Questions tagged [earth-observation]

Observations recorded on earth.

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36
votes
7answers
151k 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 ...
36
votes
3answers
9k views

Does gravity increase the closer to the core you get?

Or does the mantle and crust above you counteract the increase at one point and it actually decreases?
18
votes
9answers
6k views

How to quickly or easily prove the world is spherical?

A relative of mine has recently introduced me to the modern flat earth theory, which she believes in. Setting aside for the moment that it is ridiculous, and that sending up some balloons with cameras ...
15
votes
5answers
3k views

Is Earth an organism?

According to Wikipedia, "all known types of organism are capable of some degree of response to stimuli, reproduction, growth and development and self-regulation via homeostasis." Further, watching a ...
13
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0answers
73 views

Why were no interferometers launched on weather satellites between the '69-'72 IRIS-D and the 2002-onward AIRS?

As early as the late 1960s / early 1970s, Nimbus-3 carried Iris-B and Nimbus-4 carried Iris-D, both infrared spectroradiometers with a moderate spectral resolution. Subsequently, I believe it was not ...
12
votes
3answers
3k views

Comparing the Earth with a basketball?

(Please excuse my English) The picture above is an image of the Earth without water. We know that the picture above is a very exaggerated one. If the Earth were to shrink to the size of the picture ...
12
votes
3answers
1k views

How is global greenhouse gas emission calculated?

I am sure there are different methodologies to arrive at such a number. Can someone in layman terms describe some of the most widely used and trusted methods and what data are used? Sorry I am outside ...
10
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1answer
106 views

Why is there no High-Resolution Infrared Radiation Sounder (HIRS) on Metop-C?

The weather satellites Metop-A and Metop-B carry copies of the High-Resolution Infrared Radiation Sounder (HIRS), an instrument with a heritage back to 1975. Considering that Metop-C is part of the ...
9
votes
1answer
627 views

Why does this shoreline change this way?

There are different reasons why a shoreline can change, including tides. But I've found a phenomenon that I can't explain. It happens in a Mediterranean beach called L'Esparrelló/La Caleta (link to ...
9
votes
3answers
865 views

Why is this "independently reproducible proof of non-curvature" wrong?

I'm currently having a (possibly useless) argument with somebody over the internet who is adamantly claiming that the Earth is flat. I know that this person could just be pulling my leg or trying to ...
9
votes
1answer
133 views

How to measure the cycles of earth moving/rotation?

My knowledge of science is very basic, but after some research I have some knowledge, but I am still not clear with so many things regarding to this earth. I have read Laser's Measure the Earth's ...
8
votes
4answers
4k views

What are we seeing when we see the curvature of Earth?

I don't know if this question's for here, physics, maths, or geometry. I know that this or something similar has been asked a million times, but I've recently come to the concept that since the ...
8
votes
2answers
471 views

What are these Gizmos at Izaña Atmospheric Research Center in Spain?

This tweet from the account of the Centro de Investigación Atmosférica de Izaña (AEMET) http://izana.aemet.es Izaña Atmospheric Research Center (AEMET) shows images of meteorological instruments ...
8
votes
1answer
260 views

Seeming correlation between time of day and earthquakes

I live in a generally geographically active area (Southern California, near the San Andreas fault, if that matters), that has had two relatively minor earthquakes that I have felt in the last week (in ...
7
votes
2answers
2k views

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 ...
7
votes
1answer
217 views

What physical measurement / elevation is used to define Earth's radius?

Earth's radius is usually given as 6378137 meters (equatorial radius), its flattening is defined as 1/298.257223 (WGS84), and thus its polar radius is calculated as 6356752 meters. However, the ...
7
votes
1answer
58 views

Would the subsurface event leading to tree death at West Tern Lake in Yellowstone be visible in thermal imaging?

The New York Times article It’s Warm and Stealthy, and It Killed Yellowstone Trees and Turned Soil Pale describes an even that took place over the past few decades where a small and well-defined ...
6
votes
5answers
3k views

Why wouldn't the earth be "always daytime" if the "daily cycle of sunlight" was drawn full-scale?

The question is clear enough in my opinion but, I've found out that if you redraw this picture here: You'll notice that the Sun is as big as the Earth. But if you scale up the Sun to it's real size ...
6
votes
2answers
2k views

How would the Earth look without water in the oceans?

Has there ever been a movie, a documentary, or an image that provides a visualization of the oceans without water? I'm writing an article on geology and I thought a visual representation would be of ...
6
votes
1answer
1k views

How to locally identify a cold front passage?

I know that the passage of a cold front affects local conditions by decreasing the temperature and shifting the winds. Some precipitation could happen as well. How do software that analyze weather ...
6
votes
2answers
130 views

Time standard for IERS Bulletin A

IERS Bulletin A and Bulletin B contains Earth orientation parameters. These include the time difference between UT1 and UTC and pole position. The values for these parameters are listed once per day, ...
5
votes
1answer
530 views

What is this narrow band of clouds?

I came across a narrow streak of clouds in Asia when playing with Google Earth. Does anyone know what that is?
4
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1answer
643 views

Every 202,500 years, Earth wanders in a new direction; does it affect climate?

I refer to this article on nytimes.com: Every 202,500 Years, Earth Wanders in a New Direction TLDR: Scientists believe the earth's orbit oscillates between circular and more elliptical due to the ...
4
votes
1answer
25k views

What time and date is the sun directly overhead a given place on Earth?

In different regions, the sun is directly overhead at different times of the year. When do these event happen?
4
votes
1answer
179 views

Are the magnetic elements of meteorites that have struck Earth aligned with the magnetic field?

I was just pondering this question; do meteorites containing significant magnetic metal elements displace paleomagnetism the same way that magnetic striping on the ocean floor occurs? When the ...
4
votes
1answer
190 views

What is the use of HV or VH polarization in Radar?

Radar is a common tool in remote sensing, it is a so-called active instrument, hence it emits and receives energy. Modern Syntethic Aperture Radar (SAR) systems are capable of both transmitting and ...
4
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0answers
71 views

Earth's Electricity

This question s titled according to of one of the Nikola Tesla's patents. There he stated that lightning generates electric waves in Earth. "In the course of certain investigations which I carried ...
4
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0answers
41 views

Distribution of thermometric devices on earth

In complex climate models, measurements of Earth-based thermometers are used. What is their geographic distribution - historically? Does each measurement get equal weight?
4
votes
0answers
132 views

meaning of Grid resolution [duplicate]

I have some queries regarding grid. What does this mean. The grid has spatial resolution of 1/2 degrees latitude × 2/3 degrees longitude.?
3
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2answers
645 views

Climate change hoax [closed]

I see many scientific articles and newspapers out there saying that the climate change is happening. Yet, there are people who believe climate change is a hoax and a lie. But I haven't seen any '...
3
votes
2answers
197 views

Measuring the circumference of the earth - revisited

I have done a bit of research on this topic already and the easiest way seems to be the experiment by Eratosthenes. We pick two locations on the same latitude (of which we know the distance) and then ...
3
votes
1answer
76 views

What Earth Science research will be done from the International Space Station?

The April 9, 2020 NASA press release NASA Astronaut Chris Cassidy, Crewmates Arrive Safely at Space Station mentions: It is the third spaceflight for Cassidy and Ivanishin and the first for Vagner, ...
3
votes
3answers
219 views

Had the climatologists predicted climate change as the deviations to both extremely cold and hot temperatures before?

Recently I read that the current extreme snowfall in northern temperate climate is caused by the increased evaporation due to the global warming. Had any scientist predicted these extremes before ...
3
votes
1answer
117 views

Has PAZ satellite been launched?

There are several mentions in the net about Spanish radar satellite called "PAZ", which should work in tandem with German TerraSAR-X and should have been launched in 2015. But most results I can find ...
3
votes
0answers
64 views

Why is the Regener-Pfotzer maximum (radiation in upper atmosphere) above central California?

The site https://spaceweather.com/ has a section called Space Weather Balloon Data which shows the image below and says: The data points in the graph above correspond to the peak of the Regener-...
3
votes
0answers
37 views

Which unsupervised classification method for non linear multivariate time series earth observation data in python

I have collect several data sets for a small region in Germany called Hessisches Ried (about 90 km²) from different sources for a time period from 2015 to 2019. Daily rainfall amount & daily ...
3
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0answers
18 views

Why does the OSCAR database describe Landsats fire identification as "daylight only"?

The World Meteorological Organisation (WMO) Observing Systems Capability Analysis and Review (OSCAR) Tool describes the High-Resolution Imager (HRI) (which flies on Pléades-1A and -1B, among other ...
3
votes
0answers
427 views

Trewartha climate classification overlap?

By my reading of the wikipedia page on the Trewartha climate classification, climate classifications are not mutually exclusive. Let's take a look at the climate classification of Iowa City, IA. The ...
3
votes
0answers
46 views

Does the hour of the day and the position on the sun have any influences on the formation of a hurricane?

I am writing an essay and cannot find if a hurricane is influenced by the position of the sun or the hour of the day.
2
votes
1answer
156 views

Volcano in ocean?

Is it a volcano in this image ? The magnified version. I was browsing through earth images here when I spotted this orange thing. Is it some oceanic volcano? It may be an absurd question but is it ...
2
votes
2answers
300 views

At what latitudes does daytime last exactly 24 hours once in the year?

I assume at the Solstice - a definite latitude would have exactly 24 hours of daylight. What latitudes (North and South) are these - they might vary a little with longitude?
2
votes
1answer
193 views

What are these Gizmos at Mauna Loa Observatory?

Artist Rosten Wu's Vimeo channel has a video title Bridging Time and there is discussion about the Keeling Curve and the site where it all began in Hawaii. In the video there is a shot of a weather ...
2
votes
1answer
63 views

How to obtain the saturation point of a soil layer from the volumetric soil water content data?

Would you please let me know if the following is accurate as an answer to the question: Suppose we have sensors which measure the volumetric soil water content of a soil layer for a long period (more ...
2
votes
1answer
421 views

Understanding pushbroom sensors

Does a push broom scanner scan a path perpendicular to the direction of satellite travel? I am confused because its detectors are arranged across track even though it scans along track.
2
votes
1answer
79 views

How can parameters of the ionosphere be calculated?

How can parameters of the ionosphere be calculated? Specifically, how do we calculate total ion density, total ion temperature and individual major ion densities from I-V Characteristics curve of ...
2
votes
0answers
35 views

Earth's magnetic and electric field in Hilly Areas

Can you please guide me as to what is the intensity of earth's magnetic and electric fields in different regions of earth. Also, specifically in case of hilly or mountainious regions.
2
votes
0answers
24 views

Why are Nowcasting SAF daytime products apparently truncated at solar angles of 20° (rather than the documented 10°)?

This image shows the Nowcasting Satellite Application Facility (NWCSAF) Cloud Liquid Water Path (LWP) product for 2020-01-08T12:00:00Z: Cloud LWP from NWCSAF. Source: NWCSAF. The Algorithm ...
2
votes
0answers
26 views

The differences on the atmospheric transportation for various trace metal in atmosphere

I have known that the atmospheric lifetimes of chemical species were highly dependent on their physicochemical properties. For example, $SO_2$ might exist for 5-8 days, while $NO_2$ could only exist ...
2
votes
0answers
88 views

WMM and IGRF model?

I am studying about World Magnetic Model (WMM) and International Geomagnetic Reference Field (IGRF) model provides the seven parameters about the earth magnetic field. These models have to be deployed ...
1
vote
1answer
59 views

Is there a name for a "moving meridian" corresponding to particular solar time?

Imagine a meridian that moves over the Earth's surface such that it remains at the longitude that corresponds to a particular solar time (e.g. midday). This meridian would remain stationary relative ...