|
Darling showerA duststorm caused by cyclonic winds in the vicinity of the River Darling in Australia.
|
|
dart leader(Also called continuous leader.) The leader which, after the first stroke, typically initiates each succeeding stroke of a multiple-stroke flash lightning. (The first stroke is initiated by a stepped leader.) The dart leader derives its name from its appearance on photographs taken with streak cameras. The dart leader's brightest luminosity is at its tip which is tens of meters in length, propagating downward at about 107 m s−1. In contrast to stepped leaders, dart leaders do not typically exhibit branching because the previously established channel's low gas density and residual ionization provide a more favorable path for this leader than do any alternative ones.
Chalmers, J. A., 1957: Atmospheric Electricity, p. 239.
|
|
data acquisition systemA collection of sensors and communication links to sample or collect and then return data to a central location for further processing, display, or archiving.
|
|
data assimilationThe combining of diverse data, possibly sampled at different times and intervals and different locations, into a unified and consistent description of a physical system, such as the state of the atmosphere.
|
|
data collection platformAutomatic digital or analog measuring device with recording and data transmission system.
|
|
data collection system1. Coordinated system for collection, reduction, and archival of observations from a hydrometeorological network. It may include automatic transmission of the observations to a remote receiving location. 2. (Abbreviated DCS.) The GOES data collection system, which receives environmental data transmissions that originate at remote automatic data collection platforms and relays the signal to central ground stations.
|
|
data directoryA set of descriptions of a large number of datasets containing high-level information suitable for making an initial determination of the potential usefulness of a dataset for some application. Information on the location of more detailed descriptions or the latest dataset itself is found in the data directory.
|
|
data loggerA device deployed in the field that records weather data from one or more external sensors. Most modern data loggers are miniature digital computers that sample the data inputs and digitize the results at regular intervals, apply preset calibrations to convert from raw voltages or currents into meteorological variables, compute statistics such as mean values and variances, and record the results either internally in memory, locally on attached storage media, or transmit the results to a remote user or computer site via telephone line or radio link. Those data loggers that record the results in memory must be periodically serviced to download the data and then clear the memory to allow new data to be stored.
|
|
data windowThe finite time or space interval during which measurements are obtained. Meteorological data can be viewed as occurring along an infinite time line from the distant past into the distant future, but measurements for a limited time, for example, during a field experiment or period of routine weather observations, provide only a window on a portion of the time line.
|
|
dataset catalogA list of the contents of a collection of datasets with sufficient information to allow for identification and retrieval of datasets of interest.
|
|
