Henry B. Selkirk, USRA/NASA GSFC Holger Vömel, DWD Jorge Andrés Diaz, UCR Gary Morris, Valpo Univ. Acknowledgments: Sam Oltmans & Bryan Johnson, NOAA ESRL Jessica Valverde-Canossa, UNA Anne Thompson, Penn State Mark Schoeberl, STC Henry B. Selkirk, USRA/NASA GSFC Holger Vömel, DWD Jorge Andrés Diaz, UCR Gary Morris, Valpo Univ. Acknowledgments: Sam Oltmans & Bryan Johnson, NOAA ESRL Jessica Valverde-Canossa, UNA Anne Thompson, Penn State Mark Schoeberl, STC Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer

Motivation, science questions and approach  What do the fine-scale structures of water vapor and ozone reveal about processes of stratosphere exchange, LS in-mixing, and dehydration? How do these vary seasonally?  Seasonal mean profiles of water vapor and ozone  Distribution of relative humidity and frequency of supersaturation  Covariances of water vapor and ozone  Trajectory analyses anomalous high ozone events in UTLS  How does the behavior of ozone in the UT/LS compare to other (SHADOZ) stations in the tropics? What does this reveal about in-mixing and influence of deep convection?  Comparisons with MLS water vapor, relative humidity and ozone  Compare with other in situ water vapor measurements in the tropics  Construct hi-res profiles from MLS WV and ozone using trajectory techniques  How representative is this station in the American tropics of water vapor and ozone in the UT/LS and above globally? How do our measurements compare with satellite profiling from Aura MLS and OMPS on NPP?  Collaborative studies with SHADOZ investigators Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer

Ticosonde CFH water vapor and ECC ozone soundings YEARCFHECCTotal soundings Intensive campaigns 2005 (from Jul)293132TCSP (July) CR-AVE (Jan-Feb); Veranillo (Jul) TC4 (Jul-Aug) (thru Aug)531 TOTAL One current and two former and one current sites in Costa Rica: Alajuela [10°N, 84.2°W], Heredia [10°N, 84.1°W], San Pedro [9.9°N, 84.0°W] Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer

100 hPa freq (  > 100 ppb 100%100%0%0% hPa hPa CFH RH ice – NH winter Selkirk, et al., 2010 Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer

CFH RH ice – NH summer freq (  > 100 ppb 100%100%0%0% 100 hPa hPa Selkirk, et al., 2010 Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer

Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer Water Vapor vs. Ozone

Comparison with MLS water vapor Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer Figure courtesy of Karen Rosenlof

PlansPlans Four-year proposal to NASA currently under review Collaboration between GESTAR/NASA GSFC, Gary Morris at Valparaiso University and Jorge Andrés Diaz at the Universidad de Costa Rica Weekly SHADOZ ozone soundings with ECC ozone sonde payload Monthly CFH/ECC water vapor-ozone sonde payload NEW: Twice-monthly SO 2 soundings with dual ozone sonde system perfected o Validation of OMI SO 2 product o Collaboration with Joanna Joiner and Nick Krotkov of OMI team at GSFC Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer

Tropopause Saturation Layer [Selkirk et al., 2010 JGR] TSL TTL TSL TTL Locus of final dehydration before entry into LS and water vapor tape recorder Distinguished from lower TTL by episodic in-mixing of stratsopheric air Conceptual framework for understanding relationship between local coldpoint and slow, quasi-horizontal ascent Locus of final dehydration before entry into LS and water vapor tape recorder Distinguished from lower TTL by episodic in-mixing of stratsopheric air Conceptual framework for understanding relationship between local coldpoint and slow, quasi-horizontal ascent Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer

TSL and variability gradients Ozone (ppmv) K 350 K 360 K 370 K 380 K 390 K TSL Potential Temperature (K) Ozone/ sd Ozone (ppmv) sd T (°C) Ozone/ sd Ozone (ppmv) N 2 (s -2 ) TSL O3O3 O3O3 sd(T) N2N2 N2N2 sd(O 3 ) sd(T) sd(O 3 ) JJA DJF region of low N 2 (< 2x10 -2 s -2 ): gravity wave-breaking and mixing lower edge of TTL (~350 K/LNB) near minimum of N 2 lower edge of TSL (B: lowest WV min ) near N 2 ≈3 x s -2 : region of wave propagation upper edge of TSL near local max of sd(T): beginning of wave evanescence Honolulu, HI 17 October 2012 US-Japan Workshop on the Tropical Tropopause Layer