# SDOO

### Spontaneous Dansgaard-Oeschger type oscillations in climate models

Start date
1 January, 2020
End date
1 August, 2021

Abrupt warming episodes punctuate Greenland ice core records throughout the last glacial period. These events were first identified in two Greenland stable water isotope records (Dansgaard et al., 1993), and are generally referred to as Dansgaard-Oeschger (DO) events. During an event, Greenland transitions from cold stadial (GS) to warmer Greenland Interstadial (GI) conditions within a decade (Kindler et al., 2014; Huber et al., 2006). Surface air temperatures (SATs) over Greenland increase by 10-15°C and local snow accumulation almost doubles (Andersen et al., 2006; Kindler et al., 2014; Huber et al., 2006). These events occur at the onset of an oscillation that is of millennial timescale and are rather pronounced during Marine Isotope Stage3 (MIS3; between approximately 25 – 60 thousand of years BP, hereafter ka) (Fig. 1; Johnsen et al. (2001), Voelker et al.(2002)).

SDOO is an ongoing model intercomparison project to study spontaneous, DO-type oscillations in climate models. SDOO is currently gathering model output for any spontaneously oscillating simulations (published or unpublished). The main goal of SDOO is to cross compare existing simulations using a common set of diagnostics so we can analyse the mechanisms and the characteristics of the oscillations.

The only condition to participate is a simulation that shows spontaneous, long time scale, oscillations. Table 1 shows the simulations and models currently involved in this initiative.