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

1
NAME Upper-Air Gridded Datasets Description and
Some Preliminary Results

• Paul E. Ciesielski (paulc_at_atmos.colostate.edu),
  Richard H. Johnson, Peter J. Rogers and Richard
  K. Taft
• Colorado State University

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 1x1 grids (shown below) with
  25-hPa vertical resolution from surface to 50 hPa
  using multiquadric interpolation.
• In addition to V2 QCd 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 (QCd) 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/
Inventory of QCd 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
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
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 (lt 3 of sondes
missing)!