DICE at the GEWEX conference

• Presentation (to be uploaded) in the land-atmosphere oral session, giving brief overview of DICE

DICE break-out: Tuesday 15th July 2014

• Updates on case analysis from Martin Best, LSMs(to be uploaded), and Adrian Lock, SCMs plus summary and next steps

Notes from discussion

• missing data and reruns
  • Sanity check: please could all participants take a look at the above presentations and check that the results we are plotting for their model are consistent with how it looks to them
  • stage 1a: LSMs resubmit including surface stress and skin temperature (both 2m and 55m forcing), if they haven't already
  • stage 1a: could all LSMs submit their ancillary data (ie, number of tiles, tile fractions, LAI, green fraction, root depth, canopy height, etc as appropriate)
  • stage 3b: SCMs will then need to rerun with consistent surface data from the LSMs
• points for further analysis:
  • Stage 1a: should be straightforward to understand reasons for excessive u_* in some LSMs
    • Simply excessive z0? If so why (eg canopy height, LAI)?
  • Stage 1a: u_* distributions very different (fall into 2 groups)
    • Could all groups provide u_* from LSMs
  • Stage 1a: some LSMs have different daytime fluxes forced by 2m and 55m
    • Similarity theory not holding?
  • Stage 2 coupling: some positive, some negative feedbacks on surface fluxes (cf stage 1a)
  • Stage 2 coupling: net LW enhanced by day (increased upward LW) with less SHF
    • implies change in near surface T gradients?
  • Interesting soil heat flux "hysteresis" between day and night in some models
    • Why this difference and what is the impact?
  • Stage 1b,3b: why do some SCM mix out the inversion?
    • Dependent on parametrization structure (eg non-local vs EDMF vs higher order)?
    • Does it matter? Affects PBL budget so can effects be seen in going from stage 1a -> 2?
• next steps:
  • Timetable for reruns:
    • end August: additional data back from stage 1a
    • start of September: release revised stage 3b forcing data
    • end September: revised stage 3b runs submitted
  • Martin and Adrian to write up intercomparison
    • Overview paper plus two separate papers on LSM and SCM analyses, respectively
  • Special issue (eg BLM): to include participants' own analyses, model sensitivities, etc
  • DICE datasets: should submitted data be put on the web too?
    • issues with lack of consistency in data formats between models, etc
    • Martin/Adrian could send link to data on request?
  • Possible follow-up workshop joint with GABLS4 in Spring 2015 (location TBD)
  • Future case possibilities, extending to clouds and precipitation:
    • based around the 4 AMMA sites in Couvreux et al (BLM 2014)
    • another SGP ARM site case, potentially linked to CAUSES