today

8:30 a.m. 4th Annual Redwood Coast Broadband Forum Fortuna River Lodge

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9 a.m. Learn To Row! Humboldt Bay Rowing Association

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10 a.m. Eureka Farmers Market Henderson Center

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11 a.m. Kindergarten, Here I Come! Willow Creek Library

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noon Redwood Art Association Summer Exhibition Redwood Art Association Gallery

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noon August Farmers' Market-Style Produce Distribution Food for People

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1 p.m. Kindergarten, Here I Come! Hoopa Library

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3 p.m. TeenArts Morris Graves Museum of Art

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3:30 p.m. McKinleyville Farmers' Market McKinleyville Safeway Shopping Plaza

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6 p.m. Americans for Safe Access Bayview Courtyard Complex

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6 p.m. Matthew Cook Cher-Ae-Heights Casino

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6 p.m. Bill McBride and Friends Hotel Ivanhoe

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6 p.m. McKinleyville Concerts in the Park: Triple Junction Pierson Park

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6:30 p.m. Seabury Gould at Gallagher's Gallagher's

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7 p.m. Blue Grass Jam Old Town Coffee & Chocolates

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7 p.m. All ages Open Mic East Side Deli

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7 p.m. Yo Tango Jambalaya

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7 p.m. Benbow Summer Jazz Series: Lee Waterman Jazz Caliente Benbow Inn

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8 p.m. Karaoke WAVE @ blue lake casino

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8 p.m. Karaoke at Bear River Casino Bear River Casino

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8 p.m. Dave Wilson Muddy's Hot Cup

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8 p.m. AuralScopic Accident Gallery

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9 p.m. Soldiers of Shangri-la Six Rivers Brewery

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9 p.m. Dancehall/Reggae Thursday with Rude Lion Sound DJ Jimmy Jonz The Red Fox Tavern

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9 p.m. Idle Threat, No Cigar, Social Ills The Boiler Room

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9 p.m. Hello Echo Humboldt Brews

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10 p.m. Music by DJ Sidelines

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10 p.m. Indian Jewelry, The Invasions, Sweaty Sweaters The Lil' Red Lion

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previous columns

Jan. 31, 2008

Stick-Slip Slug Slime

Banana slugs evolved from snails, and both are classified as ...

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Jan. 24, 2008

Watts in Coffee, Pot and Brakes?

I am reading a full page ad in our local ...

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Jan. 17, 2008

What is Our Bedrock?

Our bedrock consists of an exceptional diversity of rocks spanning ...

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  • Diagram of atmospheric absorption of radiation ranging from ultraviolet to thermal infrared. By Don Garlick. Diagram of atmospheric absorption of radiation ranging from ultraviolet to thermal infrared. By Don Garlick.
Can You Predict Rain?

Can You Predict Rain?

By Don Garlick

Yes, by simply learning how to interpret available data. The best window into tomorrow's weather is a movie which compresses several hours of satellite-observations into a few seconds: Google "Eureka Weather" and click Current Conditions — East Pacific — Infrared — Loop. After some experience you will be able to reasonably forecast our weather by extrapolating those satellite observations. For precipitation within the next few hours, click Doppler Radar. The following is an introduction to the science behind these sophisticated tools.

The diagram plots the atmospheric absorption of radiation ranging from ultraviolet (wavelength < 0.4 microns) through visible light (0.4-0.7 microns) and reflected infrared (0.7-3 microns) to thermal infrared (wavelength > 3 microns). The UV absorption is due to ozone. Most of the rest is due to water vapor, excepting those bands shown darker which are due to carbon dioxide. Absorption near 13 microns is of global warming concern.

A geostationary satellite 35,786 km above the equator detects radiation at a variety of wavelengths. One detector near 0.7 microns provides the positive "VIS" image composed of reflected visible sunlight. One near 11 microns yields the negative "IR" image. It is centered on an atmospheric window which transmits thermal infrared energy from the Earth's surface, providing clouds are absent. When clouds are present, their cool tops radiate less energy (lighter tones in the negative image). When storm clouds reach very cold altitudes, the IR image is enhanced with false colors. A detector near 7 microns cannot see the Earth's surface because of intervening water vapor. However, when the atmosphere is drier it detects thermal radiation from lower warmer air. This detector yields the water vapor "WV" image (also negative). The IR and WV images are produced day and night. But don't let them keep you awake.

Rain-detecting Doppler radar is next-week's topic.

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