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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4
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1answer
78 views

NCDC Snowfall Data - Interpretation?

This is my first time using this dataset, so I have probably made an elementary mistake. I am having trouble understanding a file from the NCDC's climate normal dataset: http://www1.ncdc.noaa.gov/pub/...
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0answers
240 views

What is the finest horizontal grid spacing that Eulerian grid-cell air-dispersion models should use?

My colleagues run the Advanced Research Weather Research & Forecasting (WRF) model in predictive mode, and then test the skill of the model anywhere from 12 - 84 hours out from the initialization ...
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2answers
937 views

How do I represent wind direction on a UTM (Universal Transverse Mercator) map projection?

What does it mean when I say "the wind direction is 50o" on a UTM map? Which direction is the 0o reference? For example, if I draw a wind vector V as seen in the ...
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0answers
130 views

Correlation of El Nino and south indian monsoon

A recent article in New Scientist reports the following claim made by Wenju Cai at CSIRO Melbourne. Southern India is having a lot of rain as it goes into winter, having come out of the dry ...
12
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1answer
5k views

Plotting wind barbs in python

I'm trying to plot wind barbs in basemap and I have two separate netCDF files. Here is what I am trying to produce, or something like it: How do I read a uwnd variable in a netCDF file in python? <...
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1answer
50 views

Meteorology in Canada

I'm interested in understanding how meteorology works in Canada (esp. from an Open Data perspective). Can someone explain, or provide resources, that indicates an overview of the actors involved on ...
5
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2answers
5k views

Why doesn't it snow even when it is below freezing?

I know the temperature of a place is determined by various factors, a few of which I can think of are: Altitude, distance from sea, latitude, wind etc. My question is basically regarding latitude. ...
4
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1answer
94 views

Are oceans a major factor in creating high winds on a planet?

This question only pertains to oceans of water and how much they account for the process of creating high winds on a planet with any type of atmosphere.
10
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1answer
230 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 ...
4
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2answers
127 views

Need help understanding variables that relate to meterology terminology

I am working on a project in predicting the weather and I had a few brief questions. I understand that radar works by bouncing waves off of precipitation and measuring reflectivity. I have a variable ...
9
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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 ...
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3answers
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Does rain (temporarily) deplete the surrounding atmosphere of carbon dioxide?

CO2 in the air dissolves into rain water, making them slightly acidic. Is that enough to deplete the surrounding air out of CO2? If yes, how fast does this occur? Is it only with the first drops of ...
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0answers
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What happens if humidity is 100%? [duplicate]

What happens when the humidity is 100% in atmosphere. Does it heavily rains or fog formation occurs? Or is there any other possibilities?
2
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1answer
73 views

References on hurricanes

Would anyone know of references (available online or not) that give detailed explanations and especially the physics behind violent meteorological events such as hurricanes?
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6answers
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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 ...
6
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3answers
1k views

Would there still be wind if Earth had no water?

If there was no water on the earth would there still be wind? If the planet was basically a desert from pole to pole, east to west, would the wind still blow? I understand that wind is a result of a ...
4
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1answer
70 views

What type of cloud is this?

I live in a sub-tropical region of Australia. Earlier today, we experienced temperatures of 31C and it was clear about 2 hours before I went out and noticed the following clouds directly above my ...
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3answers
2k views

El Nino in the Middle East

According to reports and charts meteorological phenomenon El Niño is close to Iran, but the question is, El Niño phenomenon in Iran is likely to achieve? What are the consequences?
15
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2answers
4k views

Why One Side of Mountain Range is Lush

I'm new to this site and certainly not someone with any real background in atmospheric science, so please forgive me if this question is a little stupid. I recall learning in High School about ...
3
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1answer
419 views

Website that contains the maps of atmospheric pressure and wind speeds

Is there a website that contains the maps of atmospheric pressure and wind speeds for specific climatic events such as hurricanes day after day ?
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0answers
78 views

Spatial variability in ocean surface winds

For the near-surface winds over the ocean, many model products and satellite footprints have spatial resolutions on the order of tens of kilometers. I'm interested in knowing how much the winds (both ...
18
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2answers
568 views

Is this ice cover real - and what circumstances are required to make it?

The title says it all... I assume it requires very slow freezing sheltered from the wind. Undercooled water, maybe? A Reddit thread talks about Delaunay triangulation, but that does not explain how ...
4
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1answer
107 views

What are the possible mechanisms that could cause a rapid drop of temperature over few days?

I live in Hong Kong. Two days ago, the average daily temperature was around 27–28 °C and in yesterday, it was around 22–23 °C (during daytime it was rather hot i.e. 26–27 °C and it was at night that ...
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0answers
76 views

NCEP reanalysis latitude and longitude represent center of cell?

I can't find any information regarding the lat and long in the NCEP Reanalysis. Do they represent the center of the cell?
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0answers
48 views

What determines the number of Hadley cells on a planet? [duplicate]

I know it has something to do with the rotation speed, but what exactly? And why?
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2answers
310 views

What kind of cloud is this?

I would like to know if anybody knows the name of this cloud formation. The picture was taken in Bern Switzerland, just before a cold front moved in. I am thinking about roll clouds or Asperatus ...
8
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1answer
636 views

How is the vertical velocity defined in sigma-pressure-coordinates?

I have a problem in deriving/understanding the vertical velocity in sigma-pressure coordinates. The vertical coordinate is defined as: $$\sigma(x,y,p)=\frac{p(x,y)-p_t}{p_s(x,y)-p_t}$$ where $p(x,y)...
3
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1answer
90 views

How to calculate hourly rainfall projections?

If the National Weather Service website shows increasing probability of precipitation (POP) over a 6 hour period (e.g. 10% rising gradually to 60%), what is the POP in this time interval if the ...
2
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2answers
112 views

Global warming and winter temperatures

What causes cold temperatures to move earlier than they usually move? Here in Buffalo the weather was 9 °C. However, everyone had winter coats and hats on. There was no snow, but it was very very ...
8
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0answers
139 views

What meteorological factors contribute to springtime Trans-Pacific air-pollution events?

The transport of tropospheric ozone, ozone precursors, carbon monoxide, etc from Asia to North America is an active area of research (see J.L. Ambrose, et al., 2011) These types of events occur ...
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0answers
78 views

practice papers for IESO [duplicate]

I am from India. Please suggest where to find practice questions for earth science Olympiad? Are papers apart from the 2010,2011 entrance test available?
9
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2answers
254 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 ...
6
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1answer
82 views

Unusual light at sunset?

This evening in Boston there was quite a spectacular sunset. However, many people noticed this odd vertical "stripe" in the west. Has anyone seen this before? It looked as though it was projected ...
9
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3answers
376 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 ...
8
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2answers
1k views

How accurate is a tipping-bucket rain gauge?

My question is simple - how accurate is a tipping-bucket rain gauge? I have read about what causes the errors (wind, bucket mechanics for extreme events, ...) and I know the accuracy is strictly ...
12
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1answer
338 views

Do clouds float on anything?

Clouds of the same type have such a consistent altitude, it appears as if they're floating on an invisible layer. Is this true? Put another way, is there a significant change in air composition at ...
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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 ...
9
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2answers
19k 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 ...
4
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0answers
40 views

Why did Hudson Bay melt so late this year?

The fear with the polar bears is that the ice-free period in the bay is getting longer, right? Did the consecutive polar vortex years from all this global weirding make the bay's winters colder? It ...
4
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1answer
248 views

Why is it always rainy in Addis Ababa?

I watch the news and in the weather forecast it's always rainy in central Africa, especially in Addis Ababa. Why is that?
3
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1answer
73 views

Is it possible to have a busier tropical storm season in the eastern Pacific basin than in the western Pacific basin?

It is known that hurricane activity in Atlantic basin is less active than in East Pacific basin in seasons past, but for the 2005 and 2010 seasons, the Atlantic basin is busier than western Pacific ...
11
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3answers
520 views

Is increase in atmospheric $\mathrm{CO}_2$ concentration affecting Earth's atmospheric pressure?

It's well known that the $\mathrm{CO}_2$ levels around the world are increasing, leading to an increase in overall surface temperature, etc. But I'm wondering, are these gases (or the effects from ...
12
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2answers
2k views

Can an Atlantic hurricane enter Mediterranean sea?

I can't find any examples, has it just never happened before or is it impossible because of environmental factors?
9
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1answer
700 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?
6
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2answers
2k views

How to plot lat-lon-rainfall in MATLAB?

I have average annual rainfall values at few grids, as shown in below example; Lat: 25.5 26.5 33.5 34.5 35.5 36.5 41.5 42.5 Lon: 89.5 91.5 78.5 79.5 83.5 84.5 75.5 76.5 Rain: 110 120 122 135 114 ...
8
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2answers
620 views

How to perform regridding (1.0d to 0.5d) using bilinear interpolation for an irregular area?

I need to regrid temperature dataset from 1 degree to 0.5 degree. In case we have data available for all grids falling in a square, as shown below, we can simply regrid it using bilinear/bicubic ...
7
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2answers
581 views

Dew point variation in a day

Is this true? "If there are no weather front or severe weather systems, then the dew point within a single day is fairly constant, no matter how large the day/night temperature variation."
11
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3answers
333 views

Wind profile below the aerodynamic roughness length

The vertical profile of horizontal windspeed is often given by the so-called "log-law": $$u(z)=(u^*/k)\ln(z/z_0),\ \mathrm{for}\ z>z_0,$$ which can be found here. As can be seen from the ...
4
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0answers
635 views

Explanation of yellow/pinkish sky? [closed]

Last night the sky suddenly went yellow/pinkish colour. It looked like someone placed a transparent yellow/red plastic over our windows. I went outside and everything looked a pink/yellow colour, ...
10
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1answer
23k 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 ...