Questions tagged [meteorology]

The study of how the earth's atmosphere works, including weather forecasting. Use this tag for questions about the earth's weather. When asking questions specifically about the atmosphere, also include the [atmosphere] tag.

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11
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1answer
2k views

Intuitive explanation of precipitation amount

I'm trying to learn how to make sense of numbers in a forecast. I can interpret temperature and wind speed, but I don't know what to make of rainfall. What does it mean, for a human, that there will ...
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1answer
1k views

What is the difference between an inertial instability and a symmetric instability?

Inertial and symmetric instabilities are fluid instabilities present in atmosphere and ocean. What are the difference between an inertial instability and a symmetric instability?
11
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1answer
1k views

How to tell the difference between real rain and fake rain (cloud seeding)?

I live in a city where the pollution is bad, so bad that sometimes we get 'fake' rain (from cloud seeding). This may last for an extended period. There have been times before when it has “rained” and ...
11
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1answer
219 views

Synoptic weather predictibility under climate change scenarios

Under climate change scenarios, it is quite certain that high latitude regions will experience more warming than at low latitudes. For example, in winter the reduced area of sea ice and snow cover ...
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3answers
23k views

How to interpolate scattered data to a regular grid in Python?

I have three txt files for longitude, latitude and temperature (or let's say three lists lon, lat, temp) from scattered weather station in the UK. I would like firstly to interpolate these data in ...
10
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3answers
6k views

What does the notation “kg kg-1” for units mean for specific humidity

I am using a data set from Justin Sheffield at Princeton that includes specific humidity. The description is as follows: "Reanalysis 6-hourly specific humidity interpolated to 1.0deg with account ...
10
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3answers
1k views

Can volcanos change the climate?

I have heard politicians claiming that volcanoes are the sole cause of global warming and using so called "NASA data" to show that the Earth is actually cooling instead of warming. While the nature ...
10
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2answers
696 views

Why is q used for specific humidity?

$q$ is the symbol used for specific humidity in many textbooks and papers (at least in meteorology and climatology, I'm not familiar with it in other disciplines). Where does this symbol come from, ...
10
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2answers
772 views

Can the Bering Sea Rule be used to predict the weather?

Recently, a colleague explained that the recent cold spell in the eastern United States could have been predicted using the Bering Sea Rule. The idea is that 17-21 days after a storm appears in the ...
10
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1answer
3k views

Why is the South Pole colder than the North Pole?

This question popped into my head because I am designing a fictional world map, and I was wondering what factors influence the amount of ice at poles. I want to know why there is much more ice ...
10
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1answer
663 views

Resources for learning the technical parts of atmospheric modeling

I'm a computer/atmospheric science undergrad and I'm trying to get into atmospheric modeling. Any recommendations for resources to get going or to learn about approaches? I can handle fairly technical ...
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1answer
1k views

How to calculate relative humidity?

I am involved in developing a weather based application which needs to calculate relative humidity and display it. I grab other weather variables like temperature, precipitation, wind speed and ...
10
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2answers
180 views

Why does the rising of high clouds due to climate change impart positive radiative feedback on radiative forcing?

As seen in the figure below. The larger the temperature difference between surface and cloud, the more positive the radiative forcing is from the cloud. So as the cloud moves up, it supposedly ...
10
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1answer
309 views

Unstable North Polar Vortex?

What would cause a polar vortex to become unstable a split into 3 smaller ones? How rare is this and what long term effects could this cause if the vortex stays unstable? http://www.severe-weather.eu/...
10
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1answer
443 views

Explanation for growing circular echo on weather radar?

Does anybody have an explanation for the growing ring/growing circular echo that I occasionally see on weather radar? Attached is a gif of a NEXRAD loop showing areas around Denver, CO, Aug. 2, 2015 3:...
10
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1answer
536 views

Why do rainbows appear to have a fixed structure?

Why do rainbows appear to have a fixed structure when a bunch of raindrops are 1. moving, and 2. granular?
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2answers
678 views

How can daily brightness be quantified or measured?

It occurred to me that there might very will be a metric out there that measures and quantifies "daily brightness". Meaning, how bright any given day is, taking weather conditions and cloud coverage ...
10
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2answers
4k views

Is the urban heat island effect stronger during a particular season or part of the year?

It is known that cities tend to be warmer than the surrounding landscapes, and this is known as the "urban heat island effect". In the summer there is greater heat output from air conditioning ...
10
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1answer
96 views

North Indian ocean tropical cyclones

Why are tropical cyclones in the Bay of Bengal more frequent and stronger than those in the Arabian Sea?
10
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1answer
127 views

Is there a convenient place to get vertical wind shear info for my location?

Now that it's thunderstorm season here in New Hampshire, it would be nice to be able to find out what the vertical wind shear is like at the altitudes that affect thunderstorm formation, to guess ...
10
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1answer
876 views

How does evapotranspiration affect rainfall?

Evapotranspiration is when a plant evaporates water off the surface of its leaves in order to move water throughout its system with cohesive and adheisiveforces. My question is how will a sudden ...
10
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1answer
4k views

What causes the 'calm before the storm'?

The old adage "The calm before the storm" certainly has an observational scientific meaning to it -- something that many (including myself) have experienced -- that on a hot summer's day, when a ...
10
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1answer
402 views

Optimal vertical coordinate for complex topography

There are plenty of choices in models in so far as choice of vertical coordinate is concerned for meteorological models. Five that I know of: The sigma coordinate system - Hybrid coordinate system(...
10
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1answer
3k views

Wet and dry seasons - what are they and how do they form?

While asking questions on Worldbuilding, I keep hearing about wet/dry seasons. Obviously, one has rain and the other doesn't, and I've gathered that they occur with regularity on an annual basis, but ...
10
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1answer
294 views

Regarding various types of atmospheric pollution

Does all the car pollution (from about 150 million cars at least in the U.S. and a lot more in all of North America and the rest of the world) all the smoke-stack pollution of various factories and ...
10
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1answer
111 views

Rainbow dynamics?

How would steam refract light compared to fog and how would the rainbow appear? Does the temperature of the water drop or ice crystal effect the rainbow in any way? I know the size of the water drop ...
10
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2answers
212 views

How do the various types of clouds affect the atmosphere below them in a polluted environment?

I am working through this problem on my own as well, but am feeling that some perspective is in order. So, ignoring the obvious effects where precipitation will wash stuff out of the air, and blocking ...
10
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2answers
677 views

Technique to delete spin-up frames from WRF

I'm a user of WRF V3.5 aiming at meteorological simulation. Sometimes, I'll run the model for a long period. My attempt I split the long period(e.g 1 year) into serval short ones. For ...
10
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1answer
225 views

Does this optical phenomenon have a name?

Last summer, I snuck out with a row boat around 4am. Eventually with the sun risen but still quite low in the horizon, I was rowing in the middle of the absolutely still lake when I witnessed an ...
10
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1answer
863 views

What are Tetens coefficients?

Tetens coefficients appear in a few meteorological/climatological models that I've been looking at,for example APSIM: svp_A = 6.106 svp_B = 17.27 svp_C = 237.3 ...
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1answer
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What is the primary cause of the “Norwester” winds that affect parts of India & Bangladesh?

I am primarily interested to know: What is Norwester (localy called Kalboishaku as because in occurs during the Bengali Month Boishak which falls between Mid April to Mid May). What causes Norwester....
10
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2answers
337 views

The origin of spurious high frequency waves in numerical weather prediction

I am currently reading this paper on digital filters and their relevance to meteorological models Digital Filter Initialization . My question relates to this following text - "The requirement to ...
10
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1answer
687 views

How could humans alter storm intensity or direction other than cloud seeding?

I am familiar with the concept of cloud seeding, where precipitation can be induced with aerosols, thereby altering storm intensity further downwind. Are there methods that could be used to ...
10
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2answers
186 views

Do warnings verify better nearer radars?

As radar beams travel away from radars, they increase in elevation and widen. Have any studies attempted to quantify the rate at which warning skill (such as in FAR and POD) deteriorates as a ...
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0answers
76 views

How are scatterometer observations standardised before being fed into reanalysis models?

This very basic question occurred to me during a talk on reanalysis data sets. Often we know the observations produced by a particular instrument, say rain radar, are biased from one year to the next ...
10
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2answers
385 views

Are weather forecast models more accurate for either high or low temperatures?

The other day our low temperature for the day was ~10 degrees F below our forecast low. I've noticed this before in the winter, especially when temperatures start to go below 0 degrees F (-18 degrees ...
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4answers
1k views

Have there ever been simultaneous cyclones in the same ocean but different hemispheres?

I'm teaching a physics class, and I'm getting to the point where we are talking about the Coriolis effect. I usually show a couple of photos/videos showing a storm in the Northern Hemisphere and a ...
9
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3answers
576 views

Obtaining hourly weather data, including direct and diffuse insolation

I really need some reliable measured hourly weather data for a few sites across the world. It needs to include solar diffuse and direct values or their equivalents. I've tried the usual sources: Met ...
9
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3answers
745 views

First to Sail the Jet Stream Around the World

My questions are related to a scenario discussed on Earth Science: A huge (heavier-than-air) kite sailing in and out of the jet streams. The kite: The scenario: The assumptions: Such an airship ...
9
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2answers
346 views

What are the sunniest places on Earth? (including oceans)

This question did arise when thinking on offshore solar power plants, what's their potential, and how efficient would they be compared with land based counterparts. Recently, it is becoming more ...
9
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2answers
18k views

Have two hurricanes ever merged? And what was the result?

I was just reading this about how Hurricane Ethel could have merged with Hurricane Dora in 1964. Has such a merge ever happened before in history? If so, what was the result? Would storms become ...
9
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3answers
863 views

What is the reason why there are radiosonde measurements in the atmosphere?

I have seen weather balloon measurements of air. Why is this done? Aren't the measurements we take on the ground enough?
9
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1answer
1k views

How does the pole-to-equator temperature gradient scale with height contours?

Are the pole-to-equator temperature gradients lower at higher heights than at lower heights (like 850 mb/500 mb)? If so, why is it the case? Especially given that the zonal circulation tends to be ...
9
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2answers
228 views

Does lapse rate apply below sea level?

In many parts of the world there are dry lands below sea level, such as parts of the Netherlands. Since we know that temperature decreases with increasing altitude, does it mean that temperature will ...
9
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3answers
373 views

Paper result validation and the scientific method in earth science

The context of this question is computational earth science specifically meteorology/climatology but I am sure it applies to all the scientific disciplines where numerical methods are used. Recently ...
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2answers
3k views

Why do certain areas on Earth have a higher or lower air pressure at sea level?

For instance, looking at this map of world air pressure in January and this map of July, why do some land surfaces have a higher pressure during the winter? I know that the tropics and Coriolis ...
9
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1answer
684 views

Why are there different vertical gradients of temperature in different layers of the atmosphere?

The temperature of the troposphere decreases with altitude whereas it is opposite in the stratosphere and again fluctuates. Why is this so?
9
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1answer
21k views

Why does it rain more at night than during the day?

I'm living near a sea, and it rains mostly and heavily at night from 11 PM to 3 AM. The weather is mostly clear during daytime. Air is generally cooler at night, and cool air holds less moisture ...
9
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1answer
1k views

A parcel of air in an isothermal layer

I'm having a bit of trouble figuring out a solution to this problem: There is an isothermal layer of air which has a temperature of 0 °C extending from the surface to 1 km height. A parcel is 0.5 °C ...