Ahead of today's opening session, the air temperature is 13 degrees C, whilst the track temperature is 27 degrees. It is a lot, lot cooler here than in Malaysia two weeks ago and Bahrain next week however, for once the sun is shining and there is no sign of the traditional smog..

Whilst some claim Sebastian Vettel's win at Sepang was largely down to the warmer temperatures, Ferrari is confident that it will be competitive here also. Indeed, Kimi Raikkonen claims he is confident the SF15-T will be good everywhere.

Which leaves us wondering as to when Williams is going to start showing the sort of pace we witnessed at the end of 2014.

The only reserve driver on duty this morning is 2014 GP2 champion Jolyon Palmer, who is at the wheel of Romain Grosjean's Lotus.

Most of the teams are running updates here this weekend, Mercedes, in particular, keen to move things up a notch, whilst Williams has, among other things, a new rear suspension.

Tyre compounds are medium (prime) and soft (option), whilst there are two DRS zones, one on the start-finish straight and the second on the back straight leading to T14.

That long back straight leading to T14, will also give us the first opportunity to see how the Ferrari engine really measures up to the Mercedes in terms of grunt... and then there's Renault and Honda.

The lights go green and Merhi is first out, followed by Sainz, Bottas, Massa and Verstappen. In moments there are twelve cars on track.

Button is confused by one of the track side warning lights that is flashing red however, the team assures him that the session has not been red-flagged.

Seven minutes into the session all but Rosberg have been out. Massa has completed three laps, but no time, whilst Button, Alonso, Palmer, Maldonado, Palmer and Ricciardo have completed two.

Finally, ten minutes in, the German heads out of his garage and down the pitlane.

He might have been last out but the Mercedes driver looks likely to be the first to post a time, stopping the clock at 1:41.052. Like his teammate, Rosberg sends out a spectacular shower of sparks as his car bottoms.

Nasr is next out, the Brazilian looking to do four timed laps before changing his front wing in a 'live' pit stop. Palmer also heads down the pitlane for a second run.

As Rosberg improves to 40.412, which compares to Alonso's 39.783 which topped the sheets here last year, Nasr posts 42.443 and teammate Ericsson 45.922.

More and more drivers head out, Palmer blotting his copybook with a spin at T9.

As Sainz mirrors Palmer's error, albeit at T2, Vettel goes second (41.692) only to be demoted by Maranello teammate Raikkonen who crosses the line at 41.554.

Sainz goes fourth (42.194), ahead of Nasr, Kvyat, Button, Maldonado, Hulkenberg and Verstappen. Button complains of "lots of rear locking".

With 24 minutes gone, and just six minutes of the opening half-hour remaining, Stevens, Hamilton and Ricciardo are the only drivers yet to post a time.

A minor off for Maldonado at T1, Raikkonen out runs himself at T15 and a big lock-up for Verstappen, incident aplenty in this session.

Hamilton's first flying lap sees the Briton go nineteenth (49.305), the world champion losing time in traffic. His cause is not helped by a mistake which sees him run wide at T14.

The opening half hour, during which the drivers have a 'free' set of tyres, comes to an end, Rosberg is quickest, ahead of Maldonado, Vettel, Raikkonen, Sainz, Bottas, Alonso, Massa, Verstappen and Nasr.

After a few minutes silence, Stevens heads down the pitlane. He is subsequently joined by Rosberg.

A lock-up sees Rosberg head off into the run-off at T6, the German having posted a PB in the first sector. He asks his engineer for the cause of the lock-up and is subsequently told "too much pressure". Rosberg responds by posting a 39.574 a couple of laps later.

Alonso, currently seventh, looks to improve as Hamilton heads back on to the track. Along with Perez (and Rosberg), they are the only drivers on track.

Going quickest in S1 and again in S3, Hamilton goes quickest (39.033), eclipsing his teammate by 0.541s. He even had time for a minor lock-up in T14 according to the team.

Whilst Rosberg is 0.5s off Hamilton's pace, third placed Sainz is 2s adrift.