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University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice CLASSIC –AMMA Fieldwork 2005/2006 and modelling activities Jon.

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Presentation on theme: "University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice CLASSIC –AMMA Fieldwork 2005/2006 and modelling activities Jon."— Presentation transcript:

1 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice CLASSIC –AMMA Fieldwork 2005/2006 and modelling activities Jon Bennie, Claire Damesin, Josiane Seghieri and Lina Mercado

2 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Outline Motivation and objectives About the JULES model CLASSIC –CESBIO measurements What have we learned from measurements Model evaluation using physiological measurements 2006 Fieldwork campaign

3 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Aim: To collect physiological and environmental data to improve the performance of land-surface models, particularly JULES (The Joint UK land atmosphere simulator) in arid environments. Evaluate the sensitivity of plant physiological processes to temporal and spatial variations in climate. Sensitivity analysis – what parameters are most important in constraining fluxes in the land surface scheme? Objectives:

4 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Campaign (2005/2006) objectives :  Characterise diurnal cycle and spatial variability of surface temperatures (soil and plants) and soil moisture.  Characterise diurnal cycle of Photosynthesis and stomatal conductance – interspecies comparison under the same conditions.  Changes in leaf area index and plant fractional cover during the measuring period.

5 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice What did we measure? Diurnal cycles of:  Photosynthesis and transpiration (IRGA)  Stomatal conductance (porometer, IRGA)  Leaf water potential (pressure chamber) Characterisation of species leaf-level response to light and temperature (IRGA). Leaf level measurements on herbaceous and woody plants

6 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice What did we measure? Soil and leaf temperatures : Tsoil :bare soil, soil under vegetation Tvegetation: sun/shade leaf herbaceous woody plants Tstems Soil moisture -Sampled within the flux tower footprint - Within a 1km transect

7 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Continuous surface and sub-surface temperatures and soil moisture What did we measure?

8 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice What did we measure? LAI, fractional cover and vegetation classifications (CESBIO protocols)

9 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice The sun Team What have we learned ?

10 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Comparison of G s and LWP among C 3 and C 4 species 12/08/05 13/08/05 15/08/05 TragusAlysicarpus Cenchrus ZorniaDact.BalanitesComb. YComb. A C3C3 C3C3 C3C3

11 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice The ‘shade’ Team

12 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Transect sampling of surface temperature herbs bare soil 11 th Aug. 05 Sampling along 1 km transects within the footprint of the flux tower

13 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice JULES The Joint UK Land Environment Simulator (JULES), based on MOSES, the original land surface scheme of the Hadley Centre GCM. JULES is being developed with regular “official” releases (currently JULES v.1.0) and a modular structure. The flexible structure is intended to allow it to be modified and developed by the community to suit different requirements, spatial scales (from flux-tower to global models) and complexity.

14 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Assessing JULES

15 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice JULES runs using Agoufou met data. August 14 th Surface conductanceGross primary productivity Evapotranspiration

16 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Preliminary analysis suggests : -Current JULES parameterisation of the Farquhar model of photosynthesis for C 3 plants leads to much lower g s than observed in leaf-level field measurements. -We expect an underestimation of water fluxes from the landscape even when C 3 plants are not the dominant functional type. -e.g. If the ratio of C3/C4 cover is 0.35, mean daily error for July-August 2005 water flux would be 25%. -Full sensitivity analysis of JULES to soil and plant physiological parameters at the site is planned.

17 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Fieldwork campaign 2006 Continue measurements initiated in 2005  Further diurnal cycles of physiological variables stomatal conductance and photosynthesis  Complete data-set of leaf-level responses for dominant woody and herbaceous species at the site – temperature, PAR, CO 2, soil moisture.  Continuous surface measurements (IRT) and (transects within tower flux print and 1km) Soil moisture Plant and soil temperature

18 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Fieldwork campaign 2006 Possible new measurements in 2006 (to discuss) Within the flux foot print  Leaf optical properties Measurements of reflectance and transmittance to infer leaf absorptance (possible use of Field spectroradiometer)  Soil properties Bulk density/porosity; soil moisture release data Heat conductivity and heat capacity Water potential/water content curve

19 University of Wales Swansea CEH Wallingford CEH Monks Wood University of Durham MetOffice Aknowledgements Valerie Le Dantec, Eric Mougin,Frank Timouk, Francois Lavenu, Francoise Guichard, Laurent Kergoat, Colin Lloyd, Chris Taylor, Caroline Bain, Caroline Houldcroft,Frederic Baup, Alexi Berg, Richard Dupont,Amusthapha Traore, Amusthapha, Yacuba,Taraweti


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