NAME Upper-Air Gridded Datasets: Description and Some Preliminary Results

1. For 1 July – 15 August, gridded fields are produced over T2A (Tier 2 array) at 00 and 12 UTC. • For 40 day period (7 July – 15 August), gridded fields are produced over T1A (Tier 1 array) at 00, 06, 12 and 18 UTC. • For ~15 IOP days with (6 sondes/day), gridded fields are produced over EBA (Enhanced Budget Array) at 00, 04, 08, 12, 16 and 20 UTC. T2A T1A EBA NAME Upper-Air Gridded Datasets: Description and Some Preliminary Results Objective: To provide the scientific community with a research quality upper-air sounding dataset for the North American Monsoon Experiment (NAME) from 1 July – 15 August 2004, along with an objectively analyzed gridded dataset based primarily on these sounding data. Objectively analyzed NAME gridded datasets: • Diurnal cycle of diagnosed fields over budget arrays shows a strong convective signature over land at 18 LT transitioning to stratiform at subsequent times. Over the gulf, strong low-level subsidence at 18 LT is associated with a shallow sea-breeze circulation. • Basic fields (z, T, q, u and v) were analyzed onto a variety of 1°x1° grids (shown below) with 25-hPa vertical resolution from surface to 50 hPa using multiquadric interpolation. • In addition to V2 QC’d sonde data, these analyses used profiler winds data, QuikSCAT surface winds and NCEP reanalyses in data-sparse oceanic regions. • Over land, analyzed fields are independent of model analyses, and thus not influenced by model parameterization schemes. • From the basic fields, derived fields (divergence, vorticity, Q1 and Q2) were also computed. 5-hPa Quality Controlled (QC’d) sonde dataset: • Objective checks (i.e., gross limit, vertical consistency) and visual QC were performed to flag questionable and bad data. • Unless a correction was known, questionable/bad data were not changed, only flagged. • Data were interpolated to a uniform 5-hPa resolution. • Version 2 (V2) of this dataset is currently available at: N • Along-gulf cross sections (shown below) capture cooling and moistening in northern gulf associated with 13 July 2004 gulf surge. EBA http://tornado.atmos.colostate.edu/name/ Paul E. Ciesielski (paulc@atmos.colostate.edu), Richard H. Johnson, Peter J. Rogers and Richard K. Taft Colorado State University Inventory of QC’d V2 sonde dataset: • ~120 sondes /day prior to 7 July • ~170 sondes/day from 7 July – 15 August • ~200 sondes/day on most IOP days S Preliminary results using gridded dataset: N N S S Performance of NAME sonde network: • Vertical motion time series over the EBA show that the IOPs captured several periods of strong upward motion (indicated by arrows) associated with convective events. Land EBA Future work: • Perform higher level QC checks on the upper-air sondes to ensure the veracity of the data. • Incorporate pibal and aircraft data into the gridded analyses to better resolve circulation features over the Gulf of California and the Baja Peninsula. • Compute budget-derived rainfall and compare to independent estimates. • Compare objectively gridded analyses to NARR and NCEP reanalyses. • Use budget analyses in conjunction with radar data to study diurnal cycle of convection over EBA. Gulf EBA Research supported by NOAA-NA17RJ1228 and NSF-ATM0340602 (PI: Richard H. Johnson) Overall, the NAME upper-air sonde network performed extremely well (< 3% of sondes missing)!