Australian Nuclear Science & Technology Organisation First IPILPS Workshop: Closure & Thanks Ann Henderson-Sellers and the IPILPS Team

IPILPS - Why Are We All Here? Fluxes & reservoirs of isotopes H 2 18 O & HD 16 O have utility in surface energy & water budgets Stable isotopic interpretation of basin water budgets adds information on gross water fluxes The promise for isotopic finger-printing of near- surface water cycle has real breakthru’ potential Goals this week: Demonstrate that our ILSSs generate plausible simulations and/or improve them Journal papers: – Global & Planetary Change Better links H 18 O H H D 16 O H H

Workshop Goal 1: “Plausibility” Plausibility: are simulations ‘good enough’ can we define ‘plausibility’? gross fluxes first e.g.PILPS plots To demonstrate that Isotopically-enabled Land Surface Schemes (ILSSs) generate plausible simulations at the diurnal scale of the exchanges of Stable Water Isotopes (SWIs) at the soil, plant, air interfaces or to identify their shortcomings and propose ways of improving the simulations. Latent Heat (W m -2 ) Sensible Heat (W m -2 ) Manaus Tumbarumba Munich Manaus

ILSSs Evaluation Procedures How to evaluate current and future ILSS simulations & provide useful feedback : Check the gross water and energy FIRST Need conservation, equilibration and ‘plausibility’ Diurnal ‘shapes’ should ‘look right’ –Ranges of each models’ simulation ‘reasonable’ Some ‘metrics’ need to be met adequately –Bungy chords not too stretched  D v  18 O plots should ‘look right’ –polar diagrams in correct sectors –polar plots from a ‘known’ base – polar plots with radius ‘r’ & angle Net Rad LWnet SWnet Evap r  DD  18 O

ILSSs Evaluation Methods: Metrics ?What can we assert SWIs ought to be like? PR-C<0.1‰ TR-S<10‰ RS-S??? ‰ CE-C<20‰ TR-P<10‰ PR-RS<10‰ SE-S<20‰

Plausible budget & seasonal variability δ 18 O in water flux (‰) Water Flux (mm/year) δ 18 O in water flux (‰) Water Flux (mm/year) Manaus Tumbarumba Manaus Tumbarumba

ILSSs Evaluation Methods: Values Check: Conservation; Equilibration; Plausibility ENERGYGROSS H 2 OStable Isotopes Conservation< 0.1 Wm -2 <0.1 mmd -1 <0.1*SMOW Equilibration< 0.1 Wm -2 <0.1 mmd -1 <0.1*SMOW Plausibility Seasonal < 1 Wm -2 <1 mmd -1 <1*SMOW Plausibility 3-hour avs < 10 Wm -2 <10 mm<10*SMOW

Workshop Goal 2: Improving ILSSs  Specific Foci: 1.are simulation diffs due to (i) sensitivity to forcing; (ii) parameterisation differences; (iii) both? 2.is Craig & Gordon ‘adequate’? ( & if not what is required?) 3.on diurnal scales how large are SWI differences; what observations could illuminate ‘adequacy’? To demonstrate that Isotopically-enabled Land Surface Schemes (ILSSs) generate plausible simulations at the diurnal scale of the exchanges of Stable Water Isotopes (SWIs) at the soil, plant, air interfaces or to identify their shortcomings and propose ways of improving the simulations.

Diurnal Isotopic Flux Simulations ‘Other’ evaporation differs very much B doesn’t seem to do transpiration D has single value Transpiration range similar for C & A But C shows much more depletion in middle of the day This is winter (Tumbarumba) Jan is summer Transpiration (‰) Soil & Veg Evap (‰)  D moisture fluxes: transpiration & other evap (A-D)

Workshop Goal 3: Good Observations Transpiration (‰)  D flux ?are simulation diffs due to (i) sensitivity to forcing; (ii) parameterisation differences; and/or (iii) both? ?is Craig & Gordon ‘adequate’? ( & if not what is?) ?on diurnal scales how large are SWI differences; what observations could illuminate ‘adequacy’? This plot suggests parameterisation diffs here Might suggest C&G not adequate Obs here need to be < ‰ (  D transp n ) Let’s measure what we CAN measure well, well

Workshop Output: Special Issue G&P Henderson-SellersOverview of IPILPS & Phase 1 Gat & AireySWIS at the Soil, Plant Atmosphere Interface GatScaling issues for SWIs GibsonBasins & SWIs Fischer & SturmREMOiso Forcing for IPILPS Fischer et alIPILPS Phase 1 First results TwiningMIBA at Tumbarumba SturmSWIs at Heidelburg GriffithFTIR for SWI observations for IPILPS YoshimuraMATSIROiso in IPILPS FischerICHASM in IPILPS Schmidt & AleinovGISSEiso in IPILPS  Papers due with Kendal by 31 May

Future: Sensitivity Experiments: Soon PLAN Use current IPILPS forcings and locations Quick ‘add on’ for ILSSs that pass gross and isotope plausibility tests FORCING Precipitation isotopes –Fixed –Step-function Vapour isotopes –Fixed (needs to be linked to precip.) MODEL PARAMETERS –Water reservoir capacities HOW-TO ICHASM a ‘test case’ + maybe MATSIROiso

very Isotopes in LSSs are very young Named Sam by his parents who haven’t yet told him this stands for  “Soil Atmosphere Model”  But clearly worth nurturing

Great Group – many thanks