Drizzle

<h2 id="effects">Effects</h2>

<p>While most drizzle has only a minor immediate impact upon humans, <a href="/facts/Freezing_drizzle/EC91ewMx">freezing drizzle</a> can lead to treacherous conditions. Freezing drizzle occurs when supercooled drizzle drops land on a surface whose temperature is below freezing.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a>  These drops immediately freeze upon impact, leading to the buildup of sheet ice (sometimes called <a href="/facts/Black_ice/6NsBwANv">black ice</a>) on the surface of roads.
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<h2 id="occurrence">Occurrence</h2>

<p>Drizzle tends to be the most frequent form of precipitation over large areas of the world's oceans, particularly in the colder regions of the <a href="/facts/Subtropics/gK0KyFUD">subtropics</a>. These regions are dominated by shallow marine <a href="/facts/Stratocumulus_cloud/xMpHbmbj">stratocumulus</a> and <a href="/facts/Trade_wind_cumulus_cloud/e0emoyEp">trade wind cumulus clouds</a>, which exist entirely within the marine <a href="/facts/Boundary_layer/go8gqWM1">boundary layer</a>. Despite the low rates of surface accumulation, drizzle exerts a major influence over the structure, coverage, and radiative properties of clouds in these regions.
</p><p>This has motivated scientists to design more sophisticated and sensitive instruments such as high-frequency <a href="/facts/Radar/jk9BTbFA">radars</a> which can detect drizzle. These studies have shown that the quantity of drizzle is strongly linked to cloud morphology and tends to be associated with updrafts within the marine boundary layer. Increased amounts of drizzle tend to be found in marine clouds that form in clean air masses that have low concentrations of cloud droplets. This interconnection between clouds and drizzle can be explored using high-resolution numerical modelling such as <a href="/facts/Large_eddy_simulation/ULBNg1SY">large eddy simulation</a>.
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<h2 id="influence-of-aerosols">Influence of aerosols</h2>
<p>It has been hypothesized by a group of atmospheric scientists at <a href="/facts/Texas_A%26M_University/s1zDpnxa">Texas A&M University</a><a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> that <a href="/facts/Particulates/RleGr5E6">particulates</a> in the atmosphere caused by human activities may suppress drizzle. According to this hypothesis, because drizzle can be an effective means of removing moisture from a cloud, its suppression could help to increase the thickness, coverage, and longevity of marine <a href="/facts/Stratocumulus_cloud/xMpHbmbj">stratocumulus</a> clouds. This would lead to increased cloud <a href="/facts/Albedo/TJDRdKEB">albedo</a> on a regional to global scale, and a cooling effect on the atmosphere. Estimates using complex global <a href="/facts/Climate_model/5xQBYLcl">climate models</a> suggest that this effect may be partially masking the effects of <a href="/facts/Greenhouse_effect/LGdNYYj3">greenhouse gas</a> increases on <a href="/facts/Global_surface_temperature/oddUmrb4">global surface temperature</a>. However, it is not clear that the representation of the chemical and physical processes needed to accurately simulate the interaction between aerosols, clouds, and drizzle in current (as of 2005<a href="https://en.wikipedia.org/w/index.php?title=Drizzle&action=edit">[update]</a>) climate models is sufficient to fully understand the global impacts of changes in particulates.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a>
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<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Fog/mrIdyIc7">Fog</a></li>
<li><a href="/facts/Mist/BywtmoJd">Mist</a></li>
<li><a href="/facts/Rain/MLqcQEyx">Rain</a></li>
<li><a href="/facts/Snow_grains/ULorDjDR">Snow grains</a></li></ul>

Wikimedia Commons has media related to Drizzle.

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>National Weather Service Observing Handbook No. 8, Aviation Weather Observations for Supplementary Aviation Weather Reporting Stations (SAWRS), Manual Observations, October 1996 <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Spence, Charles F. (2006). Aim/Far. McGraw Hill Professional. p. 294. ISBN 978-0-07-147924-0. <a href="978-0-07-147924-0" target="_blank">978-0-07-147924-0</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Henson, Robert; Guides, Rough (2007). The Rough Guide to Weather. Penguin. p. 63. ISBN 978-1-4053-8461-2. <a href="978-1-4053-8461-2" target="_blank">978-1-4053-8461-2</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>"Can Aerosols Influence Weather Patterns?". Texas A&M Today. 2018-01-22. Retrieved 2019-05-24. <a href="https://today.tamu.edu/2018/01/22/texas-am-researcher-examines-aerosols-and-their-impact-on-clouds-weather/" target="_blank">https://today.tamu.edu/2018/01/22/texas-am-researcher-examines-aerosols-and-their-impact-on-clouds-weather/</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
<li id="fn:5"><p>"Are aerosols reducing coastal drizzle and increasing cloud cover?". Eurekalert.org. 2005-06-30. Retrieved 2013-08-25. <a href="http://www.eurekalert.org/pub_releases/2005-06/ddoe-aar063005.php" target="_blank">http://www.eurekalert.org/pub_releases/2005-06/ddoe-aar063005.php</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li>
</ol>

Drizzle open-in-new

Drizzle