cesm/esmf progress report
DESCRIPTION
CESM/ESMF Progress Report. Mariana Vertenstein NCAR Earth System Laboratory CESM Software Engineering Group (CSEG). NCAR is sponsored by the National Science Foundation. CESM Community. Registered CESM Release Users 4240 Total registered users 1110 New users in past 12 months - PowerPoint PPT PresentationTRANSCRIPT
CESM/ESMF Progress CESM/ESMF Progress ReportReport
Mariana Vertenstein
NCAR Earth System LaboratoryCESM Software Engineering Group (CSEG)
NCAR is sponsored by the National Science Foundation
CESM CommunityCESM Community Registered CESM Release Users
• 4240 Total registered users• 1110 New users in past 12 months
DiscussCESM Forums Bulletin Board http://bb.cgd.ucar.edu
• 1793 Total Registered users• 14 Top level forums with 77 sub-forums• 5229 Total posts (topics + comments) • 800 posts since March 2014
Registered CESM Developers• 290 Total registered users – vetted annually
CESM Architecture (CPL7)CESM Architecture (CPL7) Single executable 7 geophysical components / 1 coupler (hub)
– atm, land, river, land-ice, sea-ice, ocean, wave– run on potentially different grids – exchange boundary data with each other
Hub and Spoke architecture– components communicate with each other ONLY a
coupler (hub and spoke architecture)– components/hub can run on unique PES
concurrently) or overlapping PES (sequentially) or hybrid layout
– components can be prognostic or prescribed -data Model Driver
– runs on union of all component/hub PES – coordinates time evolution of system
CESM Architecture (cont) CESM Architecture (cont)
processors
tim
e CPL (regridding, merging)
CAM
CLM
CICE
Driver (controls time evolution)
POP
Sequential Layout
processors
Hybrid Sequential/Concurrent Layout
CAM
CLM CICE
POP
Driver
CPL
CPL
Driver (controls time evolution)
Concurrent Layout
CAM CLM CICE POP
processors
tim
e
CESM/ESMF Offline CESM/ESMF Offline RegriddingRegridding
ESMF offline regridding has – completely changed the ability of CESM to
run on new grids – both structured and unstructured
– Enabled new science! CESM has now introduced new tool chain
based on the ESMF offline regridding– capability has been introduced as part of the
CESM releases in top level directory What took days (even weeks) now takes
hours to create
Recent ExampleRecent Example Problem: With CAM spectral element dycore, ocean
is having problems spinning up from Levitus (much slower compared to using CAM finite volume dycore)
Want to examine this further by Want to examine this further by creating new polar refined gridcreating new polar refined grid
Created new atm/landgrid and mapping files and was able toobtain new coupledmodel run on this grid in < 2 weeks!
Result showed that grid was not not problem
ESMF online regridding - ESMF online regridding - why?why?
As more regionally refined grids are introduced (e.g. MPAS, SE) – need to– minimize the number of mapping files that are
needed – simplify and streamline workflow for generating
new user grid configurations Will be a requirement for run-time adaptive
mesh refinement ESMF is the only tool that currently delivers
this capability Status: Prototype implementation has been
done and is being updated for newest coupler
NUOPC/HYCOM in ESMFNUOPC/HYCOM in ESMFGoal
– Introduce HYCOM into CESM as an alternate ocean component via the NUOPC Layer.
Initial work – Redesigned the CESM driver so that it
easily accommodate both NUOPC-based components and components that use native CESM datatypes, from the Model Coupling Toolkit (MCT)
Why Redesign Driver/Hub Why Redesign Driver/Hub Implementation?Implementation?
driver code hard-coded to contain MCT types one large routine (~6K lines) with functionality
often repeated difficult to understand and MODIFY flow
through system difficult to implement use of alternative
coupling architecture (e.g. ESMF) at the driver/hub
Redesign DetailsRedesign Details Introduced a new abstraction layer between driver
and components - driver now has no references to either MCT or ESMF types – Driver LOC reduced from 6k -> 3k and much easier to
understand and modify flow Much easier to incorporate ESMF/NUOPC driver
components Permits ESMF and MCT data structures to share
memory where possible - allows significant backwards compatibility
Redesign work has been brought into CESM trunk (development code base) with both ESMF and MCT data types