============================================================================== Dataset: CSU-DYNAMO upper-air and surface gridded analyses Version: 1a Release date: 15 Oct 2013 ============================================================================== General Description: ------------------- Analyzed fields (see list below) were produced on 1 degree latitude/longitude grids, 25 hPa vertical resolution (1000 to 50 hPa) using the multiquadric interpolation scheme of Nuss and Titley (1994). Analyses are available on the following grid and for the following times: ------------------------------------------------------------------------ * 20S - 20N, 35E - 155E * at 00, 06, 12, and 18 UTC * for 1 October thru 31 December, 2011 * each data file covers 1 day Basic fields: ------------ z geopotential height (m) t temperature (C) q water vapor mixing ratio (g/kg) u zonal wind (m/s) v meridional wind (m/s) ps surface pressure (hPa) Derived fields: -------------- w vertical p-velocity (hPa/s) div divergence (1/s) vor vorticity (1/s) Q1 apparent heating (K/day) Q2 apparent drying (K/day) Notes: ----- (1) For upper-air fields, the first pressure level (labeled 1025 mb) contains the associated surface field. (2) A field is underground if the pressure level of the data is greater than the surface pressure (ps). (3) File format: netCDF self describing files See http://www.unidata.ucar.edu/software/netcdf/ for more info. (4) To quickly examine a datafile: ncdump netcdf_filename | more (5) This dataset version used no supplemental model data in data sparse regions (i.e., neither inside nor outside of enhanced sounding arrays). - as a result gridded data outide of enhanced arrays should be used with great caution. - hi-res sonde data was used at the following core sites (Male, Gan, Diego, Revelle, Mirai, Colombo) and 12 other Piority Sounding Sites (See Ciesielski et al. 2013) - humidity corrected (Level 3) data were used for the six core sites, however humidity corrections were not yet available for the 12 Meisei sonde sites over Indonesia at the time this version of the dataset was prepared. - hi-res P3 dropsonde data were used - GTS-resolution sonde data were used at 54 other sites - V1 analyses are available every 6 hours, future versions will be created at 3 hr resolution - Ciesielski et al. (2013) describes the sonde data used and their corrections - Johnson and Ciesielski (2013) describes analysis procedure and some preliminary findings - caveats: Because of the large station spacing between sites over the Northern Sounding Array (NSA) , the strong diurnal cycle and flow-blocking at low-levels at Colombo are aliased onto the large-scale analyses and adversely affect the large-scale budgets. This version of the analysis includes a preliminary attempt to adjust low-level fields in Colombo sonde data to mute these effects. This is a work in progress and details of this adjustment and its impact on the budgets are forthcoming. -while analyses are provide from 1 Oct to 31 Dec, keep in mind the following: - analyses are most reliable when ships are on-site: - Revelle was onsite (nominal position 80.5E,Eq.) from 4 Oct - 29 Oct, 10 Nov. - 04 Dec., and 18 Dec. - 31 Dec. - Mirai was on site (nominal position 80.5E,8S) from 1 Oct - 24 Oct. and 1 Nov - 27 Nov. - analyses over NSA are less reliable after 12/05 when Colombo went from 4/day to 1/day sonde observations. - Male' ended sonde operation on 15 December 2011 at 00Z - see figure "invent_vis.png" which shows a visual inventory of soundings for 6 core Indian Ocean sites (Fig. 2 of Ciesielski et al. 2013) - (for internal use only: V1 analyses is based on gridded analysis version 8a) Contact information: ------------------- If any problems are noted in these datasets, please notify Paul Ciesielski (paulc@atmos.colostate.edu). References: ---------- Nuss, W. A., and D. W. Titley, 1994: Use of multiquadric interpolation for meteorological objective analysis. Mon. Wea. Rev., 122, 1611-1631.