Kolloquien
Sommersemester 2017
URL zum ICS-Kalender dieses Seminars
Kirchhoff-Institut für Physik, Otto-Haxel-Hörsaal
freitags 17:15
Vorträge
19.5.2017 17:00
KIP, INF 227, Otto-Haxel-Hörsaal
Atmospheric nuclear weapon testing during the cold war in the 1950s and 1960s has been worrying,
though including
a unique beneficial aspect in
the area of environmental sciences. The artificial
nuclear production of more than 6 x 10
28
atoms or about 1.4 tons of
14C led to a doubling of the
14C/C
ratio in tropospheric CO
2
of the Northern Hemisphere. The
prominent so-called bomb spike peaking
in 1963 can be used as transient tracer
to understand carbon dynamics in the
Earth System.
This information is indispensable to estimate the residence times of carbon in ocean and biosphere
reservoirs. Knowing these residence times is key to model the fate of man-made CO
2
emissions from burning of fossil fuels and land-use changes. Today, the transient bomb-radiocarbon signal has
levelled-off in most carbon compartments and the anthropogenic input of
14C-free
fossil fuel CO
2
dominates the decreasing trend of the
14C/C ratio in tropospheric CO
2.
On the regional scale, the lack
of
14C in fossil fuel CO
2
emissions uniquely marks this anthropogenic CO
2
component, therewith allowing a so-called top-down verification of fossil CO
2
emissions and their changes. I will present
some prominent examples where the
14C bomb spike is successfully used to unravel dynamic
processes in the carbon cycle and introduce our activities as Central Radiocarbon Laboratory in the
recently established Integrated Carbon Observation Syste
m Research Infrastructure (ICOS RI).