Ap in real time : IUGG- Sapporo, Japan, July 2003 : session GAV.02

The 3-hourly planetary indices Kp and ap and the daily planetary index, Ap, which are derived by GeoForschungsZentrum (GFZ), Potsdam, on behalf of the International Service of Geomagnetic Indices (ISGI), are made available twice per month. This time delay is inevitable because of the need for a high quality homogenous data set. However, the process may not be sufficiently responsive to the needs of the space weather community, in particular forecasters, where small discrepancies in the data are usually less important than their timely availability. An automated algorithm has been developed by the British Geological Survey (BGS) to derive real-time estimates of the ap and Ap indices, called apest and Ap respectively. These are available on-line at www.bgs.ac.uk/gifs/apindex.html. The derivation process of these est indices is described, which has been designed to match that of the definitive indices as closely as possible. A comparison between the BGS values of ap , Ap and the corresponding definitive values is presented. Modifications to the derivation est est process are still on-going, taking advantage of the advances made by the INTERMAGNET programme in data delivery. The ultimate goal is for GFZ to take over the responsibility for derivation and delivery of the real time indices, which could be considered quick-look or provisional values.