What is the cause of strong winds?

What is the cause of strong winds?

What is the cause of strong winds? Photo: wwwuppertal The wind is simply air in motion, flowing from high atmospheric pressures to low pressures. Moving anything requires a force. Strong winds are due to a strong pressure gradient force. A… More »

What are the plant hardy zones and how do they relate to climate?

What are the plant hardy zones and how do they relate to climate?

What are the plant hardy zones and how do they relate to climate? USDA If you are involved with gardening, you probably are aware of the hardy zones listed on seed packets. The U.S. Department of Agriculture developed the zones… More »

Sun pillar

Sun pillar

Sun pillar Sun pillar at sunrise by CaptPiper The other morning, I saw a column of light above the rising sun — what was that? A rising, or setting, sun behind high clouds will sometimes project a vertical shaft of… More »

What are the northern lights?

What are the northern lights?

What are the northern lights? Aurora Borealis over Iceland, by Moyan Brenn The northern lights, also called aurora borealis, are an evening light show seen as a diffuse glow or as overlapping curtains of greenish-white and sometimes red light. Auroras… More »

Is global warming real?

Is global warming real?

Is global warming real? Image: NASA Over the past two decades, the global average surface temperature has increased noticeably. This observed warming trend indicates a significant global change and is consistent with other observed changes on our planet: There is… More »

How long have satellites been used to study Earth’s weather?

How long have satellites been used to study Earth’s weather?

How long have satellites been used to study Earth’s weather? NASA image of Explorer VII satellite, 1964 The first successful meteorological experiment conducted from a satellite was launched on Explorer VII on October 13, 1959, just over 50 years ago.… More »

Numerical Weather Forecasting is younger than rock ‘n roll!!

Numerical Weather Forecasting is younger than rock 'n roll!!

Before 1960, the idea that a reasonably accurate two-day weather forecast could be made routinely was a pipe dream – now it’s a routine reality. In fact, it was not until just after World War I that a theory concerning the structure, life cycle and precipitation distribution associated with mid-latitude cyclones, the weather systems that bring snow and rain to Madison, was first proposed by a group of Norwegian scientists, led by Vilhelm Bjerknes, an ambitious but professionally frustrated physicist. More »

How accurate are weather forecasts?

How accurate are weather forecasts?

How accurate are weather forecasts? Image: NOAA In general, weather forecasts are getting better, due to improvements in computer models, observations and our understanding of atmospheric. Accuracy depends on the purpose of the forecast and how far out it extends.… More »

Is there a relationship between sun spots and climate?

Is there a relationship between sun spots and climate?

Is there a relationship between sun spots and climate? 12th century sunspot drawing, from NASA. Since the invention of the telescope in the 1600s, observers have recorded variations in the numbers of dark spots – “sunspots” – on the Sun’s… More »

What is space weather?

What is space weather?

What is space weather? Space weather describes the conditions in space that affect Earth and its technological systems. Space weather storms originate from the sun and occur in space near Earth or in the atmosphere. Space weather, like weather here… More »

What is the dewpoint temperature?

What is the dewpoint temperature?

What is the dewpoint temperature? Dew on evergreens, by Michael Theberge at NOAA Think of a morning when you walked on a grass lawn or through a field. Did your shoes get wet? If yes, that is because the grass… More »

How does weather radar work?

How does weather radar work?

A radar unit consists of a transmitter and a receiver. The transmitter emits pulses of microwaves, a type of radio waves, outward in a circular pattern. Precipitation scatters these microwaves, sending some energy back to the transmitter, where it is detected by the radar’s receiver. The intensity of this received signal, called the radar echo, indicates the intensity of the precipitation. Measuring the time it takes for the radio wave to leave the radar and return tells us how distant the storm is. The direction the radar is pointing locates the storm. More »