PIK Biennial Report 2000-2001 - Potsdam Institute for Climate ...

TOPIK 7 - PIKuliar Culture
PIK operates in a vast scientific field - global change and
Earth system analysis - that is as yet largely unexplored.
Serious challenges arise from the complexity of the systems
considered, from the necessity for truly interdisciplinary
research which they imply, from the absence of a
comprehensive data base, and from the fact that most of
the pursued research activities rely heavily on computa-
IMEQ
Integrating Models and Ensuring their Quality
Project speaker: Gerhard Petschel-Held
PIK project members: Nicola Botta, Hermann Held,
Cezar Ionescu, Rupert Klein.
Research Questions
IMEQ’s goal is to develop principles of high-quality
integrated modelling and strategies for implementing
them. Particular emphasis was to be given to the coupling
of models with the aim of answering specific
research questions. In this context, the following issues
were raised:
• How can individual models in global change research
be classified to pave the way for integration and quality
assurance? Which categories are helpful with
respect to a model’s object (atmosphere, ocean, economics
etc.), structure, scales, implementation, capacity
for coupling, and integration? Which categories
relate to each model’s aims, i.e., the questions each
model is supposed to answer, and the questions it is
capable of answering?
• How can we classify "integrated" research questions,
i.e., questions that can be answered by coupling individual
models? How is such a classification related to
the classification of individual models? Can we
develop a joint classification scheme for models and
questions which would allow us to deduce which
models need to be coupled in which way in order to
obtain answers to specific types of integrated research
questions?
• How does uncertainty assessment, including intrinsic
model limitation assessment and error estimation,
relate to quality assurance in integrated models?
• What do model interfaces (both in a model-inherent
disciplinary, and in a software-technological sense)
look like? How general a definition can be found for
interfaces and how flexible do they have to be?
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tional modelling. In response, within "PIKuliar Culture",
PIK intends to establish a functioning interdisciplinary
dialogue, to reflect the philosophical background of its
research, to develop common priorities and standards of
quality, and to synchronize and, if necessary, extend
existing disciplinary scientific procedures.
State of Work and the Project’s Future
There are basically two complementary approaches to
tackle the questions raised:
• Analyse and categorize existing models along internal
specifics and categories like physiological/functional/
statistical or numerical/symbolic. This might be called
a bottom-up approach.
• Starting from a set of requirements on quality of individual
and integrated models, set up a catalogue of criteria
and standards to be used as a guideline for the
models and coupling procedures.
The project’s first target was the organization of the
mathematically oriented symposium in the framework of
the First Sustainability Days. From its sessions the following
conclusions were drawn:
• Concepts used in applied mathematics and computing
science offer significant potential for improvement of
current models in sustainability science and for their
quantitative assessment.
• Modern software engineering is at the core of recent
developments of model coupling technologies aiming
at the much-desired modularity of applications.
• There is a range of different uncertainty types which
might be classified according to the language used (e.g.
the temperature is 15.0 °C vs. it is warm) and the
measures quantifying the degree of uncertainties (e.g.
probability vs. possibility).
• Hybrid modelling has been advanced considerably,
combining quantitative with qualitative information.
Despite a general feeling that the conceptual work within
IMEQ is greatly needed to achieve PIK’s ambitious
goals, the project’s activities have been regrouped under
two other related PIK projects: PIAM and PIRSIQ.
PIAM (cf page42) focuses on practical implementations