Rennie Selkirk, NASA-Ames/BAER Institute Holger Vömel, University of Colorado Leonhard Pfister, NASA-Ames Jessica Valverde, Universidad Nacional Werner Stolz, Insituto Meteorológico Nacional Walter Fernández and Jorge Andrés Diaz, Universidad de Costa Rica Jimena Lopez, NASA- Ames/BAER Insitute Forecasting tropopause temperatures over Costa Rica for TC 4 BACKGROUND Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007 Vertically propagating equatorial waves, probably mixed Rossby- gravity waves, have been observed in the lower stratosphere and TTL during each of the 3 summer Ticosonde campaigns since 2004. Most prominent contribution to the variability of tropopause temperature at timescales of several days or more Temperature variations are NOT directly forced by convection Twice in 2005, wave-induced cooling was sufficient to dehydrate the tropopause to mixing ratios of 3 ppmv and lower (CFH dehydration events on July 11 and 19.) Tropopause temperature anomaly amplitudes appear to be sensitive to the phase of the QBO: the strong easterly phase in 2005 ‘bottled up’ wave energy at the tropopause, inducing larger variance than in the weak easterlies in 2004.
Forecasting tropopause temperatures over Costa Rica for TC 4. Rennie Selkirk, NASA-Ames/BAER Institute Holger V ömel, University of Colorado Leonhard Pfister, NASA-Ames Jessica Valverde, Universidad Nacional Werner Stolz, Insituto Meteorológico Nacional - PowerPoint PPT Presentation
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Rennie Selkirk, NASA-Ames/BAER InstituteHolger Vömel, University of Colorado Leonhard Pfister, NASA-Ames
Jessica Valverde, Universidad Nacional Werner Stolz, Insituto Meteorológico NacionalWalter Fernández and Jorge Andrés Diaz, Universidad de Costa Rica Jimena Lopez, NASA-Ames/BAER
Insitute
Forecasting tropopause temperatures over Costa Rica for
TC4
BACKGROUND
Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007
Vertically propagating equatorial waves, probably mixed Rossby-gravity waves, have been
observed in the lower stratosphere and TTL during each of the 3 summer Ticosonde
campaigns since 2004. Most prominent contribution to the variability of tropopause temperature at timescales of
several days or more Temperature variations are NOT directly forced by convection Twice in 2005, wave-induced cooling was sufficient to dehydrate the tropopause to mixing
ratios of 3 ppmv and lower (CFH dehydration events on July 11 and 19.) Tropopause temperature anomaly amplitudes appear to be sensitive to the phase of the
QBO: the strong easterly phase in 2005 ‘bottled up’ wave energy at the tropopause, inducing
larger variance than in the weak easterlies in 2004.
Significance for TC4
Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007
Tropopause temperatures during TC4 will exhibit regular variations on the 3-4 day timescale w/ amplitude of ~5 °C
Widespread cirrus more likely during wave-induced cold events
If strong easterly phase of QBO (like 2005), expect increased amplitude of tropopause temperature anomalies and possible dehydration events
Forecasting Ttrop during TC4
Ticosonde will provide continual updates of time-height diagrams of temperature and wind using both the sondes
and analysis/forecast datasets
• Vaisala RS92-SGP radiosondes– 4X daily: 16 July – 24 August– typically ascents to ~28 km– 2-sec resolution @ 10 m
• CU CFH and ECC ozonesondes– 24 launches: 8 – 25 July– most @ 18 UT; 5 @ 00 UT (night)– typical balloon burst at ~30 km
Time-height cross-sections from Ticosonde-Aura/TCSP 2005
Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007
Ticosonde-TCSP 2005 time-height X-section:
Temperature anomalies
Cold point range
T
July 11 Dehydration observed by
CFH
July 19 Dehydration observed by
CFH
CFH observations
Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007
Ticosonde-TCSP 2005 time-height X-section:
Temperature anomalies
Cold point range
T
Arrows = cold T anoms
July 11 Dehydration observed by
CFH
July 19 Dehydration observed by
CFH
CFH observations
Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007
Ticosonde-TCSP 2005 time-height X-section:
zonal wind anomalies
Cold point range
July 11 Dehydration observed by
CFH
July 19 Dehydration observed by
CFH UCFH observations
Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007
Ticosonde-TCSP 2005 time-height X-section:
zonal wind anomalies
Cold point range
U
arrows = cold T anoms
July 11 Dehydration observed by
CFH
July 19 Dehydration observed by
CFH
CFH observations
Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007
Ticosonde-TCSP 2005 time-height X-section:
meridional wind anomalies
Cold point range
July 11 Dehydration observed by
CFH
July 19 Dehydration observed by
CFH VCFH observations
Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007
Ticosonde-TCSP 2005 time-height X-section:
meridional wind anoms
Cold point range
V
July 11 Dehydration observed by
CFH
July 19 Dehydration observed by
CFH
arrows = cold T anoms CFH observations
Supplementary material for NASA TC4 Science Team meeting, Lanham-Seabrook, MD, April 2007