Bayesian estimation of basal conditions on Rutford Ice Stream, West Antarctica, from surface data

first_imgThe determination of basal properties on ice streams from surface data is formulated as a Bayesian statistical inference problem. The theory is applied to a flowline on Rutford Ice Stream, West Antarctica. Estimates of bed topography and basal slipperiness are updated using measurements of surface topography and the horizontal and vertical components of the surface velocity. The surfacetopography is allowed to vary within measurement errors. We calculate the transient evolution of the surface until rates of surface elevation change are within limits given by measurements. For our final estimation of basal properties, modelled rates of elevation change are in full agreement with estimates of surface elevation changes. Results are discarded from a section of the flowline where the distribution of surface residuals is not consistent with error estimates. Apart from a general increasein basal slipperiness toward the grounding line, we find no evidence for any spatial variations in basal slipperiness. In particular, we find that short-scale variability (<10× ice thickness) in surface topography and surface velocities can be reproduced by the model by variations in basal topography only. Assuming steady-state conditions, an almost perfect agreement is found between modelled and measured surface geometry, suggesting that Rutford Ice Stream is currently close to a steady state.last_img read more

Jordan Ayew equals best Premier League scoring season with Crystal Palace’s winner at Brighton

first_imgJordan Ayew is having arguably his best season ever in the Premier League.The Ghanaian striker has seven goals so far this season for Crystal Palace, scoring the seventh in the Eagles’ 1-0 win at Brighton on Saturday.With ten matches still to go for Palace, Jordan has equalled his best-ever goalscoring tally in the English top-flight and could finally surpass the tally.The forward has scored seven goals in the Premier League twice before – for Aston Villa and for Swansea.He scored seven goals in his first season in the Premier League with Villa before netting once in the 2016-17 season while at Swansea.The next season he scored seven more for the Welsh club.He earned a loan move to Palace after Swansea went down to the Championship but endured a difficult goalscoring season, finding the net just once in 20 appearances.However, this season he has already scored seven times in 27 starts including today’s winner.He has already scored home and away against both Arsenal and West Ham and at Old Trafford against Manchester United as well.Jordan Ayew’s career in the Premier League2015-16 – 30 appearances – 7 goals (Aston Villa)2016-17 – 14 appearances – 1 goal (Swansea)2017-18 – 36 appearances – 7 goals (Swansea)2018-19 – 20 appearances – 1 goal (Crystal Palace [loan])2019-20 – 27 appearances – 7 goals (Crystal Palace) – **current seasonGames Ayew has scored in this seasonMan United 1-2 Crystal PalaceWest Ham 1-2 Crystal PalaceArsenal 2-2 Crystal PalaceCrystal Palace 2-1 West HamCrystal Palace 1-1 ArsenalBrighton 0-1 Crystal PalaceAyew and Crystal Palace’s remaining Premier League gamesSaturday 7 March 2020 – vs Watford (H)Saturday 14 March 2020 – vs Bournemouth (A)Saturday 21 March 2020 – vs Liverpool (A)Saturday 4 April 2020 – vs Burnley (H)Saturday 11 April 2020 – vs Leicester City (A)Saturday 18 April 2020 – vs Chelsea (H)Monday 27 April 2020 – vs Aston Villa (A)Saturday 2 May 2020 – vs Manchester United (H)Saturday 9 May 2020 – vs Wolverhampton Wanderers (A)Sunday 17 May 2020 – vs Tottenham Hotspur (H)last_img read more