled part of the entire warming system? I had someone tell me that the a warming atmosphere could not warm the ocean beyond an infinitesimal amount, because the atmosphere has a much lower heat capacity. But it seems to me that the constraint on the final equibilibrium temperature means that all components must warm, no matter how inefficient the means of energy transfer between them - as long as there is some means for energy transfer, increasing the overall temperature must increase each of the components. Am I right, or have I misunderstood?

My naive understanding was that our increasing the magnitude of the
  greenhouse effect meant that there was less radiation escapting to
  space

That's 100% correct.   If we assume constant solar input, there's only two ways the Earth's surface temperature can change.   Albedo and Thermal radiation.   Greenhouse gas driven climate change means exactly what you said - less heat radiates off Earth into space.    Most of this heat goes into the Ocean.

  And if it is, does it not imply that the ocean must also get warmer,
  simply because it is a thermally coupled part of the entire warming
  system? I had someone tell me that the a warming atmosphere could not
  warm the ocean beyond an infinitesimal amount, because the atmosphere
  has a much lower heat capacity.

Your friend is half right, and half wrong.   Air has a bit over 1/4th the heat capacity compared to water and it's about 800 times less dense, so he's correct, but it's not that simple.

Sunlight - somewhat counter-intuitively, isn't great at warming oceans because the photons from sunlight are energetic enough to evaporate water molecules into gas molecules.  Oceans have low albedo which means they absorb most of the energy from the sunlight, but much of that heat is lost in evaporation by visible light photons.   While that has nothing to do with your question, it's worth pointing out that sunlight isn't as good at warming oceans as one might think.   (If anyone has one of those solar mirror ovens, I'd be curious to see how well they work on pure water . . . just out of curiosity, evaporation loss vs rate of warming).

The back-radiation from the atmosphere is comparatively much less total solar energy, but oceans are good at absorbing and storing thermal back-radiation reflected back off the greenhouse gas rich atmosphere into the ocean.   This is a tiny amount of the total heat Earth gets from sunlight, and the increase of this radiation due to greenhouse gas is a fraction of one percent of solar energy, but it adds up.

One way to explain this is that 85 degree air will warm 80 degree water. That's a thermodynamic law.  It just takes a while and because the heat capacity and density of water is much greater, it takes about 4 liters of air to give 1 degree back to warm 1 cc of water 1 degree.  But despite the inefficiency, warmer air still transfers heat into colder water.  It takes many decades, perhaps centuries, for the oceans to catch up to the warming air, but air, however inefficiently, does warm the oceans.

The quirk in this, is that the oceans, despite warming much more slowly than the air, are still absorbing over 90% of the trapped heat added by the increase in greenhouse gas.   It's a matter of scale.  Oceans warm slowly because they're enormous and always circulating and it takes much more energy to war them, but they also absorb most of the heat, for the same reason, they're very good at holding heat.  Slow to heat up, but also, slow to cool down.  That's why bodies of water often feel warm when you go swimming at night.

I should probably add something about increased evaporation in higher air temperature, which effectively cools the oceans and surface air, but also increases the greenhouse effect with an increase in water vapor, but running those numbers is a bit over my pay-grade.   The greater efect is the one mentioned above.

First we need to see if your question is based on facts. If the only energy in the climate system comes from the sun, what things can increase the energy in the system, other than the sun? The answer is: nothing.
To increase temperature you need to increase the intensity of emitted heat where the temperature increase. Since the only source of energy is the sun, how could we increase the intensity anywhere, if not the intensity of solar irradiation is increased?
This is a surprising mistake done by the entire climate science. The claim is that increasing the amount of a potent heat absorber would increase the intensity of emitted heat from the surface. If you add a heat absorber that absorbs heat from a body, it cannot cause warming. Often it is claimed to retain, or delay heat loss. But that cannot be true according to thermal physics. Preventing heat loss is exactly what we do by insulating the boundary of the system we want to stay warm. Thermal insulation is a logic simple thing, you can read about it here:

https://en.wikipedia.org/wiki/Thermal_insulation

"Thermal insulation provides a region of insulation in which thermal conduction is reduced or thermal radiation is reflected rather than absorbed by the lower-temperature body."

As you can see, it is without doubt very clearly stated, that preventing heat loss, or retaining heat, is done in the exact opposite way to what the theory of global warming claims. Absorption is what you want to avoid to prevent heat loss. There is a lot of things in the warming science-camp that indicate a lack of physics education in their field of science. Actually, every single argument in the greenhouse theory is a head-on violation of known, proven 100% consensus physics.

So, first of all, according to proven physics, it is highly unlikely that there is a warming climate at all. Secondly, the ocean cannot warm, if the amount of heat from the sun doesn´t increase. And we know that it doesn´t.


Did the Geothermal Power Plant contribute to Pahoa's Lava Fissures? There was lava in the area near the wells that the Puna Geothermal Venture facility created.

  The plant has nine wells that run as deep as 8,000 feet, according to Wil Okabe, managing director for the County of Hawaii. -Washington Post

8,000 feet is really quite deep. While I understand that those are not the deepest wells created for geothermal energy, in Hawaii that seems deep enough to get to where lava would also be pooling.

For example, it would be deep enough to hit the pool at one of the main volcanoes.

  Rocks that are moving upward in the mantle beneath Hawai`i begin to melt about 40 to 60 miles (60 to 100 km) depth. The molten rock, called magma , rises because of its relatively low density. The magma "ponds" in a reservoir 1 to 4 miles (2 to 6 km) beneath the summit. https://www.nps.gov/havo/faqs.htm

In addition to the availability of lava in the area near the wells, it seems that geothermal energy has also been linked to earthquake activity in the past.

  An analysis of earthquakes in the area around the Salton Sea Geothermal Field in southern California has found a strong correlation between seismic activity and operations for production of geothermal power -UC Santa Cruz

Moreover, the facility itself is basically right on the location that the set of fissures opened up.

As location of seismic activity is in question here, I also found a map from the US Geological Survey with 30 days of activity for this portion of Hawaii.

The largest circles are a 5.4 and 6.9, the smallest ones are equal to or greater than 2.5.

Given the proximity of the facility, as well as the fact that these wells were not only near underground lava, but also have been known in other areas to produce earthquakes, what roll, if any, could the Puna GeoThermal Venture have played in the recent fissure activity in Pahoa, Hawaii?

I think we can confidently enough answer "no".

From this report (p. 23):

  Kilauea eruptions occur either at its summit or within two well-defined swaths (called rift zones) that radiate from the summit.

In the same report, you can see those rift zones on the map page 3, or on the sketch of the plumbing system page 24. Most lava flows are emplaced along these rift zones. For instance, look at this map of the 1955 eruption (public, USGS):

You can see that the flows were emplaced in a zone very similar to the 2018 eruption. Apparently the power plant opened in 1993, and the first exploratory wells were drilled in 1961-62, so after this event.

Actually, the rift zones are in the lava flow hazard zone 1, i.e. the most severe. The zone is defined as follow by Mullineaux et al. (1987):

  Zone 1 consists of the summit areas and active parts of the rift zones of Kilauea and Mauna Loa; in those areas, 25 percent or more of the land surface has been covered by lava within historical time, during the 19th and 20th centuries. These areas contain the sites of most historical eruptions, and a large majority of the lava flows that will affect other zones on Kilauea and Mauna Loa in the near future probably will originate in zone 1. [emphasis added]

So the real question is: why was the plant (and estates...) built in an area well known for lava flow hazards?!

To conclude, by researching the plant I found that it is actually where people accidentality drilled through a magma pocket for the first time (Teplow et al. 2009)! They hit a pocket of dacite; it did not trigger an eruption. This happened later in Iceland: this time, they even used it as an experimental well (there is a whole issue of Geothermics on this). Again, no eruption.

Reinjection of cooling effluent over decades has got to break down the rock, in fact it probably explodes the rock into tiny pieces which after decades crumbles and lets the lava move...

All of the scholarly industry information available says not to place geothermal plants in seismically active areas...


Is it possible for Earth to experience Polar Shift? Many accounts claim that the Magnetic Field of the Earth has been seriously degrading for the past centuries and we are currently in the process of the so called Polar Shift. How likely would it be for Earth to experience this phenomenon. Is it really possible?

What would be the possible effect to human beings if this happens?

Is it possible for Earth to experience Polar Shift?

Yes, and it has happened before.

In the past 80 million years it happened over 150 times. The last time this happened was around 800 thousand years ago. A quick note about what a polar shift is, more properly termed a geomagnetic reversal. Earth's magnetic is such that a compass points to a certain direction. For example, a modern compass would point north. In a reversal, it would point south instead because the poles are reversed. Without going too much into detail, this occurs not by spinning of the poles but rather by decreasing in intensity until it becomes negative, thus reversing the poles.

Another important thing is the intensity. A strong magnetic field shields Earth's from some kinds of radiation, for example the stuff you can see in Gordon's answer. However, a reversed but strong magnetic field is just as fine. What you should be worried about is the change in the intensity of the field, and this is going up and down all the time, quite rapidly as you can see in the following figure:

The black bit (called Brunhes) is now - when the magnetic field is "normal". The white field in the bottom is more than ~780 thousand years ago, when it was reversed (called Matuyama). As you can see, even though the magnetic field has been normal though this entire time, the intensity went up and down. So yes, a reversal would mean that at one point the intensity would be very low, but this can happen even without a reversal.

  What would be the possible effect to human beings if this happens?

In contrast to what some people on the Internet claim, there would be no earthquake or volcanoes or other scary stuff related to it. This is simply not how this works. Also, mass extinctions from the geological history are not correlated with geomagnetic reversals, so you can take that worry off your mind. What can happen is detailed in a good way in Gordon's answer. Nothing too scary.

  Magnetic Field of the earth is seriously degrading for the past centuries and we are currently in the process of the so called Polar Shift

Not necessarily. It seriously degraded many times before without associated geomagnetic reversals.

Please consider that the strength of the magnetic field determines atmospheric density and pressure. Planets with strong magnetic fields have thick oceans and atmosphere, while planets with very weak magnetic fields have no oceans and very thin atmosphere. That's because hydrogen atoms from solar winds are attracted and condensed around magnetic fields and the strength of the MF dictates the atmospheric density, and atmospheric pressure dictates the ocean levels.
Mars for example shows signs of erosion as it had oceans and atmosphere but when the dynamo inside went through a hard double flip (most probably) and slowed down so much, cooled down so much that it could never recover, the atmosphere was blown away by solar winds, oceans boiled away, etc. Mars's gravity field doesn't explain how it lost its oceans and atmosphere when Earth still has them. Mars's gravity field didn't change, it lost its magnetic field.
Jupiter's bigger moons have thick ocean frozen at the surface (frozen because of distance from the Sun) but they are smaller than Mars and have strong magnetic fields.. So size and amount of pressure inside doesn't necessarily mean a stronger magnetic field,, what all planets and terrestrial moons with strong MF have in common is an inner core that makes a small orbit around the center of the planet/moon, because of tidal effect (gravitational pull) from a big body nearby. For example, Earth's inner core is attracted by our big and heavy Moon, and it's not spinning in the dead center of Earth but has a small orbit around the center, planar to the Moon's orbit, and it stirs the soup inside as Earth spins on itself. It keeps the soup warm and generates friction thus electric currents, thus electromagnetism.
Jupiter's moons have their inner core drawing a larger orbit inside as they (moons) spin on themselves, their core is off-centered toward Jupiter.
Our Moon is actually the big core of an ancient planet that collided with our former (smaller) planet about 4.5 Billion years ago. Their liquid matter blobbed together and the smaller core bounced from the explosion as just the right speed and angle to stabilize on orbit, and the little bit of liquid matter on it cooled fast with a tide towards Earth, witch is the heavier side of the Moon that always point to Earth. With time it gathered the splash from the collision. It's a big metal core with a thin crust and this is why it rings like a bell and the craters are all shallow.
So anyway.. we're very lucky to have the Moon because otherwise Earth would be like Mars right now. Mars doesn't have a big moon so its core just spins in the center and doesn't generate enough friction. Maybe it had a moon before, with an unstable orbit destined to swing away..
Now, why does our MF tend to flip every 12-13000 years, or twice every Great Year (Precession of the Equinoxes, a 26000-year Milankovitch Cycle when the Earth's spin tilt axis wobbles 360*)?
I think it's because there are 2 critical tilt angles, during the Precession,, where the spin inertia of the iron currents, plus the angle of the inner core's orbit (planar to the Moon's orbit, not the same angle as the Earth's rotation axis),, plus the difference in speed (earth spins on itself in one day while the Moon takes 27.3 days to go around Earth),,, produce electric currents that don't agree with the magnetic field orientation and forces it to either reverse or migrate..
(to visualize this, have a pot of sauce that represents Earth, a wooden spoon that represents the inner core and an imaginary moon that goes around the pot in 27 days. Turn the pot of sauce continually to simulate earth's rotation and imagine it's tilted 23.4*,, and place the spoon (core) off-centered in the pot and tilt the spoon to simulate the difference in angles of the Earth's spin and of the moon's orbit plane. As you spin the pot, continuously, slowly orbit the spoon in the same time as your imaginary moon,, and see the currents you're generating in the sauce.. Then slowly change the tilt of the spoon to simulate Earth's precession.. It sounds fun? Do this to really get a visual)..
Now during the reversal or excursion process, the convection currents need to reorient and mix and slow down, producing less friction thus less electromagnetism, so the atmosphere gets thinner and filters out less solar and cosmic radiation. Less friction also means less heat produced inside the planet, so the volume of the planet has to shrink a little bit, and that explains the spike in seismic and volcanic activity around the Peak.
What explains how ocean levels can drop 400ft? Well if the atmosphere is thin during the day, then raw solar radiation evaporates tons and tons of ocean surface and during the night it gets very cold so all the moisture in the air has to precipitate within hours. Most of it falls back in the oceans and on land, and some of it becomes atmosphere and is eventually blown away by solar winds. That explains the biblical amounts of precipitations and erosion (Grand Canyon fills up and deserts turn into seas and the northern atmosphere is covered with very thick glaciers, big mammals flash frozen, etc).. Flash frost is also explained by rapid atmospheric density drop when a CME impacts the already thin atmosphere and temporarily blows some of it away: pressure drops fast and flash-freezes everything at the surface.
A thin atmosphere also explains the number of meteorite impacts because meteors rain down every day but usually burn with friction, blow up into small bits and only tiny bits of metal reach the ground,, but when the atmosphere is thin, meteors have much less friction so better chances to hit the ground in bigger chunks.
Those 2 critical tilt angles during the Precession are:
one as we enter Leo (the stronger magnetic Excursions (double flips) like the Gothenburg Magnetic Excursion 13000 years ago and the Leschamp Magnetic Excursion 40000 years ago, etc)
and the other one as we enter Aquarius (the mild semi-reversals (also calles Excursions) like now, or like the Lake Mungo Magnetic Excursion 26000 years ago,, etc).
This is all over ancient civilizations calendars, like the Mayan calendar, etc. For Example, the Sphinx was pointing Leo 13000 years ago, but was probably built 11000 years ago after the Younger Dryas warming, as a big immortal monument to commemorate this strong event that almost got us extinct.
Also, one important principal, heat generated inside the planet goes up slowly through the crust, then slowly raises up in the oceans, then joins the heat on the surface from solar radiations, and that heat has to go up in the atmosphere to reach the space vacuum.. The stronger the magnetic field and the thicker the oceans and the atmosphere,,, and the slower heat can reach up into space. Vice-versa, the thinner the oceans and atmosphere and the faster heat can reach up into space..
We could say that at Peak, a typical day would be like: super windy as almost unfiltered solar radiation expands the air very rapidly,, then all day would feel like a super hot sauna with tons of melting and floods, and evaporation would look like a steam engine.. Then, as the Sun starts to set the sky veils with thick condensation. Shortly after, deluges and super flash floods, turning into super ice storm breafly, then meters of snow until the air is dry and very cold, like -50C (moisture can stay in the air up to -20C but lower than that, all humidity is already deposited, so all moisture in the air has to deposit within a few hours)... Then, in the morning it starts all over again. Sometimes when there is a CME impact, it gets worse.
OK, I'll stop here, will elaborate more if there is interest.. Please give me feedback,, wherever I'm wrong and how I should rethink.. Thanks


Why doesn't the sun reach its highest point overhead at exactly 12:00 noon? Many sources state that 12:00 noon is the high-point or mid-point of the sun's path across the sky.

However, for where I am, this is obviously wrong. In my own town the high point of the sun occurs at about 13:30 in the summer (because of DST), and 12:30 in the winter, but clearly not 12:00 noon.

Why, at different longitudes, is the high-point of the sun not at 12:00?

Thank you in advance.

It's not a question of latitude but longitude and time zones.

Prior to the advent of railway transportation the time set on clocks varied from towns within close proximity because the clocks were set to noon when the Sun was at its highest in the sky. This was more apparent for towns east and west of each other (ie different longitudes).

When railway transportation was developed there was a need to standardize times so that train timetables could be developed and arrival and departure times would be accurate and consistent

This precipitated the development of time zones. Each time zone is approximately 15 degrees of longitude wide, but there are differences because of national/regional priorities. China which has a similar longitudinal extent as the contiguous states of the US has only one time zone, whereas there are four in the contiguous states of US.

Within a band of longitude the time is the same. In the time zones immediately east and west, the time is one hour more (east) and one hour less (west) - ignoring difference due to daily savings.

The reason for time zone being approximately 15 degrees of longitude wide is the rate of spin of the Earth is 15 degrees/hour (360 degrees every 24 hours).

You state that in your town, noon is either 12:30 or 13:30, depending on daylight saving time. The reason for noon occurring at half past the hour is due to the boundaries of the time zone where you live. Where I live, noon is approximately at quarter past the hour.

Well, Sun was there before people and any concept of time.
When people emerged, they naturally considered night as period when there is no Sun and Day where there was Sun on the sky.

When time was invented for the first time (ancient civilisations), most likely 12 was the time when the Sun was the highest on the sky. Then people became smarter and introduced different timezones in order to standardise the concept of time and this caused some deviations.

Then people thought they will be more productive (making more money) if there introduce the concept of Winter and Summer time what introduced further time deviations.

Therefore you do not see it anymore point 12.


Can I see curvature of the Earth on a picture I've been piloting a drone yesterday and made a video hovering at around 100m, the visibility was very good. I've shown the video to a friend of mine and we were arguing whether it's the curvature of the Earth visible at horizon, or is it just camera lens disturbing the image.

I'm rather sure it's curvature of the Earth, but still don't know how to prove it. I already checked that on the lower part of the picture the buildings-roofs are lined up straight, no disturbance. Yet the horizon is slightly bent (checked by putting a piece of paper on the screen). Which I think already proves the point: should lens disturb the picture, the disturbance would be visible both on the upper and lower part of the picture symmetricly.

I've read How high must one be for the curvature of the earth to be visible to the eye?, but it doesn't help me just yet. As far as I understand, the above link help calculating the distance to the horizon depending on the altitude. But why is the horizon bent?

I would appreciate anyone helping me straighten my thinking :).

The picture:

Make your own numbers... I will take one sample, just change your figures.

I have one 4K resolution dron camera. So I can register 3840 x 2160 pixels in one shot.

Considering the Earth as an spherical body, the distance from you to the horizon depends on Earth Radius and your height by:

  Distance = (Radius + height) * Sinus {arc-cosinus [Radius / (Radius + height)]}

So depends on your height:

| Height (m) | Dist. To Hor. (Km) |
|:----------:|:------------------:|
|    1       |         3,6        |
|    10      |        11,3        |
|    100     |        35,7        |
|    1000    |        112,9       |
|    10000   |        357,1       |

My camera have a 24mm focal (on 35mm relative), so in the photograph, I can see 84º degrees. So the distance on between the edges of my horizon is:

| Height (m) | Dist. To Hor. (Km) | Dist. Edge<>Edge (km) |
|:----------:|:------------------:|:---------------------:|
| 1          |         3,6        |          4,8          |
| 10         |        11,3        |          15,1         |
| 100        |        35,7        |          47,8         |
| 1000       |        112,9       |         151,1         |
| 10000      |        357,1       |         477,9         |

Once that you have this data, you just need to calculate the arrow of the arc expected:

  Arrow Circ. Arc = Radius * Cosinus [ Arc-Sinus (Dist/2/Radius)]

So, with this data and the initial data of the camera:

| Height (m) | Dist. To Hor. (Km) | Dist. Edge<>Edge (km) | Arrow (km) | Curvature (pixel) |
|:----------:|:------------------:|:---------------------:|------------|-------------------|
| 1          |         3,6        |          4,8          |    0,000   |         0         |
| 10         |        11,3        |          15,1         |    0,004   |         1         |
| 100        |        35,7        |          47,8         |    0,045   |         4         |
| 1000       |        112,9       |         151,1         |    0,448   |         11        |
| 10000      |        357,1       |         477,9         |    4,482   |         36        |

So finally... If you have a perfect visibility condition, your camera is completely leveled, there is no fish-eye distortion... On a 4K camera at 10 km height, the Earth curvature it will be 2% -> 36 pixels on 3840 pixels wide.

If you are interested on it, that is not the way. Human eye can not perceive clearly the Earth Sphericity at a commercial flight altitude. So forget your dron, yo should go for a balloon.

Hope it helps!

A drone can't fly high enough to show the curvature of the Earth. When the Americans were testing German V2 rockets at White Sands in the late forties and early fifties, some reached altitudes of well over 100 miles, but even from that height the curvature of the horizon was barely perceptible. Whatever illusion of a curved horizon you may perceive in your drone photo is only what you would see from a high building.

If you can't get to the heights reached by V2 rockets, the best way to see the curvature of the Earth is to watch a tall ship approaching from over the horizon. On a clear day, the tips of the masts or funnels will be visible when most of the ship is hidden by the curvature of the Earth. Likewise when the sun goes down beyond the marine horizon and your town is in twilight, a high flying aircraft overhead will be illuminated by the sun that you can't see because the curvature of the Earth is in the way.

From a high building the horizon will appear to curve because it surrounds you in a 360 degree circle, and circles by definition are curved.


Standardized scale for coastline length or mapping in general? Measuring the length of a coastline depends on the scale of the measuring tool. The smaller the scale of your tool, the longer will your measured coastline be. The reason for this is the fractal property of coastlines. This is well known since a paper by Benoît Mandelbrot "How Long Is the Coast of Britain? Statistical Self-Similarity and Fractional Dimension".

Now I was wondering if there is a standardized mapping scale to come up with global or country wise numbers of coastline length?

And furthermore, if there even is a general rule for all mapping purposes, which scale is to be used in mapping?

Is there maybe even something like an ISO standard for this?

One standard that has be used by the USA is to measure the distant between points on the coast at intervals of 30 latitude minutes, as measured on a 1:1,200,000 scale map.

See chapter 5 of Measurements from Maps: Principles and Methods of Cartometry by D. H. Maling for further information and other standards that have been used.

It is not really worth worrying about unless you are proposing to walk along it, or let your pet ant walk along it, for the ant will have to walk a much greater distance than you as it follows all the wiggles that you just stride over.

Nor does it matter a jot for coastal management, which is always concerned with water bodies or areas and never with the purely conceptual length of the coastline. Coastal reporting sometimes summarises water quality by length of affected coastline, but that is merely an administrative convenience and has no significance otherwise.

The geometric length between two points defining a straight line does not depend on the size of the intervals we use to pace it out.

However, the length of a fractal coastline is quite different. The smaller the step, the greater the length. There are mathematical ways to express this and if you google around you will find them. Try looking for Koch Snowflake for example.


Is pollution a contributing factor to freezing rain? I have been to different places with nearly the same freezing temperatures, around -2°C, but only at some specific places I repetitively experienced freezing rain. One common factor at these places was relatively more air pollution. Could it be that pollution is a contributing factor that causes freezing rain to occur?

If not, what are the main factors that cause freezing rain, and the regions on Earth that often experience them, especially in Europe?

Pollution shouldn't contribute to produce freezing rain. It might have an impact in the precipitation rate and location but not on the likelihood of freezing rain.

Freezing rain requires not only that the near-surface temperature is below freezing, but also that there is a temperature inversion that provides above zero temperature in the atmospheric layers above the surface.

Usually temperature drops as you go higher into the atmosphere. But in some areas, due to climate, geography and local weather patterns, you can often find that the temperature rises as you go up, that's called a temperature inversion (eventually as you go high enough the inversion dies and temperatures drops as you go even higher).

Such condition can melt the snow high in the atmosphere and then the water droplets enter an area near the surface that is below zero and cools them down but not for long enough to freeze solid (something that would produce sleet). Water droplets in such conditions gets below zero but remain liquid, a phenomena called supercooling. When the supercooled drops hit the surface (that is also below zero), they instantly freeze forming a thin layer of ice, hence freezing rain.

This figure from mprnews.org nicely summarize the phenomena:

Regarding why some places can be mor suitable for freezing rain, I'll highlight here the comment by @Anirudh pointing to this link that deals with the case of Guizhou Province in China.

Pollutions won't influence Freezing Rain.

  Rosemary Peters 'Freezing Rain Fact',by April 25,2017

Freezing rain starts its journey in the atmosphere as snow. The snow encounters a deep pocket of warm air, melts and becomes rain. The rain then passes through a layer of air close to the surface where the droplets cool to a temperature to just below freezing; however, the droplets don’t actually freeze over. When the “supercooled” raindrops hit the surface, like a road, tree or power line, they immediately freeze and form a thin glaze of ice.


CO₂ level is high enough that it reduces cognitive ability. Isn't that a reason to worry? I think the level of carbon dioxide in the air is high enough to reduce the intelligence of humans. This has nothing to do with climate change.

Except that both mean we should reduce CO₂.

I never heard of that, surprisingly, but deducted that from simple known facts. I hope I'm missing something.

Maybe my idea is just wrong? It's simple enough to explain here:

Elevated CO₂ levels in office air reduce the cognitive ability of office workers, that is well established.
That is measurable by experiment. Complaints about drowsiness start at about 1000 ppm CO₂ in air.
Reduction in cognitive ability does happen with drowsiness, almost by definition.

The level of CO₂ is currently a significant fraction of 1000 ppm, about 409 ppm as of November 2019.

The CO₂ level in a typical western indoor working environment raises by multiple 100 ppm over the day, exhaled by people breathing in the working environment.

With an increasing base level, an increasing level in workplace air reaches a fixed threshold sooner, because CO₂ levels are additive.

The base level does increase. Therefore a level of CO₂ that reduce the cognitive ability of humans is reached earlier in a working day.

If the base level is higher, base level plus the additional CO₂ in office air  reach a level that reduces cognitive ability sooner during a work day.

This happens globally in many workplaces.

That is true for any values of base concentration, threshold concentration and maximum of increase during a day that are of the same order of magnitude. This estimation is optimistic, because it assumes that the effect has a sudden onset at a level that causes obvious symptoms.

To summarize the central points: Some CO₂ concentration exists that has negative effects. An offset in base air concentration results in an offset in the workplace concentration. That means the detrimental concentration is reached more often. For this to be true, the exact numbers are not even relevant.

Ok, what's wrong with that deduction?
I really hope there is something wrong.

If this is a reason to care about the level of carbon dioxide in common air, it is completely independent of climate change, an alternative motivation to do exactly the same thing. That seems very relevant to me.

There looks like legitimate cause for further study, preferably by scientists breathing air under 950 ppm $\small\mathsf{CO_2}$ (this study showing a 15% decline in cognitive ability at this level).

Because it is not known what mechanisms are involved in this decline in cognitive ability it is not clear if there are threshold levels, with step changes in impacts or if the effect is linear, but changes at below 950 ppm is indicated and subtle impacts at much lower level seem likely, with one leading expert (Vivian Loftness) on Health, Productivity, and the Quality of the Built Environment suggesting atmospheric levels above 600 ppm would be cause for concern about cognitive effects. For people with poor cognitive abilities potential impacts of $\small\mathsf{CO_2}$ levels is not known, but could be significant - this, along with impacts more generally at levels that are within the range of possible $\small\mathsf{CO_2}$ concentrations people now living can expect outdoors needs more study.

The principle response in the near term is improving air quality in buildings, with raised atmospheric $\small\mathsf{CO_2}$ levels most significant with respect to rates of $\small\mathsf{CO_2}$ buildup and the required air replacement by ventilation systems. There are ample reasons to commit to actions that reduce emissions and $\small\mathsf{CO_2}$ rise in the atmosphere, but better understanding of all the potential consequences is worthwhile.

I don't doubt that CO2 has the potential to impact cognitive abilities and that poor air quality really affects many people. However, if we consider all factors impairing cognitive abilities in a typical office environment, the elephant in the room is the noise.

Therefore I believe that the impact of CO2 on cognitive abilities doesn't hit the news because it's not as significant as other factors such as the noise. It only starts to be a problem half-way though the day if ventilation is inadequate, whereas noise becomes a problem for most people even before they arrive to work (loud noise has lasting effect on the cognitive performance), and keeps being a problem the whole day.


Why is smoke considered a factor of global cooling when analyzing nuclear winter scenarios, but arent when analyzing global warming scenarios? In many articles on the internet (I'll cite a couple for the sake of the question), smoke from the fires (composed mainly of $\small\mathsf{CO_2}$ and CO) following a nuclear war would cool the atmosphere and would cause a "nuclear winter".

  Nuclear winter is a severe and prolonged global climatic cooling
  effect hypothesized1 to occur after widespread firestorms
  following a nuclear war.[3] The hypothesis is based on the fact that
  such fires can inject soot into the stratosphere, where it can block
  some direct sunlight from reaching the surface of the Earth.

Nuclear winter

  In the 1980s, using simple climate models, we discovered that global
  nuclear arsenals, if used on cities and industrial areas, could
  produce a nuclear winter and lead to global famine.

  Smoke from the fires would last for years in the upper atmosphere,
  blocking sunlight, and making it cold, dark and dry at the Earth’s
  surface.

Did bombing during second world war cool global temperature

But when we are taking about global warming, oil burning (which releases $\small\mathsf{CO_2}$) contributes towards global warming.

Why is smoke considered a factor in global cooling when analyzing nuclear winter scenarios, but one of warming when analyzing global warming scenarios?

The question contains a false assumption that climate science fails to consider the cooling effects of aerosol particles, including from smoke, that are the principle forcing expected for nuclear winter scenarios. Climate science does attempt to quantify every significant effect, both warming and cooling - not only the warming effect from increased greenhouse gases - $\small\mathsf{CO_2}$.

Whilst not as recent as I would like, the graphic shows the principal climate forcings that climate science has identified and includes the cooling affects of aerosols.

Aerosols from burning forests are short-lived, and the $\small\mathsf{CO_2}$ from burning vegetation should be drawn back down by regrowth, whether forest regrowth or grassland. The most significant, enduring climate consequence of Amazon forest being cleared and burned is not the aerosols or the $\small\mathsf{CO_2}$ from the fires, it is from land clearing turning a large existing Carbon Sink into a carbon source.

Turning the Amazon to savannah would release 200 billion metric tons of $\small\mathsf{CO_2}$. The cooling effect of the aerosols from burning will not persist long, but the raised $\small\mathsf{CO_2}$ levels from the loss of a large Carbon Sink will.

The two factions have different points to prove. The nuclear catastrophe faction have to prove that  a nuclear war would be a disaster of the first magnitude, which I don't doubt for a moment, while the global warming faction have to prove that the current warming episode is caused by burning fossil fuels. Forest fires are fairly neutral in that whatever replaces the burned forest, be it more forest, oil palm plantations or conventional farm crops, will extract almost as much CO2 as was released.

People with points to prove are apt to get carried away, like the Chicxulub enthusiasts who maintain, against the evidence, that a bolide impact on the Yucatan peninsular caused forest fires on the other side of the globe. CO2 emissions from the Deccan Traps super-volcano are usually ignored as a cause of the extinctions. Think of a million Tambora eruptions rolled into one and you have some idea of the Deccan Traps.

As you may already be aware, you don't need nuclear weopons to set cities on fire. The fire bombing of Tokyo in February 1945 killed 90,000 people, while the nuking of Nagasaki later that year killed 'only' 45,000. There were many such fire bombings during the 2nd World war, yet I have never heard it said that they contributed a  meaningful amount of CO2 to global warming. A lot of war industries were also releasing CO2.

One thing I am absolutely certain of is that there has always been climate change and there always will be, and it will not be stopped in its tracks by anything man can do in the 21st century or any other century. Slowed perhaps, but not stopped.


Is Ozone Layer a Valid Concern I’ve had a simple puzzlement concerning the ozone layer.  Succinctly, the troposphere is largely and preferably ozone free.  When it thermally rises at the tropics to become the stratosphere molecular oxygen cleaves under actinic radiation to from nascent oxygen that, in turn joins with molecular oxygen to form ozone.  The stratospheric ozone, of course, is vital to protect against harmful radiation.  Then at the polar vortices the flow once again returns to the troposphere.  Ozone is undesirable in the troposphere and is removed at this point.

If this is accurate (?), why would halides that disassociate ozone (in conjunction with ice crystals only present at the Antarctic pole) be seen as adverse?

Every time the rays of the sun come into contact with earth they have to first be reflected back to the ozone layer before returning to earth. This has a cooling effect on the earth temperature. Since the industrial revolution the ozone layer has been severely depleted by the greenhouse gas emissions. Remember the sun is a ball of burning gases, whose light reaches earth early morning within eight minutes. If the earth just moved an inch away in space from the position set approximately from the sun, earth could freeze and no living organism would survive. In the same regard if it moved an inch closer to the sun every life would be incinerated.


Identification of Iguanodon and Maiasaura What are some good ways to distinguish between Iguanodon and Maisaura fossils, or even just pictures of the two dinosaurs?

The easiest way to distinguish iguanodon from maiasaura is to look for iguanodon's hands, which are very peculiar indeed. The hand has five digits. The thumb has a large, prominent spike on it for defensive purposes. The three middle fingers are fused and end in hoof-like nails for walking on all fours. The fifth digit corresponding to our little finger sticks out at an angle from the others and is flexible. It is believed that this enabled it to gather food. It is apparent from these strange forefeet or hands that iguanodon, a herbivore, often stood upright like a biped.


Does human body temperature impact climate change? The human body temperature is about 37 °C (99 °F), so as the population increases does this cause the Earth's temperature to rise?

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 gigawatts, or 760 gigawatts using a round figure of 100 watts. That sounds like a lot, but it's only a tiny fraction of the 18 terawatts consumed by humanity, which in turn is a tiny fraction of the 174 petawatts the Earth receives from the Sun.

Indirectly, yes. A growing population and the desire for greater wealth by a growing population (third world nations and developing nations want to move themselves out of those categories) are key drivers of climate change.

No they do not , just like 1 icecube won't freeze an ocean that's what all the human population is to this planet.


How is it possible for rocks to be trapped within another type of rock? More specifically, I would like to know how the rocks in these pictures have formed:

If this is because magma has melted and trapped the other rocks inside, do they have a different melting point then?
Images are from St. Blaize Trail in Mossel Bay, South Africa

There are three major types of geological formations that contain or are composed of various rocks:

breccia
conglomerate
xenoliths

Breccia
The word breccia comes from the Italian word for rubble. There are various forms of breccia:

sedimentary
tectonic
igneous
impact
hydrothermal

The clast (rock fragments) within breccia are angular in shape and generally randomly orientated, a opposed to a conglomerate which is composed of rounded fragments.
Sedimentary beccia generally formed in ancient stream beds. Igneous breccia forms as a result of rocks being torn away during volcanic eruptions. Impact beccia results from the impact of meteorites. Hydrothermal breccia results from fissure opening up due to seismic or volcanic activity & hydrothermal fluids (hot water) entering the fissure causing the sides of the fissure to collapse inwards.
Conglomerate
Conglomerates contain rounded rocks bound within a sedimentary unit. They form either within ancient stream systems or in marine environments. They can also form as a result of glacial activity.
Xenolith
Xenoliths are fragments of rock contained with igneous rocks. Their spacing with the host rock is much greater than that of beccia or conglomerate - they are more isolated. They generally result from volcanic eruptions.

Conglomerate rocks of non sedimentary nature, are debris from other rocks mixed often with fresh lava pouring over it.
Another facet is that certain minerals have differing melting points, however subtle, cooling at differing time, creating bumpy pieces.
during various glacial advances, they carried small rocks over different rock strata where sedimentary processes made these amalgamations


Sources or strategies for stone identification I have a bunch of semi-precious stones here, but I am not very learned in geology etc and I would like to have some way to know what kind of stones they are. As far as I understand question about stone identification are considered off-topic here. Is there such a reliable source so I can identify the stones by myself?

Thank you!

Are your stones raw or are they cut & polished as they would appear if mounted in jewellery pieces? There are tests such as streak & hardness which can be done to raw stones but not to polished stones because these test would damage the polished surface.

There are a number of websites that can be used, such as:

Rock Identification Made Easy
Rocks: Igneous, Metamorphic and Sedimentary

Tests that should be done include:

Color
Luster
Hardness - usually involves testing with the blade of a pocket knife
or similar
Grain size - the size of mineral grains in the stones. If no mineral
grains are obvious the stone may be "glassy"
Streak - the color left on a piece of white ceramic when the stone is
rubbed on the ceramic.

mindat.org  - * my fav as an avid rockhound/gem junkie

USGS.gov

geology.com

TreasureNet   is cool - you send pic (good) in app and the guy returns PDQ

*p.s.   ---  dont forget    *specific gravity test


Do hurricanes cool the earth? I noticed that temperature drops in the surrounding area of a hurricane.

Is the heat converted into kinetic energy?
Could the shape of the hurricanes reflect sunlight?
Do they create more lightning in an area that would normally have lower levels of lightning for the same timeframe, in turn creating more ozone?

Hurricanes can be viewed as having primary and secondary circulations. The primary circulation is what we see in satellite photos, comprising the winds and clouds that circle the low pressure zone at the center of the hurricane. The secondary circulation is a vast heat engine that provides the energy needed to sustain the primary circulation.

The low pressure cell at the center draws surface air toward the center, gathering moisture from the warm ocean along the way. This flow is more or less isothermal.
Humid air rises in the clouds around the center of the storm, releasing moisture along the way. This rise is more or less adiabatic.
The now dry air at the top of the troposphere flows outward and radiates energy into space. This flow is roughly isothermal.
Finally, the air falls in downdrafts at the outer edges of the storm. Like the updrafts near the eye wall, the flow in these downdrafts is more or less adiabatic. From here the cycle repeats.

This heat engine, powered by a hundred kelvin temperature difference between the warm oceans and the top of the troposphere, does a very nice job of locally cooling the Earth.

A hurricane take it's energy from warm surface water, which is then cooled down. Warm, humid air is rising up more than 10 km and releasing it's heat through condensation of water vapor into water droplets in deep thunderstorms. The released energy is transformed to kinetic energy, a major part as rising movement of moister and droplets in the thunderstorms and a minor part (1/400) as the horisontal winds.

The effect of a normal hurricane is about 200 times the effect of the world-wide electrical generating capacity. And the clouds of the hurricane reflects sunlight with almost the same amount of energy. When the horisontal wind is ebbing out a four hundredth of the hurrican energy again is converted to heat energy, while the energy of the vertical winds is used to transport moister from the surface up to the troposphere (potential energy). The rain falling down also cooling the ground, first directly and then while evaporates.

The netto of all cloud formation is cooling down.

https://www.aoml.noaa.gov/hrd/tcfaq/D7.html


calculate UV index in vertical plane Due to extensive damage to my face because of an accident, I am currently undergoing skin therapy (laser/IPL/medication), that makes my skin extremely sensitive to UV radiation. So I need to stay out of the sun, at the very least between 11:00 and 16:00, need to reapply sun screen every two hours, and generally be careful with exposure. Since that makes me hyper aware to the sun, perceived warmth, UV index and all that, it made me reasearch the subject.

I live in The Netherlands and the meteorology institute published real time UV measurements (as UV index) at https://www.rivm.nl/Onderwerpen/Z/Zonkracht
However the UV index is defined as the amount energy that is radiated on the flat surface of the earth. As we humans generally have more vertical surfaces, especially sensitive surfaces like the face, would it not make more sense to not just measure in the horizontal plane? Especially during the evening and the morning the sun is at a low angle, so the (relative) energy on a vertical plane would be a lot higher than the above graph suggests.

I made a small program that parses this image, and recalculates the UV index for the vertical plain (divide the UV index by the tangent of (90 degrees minus current zenith angle). This would be the output (blue line is vertical UV index):

According to Ultraviolet Radiation, Human Health, and the Urban Forest it would seem at least the general shape you obtained is correct:

Here they tracked the irradiance at noon over different months of the year not hours of the day, but the basic change is the same: high to low to high Solar Zenith Angle when irradiating a vertical surface leads to an irradiance graph with 2 "shoulders" on both sides of the maximum solar elevation point. The irradiance is lower at the central point because the direct rays are parallel to the target surface and the only contribution are the scattered and reflected rays from the environment and the rest of the sky, and then as the SZA progresses more and more toward 90 degrees (or elevation toward 0 degrees) the increasing atmospheric absorbance comes into play and reduces the irradiation long before the rays become exactly perpendicular to the target surface.
But if the goal of the UV Index was to provide safety data for the general public, I would say it should've been measured assuming the absolute worst-case scenario of some unprotected skin being exposed to exactly perpendicular solar rays at any hour of the day (this is possible because our bodies have complex surfaces and it's always possible to have at least a little skin that's perpendicular to almost any ray direction in all of 3D space). So they should've used a detector that is rotated to face the sun at all hours of the day, and the resulting graph I suspect would not look like the official daily UV Index graph but also not like the "2 shoulders" one we have here. It would probably look more like the "IND", "SYR" and "INL" variants in the image above: a sort of "Gaussian with a wider top".
LE: Here we go, it should look like the Direct Normal Irradiance curve, with no cosine correction for horizontal receiving surfaces: https://www.researchgate.net/figure/Direct-normal-irradiance-vs-solar-time-at-Izana-Tenerife-Kaashidhoo-Maldives-and_fig1_236314638

UVvertical Index = UVdirect Index + UVdiffuse

UVdirect Index (vertical) = cos(altitude angle)*(UVhorizontal Index)/(sin(altitude angle)+coefReflection)

UVdiffuse (vertical) = (UVhorizontal Index)/(sin(altitude angle)+coefReflection)*coefReflection*0,55+0,437*cos(altitude angle)cos(45)+0,313(cos(altitude angle)*cos(45))^2

Reflection Coefficient varies during the year, its average value is 0.1.