Times and tides
MONDAY JANUARY 01, 0001
Climate scientists wrongly claim that the composition of the atmosphere in the form of certain gases put into it by Man can alter weather patterns, bringing about more cyclones and/or of greater intensity. But weather does not come from the atmosphere, the weather came first and what blew around got to be called the atmosphere. Aetmos was the Greek word for breath, in this case some god's breath. In the same way tides are the sea - tides do not come from the sea. Otherwise the sea would somehow decide on tidal timing because of something within the makeup of the water rather than from forces external to the water. Adding CO2 into the air can no more affect the weather than injecting, say, ink into the sea to attempt to alter the tides.
Weather patterns, changes and cycles are determined by forces outside of the air. The tidal forces for both sea and air come from agencies that themselves wax and wane; Sun, moon and planets. It is known by meteorologists that weather balloons float higher at new and full moon. There are king tides in the air at the same time as in the sea. Lunar forces travel through air to reach water, and at its surface all over the globe, which covers 75% of the surface of the earth, the sea joins the air in a frictional interface. At those times both the Sun and the Moon are pulling on the oceans in the same line though not necessarily in the same direction. If at one of those times the moon happens to be at its closest to Earth for the month (perigee) then it is an exceptionally high tide.
Earth (or Land) tides are the result of a visco-elastic deformation of the earth under the action of gravitational pull of the moon and the Sun. All land will rise each day between 15- 50cms to meet the transiting moon, and recede at moonset. The effect can be measured with precision instruments. Long term, it is the cutting-knives-like action of the earth moving up and down in this daily flux that slowly grinds rocks into fine soil and shell into beach sand. Otherwise, how else would these get formed?
The time of closer perigees are also the year's highest tides. This year, 2010, these occur around full moons until April, then around new moons until November. On January 30th the moon was closest to earth for the whole year. It was the day of highest tidal variation of the month. On March 2 will be the highest tidal variation of the year, not only in NZ but everywhere in the world that has tides.
Highest tides are often accompanied by low air pressure systems, followed by an upwardly trending barometer. Some of the highest tides worldwide for several decades occurred on 4 June 2008 (new moon, perigee, and northern declination). Sydney got 46mm of rain that day and Auckland, 21mm. In Dublin that day, air pressure and dew point skyrocketed downward, and the temperature was lowest for the month. Christchurch had a barometric dip and a brief but powerful hike in wind gusts which brought rain that day and three days later, snow. On the day of highest tides, effects differ for each location, but some extreme event can be expected.
In old folklore, mariners said dolphins were a sign of a storm. Orcas were sighted on 8 April 2009 in Dunedin Harbour. The next day, South Taranaki was blasted by vicious weather with waterspouts sighted near Opunake and a hailstorm pounded Pihama. Today (24 June), orcas have been sighted in Auckland harbour and a wild storm is predicted by metservices this weekend (28th/29th), accompanying the year's highest tides, accompanying very low air pressures, accompanying new moon, perigee and moon crossing equator.
Floods are common around highest tides because river water cannot get away and water backs up, submerging low lying land. Heavy rain coming from low pressure systems adds to water levels. Why low atmospheric pressure accompanies high tide levels is basic school physics. High pressure, as if you pushed the bathwater down with your hand, lowers tide heights, but low pressure, which is a pressure absence, allows water upwards. It is a chicken-and-egg situation without causality. A lowering sea invites a greater amount of air to be gathered above it, and as air has mass this creates greater pressure. Conversely an area of rising sea would tend to dispel or 'spill' air to either side of the rising part of the sea, leaving less volume of air immediately above the area under consideration, therefore of less mass. What causes what is immaterial because both sea and air work together controlled externally by the same moon.
Highest tides at the coast and in the air above our heads is not the end of the story. Under flat land is a water table responding to the sea-tide, so there are higher tides at times in groundwater. A valley already saturated by below-surface rising water will not be able to absorb any more when a nearby river breaks its banks. Water-level measurements in a deep well in a hard-rock region at the campus of the National Geophysical Research Institute, near Hyderabad, India, carried out in 2002 showed a cyclic fluctuation in the water levels. Spectral analysis found that these fluctuations had high correlation with earth tides. As coastal tides parallel earth tides it is likely that everything rises and falls together. For instance a typical annual variation of water level was found to occur with rise during the monsoon and decline in the remaining period. These fluctuations had been hitherto unobserved during manual observations made over larger time intervals, especially in locations far from a coastline.
Farmers who have farmed on the same piece of land often notice stock preferences for certain paddocks. Fluctuations in groundwater tides affects the rate and flavour of plant growth. Some fields go soggy at regular times and are avoided by cattle, or ditches smell again after a lengthy absence.
We should not be surprised to find tides everywhere, and within them, the king tide times. The behaviour of fish and bees will change. Pruning during a waning period of the moon will decrease growth. The waxing moon building toward full exerts a stronger gravitational pull upon the earth, its tides, tree sap and other energy fields, and beckons forth growth spurts. The full moon exercises maximum gravitational pull each month, and always brings the most births of human babies, so tidal variation at the coast or observable in a field may be a litmus indicator for times of increased calving and lambing.
Tree stems respond to ground conditions and shrink and swell with tides, and the ensuing sap tide will show up in insect behaviour, for example mites, which in turn attract particular birds. Southern rata supply berries to Kereru (wood pigeon) and leaf food to mites, and this tree and the rimu are the fantails’ favourite for nests. Weta prefer rimu and kowhai. Spiders typically build webs in Five finger/Whauwhapaku, and this tree is the leaf of choice for native snails. Bees take nectar from Southern rata and kowhai, while moths sip nectar from totara and rimu. Crops of these trees alive with birds at certain times of the year can indicate higher tides and potential flooding elsewhere on the farm. In nature everything "talks" to everything else, and they all talk to the moon. It seems it is only humans who seem to have forgotten.
© Ken Ring 2010