# All Questions

578 questions
420 views

### What causes the beautiful Auroras on the north and south magnetic poles?

What is the scientific reason for the majestic sights of the northern and southern lights, otherwise known as Auroras near the magnetic poles, and why do the northern lights differ from the southern ...
17k views

### Why do gold deposits form only in certain areas of the earth?

In the map above you can find that most elements are spread evenly throughout Earth's crust and that they are available all around the Earth. However, gold can only be found in certain areas of the ...
5k views

### Why is Earth's Core Iron?

The two major constituents of the Earth's core are iron and nickel. In documentaries and scientific conversations, iron gets more attention than nickel, probably because it makes up a bigger ...
1k views

### How could this pyramidal Mountain have been formed?

How could this pyramidal peak have been formed in Antarctica? Little is known about it as far as I know but what is known is that its miles away from any existing plate boundary and its shape is also ...
1k views

### Deciphering NCDC data

I need US monthly climate data for the years 1992-2012. It would be great to get down to a county level, but by state would be just fine. Every site that I go to inevitably kicks me to the NCDC, but I ...
2k views

### How often do king tides (perigean spring tides) occur?

Recently, there has been a lot of information about "King Tides" (i.e, perigean spring tides) on the news with a number of groups relating the peak king tide to future normal conditions (2050) under ...
117 views

### Relationship between tides and earthquakes

Ide et al. (2016) suggest that earthquakes (especially those of high magnitudes) are more probable during periods of high tidal stress (during full and new moons). While they show a comprehensive ...
1k views

### If the earth is a globe, what causes temperature differences across lines of latitude?

If the earth is a globe and the sun is 93 million miles away, why is the equator the hottest place on earth? In terms of distances to the sun, the distance to the equator is almost equal to that as ...
455 views

### Why cannot people burn all the atmospheric oxygen? [closed]

We are told that photosynthesis, developed a couple of billion years ago has produced all the atmospheric oxygen. I wonder, why did the process stop? Why do modern plants prefer to recover the entropy ...
338k views

### Why does lightning strike from the ground-up?

The enlightening image below is of a lightning strike slowed down at 10,000 frames per second. It can be seen that the most intense flash produced from the lightening occurs in the direction from ...
24k views

### 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 ...
3k views

### How do weather models work?

We use different weather models all the time, such as the ECMWF and the GFS. These models are simply amazing to me. How do these models work? I know they have to take in various data points - what ...
12k views

### How is the mass of the Earth determined?

According to textbook knowledge, the mass of the Earth is about $6 × 10^{24}\,\mathrm{kg}$. How is this number determined when one cannot just weight the Earth using regular scales?
3k views

### What are the major differences between weather models and climate models?

Some weather models include GFS (Global Forecast System) and NAM (North American Mesoscale Model). Some climate models include CCSM (Community Climate System Model) and the NASA GISS (Goddard ...
88k views

### How high must one be for the curvature of the earth to be visible to the eye?

I would like to ask that at what distance from the Earth's surface the curvature of the Earth is visible. What layer of the atmosphere is this? I've noticed that at the height of 9-12 Km (the view ...
3k views

### Is earthquake prediction possible?

After the Tohoku and East Coast quakes, I skimmed over several books discussing the validity of earthquake prediction as a discipline, yet found no significant breakthroughs. What should change in our ...
2k views

### Why is WRF most often configured at 3:1 nesting ratio?

In WRF application, nested domain has always been used for weather/air quality modeling for the place of interest in a better resolution. The figure below illustrates this: I have noticed that the ...
5k views

### How to get cell indices from latitude and longitude in WRF model grids?

I am using Weather Research and Forecasting model WRF and the WRF Preprocessing System WPS and could not get a satisfying answer from wrfhelp. Can anyone guide me in transforming latitude and ...
35k views

### What would be the temperature of earth if there was no atmosphere?

I do know that the atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect),and reducing temperature extremes between ...
5k views

### Is this XKCD comic an accurate timeline of the earth's average temperature?

Apologies for the length of the image, which I found at http://xkcd.com/1732/. I'm mostly interested in the temperature line itself, both the historical data and the forward projections. The reason ...
243 views

### What can we learn by studying lunar atmospheric tides?

Lunar atmospheric tides are likely insignificant for weather, although Guoqing (2005) asserts that The lunar revolution around the earth strongly influences the atmospheric circulation. They don't ...
8k views

### What are the differences between an LES-SGS model and a RANS based turbulence model?

I'm kind of new to the Large Eddy Simulation (LES) modeling world and I wondered what is the difference between an LES subgrid scale model like the Smagorinsky–Lilly model and a one-equation Reynolds-...
2k views

### What sort of climate zones would be present if Earth was tilted like Uranus?

The three main climate zones on Earth are tropics, temperate and polar. Due to Earth's axial tilt, the three zones experience different seasonal patterns: The tropics experience 2 or 4 wet/dry ...
13k views

### Why do crystals, like quartz and diamonds, form in different colors?

Some crystals, like quartz and diamonds, form in a variety of different colors. For example, quartz can be clear, 'foggy', pink, yellow, and even blue. What happens during the crystal's formation to ...
5k views

### What is the origin of the ocean's salt?

We know we cannot live without salt, but an investigation into the origins of ocean's salt leads one to believe that this issue is not fully resolved yet. What geological phenomenon caused the earth ...
13k views

### What was the first rock in the rock cycle?

I am an undergraduate student but I am a tutor at a High School, and one student asked me. Attempting to explain the rock cycle "if one rock turns into the other then which came first" my gut is ...
2k views

### What causes waves to form the characteristic “breaking” shape as they approach the shoreline?

We all know that as waves approach the shallow shores, the waves begin to form a characteristic shape. The upper portion of these breaking waves appears to curl forward and downwards over the bottom ...
296 views

### How to tell if fog is made out of water droplets or ice crystals?

I understand that clouds can be made out of water droplets and/or ice crystals. And that fog is nothing else than low-lying clouds. However, I've experienced fog in a wide ranges of temperatures. I ...
267 views

### Sun and moon anomally

Below is a photo that my son took in Scotland showing the sun and moon at the same time. I immediately noticed this anomaly that the light illuminating the moon could not possibly come from the sun. I ...
42k views

### At what humidity does it start to rain?

As far as I understand it is perfectly valid for air to have 100% humidity. At that point, all water can still exist in form of vapor, non-condensed. Does it immediately start to rain if humidity is >...
7k views

### Why do felsic materials have lower melting points than mafic?

It is clear from Bowen's reaction series that more felsic minerals have lower melting points than mafic minerals. As far as I know, the same is true of quenched glasses. Felsics have a higher degree ...
19k views

### Is the color of the sky the same everywhere on earth?

Is the color of the sky at noon (local time) in, say, NY, Buenos Aires, London, Nairobi, Sydney, New Delhi and Tokyo the same? I choose the specific time of noon to exclude the twilight colors of the ...
2k views

### Does the strength of Earth's magnetic field influence its climate?

The strength and orientation of Earth's magnetic field varies with time. Does this variation of the magnetic field have any influence upon climate? For example, is there any correlation between ice ...
2k views

### What were the tallest mountain ranges in Earth's geological past?

There have been numerous episodes of mountain building in Earth's geological history, particularly through the super-continent cycle. Many mountains and mountain ranges have been eroded, as mentioned ...
335 views

### What properties must a rocky body possess in order to exhibit plate tectonics?

The Earth exhibits plate tectonics, but the other terrestrial planets do not (though Mars and Venus may have exhibited plate tectonics in the past). What is "special" about Earth that allows it to ...
3k views

### Is there a database of global rainfall time series?

Is there any institute out there collecting time series data of precipitation, and making them accessible online? I need data for a few different locations, but: Low spatial resolution is fine. For ...
14k views

### 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 ...
1k views

### What fraction of dry land is below sea level?

Someone just asked me if it would be practical to counter the rise of sea level by pumping water into storage on land. It struck me that if there is enough land below sea level, this would require ...
41k views

### How do seismologists locate the epicenter and focus of an earthquake?

I know the focus of an earthquake is where the earthquake originated from, but what I could never figure out is, how to scientists find out where exactly the focus (and epicenter) are located?
5k views

### Do fossil fuels insulate the crust from the Earth's interior?

I was doing a project for my English class, and I came upon the article Energy conservation in the earth's crust and climate change. I can't view the full text of the article, but the abstract piqued ...
4k views

### Why don't scientists use fire entry suits to study volcanoes?

It seems like the only personal protective equipment (PPE) that volcanologists use are aluminized suits that don't provide any protection from direct contact with lava, making an unexpected splash ...
5k views

### Where is the calmest place on Earth?

I have done some research online, and I've found out that Antarctica has the calmest winds (lowest maximum wind speed) recorded on Earth. However, it is uninhabitable for human life. Other very calm ...
808 views

### Why do tropical cyclones not tear themselves apart?

A tropical cyclone is the generic term for a hurricane, typhoon, or tropical storm. Tropical cyclones derive their energy from evaporation of water at the ocean surface which ultimately recondenses ...
5k views

### Is the Earth's hot inner core necessary for life?

The inner core of the Earth has an enormous temperature of around 4300 degrees Celsius. Is this large inner core temperature an important factor contributing to the ideal temperature that is ...
279 views

### How will climate change affect the 3D distribution of lapse rate in the atmosphere?

The lapse rate is the rate at which temperature decreases with height. By "3D" distribution, I mean distribution across all latitudes, longitudes, and heights. Would climate change change the lapse ...
837 views

### How is carbon distributed among the atmosphere, the oceans, the biomass and the unburnt fossil fuels?

In relation to my other question about carbon cycle and climate change, i would like to know some estimates of the carbon distribution among the atmosphere, the oceans, the biomass and the unburnt ...
281 views

### What is likely to have happened with these newly discovered antarctic volcanos below the ice?

The Guardian article Scientists discover 91 volcanoes below Antarctic ice sheet highlights a recently published University of Edinburgh School of Geosciences discovery and cataloging of over ninety ...
1k views

### What is the formula used for atmospheric visibility?

I am working on NCEP GFS data to plot various maps. One such plot I would like to have is visibility. I have seen some of the sites showing visibility charts and the source of the data was shown as ...