edu.ucar.opensky::articles:19323 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T02:38:12.703882 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7dv1mnt https://doi.org/10.5065/D6M043C6 https Related Dataset #1 NCEP FNL Operational Model Global Tropospheric Analyses, continuing from July 1999 Dry layers in the tropical troposphere observed during CONTRAST and global behavior from GFS analyses 2016-12-16T00:00:00Z publication https://n2t.org/ark:/85065/d7dv1mnt https://doi.org/10.1002/2016JD025841 Randel, William author Rivoire, L. author Pan, Laura L. author Honomichl, Shawn B. author UCAR/NCAR - Library publisher The Convective Transport of Active Species in the Tropics (CONTRAST) experiment was an aircraft-based field campaign conducted from Guam (14°N, 145°E) during January–February 2014. Aircraft measurements included over 80 vertical profiles from the boundary layer to the upper troposphere (~15 km). A large fraction of these profiles revealed layered structures with very low water vapor (relative humidity <20%) and enhanced ozone, primarily in the lower-middle troposphere (~3–9 km). Comparing CONTRAST water vapor measurements with co-located profiles from National Centers for Environmental Prediction Global Forecast System (GFS) analyses, we find good agreement for dry layers, including profile-by-profile comparisons and statistical behavior. We then utilize GFS data to evaluate the frequency of occurrence and 3-D structure of dry layers for the CONTRAST period to provide perspective to the campaign measurements and evaluate the global climatological behavior based on a longer record. GFS data show that dry layers occur ~50-80% of the time in the subtropical troposphere, maximizing on the equatorward side of the subtropical jets in the winter hemisphere. Subtropical dry layers occur most frequently over isentropic levels ~320-340 K, which extend into the extratropical upper troposphere-lower stratosphere (UTLS). Similar statistical behavior of dry, ozone-rich layers is found in long-term balloon measurements from Reunion Island (21°S, 56°E). The climatologically frequent occurrence of dry, ozone-rich layers, plus their vertical and spatial structures linked to the subtropical jets, all suggest that dry layers are linked to quasi-isentropic transport from the extratropical UTLS and suggest a ubiquitous UTLS influence on the subtropical middle troposphere. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2016 American Geophysical Union. None eng geoscientificInformation