Influence of the Madden–Julian Oscillation on the Arctic Oscillation Prediction in S2S Operational Models

The connections between the Madden–Julian Oscillation (MJO) and Arctic (AO) are examined in both observations model forecasts. In observations, time-lag composites carried out for AO indices anomalies of 1,000-hPa geopotential height after an active or inactive initial MJO. results show that when is its positive (negative) phase at time, activity generally enhanced (weakened) Reforecast data 11 operational global circulation models from Sub-seasonal to Seasonal (S2S) Prediction Project further used examine relationship MJO prediction. When on day S2S prediction, can improve prediction skill most models. This consistent with found a leading enhance activity. However, negative phase, not among Only few provide agree observations. Furthermore, different phases. There significantly MJO-related skill. strong (weak) including MJO, tend have high (low) For example, no matter what in, 7, which strong. Thus, important predictability source forecast