9-10 November 2011 Atmospheric Waves Workshop, ESTEC Atmospheric Waves Workshop Scott Osprey 1, Corwin Wright 2 Evidence of atmospheric gravity waves and their effects from satellite data 1 AOPP, University of Oxford; 2 Laboratoire de Physique des Oceans, Universite de Bretagne Occidental

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Gravity Waves Above the Indian Ocean source: MISR (NASA)

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Lenticular Clouds, Amsterdam Island MODIS, December 2005

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Sandwich Islands, South Atlantic, January 2004 Source MODIS on AQUA (NASA)

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Outline Radio-occultation retrievals of gravity waves Limb-sounding instruments: – NASA A-Train – S-Transform High Resolution Dynamics Limb Sounder (HIRDLS) – Tropospheric sources of gravity waves (monsoon) – Filtering by background winds (Sudden Stratospheric Warmings) Evidence for gravity wave induced circulations (Titan) Summary

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Radio-Occultation: FORMOSAT-3/COSMIC

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Radio-Occultation Observations: FORMOSAT-3/COSMIC A “constellation” of six satellites, used for GPS (US, Taiwan) orbital altitude 800 km Currently being used for data assimilation (Met Office, ECMWF) Europe: Galileo Launch on April 14, 2006 Vandenberg AFB, CA Measures: Pressure, Temperature, Humidity Refractivity Ionospheric Electron Density

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Radio Occultation Profile locations 1 January 2007 Wang & Alexander (2010) CHAMP 151 COSMIC 1936

9-10 November 2011 Atmospheric Waves Workshop, ESTEC A Typical GPS RO Profile Wavenumbers 1-6 constitute ‘background’ Wang & Alexander (2010)

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Radio-Occultation: Wave-Momentum in the lower-stratosphere Wang & Alexander (2010) Vertical flux of horizontal momentum density June-August 2007

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Limb Sounding Observations of Atmospheric Gravity Waves - HIRDLS

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Source: NASA The NASA A-Train

9-10 November 2011 Atmospheric Waves Workshop, ESTEC HIRDLS The High Resolution Dynamics Limb Sounder (HIRDLS) Infrared limb sounder on the low-Earth orbiting Aura satellite Launched July 2004, data coverage from 01/2005 – 01/2008 Data extend from ~tropopause to ~80km (version 6) ~1km vertical resolution, measurements ~80km apart

Temperature Perturbations

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Temperature Perturbations

9-10 November 2011 Atmospheric Waves Workshop, ESTEC The Stockwell Transform: T’ and the vertical wavelength Temperature perturbation size Vertical wavelength In most cases, we select only the largest temperature perturbation at each height level for consideration ( ) Stockwell et al (1996); Alexander et al (2006)

9-10 November 2011 Atmospheric Waves Workshop, ESTEC The Stockwell Transform – Horizontal Wavelength Horizontal wavelength

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Tropospheric Sources of Gravity Waves - Monsoon

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Monsoon and Gravity waves

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Precipitation, OLR and Gravity Waves

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Precipitation, OLR and Gravity Waves

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Background Wind Filtering of GW – Sudden Stratospheric Warmings

9-10 November 2011 Atmospheric Waves Workshop, ESTEC NH Winter Zonal Wind 2005 & 2006

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Sudden Stratospheric Warming 2006

9-10 November 2011 Atmospheric Waves Workshop, ESTEC HIRDLS zonal wind: °N Wright et al. (2010)

9-10 November 2011 Atmospheric Waves Workshop, ESTEC HIRDLS GW MF: °N Wright et al. (2010)

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Daily GW MF: Wright et al. (2010)

9-10 November 2011 Atmospheric Waves Workshop, ESTEC >>Evidence for wind-based filtering of GWs during 2006 Sudden Stratospheric Warming High GW activity near poles in 2005 and 2007 Significant reduction in 2006, corresponding to negative zonal winds Gravity Wave Filtering

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Gravity Wave Filtering

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Evidence of a Gravity Wave Induced Circulation on Titan

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Brewer-Dobson Circulation on Earth Rossby Waves Gravity Waves

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Evidence of GW induced circulations on Titan Teanby et al, 2008

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Teanby et al, 2008

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Idealised meridional circulation on Titan Teanby et al, 2008

9-10 November 2011 Atmospheric Waves Workshop, ESTEC Summary Gravity waves are a ubiquitous dynamical feature of the Earths atmosphere. Significant regional sources of tropospheric gravity waves are seen during strong precipitation events (monsoon) Filtering by stratospheric winds is seen during extreme wintertime events in the stratosphere (SSW) Evidence of a gravity wave driven circulation is seen in the Earths mesosphere - lowest temperatures on earth being in the summer polar mesosphere. Tentative evidence of a similar circulation is seen in Titans polar mesosphere and via distributions of tracers. Radio-occultation and limb sounding observations provide useful quantitative measures of gravity waves.