2 and 3 for winter 2010 shows that even the denial of few SVPB drifters in the tropical eastern Pacific (at about 20[degrees]N, 140[degrees]W), in the western tropical Atlantic (at about 15[degrees]N, 45[degrees]W), and in the equatorial Indian Ocean (at about 0[degrees], 95[degrees]E) can have a large effect on the initial conditions, suggesting the importance of in situ SLP data at low latitudes, where SVPB drifters are not normally deployed apart from targeted small arrays in the paths of some tropical cyclones.
The beneficial effect of the SVPB data (up to five days ahead), for the geopotential height, lasts longer in the equatorial and tropical regions.
OSEs are expensive to run but have the benefit of quantifying the effect of a single perturbation--in this case, the denial of the SVPB drifter data--on all forecast metrics (root-mean-square error, for instance) at all forecast ranges.
6) shows that the SVPB drifters have the largest impact on a per-observation basis of all the data types assimilated in the ECMWF system during this period.
SLP data, including those collected by the SVPB drifters, are used in multiple ways by climate scientists, including trend computations, climate model diagnostics, and constructing climate indexes.
The OSE and FSOI studies described in this essay further highlight in a quantitative fashion the crucial role of the SVPB drifter data, collected by the U.S.
The beneficial effect of the SVPB drifter data in the forecast is detectable not only near the surface but also higher in the troposphere, up to 250 hPa (Horanyi et al.
This suggests that an attempt to extend the SVPB drifter array to the tropical region should be made and the impact of the data should be monitored and quantified with the FSOI analysis or similar diagnostics.
The participation in the activities of the DBCP, where the implementation of the SVPB array is discussed every year, is open to all United Nations member states (www.jcommops .org/dbcp/).