Ahead of today's second practice session the air temperature is 26 degrees C, whilst the track temperature is 30 degrees.

This morning's session was pretty much meaningless what with it taking place in daylight whilst all the remaining sessions, and the race, take place later in the day.

However, whilst it might have been meaningless in terms of the remainder of the weekend it proved useful for most of the teams as they look ahead to 2016. Though they are in action here on Tuesday, the all-day test is for tyres only with no aero testing allowed. Consequently, this morning provided ninety minutes of useful running which the teams took full advantage of.

With nothing of real significance to be read into the times, it is however worth noting that once again Mercedes led the way.

Tyre options this weekend are soft and supersoft, the options making their first appearance over the course of the next ninety minutes.

There are two DRS zones. The first detection point will is before T7 with the activation just after. The second detection point is after T9 with the activation point at the apex of T10.

Temperatures are only marginally lower than FP1 but will continue to fall thereby setting up a challenge unique to these twilight races.

The lights go green and Vettel is first out of the blocks, followed by Merhi and Stevens.

As he makes his way around the track, Vettel admits, "I think I forgot something this morning..." at which point he starts signing Happy Birthday, in Italian, to his engineer, Riccardo Adami. Classic.

Clearly not in the spirit of things, Raikkonen complains that he has no throttle control. Nonetheless, the Finn goes quickest, crossing the line at 1:44.237. Vettel can only manage fourth (45.009).

Raikkonen ups the ante with a 44.237, as Vettel makes it a Ferrari 1-2 with a 44.289.

Early days but Ferrari looks good here, and one cannot help but feel that the Iceman would derive great satisfaction from pipping Bottas for fourth in the standings. Providing he doesn't have to attend the FIA prize giving ceremony.

Hamilton warns, "I pulled the clutch and it didn't make a very nice noise", asking the team to check his gearbox.

Meanwhile, teammate Hamilton posts 43.305 to go quickest, as Ricciardo goes third and Hamilton fourth.

As Rosberg breaks the 1:42s barrier, Hamilton leapfrogs the German with a 42.524.

Fifteen minutes in and all but Merhi and Grosjean have posted times.

Despite being the fastest man on track, Hamilton requests a new steering wheel. He is advised that although quicker (0.243s) than Rosberg there is an "engine mode difference".

Massa discards a visor but makes a mess of it and as a result it is left flapping around behind his head.

Asked his thoughts, Sainz says his Toro Rosso is "a bit on the nose", elsewhere, Merhi explores several of the generous run-offs that populate the Yas Marina.

Twenty-five minutes in, Raikkonen is first to switch to the option rubber, improving from 43.994 to 43.875 despite running wide at the start of the lap and again in Turns 3/4.

As Vettel also switches to the red banded rubber, Raikkonen improves to 42.885 but remains third. Ricciardo and Stevens also on the supersofts.

Vettel splits the Mercedes duo with a 42.717 but moments later Ricciardo bangs in a 42.647, nonetheless, the Australian is 0.133s off Hamilton's prime pace.

Kvyat (options) goes sixth (43.386), despite a very poor final sector.

"I've got less overall grip," complains Button, "traction's a bit worse and also understeer." Apart from that...

All eyes on Hamilton and Rosberg as they head out on the option rubber.

The German posts 41.983, improving by 0.8s, whilst Hamilton can only manage 42.121

As Maldonado goes seventh (43.431), on-board footage with Massa shows the Williams to be a real handful. The Brazilian is currently eighth and his teammate fourteenth, though Bottas has yet to run the option rubber.

I the paddock Jackie Stewart is spotted greeting Prodrive boss David Richards, former chairman at Aston Martin having been involved in its purchase from Ford in 2007.

Bottas finally makes the switch to options, the Finn improving to eleventh with a 43.536.