[CF-metadata] new standard names : tidal quantities tidal_high_water, ...

From: Lowry, Roy K. <rkl>
Date: Wed, 4 Jun 2014 16:53:45 +0100

Hello Guenther,

There is a lot here and so far I have just had time to look at your first proposed Standard Name. What I don't understand is the time context of your data. There are two high tides per day (or even four in places like the Solent), each of which has a different high water level and of course these differ from day to day due to spring-neap cycles. To what period of time does tidal_high_water_above_sea_level refer?

Maybe if you explained a little about the type of data you are trying to encode into CF I might understand a little better.

Cheers, Roy.


Please note that I now work part-time from Tuesday to Thursday. E-mail response on other days is possible but not guaranteed!

From: "Lang, G?nther" [mailto:guenther.lang at baw.de]
Sent: 04 June 2014 13:51
To: cf-metadata at cgd.ucar.edu
Subject: [CF-metadata] new standard names : tidal quantities tidal_high_water, ...

Preface

It is suggested to introduce new standard names for several tidal
quantities like (tidal) high_water, low_water etc. These are geophysical
concepts and it would be not adequate to describe them with cell_methods
and/or time bounds.

---
1.) tidal_high_water_level_above_sea_level [ m ]
    The maximum height reached by a rising tide. The high water is due
    to the periodic tidal forces and the effects of meteorological,
    hydrologic, and/or oceanographic conditions. Sea_level means mean
    sea level, which is close to the geoid in sea areas.
---
2.) tidal_low_water_level_above_sea_level [ m ]
    The minimum height reached by a falling tide. The low water is due
    to the periodic tidal forces and the effects of meteorological,
    hydrologic, and/or oceanographic conditions. Sea_level means mean
    sea level, which is close to the geoid in sea areas.
---
3.) tidal_range [ m ]
    Arithmetic mean between tidal rise and tidal fall. Due to the periodic
    tidal forces and the effects of meteorological, hydrologic, and/or
    oceanographic conditions.
---
4.) half_tide_level_above_sea_level [ m ]
    Water level at half tidal range. The level midway between high
    water and mean low water for a tide. Due to the periodic tidal
    forces and the effects of meteorological, hydrologic, and/or
    oceanographic conditions. Sea_level means mean sea level, which is
    close to the geoid in sea areas.
---
5.) mean_tide_water_level_above_sea_level [ m ]
    The mean surface elevation as determined by averaging the heights
    of the water at equal intervals of time for a tidal period, which is
    the interval between two successive low waters. Differs
    from half tide level due to tidal asymmetry. Due to the periodic tidal
    forces and the effects of meteorological, hydrologic, and/or
    oceanographic conditions. Sea_level means mean sea level, which is
    close to the geoid in sea areas.
---
6.) mean_tidal_rise_water_level_above_sea_level [ m ]
    (opt) mean_flood_water_level_above_sea_level [ m]
    The mean surface elevation as determined by averaging the heights
    of the water at equal intervals of time for the period of tidal rise,
    which is the interval from low water to high water.
    Differs from mean water level during tidal fall due to tidal
    asymmetry. Due to the periodic tidal forces and the effects of
    meteorological, hydrologic, and/or oceanographic conditions.
    Sea_level means mean sea level, which is close to the geoid in
    sea areas.
---
7.) mean_tidal_fall_water_level_above_sea_level [ m ]
    (opt) mean_ebb_water_level_above_sea_level [ m]
    The mean surface elevation as determined by averaging the heights
    of the water at equal intervals of time for the period of tidal fall,
    which is the interval from high water to low water.
    Differs from mean water level during tidal rise due to tidal
    asymmetry. Due to the periodic tidal forces and the effects of
    meteorological, hydrologic, and/or oceanographic conditions.
    Sea_level means mean sea level, which is close to the geoid in
    sea areas.
---
8.) duration_of_tidal_rise [ s ]
   Duration of rise is the interval from low water to high water. In
   combination with duration_of_tidal_fall they cover, on an average,
   a period of 12.42 hours for a semidiurnal tide or a period of 24.84
   hours for a diurnal tide. In a normal semidiurnal tide, duration of
   rise and duration of fall each will be approximately equal to 6.21
   hours, but in shallow waters and in rivers there is a tendency for
   a decrease in duration of rise and a corresponding increase in
   duration of fall. Due to the periodic tidal forces and the effects
   of meteorological, hydrologic, and/or oceanographic conditions.
---
9.) duration_of_tidal_fall [ s ]
  Duration of fall is the interval from high water to low water. In
  combination with duration_of_tidal_rise they cover, on an average,
  a period of 12.42 hours for a semidiurnal tide or a period of 24.84
  hours for a diurnal tide. In a normal semidiurnal tide, duration of
  rise and duration of fall each will be approximately equal to 6.21
  hours, but in shallow waters and in rivers there is a tendency for
  a decrease in duration of rise and a corresponding increase in
  duration of fall. Due to the periodic tidal forces and the effects
  of meteorological, hydrologic, and/or oceanographic conditions.
---
10.) duration_of_tide [ s ]
     (opt) tidal_period [ s ]
  Interval between two successive low waters. Sum of duration_of_tidal_rise
  and duration_of_tidal_fall. On an average, a period of 12.42 hours for
  a semidiurnal tide or a period of 24.84 hours for a diurnal tide. Due
  to the periodic tidal forces and the effects of meteorological,
  hydrologic, and/or oceanographic conditions.
---
11.) time_of_occurrence_of_tidal_high_water [ s ]
  Time when high water occurs. Due to the periodic tidal forces and
  the effects of meteorological, hydrologic, and/or oceanographic
  conditions.
---
12.) time_of_occurrence_of_tidal_low_water [ s ]
  Time when low water occurs. Due to the periodic tidal forces and
  the effects of meteorological, hydrologic, and/or oceanographic
  conditions.
---
13.) tidal_difference_for_time_of_occurrence_of_tidal_high_water [ s ]
  Difference in time of a high water at a subordinate station and at
  a reference station. The difference, when applied according to sign
  to the time at the reference station, gives the corresponding time
  for the subordinate station. Due to the periodic tidal forces and
  the effects of meteorological, hydrologic, and/or oceanographic
  conditions.
---
14.) tidal_difference_for_time_of_occurrence_of_tidal_low_water [ s ]
  Difference in time of a low water at a subordinate station and at
  a reference station. The difference, when applied according to sign
  to the time at the reference station, gives the corresponding time
  for the subordinate station. Due to the periodic tidal forces and
  the effects of meteorological, hydrologic, and/or oceanographic
  conditions.
---
15.) tidal_rise [ m ]
  Vertical difference between the water level at low water and the
  water level at the subsequent high water. Due to the periodic tidal
  forces and the effects of meteorological, hydrologic, and/or
  oceanographic conditions.
---
16.) tidal_fall [ m ]
  Vertical difference between the water level at high water and the
  water level at the subsequent low water. Due to the periodic tidal
  forces and the effects of meteorological, hydrologic, and/or
  oceanographic conditions.
---
17.) duration_of_wetting_due_to_tidal_flooding [ s ]
  Duration for which a location is covered with water due to tidal
  flooding. Within the intertidal zone, flooding may last from 0.00
  (always dry) up to, on an average, 12.42 hours (always wet) for a
  semidiurnal tide. Or up to, on an average, 24.84 hours for a diurnal
  tide. Due to the periodic tidal forces and the effects of
  meteorological, hydrologic, and/or oceanographic conditions.
---
18.) duration_of_drying_due_to_tidal_ebbing [ s ]
  Duration for which a location is not covered with water due to tidal
  ebbing. Within the intertidal zone, ebbing may last from 0.00
  (always wet) up to, on an average, 12.42 hours (always dry) for a
  semidiurnal tide. Or up to, on an average, 24.84 hours for a diurnal
  tide. Due to the periodic tidal forces and the effects of
  meteorological, hydrologic, and/or oceanographic conditions.
G?nther Lang
Bundesanstalt f?r Wasserbau - Dienststelle Hamburg
Referat ?stuarsysteme II
Wedeler Landstra?e 157
22559 Hamburg
Telefon +49 (0) 40 81908 360
E-Mail guenther.lang at baw.de<mailto:guenther.lang at baw.de>
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Received on Wed Jun 04 2014 - 09:53:45 BST