Monday, July 28, 2008

Earth's Atmosphere -- Water Vapor

More heavy rains fell across New Mexico on Sunday, all thanks to the remnants of Dolly.

Can you believe that some places have seen nearly an entire year's worth of precipitation in just one weekend?

A large complex of strong to severe thunderstorms developed over central Iowa and pushed southeast, almost following the Mississippi River perfectly late Sunday. In fact some locations saw two rounds of storms.

These people just can't seem to catch a break from all the heavy rain and flooding.

Between 4pm Sunday and 1am Monday, the Ankeny Airport in Polk County, Iowa saw 4.88 inches of rain.

Several places also saw large hail, up to 3 inches in diameter in parts of the region.

The town of Pollock, Missouri (Sullivan County) saw up to 5 minutes of very large hail that measured 4.50" in diameter at times. There was a tremendous amount of damage to cars and windows as you can imagine.

Most of the St. Louis metro area picked up 1-3 inches of rain from the storms.

The CoCoRaHS maps will be exciting today to say the least so be sure to explore the maps and the daily comment reports.

Over 2 dozen intense rain reports were filed on Sunday -- great job volunteers!!!

On to our first weather lesson...the Earth's atmosphere.

The Earth's atmosphere is a complex, thin, gaseous envelope made up mostly of nitrogen and oxygen.

There is another gas found on Earth called water vapor. It varies greatly from place to place.

In warm, tropical places it can account for up to 4% of the atmospheric gases, but in cold, arctic areas it can be a mere fraction of the atmospheric composition.

Water vapor is invisible until it becomes either a liquid or solid, such as cloud droplets or ice crystals.

The changing of water vapor into liquid water is called condensation (think of dew) and the opposite is called evaporation.

Water vapor is EXTREMELY important to our atmosphere and the weather we experience. Not only does it form into liquid and solid cloud particles that grow in size and provide precipitation to the Earth, BUT it also releases large amounts of heat -- called latent heat -- when it changes from vapor into liquid water or ice.

Latent heat is an important source of energy for storms.

Water vapor is also a potent greenhouse gas because it abosrbs a portion of the Earth's outgoing radiant energy. (kind of like the glass in a greenhouse keeps the heat from escaping and mixing with the outsdie air)

So as you can see, water vapor plays a significant role in the Earth's heat-energy balance.


  1. Memorial to Reid Bryson announced today.
    Reid A. Bryson died at his home in Madison WI, 11 June of this year.
    He was born in Detroit 7 June 1920. He is survived by his wife and
    four children.
    He completed a BS at Dennison in 1941. Following basic meteorological
    training, he served 3 years in the Air Force during WWII as a weather
    forecaster. He completed his PhD in meteorology at the University of
    Chicago in 1948 and joined the Geography Department of the University
    of Wisconsin-Madison at that time. Recognizing the need for a
    more-thorough meteorological training and research program, he
    founded the UW Dept of Meteorology, which has grown to be the largest
    in the country (now Dept. of Atmospheric and Oceanic Studies) and one
    of the most productive departments in research and of students. He
    formed the Center for Climatic Research in 1963 and was instrumental
    in establishing the Inst. for Environmental Studies in 1970. He was a
    long-time member and strong supporter of AMQUA. He attended the first
    biennial meeting in Bozeman in 1970.

    Reid was a tower in the fields of meteorology, climatology,
    paleo-climatology and relationships between the climate, people and
    vegetation. Early on, he defined the geographic limits of the
    various airmasses which dominate different areas of the globe and
    showed how the climatic conditions of each provided a favorable
    environment for the various natural vegetation areas. He promoted
    continuing interaction with anthropologists, archeologists,
    biologists and geologists

    Bryson was a superb grad student's mentor. His mind seemed full of
    research ideas and countless means whereby they could be
    investigated. He planted innumerable seeds for
    meteorological/climatological research with his students. He
    produced over 200 research papers on the above topics during his career.

    Most recently, he developed a model to reconstruct past climates from
    pollen, tree-ring, geological and archeological evidence, but
    continued to offer thoughtful, critical comment on results of models
    still based on an incomplete understanding of the physical environment.

    A memorial gathering will be held at 10 am, 23 August in the
    auditorium of the Heritage Oaks facility, 6205 Mineral Point Rd.,
    Madison WI 53705, where friends and colleagues are invited to share
    their experiences with and impressions of this giant of environmental science. Reid's wife, Fran, continues to reside at the Heritage Oaks.
    Written by Wayne Wendland
    (I was lucky enough to work with Ried on one of his last books..."Past Climates of the Black HIlls: A Graphic Guide". He was an UNEP Global 500 Laureate and Emeritus Prof. of Meteorology, Geography and Eviormental Studies at the Center for Climatic Research, University of Wisconsin, Madison, WI. The most enjoyable time spent with Reid tho, was around our dinner table. Submitted by K.C. Anderson)

  2. Doing good on the blog!

  3. Chris;

    It's tough to take on what you've agreed to start when there is news like the passing of Mr. Bryson but be assured, most of us appreciate hearing about it all. My hat's off to Reid but please continue the blog...and thanks.