World Library  
Flag as Inappropriate
Email this Article

Diurnal temperature variation

Article Id: WHEBN0012040404
Reproduction Date:

Title: Diurnal temperature variation  
Author: World Heritage Encyclopedia
Language: English
Subject: Twyfelfontein, Viticulture, Climate of Argentina, Passive solar building design, Temperature range
Collection: Basic Meteorological Concepts and Phenomena, Viticulture
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Diurnal temperature variation

Diurnal temperature variation is a meteorological term that relates to the variation in temperature that occurs from the highs and lows during the day.

Contents

  • Temperature lag 1
  • Differences in variation 2
  • Viticulture 3
  • See also 4
  • References 5

Temperature lag

Temperature lag is an important factor in diurnal temperature variation: peak daily temperature generally occurs after noon, as air keeps net absorbing heat even after noon, and similarly minimum daily temperature generally occurs substantially after midnight, indeed occurring during early morning in the hour around dawn, since heat is lost all night long. The analogous annual phenomenon is seasonal lag.

As solar energy strikes the earth’s surface each morning, a shallow 1–3-centimetre (0.39–1.18 in) layer of air directly above the ground is heated by conduction. Heat exchange between this shallow layer of warm air and the cooler air above is very inefficient. On a warm summer’s day, for example, air temperatures may vary by 16.5 °C (30 °F) from just above the ground to waist height. Incoming solar radiation exceeds outgoing heat energy for many hours after noon and equilibrium is usually reached from 3–5 p.m. but this may be affected by a variety of different things such as large bodies of water, soil type and cover, wind, cloud cover/water vapor, and moisture on the ground.[1]

Differences in variation

Diurnal temperature variations are greatest very near the earth’s surface.

High desert areas typically have the greatest diurnal temperature variations. Low lying, humid areas typically have the least. This explains why an area like the Snake River Plain can have high temperatures of 38 °C (100 °F) during a summer day, and then have lows of 5–10 °C (41–50 °F). At the same time, Washington D.C., which is much more humid, has temperature variations of only 8 °C (14 °F);[1] urban Hong Kong has a diurnal temperature range of little more than 4 °C (7 °F). Charaña, Bolivia averages a DTR of 50 °F (28 °C) in July, while Hayfork, California averages 48 °F (27 °C) in August.[2]

While the National Park Service claimed that the world record is a variation of 102 °F (57 °C) (from 46 °F (8 °C) to −56 °F (−49 °C)) in Browning, Montana in 1916,[3] the Montana Department of Environmental Quality claimed that Loma, Montana had a variation of 103 °F (57 °C) (from −54 °F (−48 °C) to 49 °F (9 °C)) in 1972.[4]

Viticulture

Diurnal temperature variation is of particular importance in viticulture. Wine regions situated in areas of high altitude experience the most dramatic swing in temperature variation during the course of a day. In grapes, this variation has the effect of producing high acid and high sugar content as the grapes' exposure to sunlight increases the ripening qualities while the sudden drop in temperature at night preserves the balance of natural acids in the grape.[5]

See also

References

  1. ^ a b M. Hackworth "Weather & Climate" course notes, with prior permission
  2. ^ http://www.weatherbase.com/weather/weather.php3?s=958340 or use NOAA (no direct link)
  3. ^ Weather - Glacier National Park
  4. ^ Montana Department of Environmental Quality (DEQ) - FAQ
  5. ^ J. Robinson "The Oxford Companion to Wine" Third Edition pg 691 Oxford University Press 2006 ISBN 0-19-860990-6

JohnCatharine1692..

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.