Advanced Modelling of Atmospheric Chemistry, Radiation and Circulation (AMACRaC) Introduction

Advanced Modelling of Atmospheric Chemistry, Radiation and
Circulation (AMACRaC)
This is a common application for allocation of NOTUR resources from several related projects at
CICERO Center for International Climate and Environmental Research. The projects are all funded
through the Norwegian Research Council (NFR), EU and NordForsk, and are run in collaboration
with partners at the University of Oslo.
All activities presented here have previously been successfully run on NOTUR resources (titan,
grants nr nn4701k and nn9188k). The addition of more collaborators and more external funding
(e.g. the recently awarded 5-year NFR SIS grant 'SLAC') has allowed us to scale up the activities,
and we therefore submit this larger, common application.
Project description
The goal of the AMACRaC collaboration is to study the Earth's atmosphere, and how it reacts to
changes in composition. There are three connected subprojects:
Chemical modelling with OsloCTM2
We tracks the physics and chemistry of climate forcing gases and aerosols, such as black carbon,
sulphate and nitrates, from detailed emission scenarios through to modelling of atmospheric
chemistry and meteorological transport. The OsloCTM2 chemical transport model that is used for
this purpose already runs well on titan, and is well parallelized.
In addition, there is currently an ongoing effort by the collaborators to refine the model, and to
increase its efficiency. Testing of this will also be done within AMACRaC.
Radiative transfer calculations with disort
The first subproject yields detailed, time-dependent maps of aerosol and climate gas concentrations.
To connect these to effects on the radiative balance of the Earth, and hence to global warming or
cooling, the equations of radiative transfer through the Earth's atmosphere must be solved. This
involves solving coupled differential equations through the discrete ordinate method, and for this
we have a framework around public routine called disort which is also already running well on titan.
Global circulation studies with CESM1.0
Another approach to studying the atmosphere is not to look at the detailed chemistry, but rather to
model the full circulation of air as it is driven by energy from the sun, the Earth's rotation and
weather systems. This activity requires use of heavy three-dimentional computer models of the
Earth. We have set up and are presently running the Global Circulation Model (GCM) called
CESM1.0, developed at the National Center for Atmospheric Reseach (NCAR) in Boulder,
Colorado. The goal of this subproject is to study changes in surface temperature and precipitation
when changing the global conecentrations of climate gases such as CO2, methane and aerosols.
Taken together, the three AMACRaC subprojects work towards a fuller understanding of the
behaviour of the atmosphere, both in terms of chemistry, radiation balance and global circulation.
All project members are actively collaborating, and based on previous experience we expect the
simulations and modelling run on NOTUR resouces to result in a good number of publications in
peer-reviewed journals.
Current project members
Project part
Gunnar Myhre
Senior research fellow (CICERO)
Terje Koren Berntsen
Professor (UiO/CICERO)
Bjørn H. Samset
Senior research fellow (CICERO)
Ole Amund Søvde
Senior research fellow (CICERO)
Maria M. Kvalevåg
Senior research fellow (CICERO)
Stig B. Dalsøren
Senior research fellow (CICERO)
Ragnhild B. Skeie
Research fellow (CICERO)
Marianne T. Lund
Research fellow (CICERO)
Karianne Ødegård
Research fellow (UiO)