1. Observing small-scale waves with satellite nadir and limb techniques Dong Wu NCAR gravity wave retreat, 26-30 July 2006, Boulder, CO

2. What atmospheric variables (e.g., T, ρ, ρ electron clouds) cause radiance fluctuations? What wave scales are these instruments sensitive to (i.e., visibility function, smoothing, cutoff, noise)? How can these observations be used to improve model physics and parameterization (e.g., wave source, propagation, breakdown)? Key Questions Associated with Satellite Observations: Radiance I' Atmosphere T', ρ', u', v'

3. e.g. MLS Waves (A) Nadir or Slant Path good horizontal resolution limited vertical resolution sensitive to waves of large z / h ratios in T instruments: e.g., AMSU-A, AIRS, SSMIS (B) Limb and Opaque Path good horizontal resolution limited vertical resolution sensitive to waves of moderate z / h ratios in T instruments: e.g., MLS (C) Limb and Transparent Path good vertical resolution limited horizontal resolution sensitive to waves of small z / h ratios in ρ instruments: e.g., LIMS, CRISTA, GPS, SABER, MLS, CLAES, HIRDLS e.g. CLAES, GPS Waves e.g. AIRS, AMSU Waves Convolution Between Small-Scale Waves with Sensor Weighting Functions

4. Possible cloud contamination MLS UARS (1991-1997) Aura (2004-) AIRS (Aqua 2002-) Temp Weighting Func Instruments for T Sounding (Types A and B) Temp Weighting Func AMSU-A N-15 (1998-) N-16 (2000-) N-17 (2002-2004) N-18 (2005-) Aqua (2002-) UARS MLS

5. 21 Jan. 2003 Wu and Zhang (JGR 2004) Jet Streaks over N. Atlantic Mountain Waves over Scandinavia Eckermann et al. (ACPD 2006) 80 hPa, 14 Jan. 2003 80 hPa 40 hPa 20 hPa 10 hPa 5 hPa 2 hPa

6. Heard Is. Prince Edward Is. New Zealand & Islands Macquario Is. South Sandwich Is. Antarctic Peninsula AndesSouth Georgia Is. Tasmania Falkland Is. Crozet Is. Kerguelen Is. Victoria Land Wu et al (ASR 2006) AMSU-A radiance variance at 5 hPa for June-Aug 2003

7. ? TES (nadir) AMSU-A AIRS Aura MLS GPS (1 profile) CRISTA-1 CLAES (1 profile) Convectively generated waves Mountain Waves Gravity wave dispersion relation ? UARS MLS

8. GPS/CHAMP 50-Hz Data E-region irregularities Raw data Perturbations SNR L1 phase Iono-free phase Iono-free phase Neutral atmos. irregularities Wu et al. (JASTP, 2005) Receiver power L1 Phase Delay

9. GPS/CHAMP Variances for July 2002 Receiver powerL1 Phase DelayL2 Phase Delay

10. CHAMP variances in the upper troposphere and lower stratosphere Short-scale components Long-scale components 28km 25km 22km 18km Receiver powerL1 Phase Delay 20012003200520072001200320052007

11. CHAMP variances in the E-region ionosphere 120km 100km 80km 60km Annual variations dominate QBO variations make the variances stronger in NH 2003 and 2005; in SH 2002 and 2004. Variations are stronger in NH than in SH. Effects of the 11- year solar activity are evident mostly at latitudes > 60. 20012003200520072001200320052007 Receiver powerL1 Phase Delay

12. The Quasi-Biennial Oscillation Baldwin et al. (1999) UARS HRDI winds

13. Discussions Consistency among observations: CRISTA, MLS, LIMS MLS, AMSU-A, AIRS GPS, radiosonde MLS, GPS Observational constraints on model parameters GCM Mesoscale models Sampling issues and statistics of transient processes

14. Backup materials

15. Multiple wave sources Filtering at different altitudes

16. Figure 3a: GPS/CHAMP January 2002

17. Figure 5: GPS/CHAMP July 2002

18. Chen et al. (2006) Gravity waves excited by typhoons

19. Waves excited by convective storms AIRS Radiance perturbations 13 Jan 2003 14 Jan 2003 15 Jan 2003

20. 24 January 2005 Study of gravity waves with extended ARPS (Limpasuvan et al. 2006) Simulated T’ T’ after convolved with AIRS wfunc AIRS T’ Estimated Mean wind beforeMean wind after