مؤتمر
Momentum, sensible heat and CO2 correlation coefficient: what can we learn from 20 years of eddy covariance measurements
| العنوان: | Momentum, sensible heat and CO2 correlation coefficient: what can we learn from 20 years of eddy covariance measurements Coefficients de correlation pour la quantité de mouvement, la chaleur sensible et le CO2: que peux-t'on apprendre de 20 années de mesures d'Eddy Covariance |
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| المؤلفون: | Hurdebise, Quentin, De Ligne, Anne, Vincke, Caroline, Heinesch, Bernard, Aubinet, Marc |
| المساهمون: | Service public de Wallonie : Direction générale opérationnelle de l'agriculture, des ressources naturelles et de l'environnement - DG03, sponsor, TERRA Teaching and Research Centre - TERRA, research center |
| سنة النشر: | 2017 |
| مصطلحات موضوعية: | Canopy aerodynamic distance, Turbulence, Eddy covariance, Physical, chemical, mathematical & earth Sciences :: Physics, Physique, chimie, mathématiques & sciences de la terre :: Physique |
| جغرافية الموضوع: | international |
| الوصف: | Long-term data series of carbon dioxide and other gas exchanges between terrestrial ecosystems and atmospherebecome more and more numerous. Long-term analyses of such exchanges require a good understanding ofmeasurement conditions during the investigated period. Independently of climate drivers, measurements mayindeed be influenced by measurement conditions themselves subjected to long-term variability due to vegetationgrowth or set-up changes.The present research refers to the Vielsalm Terrestrial Observatory (VTO) an ICOS candidate site locatedin a mixed forest (beech, silver fir, Douglas fir, Norway spruce) in the Belgian Ardenne. Fluxes of momentum,carbon dioxide and sensible heat have been continuously measured there by eddy covariance for more than 20years. During this period, changes in canopy height and measurement height occurred.The correlation coefficients (for momemtum, sensible heat and CO2) and the normalized standard deviationsmeasured for the past 20 years at the Vielsalm Terrestrial Observatory (VTO) were analysed in orderto define how the fluxes, independently of climate conditions, were affected by the surrounding environmentevolution, including tree growth, forest thinning and tower height change.A relationship between canopy aerodynamic distance and the momentum correlation coefficient was foundwhich is characteristic of the roughness sublayer, and suggests that momentum transport processes were affectedby z-d. In contrast, no relationship was found for sensible heat and CO2 correlation coefficients, suggestingthat the z-d variability observed did not affect their turbulent transport. There were strong differences in thesecoefficients, however, between two wind sectors, characterized by contrasted stands (height differences, homogeneity)and different hypotheses were raised to explain it. This study highlighted the importance of takingthe surrounding environment variability into account in order to ensure the spatio-temporal consistency of datasets. |
| نوع الوثيقة: | conferencePoster |
| وصف الملف: | A0 |
| اللغة: | English |
| Relation: | European Goesciences Union General Assembly 2017, Vienna, Austria (du 23 avril 2017 au 28 avril 2017) |
| URL الوصول: | https://orbi.uliege.be/handle/2268/211448 |
| حقوق: | info:eu-repo/semantics/openAccess |
| رقم الأكسشن: | edsorb.211448 |
| قاعدة البيانات: | ORBi |
| الوصف غير متاح. |