Thailand under Water 4: Winds, Waves and Wild Weather

So far we have watched the global warming (from greenhouse gases produced by human activities in the name of productivity and services demanded by humanity) and sea level rising (yes sea level is UP, though slowly -- 1-2 mm per year -- from melting ice caps, glaciers and permanent snow because of rising global temperature). We have also noticed (from news) that many islands are being washed out by sea water. Yes! Sea water is creating havoc not from melting ice and snow alone but through other chains (or cycles) of events.

Let me talk about terminolgy and concepts involved in weather and suggest a chain of events that will make "Thailand under Water" a likely outcome.


We know winds are air flows from high pressure cells to nearby low pressure cells. We have observed that pressure differences of a few percents can cause winds of speed 36 km per hour (20 knots). Earth rotation affects winds directions and speeds especially when the flows are West to East (the same as the Earth rotation).

We also know that water surface waves (in oceans, lakes and ponds) are created by winds. And one type of wind (generated) waves known as "storm surge" can wash over coasts with great height and energy.

We know about high and (especially are very mindful of) low pressure (or depression) systems in our weather. We know warm air expands and rises up; creates a low pressure zone that cooler and denser air flows in and so winds are generated; earth rotation twists the flows of winds (in the manner we call "Coriolis"). Under certain conditions (generally at certain times of year) the air flows can be so strong (with speed of 200 kilometre per hour or more), we have storms, "typhoons", " hurricanes" and "cyclones" (in southern hemisphere).

Winds (or air flows) over the surface of large bodies of water (like lakes, seas and oceaans) create waves. The height and speed of waves depend on wind speed, energy in winds release to water and many more factors (like 'fetch' or the distance winds can flow unobstructed).

Temperature. Yes the greater the temperature difference, the greater the pressure difference and the higher the wind speed and the higher the wave.

Here, we come to stare at the long chain of physical events from increase in CO2 to increase in severe weather and sea water rising. But this is not the end of the chain. (NB. Earth quakes/movements, tides, planetary alignments/gravity, rains, floods. etc.  have impacts on 'waves and sea water levels' too.)

We will stop here to visualize the sea water rising with storm surges and tides and rains (at seas and at lands)... All because we --human-- use too much energy, burn carbon fuels, cut down trees, ... And we --human-- can't care less...

I attach below a note that may help to explain the weather better. It is unfortunate that we don't have more of this very important information on 'www.tmd.go.th' (perhaps if we visit tmd.go.th more and ask for more, we may see a response that our children can benefit too).

Nevertheless, we have come to a point where we can ponder or 'คิดเป็นตัวเลขเล่นๆให้หน่อย...(จ้า) about the possibilities of sea level rise for Thailand. Of course I am not going to ruin your fun by giving out numbers and directions. (For those budding scientists here is your chance to shine and save Thailand! ;-)

We will later move on to impacts on social, political and economics. Think about Winds, Waves and Weather while we wait, eh?

<Notes. Please see

http://en.wikipedia.org/wiki/Storm_surge

http://en.wikipedia.org/wiki/Wind_wave

http://en.wikipedia.org/wiki/Tide

https://www.gombergkites.com/nkm/wind1.html

http://science.nationalgeographic.com.au/science/e...

http://arxiv.org/abs/1004.0355
Where do winds come from? A new theory on how water vapor condensation influences atmospheric pressure and dynamics
A.M. Makarieva, V.G. Gorshkov, D. Sheil, A.D. Nobre, B.-L. Li
(Submitted on 2 Apr 2010)

http://geography.about.com/od/climate/a/highlowpre...

http://geography.about.com/od/climate/a/windpressu...

http://en.wikipedia.org/wiki/Low-pressure_area

http://www.abc.net.au/science/articles/2013/01/31/...

http://scipp.ucsc.edu/outreach/26ThePhysicsofGloba...

pV=nRt is the combined gas law, pressure times volume equals mols of gas times the ideal gas constant times pressure in Kelvin.

http://www.ehow.com/about_5052107_relationship-pre...

http://en.wikipedia.org/wiki/Effects_of_global_war...

http://en.wikipedia.org/wiki/Current_sea_level_ris...
http://en.wikipedia.org/wiki/Future_sea_level

http://hsc.csu.edu.au/primary_ind/prim_ind_240/com...

http://weather.mailasail.com/Franks-Weather/Wind-M...

http://www.oceannavigator.com/January-February-200... Jan 1, 2003

Look at the equation below. If G and Lat respectively denote the pressure gradient in millibars per degree of latitude (millibars per 60 nautical miles) and the latitude of the area of interest and if, in addition, the isobars are almost straight and parallel, then (approximately):

wind speed = 6.8 x G/sin(Lat) where G: millibars per degree = (millibars per millimeter) x (millimeters per degree)

http://www.sailnet.com/forums/seamanship-articles/...
Isobar Lines and Geostrophic Wind Diagram

http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/f...
http://www.aos.wisc.edu/~aalopez/aos101/wk11.html

WIND WAVES, SEA, AND SWELL:
http://earthsci.org/processes/weather/waves/Waves....

http://oceanservice.noaa.gov/facts/seiche.html

A table for estimating wave size by wind speed

Conditions Necessary for a Fully Developed Sea at Given Wind Speeds, and the Parameters of the Resulting Waves
Wind Conditions Wave Size
Wind Speed in One Direction Fetch Wind Duration Average Height Average Wavelength Average Period and Speed
19 km/hr (12 mi/hr) 19 km (12 mi) 2 hr 0.27 m (0.9 ft) 8.5 m (28 ft) 3.0 sec 9.3 ft/sec
37 km/hr (23 mi/hr) 139 km (86 mi) 10 hr 1.5 m (4.9 ft) 33.8 m (111 ft) 5.7 sec 19.5 ft/sec
56 km/hr (35 mi/hr) 518 km (322 mi) 23 hr 4.1 m (13.6 ft) 76.5 m (251 ft) 8.6 sec 29.2 ft/sec
74 km/hr (46 mi/hr) 1,313 km (816 mi) 42 hr 8.5 m (27.9 ft) 136 m (446 ft) 11.4 sec 39.1 ft/sec
92 km/hr (58 mi/hr) 2,627 km (1,633 mi) 69 hr 14.8 m (48.7 ft) 212.2 m (696 ft) 14.3 sec 48.7 ft/sec

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http://www.thaipost.net/news/110914/95990