1. Variability of TTL water vapor A filtered CFH climatology and MLS water vapor for Ticosonde/Costa Rica Rennie Selkirk, NASA GSFC/GESTAR Mark Schoeberl, STC Rennie Selkirk, NASA GSFC/GESTAR Mark Schoeberl, STC ATTREX Science Team Meeting NCAR – 24 October 2013

2. Sonde processing Objectives: – Highlight the large seasonal variability in TTL WV – Need to remove CFH noise in at scale of ~100 m Approach: – Low-pass filter – with attention to data gaps – Apply to all variables – Calculate seasonal climo on data from 2005-2011 – Will soon add 2012 and 2013

3. Temperatures at Costa Rica

4. CFH Water Vapor with previous season

5. RH ice Both seasons show rapid fall off of mean RH ice profile at mean coldpoint (dashed lines)

6. WV tape recorder at Costa Rica (seasonal time averages) SeasonMin T (“coldpoint tropopause ”) WV at Tmin 1 st WV tape recorder min (“hygropause”) 1 st WV tape recorder max Upper WV tape recorder min DJF-82.6° C (17.4 km) 2.7 ppmv2.5 ppmv (17.9 km) 4.4 ppmv (20.5 km) 3.4 ppmv (23 km) MAM-81.3° C (17.2 km) 3.3 ppmv2.9 ppmv (17.4 km) 4.5 ppmv (22 km) n/a JJA-76.7° C (16.1 km) 6.5 ppmv3.5 ppmv (19.7 km) 4.9 ppmv (24.1 km) n/a SON-79.3° C (16.7 km) 4.2 ppmv (16.8 km) 5.3 ppmv (17.8 km) 3.5 ppmv (21.6 km)

7. Water Vapor vs Ozone DJF JJA

8. MLS water vapor intecomparisons Long-term average data – MLS WV, version 3, interpolated via MERRA to San Jose and in potential temperature – Can be used to compare to CFH seasonal climatology MLS RDFs: – Back-trajectory-based product – Synthetic high-vertical resolution water vapor (and ozone) profiles – Use to infer day-to-day variability at a sounding location

9. Sondes vs. MLS v.3 Winter composite (36 sondes) Summer composite (60 sondes)

10. MLS RDF @ SJO Summer 2007

11. MLS RDFs vs CFH * * * * * * * MLS RDF profile (previous slide)

12. Summary Strong seasonal cycle of water vapor in UTLS at Costa Rica Low-pass filtering of CFH data – Tape recorder prominent Low-pass filtering reduces instrumental noise – But may reduce frequency of high RH in TTL too strongly Seasonal average fields consistent with MLS, v.3 MLS RDFs promising technique for reproducing vertical structure seen in sondes