  In this paper we present the first comprehensive statistical study of EUV
coronal jets observed with the SECCHI imaging suites of the two STEREO
spacecraft. A catalogue of 79 polar jets is presented, identified from
simultaneous EUV and white-light coronagraph observations, taken during the
time period March 2007 to April 2008. The appearances of the coronal jets were
always correlated with underlying small-scale chromospheric bright points. A
basic characterisation of the morphology and identification of the presence of
helical structure were established with respect to recently proposed models for
their origin and temporal evolution. A classification of the events with
respect to previous jet studies shows that amongst the 79 events there were 37
Eiffel tower-type jet events commonly interpreted as a small-scale (about 35
arcsec) magnetic bipole reconnecting with the ambient unipolar open coronal
magnetic fields at its looptops, and 12 lambda-type jet events commonly
interpreted as reconnection with the ambient field happening at the bipoles
footpoints. Five events were termed micro-CME type jet events because they
resembled the classical coronal mass ejections (CMEs) but on much smaller
scales. A few jets are also found in equatorial coronal holes. The typical
lifetimes in the SECCHI/EUVI (Extreme UltraViolet Imager) field of view between
1.0 to 1.7 solar radius and in SECCHI/COR1 field of view between 1.4 to 4 solar
radius are obtained, and the derived speed are roughly estimated. In summary,
the observations support the assumption of continuous small-scale reconnection
as an intrinsic feature of the solar corona, with its role for the heating of
the corona, particle acceleration, structuring and acceleration of the solar
wind remaining to be explored in more details in further studies.
