Lifted temperature minimum during the atmospheric evening transition
Observations of lifted temperature minimum (LTM) profiles in the nocturnal boundary layer were first reported in 1932. It was defined by the existence of a temperature minimum some centimetres above the ground. During the following decades, several research studies analysed this phenomenon verifying...
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doaj-1ec102b11513404bbff5af62dd2bc8f92020-11-24T21:38:05ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242015-06-0115126981699110.5194/acp-15-6981-2015Lifted temperature minimum during the atmospheric evening transitionE. Blay-Carreras0E. R. Pardyjak1D. Pino2S. W. Hoch3J. Cuxart4D. Martínez5J. Reuder6Department of Applied Physics, Universitat Politècnica de Catalunya, BarcelonaTech, Barcelona, SpainDepartment of Mechanical Engineering, University of Utah, Salt Lake City, UT, USADepartment of Applied Physics, Universitat Politècnica de Catalunya, BarcelonaTech, Barcelona, SpainDepartment of Atmospheric Sciences, University of Utah, Salt Lake City, UT, USAGrup de Meteorologia, Departament de Física, Universitat de les Illes Balears, Palma de Mallorca, SpainCenter for Applied Geoscience, University of Tübingen, Tübingen, GermanyGeophysical Institute, University of Bergen, Bergen, NorwayObservations of lifted temperature minimum (LTM) profiles in the nocturnal boundary layer were first reported in 1932. It was defined by the existence of a temperature minimum some centimetres above the ground. During the following decades, several research studies analysed this phenomenon verifying its existence and postulating different hypotheses about its origin. <br><br> The aim of this work is to study the existence and characteristics of LTM during the evening transition by using observations obtained during the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) campaign. Data obtained from two masts instrumented with thermocouples and wind sensors at different heights close to the ground and a mast with radiometers are used to study the role of mechanical turbulence and radiation in LTM development. <br><br> The study shows that LTM can be detected under calm conditions during the day–night transition, several hours earlier than reported in previous work. These conditions are fulfilled under weak synoptic forcing when the local flow shifts associated with a mountain–plain circulation in relatively complex orography. Under these special conditions, turbulence becomes a crucial parameter in determining the ideal conditions for observing LTM. Additionally, LTM observed profiles are also related to a change in the atmospheric radiative characteristics under calm conditions.http://www.atmos-chem-phys.net/15/6981/2015/acp-15-6981-2015.pdf |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
E. Blay-Carreras E. R. Pardyjak D. Pino S. W. Hoch J. Cuxart D. Martínez J. Reuder |
spellingShingle |
E. Blay-Carreras E. R. Pardyjak D. Pino S. W. Hoch J. Cuxart D. Martínez J. Reuder Lifted temperature minimum during the atmospheric evening transition Atmospheric Chemistry and Physics |
author_facet |
E. Blay-Carreras E. R. Pardyjak D. Pino S. W. Hoch J. Cuxart D. Martínez J. Reuder |
author_sort |
E. Blay-Carreras |
title |
Lifted temperature minimum during the atmospheric evening transition |
title_short |
Lifted temperature minimum during the atmospheric evening transition |
title_full |
Lifted temperature minimum during the atmospheric evening transition |
title_fullStr |
Lifted temperature minimum during the atmospheric evening transition |
title_full_unstemmed |
Lifted temperature minimum during the atmospheric evening transition |
title_sort |
lifted temperature minimum during the atmospheric evening transition |
publisher |
Copernicus Publications |
series |
Atmospheric Chemistry and Physics |
issn |
1680-7316 1680-7324 |
publishDate |
2015-06-01 |
description |
Observations of lifted temperature minimum (LTM) profiles in the nocturnal
boundary layer were first reported in 1932. It was defined by the existence
of a temperature minimum some centimetres above the ground. During the
following decades, several research studies analysed this phenomenon
verifying its existence and postulating different hypotheses about its
origin.
<br><br>
The aim of this work is to study the existence and characteristics of LTM
during the evening transition by using observations obtained during the
Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) campaign. Data
obtained from two masts instrumented with thermocouples and wind sensors at
different heights close to the ground and a mast with radiometers are used
to study the role of mechanical turbulence and radiation in LTM development.
<br><br>
The study shows that LTM can be detected under calm conditions
during the day–night transition, several hours earlier than reported in
previous work. These conditions are fulfilled under weak synoptic forcing
when the local flow shifts associated with a mountain–plain circulation in
relatively complex orography. Under these special conditions, turbulence
becomes a crucial parameter in determining the ideal conditions for observing
LTM. Additionally, LTM observed profiles are also related to
a change in the atmospheric radiative characteristics under calm conditions. |
url |
http://www.atmos-chem-phys.net/15/6981/2015/acp-15-6981-2015.pdf |
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AT eblaycarreras liftedtemperatureminimumduringtheatmosphericeveningtransition AT erpardyjak liftedtemperatureminimumduringtheatmosphericeveningtransition AT dpino liftedtemperatureminimumduringtheatmosphericeveningtransition AT swhoch liftedtemperatureminimumduringtheatmosphericeveningtransition AT jcuxart liftedtemperatureminimumduringtheatmosphericeveningtransition AT dmartinez liftedtemperatureminimumduringtheatmosphericeveningtransition AT jreuder liftedtemperatureminimumduringtheatmosphericeveningtransition |
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