follow Dictionary.com

11 Trending Words of 2014

transition region

noun, Astronomy
1.
a thin and very irregular layer of the sun's atmosphere that separates the hot corona from the much cooler chromosphere.
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
transition region in Science
transition region  
  1. The area in a seed-bearing plant where the vascular tissue of the root changes into the vascular tissue of the stem. In eudicotyledons, the roots have a solid cylinder of vascular tissue surrounded by cortex. The vascular tissues gradually branch apart and reorient themselves in the stem around a central pith.

  2. The thin layer of the solar atmosphere that separates the chromosphere from the corona. In the transition region, temperatures increase from a relatively cool 20,000°K in the chromosphere to the 1,000,000°K and higher temperatures of the corona. Transition region chemistry involves the ionization of hydrogen and other elements; the light produced by this region comes from ionized forms of carbon, oxygen, and silicon.


The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for transition region

Few English speakers likely know this word

Word Value for transition

10
12
Scrabble Words With Friends