The Bowen Ratio/Energy Balance method and detailed temperature profile measurements to improve data quality control

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62156489%3A43210%2F15%3A43908078" target="_blank" >RIV/62156489:43210/15:43908078 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/67179843:_____/15:00456516

Výsledek na webu

<a href="http://envimet.czechglobe.cz/files/present/akce/SbornikKonference.pdf" target="_blank" >http://envimet.czechglobe.cz/files/present/akce/SbornikKonference.pdf</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

The Bowen Ratio/Energy Balance method and detailed temperature profile measurements to improve data quality control

Popis výsledku v původním jazyce

Water plays a key role in the functionality and sustainability of ecosystems. In light of predicted climate change, research should focus on the water cycle and its individual components. The main component of water balance driving water from ecosystems is evapotranspiration (ET). One standard method for measuring ET is the Bowen Ratio/Energy Balance (BREB) method. It is based on the assumption that water vapour and heat are transported by identical eddies with equal efficiency. When using the BREB method, we assume that the profiles of temperature and air humidity are ideally logarithmic or at least consistent. Since the BREB method is usually based on measurements of temperature and humidity at only two heights, it is difficult to verify whether this assumption has been fulfilled. Potential profile inconsistencies are more likely for temperature because the sensible heat flux changes its sign more often and negative latent heat flux is not physically possible during positive sensible heat flux. We therefore conducted a field experiment using a 4-m-high measurement mast with 20 thermocouples for detailed measurement of air temperature profiles above different covers, e.g. grassland, spring barley, and poplar plantations. Our main objective was to investigate the basic assumptions of the BREB method, i.e. the temperature profile's consistency under various weather conditions. To be more specific, we aimed to investigate whether inflexion points occurred within the temperature profile and if so when.

Název v anglickém jazyce

The Bowen Ratio/Energy Balance method and detailed temperature profile measurements to improve data quality control

Popis výsledku anglicky

Water plays a key role in the functionality and sustainability of ecosystems. In light of predicted climate change, research should focus on the water cycle and its individual components. The main component of water balance driving water from ecosystems is evapotranspiration (ET). One standard method for measuring ET is the Bowen Ratio/Energy Balance (BREB) method. It is based on the assumption that water vapour and heat are transported by identical eddies with equal efficiency. When using the BREB method, we assume that the profiles of temperature and air humidity are ideally logarithmic or at least consistent. Since the BREB method is usually based on measurements of temperature and humidity at only two heights, it is difficult to verify whether this assumption has been fulfilled. Potential profile inconsistencies are more likely for temperature because the sensible heat flux changes its sign more often and negative latent heat flux is not physically possible during positive sensible heat flux. We therefore conducted a field experiment using a 4-m-high measurement mast with 20 thermocouples for detailed measurement of air temperature profiles above different covers, e.g. grassland, spring barley, and poplar plantations. Our main objective was to investigate the basic assumptions of the BREB method, i.e. the temperature profile's consistency under various weather conditions. To be more specific, we aimed to investigate whether inflexion points occurred within the temperature profile and if so when.

Druh

D - Stať ve sborníku

CEP obor

GC - Pěstování rostlin, osevní postupy

OECD FORD obor

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Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Global Change: a Complex Challenge

ISBN

978-80-87902-10-3

ISSN

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e-ISSN

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Počet stran výsledku

4

Strana od-do

62-65

Název nakladatele

Centrum výzkumu globální změny AV ČR, v.v.i.

Místo vydání

Brno

Místo konání akce

Brno

Datum konání akce

23. 3. 2015

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

000381161600014