Is it possible to manually clear records in dba_advisor_log

In my database the records in dba_advisor_log seems to be kept about 35 days

select max(execution_start),min(execution_start),sysdate from dba_advisor_log;

MAX(EXECUTION_START) MIN(EXECUTION_START) SYSDATE

2015/3/3 1:02:17 2015/2/11 23:01:03 2015/3/14 8:11:28

The 35 days is based on the AWR data retention settings. The oldest records will be cleared automatically by oracle

select snap_interval, retention from DBA_HIST_WR_CONTROL;

SNAP_INTERVAL RETENTION

+00000 01:00:00.0 +00035 00:00:00.0

Now I need to know whether i can manually purge all or some of the records in dba_advisor_log ?