Seasonal variations of the gravity wave momentum flux in the Antarctic mesosphere and lower thermosphere


first_imgAirglow imager and dynasonde/imaging Doppler interferometer (IDI) radar wind measurements at Halley Station, Antarctica (75.6degreesS, 26.6degreesW) have been used to estimate the seasonal variation of the vertical fluxes of horizontal momentum carried by high-frequency atmospheric gravity waves. The cross-correlation coefficients between the vertical and horizontal wind perturbations were calculated from sodium (Na) airglow imager data collected during the austral winter seasons of 2000 and 2001. These were combined with wind velocity variances from coincident radar measurements to estimate the daily averaged upper limit of the vertical flux of horizontal momentum due to gravity waves. The resulting momentum flux at the Na airglow altitudes, while displaying a large day-to-day variability, showed a marked rotation from the northwest to the southeast throughout the winter season. Calculations show that this rotation is consistent with seasonal changes in the wind field filtering of gravity waves below the Na airglow region. The calculations also indicate that while the magnitude of the meridional wind is small, this filtering leads to the observed seasonal changes in the meridional momentum flux.last_img read more

Aguero one goal to equaling Henry’s record ahead Villa clash


first_img He said: “All the players want to play every game, Sergio is not an exception. I want him to play too.” But the manager hailed his striker’s impending achievement, as he is due to move level with Arsenal legend Henry, who also won a Champions League and two La Liga titles under Guardiola at Barcelona. “He scored equal goals, or more goals than a legend like Titi Henry – incredible achievement, that’s many, many goals. read also: Premier League title race: Sergio Aguero surrenders to Liverpool “He’s adapted perfectly he’s a guy in the box with a sense of goal, he can score from everywhere and he’s an incredible striker, incredible.” FacebookTwitterWhatsAppEmail分享 Aguero is hoping for a recall to the team at Aston Villa on Sunday after being left on the bench for the midweek win at Manchester United . The Argentinian legend turns 32 in the summer and is contracted to the Blues for another year. Guardiola said that the fact Aguero is not an automatic choice any longer – he has been rotated with Gabriel Jesus more this season, and at Old Trafford both were names among the substitutes – is not due to his age.Advertisement Loading… Pep Guardiola says Sergio Aguero is as hungry as ever as he stands on the brink of Premier League history. The Manchester City star needs one goal to equal Thierry Henry’s record of 175 goals, the highest total by a foreign star in English football. Promoted ContentYou’ve Only Seen Such Colorful Hairdos In A Handful Of AnimeWho Is The Most Powerful Woman On Earth?Who’s The Best Car Manufacturer Of All Time?Some Impressive And Almost Shocking Robots That ExistTop 10 Tiniest Phones Ever Made7 Universities In The World With The Highest Market ValueWhat Happens To Your Brain When You Play Too Much Video Games?The Best Cars Of All TimeThe Very Last Bitcoin Will Be Mined Around 2140. Read More11 Most Immersive Game To Play On Your Table TopPlaying Games For Hours Can Do This To Your Body6 Incredibly Strange Facts About Hurricaneslast_img read more

Kane buoyed by timely hat-trick


first_img The 21-year-old’s scarcely-believable rise continues apace, with the Chingford-born forward making it 29 goals in all competitions with his treble against Leicester on Saturday. Kane’s performance helped inspire out-of-sorts Tottenham to a 4-3 win and saw him move top of the top-flight scoring charts – a remarkable feat considering the first of 19 league goals did not arrive until November 2. It capped a whirlwind few days for the striker, who on Sunday is meeting up with the England senior squad for the first time ahead of the matches with Lithuania and Italy. “I can’t wait,” Kane said. “It has been a dream to be called up but obviously I want to go and play. “There is great competition for places and hopefully I can just do my best whilst I am away and see what happens. “(I want to play for England) like any boy would. That’s what I want to do. “There is great competition and I have to keep working hard if I want to get a place in the team.” Kane insists he is able to savour such moments, despite so many things coming “thick and fast”. It is form he wants to keep up and, as much as he wants to impress for England, retains a focus on club matters. Saturday’s win kept Spurs’ hopes of a top-four finish alive and was the perfect response to their insipid display in the 3-0 defeat at Manchester United. Press Association “Obviously we all know that was a poor game from us,” Kane said, speaking to Sky Sports. “There is no hiding away from that, but it is how you react. “I’ve always said we’ve got a great bunch of lads here and again we’ve proved that. We’ve come back with a great win today. “We have got a great squad, we all enjoy it. We’re loving every minute, obviously we want to keep the wins coming and see how far we can get up the table.” The emotions those connected to Leicester are feeling could not be much different. The Foxes are seven points from safety with only nine matches left after the harsh defeat in north London. City’s performance belied that of a side rock-bottom of the standings and manager Nigel Pearson praised his players’ character afterwards. “It’s a very disappointing result for us because I think we deserved more,” he said. “I don’t think we deserved to be on the receiving end of a defeat today. “To be 2-0 down after 13 minutes and really stretch one of the top sides away from home all the way to the end is a measure of the commitment that the players have shown today. “To a man I thought they were really excellent in terms of how they went about trying to win the game.” Harry Kane is “loving every minute” right now as the Tottenham striker prepares to meet up with England for the first time buoyed by a maiden Premier League hat-trick.last_img read more