Highlights from CCSM3’s Special Issue of the Journal of Climate Bill Collins http://www.cgd.ucar.edu/~wcollins National Center for Atmospheric Research Boulder, Colorado

Special Issue of IJHPCA (International Journal of High Performance Computing Applications) Guest editors: John Drake (ORNL) Phil Jones (LANL) George Carr (NCAR) Schedule: May 2004: Call for papers Oct. 2004: Deadline for papers Fall 2005: Publication of special issue (V. 18,#3) Major topics: Software engineering for climate models Performance and portability of climate model codes INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS Call for Papers Special Issue on Climate Modeling Algorithms and Software Practices Guest editors: John Drake (Oak Ridge National Laboratory), Phil Jones (Los Alamos National Laboratory), Tom Henderson (National Center for Atmospheric Research) The International Journal of High Performance Computing Applications (IJHPCA) invites the submission of papers for a special issue entitled Climate Modeling Algorithms and Software Practice. Coupled ocean, atmosphere and sea ice general circulation models have increasingly gained acceptance as the basis for climate prediction studies. The complexity of the modeled physics and nonlinear coupling across spatial and temporal scales poses challenges for component developers and software engineers. The Community Climate System Model (CCSM3) is the most recent generation of an evolving earth system model released by the National Center for Atmospheric Research. This special issue focuses on the parallel algorithms and software practices of climate modeling research and development resulting from the need to support a variety of high performance parallel computers while maintaining high scientific standards, testing procedures for verification and validation, coding standards and coordination of geographically distant developers. Papers are solicited on the following topics: * Software infrastructure and software architectures for climate modeling and simulation, preferably with reference to working models that are publicly available. * Software engineering and practice supporting Community models. Papers should describe how the practice evolved and what software design and engineering principles are effective in the development of climate models. * Parallel algorithms and performance optimization techniques used for climate modeling. * Investigations into the parallel performance and/or scalability of component ocean and atmosphere models in high resolution configurations. * Innovative approaches to support production use and operational forecasting by centers with ongoing development projects. It is anticipated that most of the papers comprising the special issue will present original and unpublished research results. Schedule and Deadlines The schedule for the publication of the special issue is as follows: 1 May 2004 Distribution of Call for Papers 1 October 2004 Deadline for submission of papers 1 November 2004 Notification of authors 1 January 2005 Final submission of accepted papers 1 May 2005 Papers to Sage Publishing Fall 2005 (Volume 19, Number 3, August) Publication of special issue

Special Issue of Journal of Climate Objectives: Describe CCSM3 to the climate community Document CCSM3 for the IPCC 4th Assessment Report Topics: Overview of CCSM Description of features & climate state for each component Climate sensitivity Response of CCSM to paleo, pre-industrial conditions Major modes of coupled variability Editor: Dave Randall Deadline: Jan. 1, 2005 Contents: 24 papers proposed by seven working groups

Papers in the Special Issue Scientific Steering Committee: Collins et al, The Community Climate System Model, Version 3 Atmospheric Model Working Group: Collins et al, The formulation and atmospheric simulation of the Community Atmosphere Model: CAM3 Boville et al, Representation of clouds and precipitation processes in the Community Atmosphere Model (CAM3) Hack et al, Simulation of the global hydrological cycle in the CCSM Community Atmosphere Model (CAM3): Mean Features Rasch et al, A characterization of tropical transient activity in the CAM3 atmospheric hydrologic cycle Rasch et al, Characteristics of transport using three formulations of atmospheric dynamics in a single GCM framework Hack et al, Climate simulation sensitivity for the CCSM CAM3 to changes in horizontal resolution

Papers in the Special Issue Climate Change Working Group: Meehl et al, Climate change in the 20th and 21st centuries and climate change commitment in the CCSM3 Kiehl et al, The climate sensitivity of the Community Climate System Model CCSM3 Collins et al, Impact of pre-industrial vs present day forcing on the atmosphere Climate Variability Working Group: Deser et al, Tropical Pacific and Atlantic variability in CCSM3 Alexander et al, Extratropical atmosphere-ocean variability in the CCSM3 Meehl et al, Monsoon regimes in CCSM3 Hurrell et al, The dynamical simulation of the Community Atmospheric Model Version 3 (CAM3)

Papers in the Special Issue Land Model Working Group: Dickinson et al, The Community Land Model and its climate statistics as a component of the Community Climate System Model Levis et al, Evaluating aspects of the Community Land and Atmosphere Models (CLM and CAM) using the CLM's Dynamic Global Vegetation Model Ocean Model Working Group: Large et al, Attribution and impacts of upper ocean biases in CCSM3 Danabasoglu et al, Diurnal ocean-atmosphere coupling Gent et al, Ocean Chlorofluorocarbon and Heat Uptake During the 20th Century in the CCSM3 Bryan et al, Response of the north Atlantic thermohaline circulation and ventilation to increasing carbon dioxide in CCSM3

Papers in the Special Issue Paleoclimate Working Group: Otto-Bliesner et al, Sensitivity of the climate system to glacial-interglacial forcing in CCSM3 Yeager et al, The low resolution CCSM3 Otto-Bliesner et al, Pre-industrial climate change in CCSM3 Polar Climate Working Group: Holland et al, Influence of the parameterized sea ice thickness distribution on polar climate in CCSM3 DeWeaver et al, Atmospheric circulation and its effect on Arctic sea ice in CCSM3 simulations at medium and high resolution Bitz et al, The influence of sea ice on ocean heat uptake in response to increasing CO2 Qu et al, An evaluation of snow-induced planetary albedo variability in CCSM3

Fidelity of the Atmospheric Winds (Collins et al) Green: Unconditional bias, an estimate of mean error; Yellow: Conditional bias, a measure of errors in phase and amplitude; Red: Lack of correlation; and Blue: scaled variance ratio, a measure of whether the model variance is greater or lesser than that of the atmosphere.

Resolved 3D Advective Temperature Tendency (Hack et al)

Resolved 3D Advective Temperature Tendency @ 400mb (Hack et al)

Zonal Average Warming from High Resolution (Hack et al)

Precipitation over the Warm Pool (Hack et al)