Gridded Datasets

Brief Description

Gridded fields of geopotential height (z), zonal wind (u), meridional wind (v), temperature (T) and specific humidity (q) were analyzed using multiquadric interpolation (Nuss and Titley 1994). The data used in constructing these fields came from the merged profiler/rawinsonde dataset (Ciesielski et. al 1997) and sounding data from other Priority Sounding Sites (PSS) . Gridded analyses were produced over two regions: the Large Scale Array (LSA) and the Intensive Flux Array (IFA) of TOGA/COARE. Gridded fields are available at 25 mb resolution from 1000 to 25 mb and at 1 degree resolution in both the latitude and longitude directions. Surface fields and surface pressure were also analyzed. These analyses were done for 480 six hour intervals (00, 06, 12, and 18UTC) during the COARE Intensive Observing Period (IOP - 1 November, 1992 through 28 February, 1993).

Version 1 (V1) LSA Gridded Dataset (released 10/03/1996)

Click here to view and download ASCII versions of the gridded datasets over the LSA. Refer to the Readme file for important documentation on using this dataset. This dataset does not use any humidity corrected data (see V2).

** Users are cautioned: analyzed height field in V1 contains numerous errors such that computing horizontal gradients with this field is not recommended.

Version 2.1 (V2.1) LSA Gridded Dataset (released 10/21/2002)

Click here to view and download ASCII versions of the gridded datasets over the LSA. Refer to the Readme file for important documentation on using this dataset. This dataset was prepared using the humidity corrected sonde data prepared by NCAR/ATD (Wang et al. 2002). Some of the impacts of using the humidity corrected are described in this short article . In addition, this version of the gridded data contains the diagnosed fields of divergence and vertical motion, where the analysis of the divergence field has been improved using a technique described briefly here. Users of the version 2 analyses should reference the submitted manuscript by Ciesielski et. al (2002) listed below in the references.

Note: V2.1 updates the specific humidity field with a correction to V2.0 of this field for temperatures below 0C.

** Users are cautioned: analyzed height field in V2 contains numerous errors such that computing horizontal gradients with this field is not recommended. If horizontal height gradients are required, we recommend that the ECMWF height analysis (from a special ECMWF TOGA COARE reanalysis) be used. For this purpose as part of V2 LSA gridded dataset, we have included the ECMWF height analysis.




References

Ciesielski, P.E., L.M. Hartten, and R.H. Johnson, 1997: Impacts of merging profiler and rawinsonde winds on Toga COARE analyses. J. of Atmos. Oceanic Tech. 14, 1264-1279.

Ciesielski, P.E., R.H. Johnson, P.T. Haertel and J. Wang: 2003: Corrected TOGA COARE sounding humidity data: Impact on diagnosed properties of convection and climate over the warm pool. J. Clim., 16, 2370-2384. [ PDF]

Nuss W.A. and D.W. Titley, 1994: Use of multiquadric interpolation for meteorological objective analysis. Mon. Wea. Rev., 22, 1611-1631.

Wang, J., H.L. Cole, D.J. Carlson, E.R. Miller and K. Beierle, 2002: Corrections of humidity measurements errors from the Vaisala RS80 radiosonde -- application to TOGA COARE data. J. of Atmos. Oceanic Tech. (In press)

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