downwell

English

Etymology

down- +‎ well

Verb

downwell (third-person singular simple present downwells, present participle downwelling, simple past and past participle downwelled)

1. To sink below material of lower density.
   • 1996, Tong Lee, Jochem Marotzke, Inferring Meridional Mass and Heat Transports of the Indian Ocean by Fitting a General Circulation Model to Climatological Data, page 12:

     Some of the northward-flowing waters turn eastward and enter the Throughflow sponge above 1300 m (Figure 5b), where they downwell and return to the interior and spread both to the south and the north (Figure 5c).

   • 1999, Katherine Anne Duderstadt, Summertime tropospheric ozone photochemistry over the western Atlantic Ocean, page 10:

     Ozone in the upper troposphere which downwells to the surface can also result from photochemical production enhanced by high levels of NOx from the natural stratosphere, aircraft emissions of NOx in the upper troposphere [Liu et al., 1980],

   • 1999, Alison Duxbury, Alyn C. Duxbury, Fundamentals of Oceanography, page 141:

     This cold water downwells and flows below the saltier but warmer surface water.

2. (of radiation) To penetrate water downward.
   • 1983, State Waters Resources Control Board, Environmental Impact Report: Amendment of the Water Quality Control Plan, Ocean Waters of California:

     This measurement, as Region 4 stated, has been "commonly used to measure marine turbidity; it does not measure downwelling ambient light."

   • 1988, J. A. Pyle, K. A. Browning, L. Thomas, Towards improved methods of exploiting remotely sensed imagery, page 329:

     There is a practical depth limit from which the radiance is reflected. Gordon & McCluny (1975) call the depth at which the spectral radiance downwelled from the surface falls to 1/e of its initial energy 'the first optical attenuation length'.

   • 2001, James Willard Nybakken, Marine Biology: An Ecological Approach, page 153:

     For those animals living in the mesopelagic zone, where some light downwells from the surface, a visual predator looking up at them could see a silhouette.

   • 2012 January 17, “Typhoon Tip”, in American Weather:

     In other words, the signal always weakens while it downwells.

Noun

downwell (plural downwells)

1. A vertical shaft or well in which water flows downward.
   • 1981, Final Budget of Stanislaus County and Financial Report:

     The proposed work includes enlarging the basin and installing downwells for percolation.

   • 1986, Robert L. Schuster, Landslide dams: processes, risk and mitigation, page 206:

     A 14-foot by 14-foot shaft, or downwell, located downstream of the intake structure permits flow to fall approximately 36 feet to a pool Torraed by a 10-foot deep rock trap.

   • 1989, T. A. Broadley, William Edward Lorne Clayton, British Columbia Manila Clam Culture Workshop, page 167:

     You can make this system a downwell by adding a water source above the tanks.

   • 1994, Lower Snake River Biological Drawdown Test, page 20:

     A six-foot diameter steel transportation pipe connects the downwell at the end of the collection channel to the upwell box at the existing juvenile fish facility. The downwell ensures that the pipe is pressurised and eliminates air entrainment.

   • 1995, Evaluation of Juvenile Fish Bypass and Adult Fish Passage Facilities at Water Diversions on the Umatilla River, page 44:

     The Furnish Canal juvenile fish bypass facility caused few injuries to fall chinook salmon test fish that traveled through the headworks canal, past the screens, and through the downwell, bypass pipe, and outlet when canal flow was 67% of maximum and bypass flow was at maximum.

2. Synonym of downwelling
   • 1986, Sea Frontiers, Sea Secrets - Volume 32, page 309:

     Warm-water eddies are downwells and cold-water eddies facilitate vertical mixing rather than induce upwelling.

Adjective

downwell (comparative more downwell, superlative most downwell)

1. In the lower part of a well.
   • 1982, American Institute of Aeronautics and Astronautics, A Collection of Technical Papers: AIAA/EPRI International Conference on Underground Pumped Hydro and Compressed Air Energy Storage:

     By measuring downwell and wellhead temperature, wellbore heat losses through the casing to the formation can be measured.

   • 1999, Paul Kruger, Henry J. Ramey, Proceedings -Stanford Geothermal Program Volume 24:

     ln general, the present-day measured downwell temperatures are lower than those indicated by the alteration mineralogy (i.e. epidote, wairakite, laumontite, and clays)

   • 2000, Anbo Wang, Eric Udd, Industrial Sensing Systems, page 56:

     This paper describes the applications for large scale fibre optic sensing arrays in geophysical metrology. The main applications considered here are ocean bottom cables and streamers for marine seismic, and downwell seismic systems.

Adverb

downwell (comparative more downwell, superlative most downwell)

1. In the lower part of a well.
   • 1979, U.S. Nuclear Regulatory Commission, Annual Report, page 216:

     These identification plaques will serve as one aspect of continuing control and are intended to be a long-term indication of a sealed radioactive source downwell.

   • 1984, The Geophysical Journal of the Royal Astronomical Society, page 12:

     One of the principal techniques available for estimating the distribution of cracks in HDR reservoirs is by the analysis of acoustic events recorded downwell on three-component geophones during hydraulic fracturing.

   • 1990, Journal of Physical Oceanography - Volume 20, page 1438:

     A careful analysis of Fig, 19B (and other similar photographs) indicates some of the long exposure particle streaks "downwell" near the topography.