NAME Upper-Air Gridded Datasets: Description NAME Upper-Air Gridded Datasets: Description and Some Preliminary Resultsand Some Preliminary ResultsPaul E. Ciesielski (paulc@atmos.colostate.edu), Paul E. Ciesielski (paulc@atmos.colostate.edu),

Richard H. Johnson, Peter J. Rogers and Richard H. Johnson, Peter J. Rogers and Richard K. TaftRichard K. Taft

Colorado State UniversityColorado State University

Research supported by NOAA-NA17RJ1228 and NSF-ATM0340602 (PI: Richard H. Johnson)

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.

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:

http://tornado.atmos.colostate.edu/name/Inventory of QC’d V2 sonde dataset:

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.

Number of sites

Type of site Number of

sondes

Number missed

Percent missing

10 USA-NWS enhanced 1380 17 1.2%

6 ISS, Loreto, 2 R/Vs 815 10 1.2%7 SMN enhanced 1057 30 2.8%1 Yuma (4 sites) 377 9 2.3%1 San Jose 173 12 6.9%

25 Subtotal enhanced sites

3802 78 2.1%

42 Operational 3507 115 3.3%67 All sites 7309 193 2.6%

Performance of NAME sonde network:

Objectively analyzed NAME gridded datasets:• 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.

Preliminary results using gridded dataset:

• Along-gulf cross sections (shown below) capture cooling and moistening in northern gulf associated with 13 July 2004 gulf surge.• ~120 sondes /day prior

to 7 July

• ~170 sondes/day from 7 July – 15 August

• ~200 sondes/day on most IOP days

Overall, the NAME upper-air sonde network performed extremely well (< 3% of sondes missing)!

•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 S

S SN N

EBA

•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.

Land EBA

Gulf EBA

•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.

N