S-126

Physical Environment
a place to discuss and follow the work

Knowledgeable WG members: briana sullivan (UNH), Jens Schröder-Fürstenberg (Germany), Tom Loeper (USA), Yves Le Franc (SHOM)

OLD ORIGINAL - Sample Test Data File:Physical Environment Test Data Sample.docx (NOTE: we are now using real samples from US Coast Pilot and US Sailing Directions)

NEW listing of terms with data source (Annex A)

File:Coast Chart Term Frequency NIPWG Version.xlsx - a new list of terms compiled from all possible sources related to the Physical Environment that contains statistics on the frequency of word use within the 9 volumes of the US Coast Pilot. It will be used as a guide to focus on terms to research and build use case scenarios so we know what is of value to model and what doesn't need representation.

Magnetic Variations and Local Anomalies

• Magnetic Variations
• Magnetic Anomalies

S-101

From DCEG Geo Feature Magnetic Data

Magnetic Variation - MAGVAR (4.1)

S-101 Geo Feature

The angle between the magnetic and geographic meridians at any place, expressed in degrees east or west to indicate the direction of magnetic north from true north. Also called magnetic declination. (IHO Dictionary –S-32).

(until a world magnetic model is universally available for inclusion in ECDIS mag var is most important magnetic data for the mariner. Updates should be supplied every five years to coincide with changes of epoch).

S-101 Attributes

  RYRMGV - reference year for magnetic variation. (YYYY)
  VALACM - value of annual change in magnetic variation. (+/- minutes: easterly/westerly)
  SCAMIN - scale minimum

Local Magnetic Anomaly - LOCMAG (4.2)

S-101 Geo Feature

An anomaly of the magnetic field of the Earth, extending over a relatively small area, due to local magnetic influences. Also called local attraction or magnetic anomaly. (IHO Dictionary –S-32).

If it is required to encode an abnormality in magnetic variation for a localised area, it must be done using the feature Local Magnetic Anomaly. If the area cannot be defined, the feature should be represented as a point.

S-101 Attributes

Feature Name
   display name
   language
   name OBJNAM/NOBJNM

reported date SORDAT

value of local magnetic anomaly
    magnetic anomaly value maximum VALLMA
    magnetic anomaly value minimum 

scale minimum SCAMIN

Remarks

Where the mandatory complex attribute value of local magnetic anomaly contains a value in the sub-attribute magnetic anomaly value maximum only, the deviation is assumed to be positive and negative by that amount. Where the positive and negative values for the local magnetic anomaly differ, the positive value must be populated in anomaly value maximum, and the negative value in the sub-attribute magnetic anomaly value minimum. The plus/minus character must not be encoded.

Abnormal magnetic variation should not be encoded unless it varies by more than about 3° from the normal magnetic variation (see clause 4.1) for the area.

Coast Pilot examples

(120) Differences of as much as 5° from the normal variation have been observed near the mouth of Smyrna River.   

(166) Differences of as much as 2° to 5° from normal variation have been observed along the channel from Artificial Island to Marcus Hook. 

(232) Differences of 2° to 5° from normal variation have been observed astride the Delaware River Channel from Oldmans Point to the mouth of Oldmans Creek.  

(79) Differences of as much as 6° from the normal variation have been observed in Elk River Channel from Courthouse Point to Old Town Point. 

(30) Differences of as much as 6° from the normal variation have been observed 3 to 17 miles offshore from Cape Henry to Currituck Beach Light. 

(130) Differences of as much as 5° from the normal variation have been observed in the channel from Pooles Island to Howell Point (chart 12274). 

(180) Differences of 3° to 8° from normal variation have been observed in Elk River channel from Grove Point to Courthouse Point. 

Possible Data Elements Needed

Observation location description - would it be HELPFUL to have the cultural points within the area maintained?

(perhaps it is more understandable for someone to keep in their mind map of the area the familiar names delineating the locations vs only an outline on the chart?)

NOTES

For the US... the Magnetic Variation area is the bounds of a given chart...yet the Coast Pilot clearly has variations that are within the magnetic variation bounds of the chart. (Yet there are none encoded in the ENC).

Ice Conditions

• Drift Ice
• Icebergs

S-101

From DCEG

Ice Area ICEARE (5.13)

S-101 Geo Feature (Surface)

An area of ice over land or water. (S-57 Edition 3.1, Appendix A –Chapter 1, Page 1.84, November 2000).

S-101 Attributes

category of ice (CATICE)
    1 : fast ice
    5 : glacier
    8 : polar ice
elevation (ELEVAT)
feature name  
    display name
    language
    name(OBJNAM)/(NOBJNM)
height  (HEIGHT)
periodic date range
    date end(PEREND)
    date start(PERSTA)
reported date(SORDAT)
status(STATUS)
    1 : permanent
    5 : periodic/intermittent
    18 : existence doubtful
vertical length(VERLEN)
visually conspicuous  (CONVIS)        
    1 : visually conspicuous
    2 : not visually conspicuous
    3 : prominent
scale minimum (SCAMIN)

Remarks

Ice Area features that are located in the sea must be covered by an Unsurveyed Area feature, if the depth of water beneath them is unknown, or covered by a Depth Area feature, if the depth is known.

As ice fronts move, a date when the limit was surveyed should be included, if possible, using the attribute reported date.

Glaciers(see S-4 –B-353.8) If it is required to encode the portion of a glacier that is on land, it must be done using an Ice Area feature, with attribute category of ice= 5 (glacier) covered by a Land Area feature (that is, the glacier does not form a hole in the land area).

If the seaward edge of an encoded glacier is coincident with the coastline, this edge should be encoded using a Coastline feature, with attribute category of coastline=6 (glacier (seaward end)), and the coastline’s spatial type should have the attribute quality of horizontal measurement=4 (approximate) for the visible coastline.

Coast Pilot examples

(97) The intracoastal passages of New Jersey, Delaware and Maryland usually are closed by ice during ordinary winters; the Virginia passages are closed only during severe winters and then only for short periods. Local vessels use all the inlets and adjacent channels from Sandy Hook to Cape Charles all winter, even when through navigation is blocked.

(98) In Delaware River, ice is present in sufficient amounts even in ordinary winters to be of some concern. The Chesapeake and Delaware Canal is kept open as long as possible but may be closed at times. In severe winters, navigation has been interrupted above Chester but tugs and large vessels keep the channels open to Philadelphia. Above Philadelphia, the river may be closed for extended periods in January and February, and navigation is practically suspended during severe winters.

(99) Ice seldom interferes with navigation of full-powered vessels in Hampton Roads even in severe winters. Large vessels can always pass up and down Chesapeake Bay, but ice jams are of frequent occurrence off Baltimore Harbor. The harbor itself sometimes freezes over and navigation may be blocked for small, low-powered vessels for limited periods.

(100) Conditions in other Chesapeake Bay tributaries are somewhat similar to those in the same latitudes along the coast. Ice is not much of a problem in the southerly tributaries. The upper part of Potomac River is closed during severe winters, and Patuxent River is closed nearly to the mouth. Severn River, strangely enough, is said to remain open except for short periods in severe winters. Susquehanna River, at the head of the bay, usually is completely closed for about 3 months. Ice conditions in the Eastern Shore tributaries correspond roughly to those across the bay.

(101) During some winter months or when threatened by icing conditions, lighted buoys may be removed from station or replaced by unlighted buoys; unlighted buoys, daybeacons and lights on marine sites also may be removed. (See LIGHT LIST.)

(102) For icing hazards to vessels see Superstructure icing, following.

(135) Ice may be encountered on Maurice River from the latter part of December through the early part of March.

(87) Ice sufficient to interfere with the navigation of small craft may be expected at any time between December and April and is worst during January and February. The canal is kept open as long as possible. During mild winters, local vessels use the canal throughout most of the season, but strangers should make inquiries before attempting passage. Wooden vessels passing through thin ice are liable to be cut through at the waterline. Vessels with low horsepower are cautioned against transiting the canal in heavy ice. 

Possible Data Elements Needed

type of ice - ice barriers, impoundments, pack ice (Germany), thin ice, heavy/heavier ice, sufficient ice (US) disability - ice pressure, passage disability (Germany), interruption closure times - ordinary winters, severe winters (US) closure duration - short periods, extended periods, entire winter (data range) (US) seasonal notes on passage/navigation - ice seldom forms before January applicability - local vessels, strangers, small, low-powered/low horsepower vessels, large vessels, full-powered vessels, Wooden vessels

NOTES

would S-101 feature name contain the ice area names included in the text (ex: New Jersey, Delaware, Maryland intracoastal passages, Virginia passages, channels from Sandy Hook to Cape Charles). If not, it might be a data element for S-126 Ice Area Name(s).

S-101 ICEARE - CATICE - is fast ice also "running ice" or "moving ice"? S-101 ICEARE - periodic date range - textual descriptions have ranges with types of ice (ex. Thin ice has been known to form early in December between Chester and Philadelphia, but the heavier ice usually does not begin to run before January.)

Currents and Flow

• • General Information
  • Named Currents
  • Seasonal Currents

Current –non-gravitational

S-101

From DCEG S-101 Geo Feature:Current –Non-Gravitational (CURENT) 10.3

IHO Definition: CURRENT –NON-GRAVITATIONAL. Any current that is caused by other than tide producing forces. Also called non-tidal current.(IHO Dictionary –S-32).

Tidal Streams - flood/ebb

S-101

From DCEG Geo Feature: TidalStream –Flood/Ebb (TS_FEB)

IHO Definition: TIDAL STREAMS. The alternating horizontal movement of water associated with the rise and fall of the tide caused by tide-producing forces. Also called tidal current. (IHO Dictionary –S-32). Approximate tidal stream rates may be given as discrete rate values for flood and ebb flow during springs. (S-57 Edition 3.1, Appendix A –Chapter 1, Page 1.173, November 2000).

Sea Level and Tides

• Sea Level
• Tides

Sea and Swell

• Sea Conditions
• Swell Conditions
• Tropical Disturbances
• Abnormal Waves

Sea Water Characteristics

• Salinity
• Density
• Sea Surface Temperature

Maritime Topography

(these terms origniated from scanning the publications and discussing among the group which were the most SIGNIFICANT features a mariner needed for navigation)

• General Remarks
  • Chart reference
  • general description of the area (topological as well as submarine)
• Seabed and Features
  • Deeps
  • Ridges and Plateaux
  • Shoals and Banks
• Submarine Springs
• Volcanic Activity
• Seismic Activity

Climate and Weather

• General Information
• General Conditions
  • Climate
  • Visibility
  • Cyclones
• Pressure
  • Average Distribution
  • Variability
  • Diurnal Variation
  • Abnormal Falls
• Anticyclones
  • Sub-tropical high pressure belt
• Depressions
  • General Information
  • Cyclones, tropical storms, tropical depressions
  • Classification
  • Occurrence
  • Average occurrence of tropical storms and cyclones in the SW indian ocean (this seems too specific for a heading)
  • Movement
• Fronts
  • Cold Fronts
  • The intertropical convergence zone
• Winds
  • General information
  • South-east trade winds
  • The North-west monsoon
  • Light or moderate variable winds
  • The Westerlies
  • Coastal Areas
  • Land and sea breeze
• Gales
  • General Information
  • Winds north of 30°S
  • Winds south of 30°S
  • Squalls
  • Waterspouts
• Cloud
  • North of 30°S
  • The sub-tropical belt of high pressure
  • South of 30°S
• Precipitation
  • General Information
  • The North-west monsoon and ITCZ
  • Madagascar
  • La Reunion, tec
  • Cycolones
  • The sub-tropical belt of high pressure
• Fog and visibility
  • Sea fog
  • Radiation fog
• Air Temperature
  • Open sea
  • Coastal areas
• Humidity
  • General Information
  • Open sea N of 30°S
  • South of 30°S

Climate Information

• Climate Station Information

QUESTIONS/COMMENTS/MISSING ITEMS

• Where are the Physical Descriptions of features, approaches, ports, anchorages, etc?
• Are references to external documents (i.e. Mariner's Handbook) to be kept or actual data from the reference or attach pdf?
• S-26 ?(undersea feature names) should be incorporated into this