Subj : Wx Terms (D)(3) To : All From : Daryl Stout Date : Thu Oct 05 2017 12:06 am Discharge In hydrologic terms, the rate at which water passes a given point. Discharge is expressed in a volume per time with units of L3/T. Discharge is often used interchangeably with streamflow. Discharge Curve In hydrologic terms, a curve that expresses the relation between the discharge of a stream or open conduit at a given location and the stage or elevation of the liquid surface at or near that location. Also called Rating Curve and Discharge Rating Curve. Discharge Table In hydrologic terms, 1. A table showing the relation between two mutually dependant quantities or variable over a given range of magnitude. 2. A table showing the relation between the gage height and the discharge of a stream or conduit at a given gaging station. Also called a Rating Table. Disdrometer Equipment that measures and records the size distribution of raindrops. Disk The visible surface of the sun (or any heavenly body) projected against the sky. Dispersion The process of separating radiation into various wavelengths. Distribution (Hydro)Graph In hydrologic terms, a unit hydrograph of direct runoff modified to show the proportions of the volume of runoff that occur during successive equal units of time. Diurnal Daily; related to actions which are completed in the course of a calendar day, and which typically recur every calendar day (e.g., diurnal temperature rises during the day, and diurnal falls at night). Diurnal Cycles Variations in meteorological parameters such as temperature and relative humidity over the course of a day which result from the rotation of the Earth about its axis and the resultant change in incoming and outgoing radiation. Diurnal Temperature Range The temperature difference between the minimum at night (low) and the maximum during the day (high). Divergence The expansion or spreading out of a vector field; usually said of horizontal winds. It is the opposite of convergence. Divergence at upper levels of the atmosphere enhances upward motion, and hence the potential for thunderstorm development (if other factors also are favorable). Diversion In hydrologic terms, the taking of water from a stream or other body of water into a canal, pipe, or other conduit. Divide In hydrologic terms, the high ground that forms the boundary of a watershed. A divide is also called a ridge. Dividing Streamline In the blocked flow region upwind of a mountain barrier, the streamline that separates the blocked flow region near the ground from the streamlines above which go over the barrier. Dividing Streamline Height The height above ground of the dividing streamline, as measured far upwind of a mountain barrier. See dividing streamline. DMNT Dominant DMSH Diminish DNR Department of Natural Resources DNS Dense DNSTRM Downstream Dobson Unit Unit used to measure the abundance of ozone in the atmosphere. One Dobson unit is the equivalent of 2.69/ x 1016 molecules of ozone/cm2. DOC Department of Commerce DOH Development and Operations Hydrologist Doldrums The regions on either side of the equator where air pressure is low and winds are light. Domain In air pollution modeling, the geographical area over which a simulation is performed. Domestic Consumption In hydrologic terms, the quantity, or quantity per capita, of water consumed in a municipality or district for domestic uses or purposes during a given period, generally one day. It is usually taken to include all uses included within the term Municipal Use of Water and quantity wasted, lost, or otherwise unaccounted for. Domestic Use of water In hydrologic terms, the use of water primarily for household purposes, the watering of livestock, the irrigation of gardens, lawns, shrubbery, etc., surrounding a house or domicile. Doppler Radar Radar that can measure radial velocity, the instantaneous component of motion parallel to the radar beam (i.e., toward or away from the radar antenna). Down-Valley Wind A thermally driven wind directed down a valley's axis, usually occurring during nighttime; part of the along-valley wind system. Downburst A strong downdraft current of air from a cumulonimbus cloud, often associated with intense thunderstorms. Downdrafts may produce damaging winds at the surface. Downdraft (Abbrev. DWNDFT) - A small-scale column of air that rapidly sinks toward the ground, usually accompanied by precipitation as in a shower or thunderstorm. A downburst is the result of a strong downdraft. Downslope Flow A thermally driven wind directed down a mountain slope and usually occurring at night; part of the along-slope wind system. Downstream In the same direction as a stream or other flow, or toward the direction in which the flow is moving. Downstream Slope In hydrologic terms, the slope or face of the dam away from the reservoir water. This slope requires some kind of protection (e.g.; grass) from the erosive effects of rain and surface flow. Downwash A deflection of air downward relative to an object that causes the deflection. Downwelling Radiation The component of radiation directed toward the earth's surface from the sun or the atmosphere, opposite of upwelling radiation. DP 1. Deep 2. Dew Point DPD On a buoy report, dominant wave period (seconds) is the period with the maximum wave energy. DPNG Deepening DPTH Depth DPTR Departure DR Direction Drainage Area In hydrologic terms, an area having a common outlet for its surface runoff (also see Watershed and Catchment Area). Drainage Basin In hydrologic terms, a part of the surface of the earth that is occupied by a drainage system, which consists of a surface stream or a body of impounded surface water together with all tributary surface streams and bodies of impounded surface water. --- þ Synchronet þ The Thunderbolt BBS - wx1der.dyndns.org .