Preliminary Analyses of S-Pol’s Refractivity Field Tammy M. Weckwerth and Crystalyne Pettet NCAR/ATD IHOP Science Workshop, Boulder, March 2003

Our Objectives Evaluate representativeness of low-level refractivity retrieval Fixed and mobile mesonets Evaluate layer over which refractivity retrieval is representative Aircraft in situ measurements SRL vertical profiles

IHOP_2002

S-Pol Refractivity Retrieval Variations in q, T and p Boundary detection Advection QPF, CI, ABL, bores and instrumentation dryline dryline cool/moist warm/dry

22 May 2002 Reflectivity Refractivity warm/dry cool/moist

S-Pol Surface Station Courtesy of Rita Roberts (NCAR) & Fleur Couvreux (Meteo/France)

22 May 2002 2000 UTC P-3 MM6

22 May 2002 2000 UTC MM6 Small N variation Corresponding small q, T variations NRL P-3 Strong q correlation Weaker inverse T relationship

22 May 2002 2200 UTC MM6 MM8

22 May 2002 2200 UTC MM6 Comparable N, q trends Abrupt q gradients not in N (20m vs. 4 km) Inverse T relationship MM8 Strong q correlation Weaker inverse T relationship

22 May 2002 2209 UTC UWKA

22 May 2002 2209 UTC UWKA Mid CBL Strong q, N correlation Weak inverse T relationship N gradient is wider than fine line

22 May 2002 2350 UTC UWKA MM7

22 May 2002 2350 UTC MM7 q and inverse T trends are more abrupt than N gradient N gradient and fine line are comparable UWKA q and inverse T trends are more abrupt than N gradient N gradient and fine line are comparable

NASA/GSFC Scanning Raman Lidar Courtesy of Belay Demoz (NASA/GSFC)

Summary Evaluate representativeness of low-level refractivity retrieval Strong direct relationship with surface q measurements Weaker inverse relationship with surface T measurements Evaluate layer over which refractivity retrieval is representative Aircraft measurements suggest direct relationship with CBL q measurements and inverse T relationship SRL comparison suggests direct relationship with q during significant boundary passage but no N variation during other boundary layer circulation passages

Ongoing Work Evaluate representativeness of low-level refractivity retrieval Fixed and mobile mesonets Plan to: Add GPS intercomparisons Plan to: Add DRI MMR intercomparisons Evaluate layer over which refractivity retrieval is representative Aircraft in situ measurements SRL intercomparisons Plan to: Add AERI vertical profiles Plan to: Add Sounding & Dropsonde comparisons Plan to: Add horizontal and vertical pointing airborne DIAL Plan to: Add TAOS intercomparisons Possibly add: MIPS profiling radiometer intercomparisons Plan to: Evaluate two more days

AERI measurements

Mobile mesonet measurements

AERI measurements

Mobile mesonet measurements