Thailand under Water 4: Winds, Waves and Wild Weather
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
สพฐ.ผุดหลักสูตรอุทกภัย สอน‘นร.’พายเรือ-ว่ายยนํ้า
http://www.thaipost.net/news/110914/95990
ความเห็น (9)
(ชอบ..ตรงนี้..๕)...สพฐ.ผุด..หลักสูตรอุทกภัยสอน นร.พายเรือ ว่ายน้ำ..(.๕)..เรื่องจริงหรือ..ล้อกันเล่น.. ล เนี่ยะ...ว่ายไหว..รึ..?...?...น้ำ..อุกทกภัย..น่ะะะะะ...
I kid you not! ยายธี:
สพฐ.ผุดหลักสูตรอุทกภัย สอน‘นร.’พายเรือ-ว่ายยนํ้า
http://www.thaipost.net/news/110914/95990 is the utl (and note the spelling). It's time to go back to primary school, eh? SO we can learn an essential skill for surviva; ;-)
I added this reference just for you ;-) as a preview for the next part -
Study finds wind speeds on the rise Friday, 25 March 2011 by Carl Holm ABC
<http://www.abc.net.au/science/articles/2011/03/25/3172755.htm>
Wave heights and windspeeds at higher latitudes have been steadily increasing for the last 23 years (Source: Irina Belousa/iStockphoto)
...(Professor Alexander) Babanin says the data are potentially useful because they can provide independent validation and verification of what happens to the climate.
"Suppose it's the case that the temperature is rising globally. It will not do that uniformly, because of land influences, because of the ocean circulation," he says.
"The ocean will be warmer in some parts and colder in other parts. That creates pressure differences and that creates winds."
Maybe, we should learn about winds and their effects on buildings, trees, food crops, ...
I looked at the result of (G2K) rendering of a table in my note (above) and found it unreadable. Let see if I could do better here:
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 / Speed (kph)
19 kph 19 km 2 hr 0.27 m 8.5 m 3.0 sec 2.83 m/sec (10.2 kph)
37 kph 139 km 10 hr 1.5 m 33.8 m 5.7 sec 5.94 m/sec (21.4 kph)
56 kph 518 km 23 hr 4.1 m 76.5 m 8.6 sec 8.90 m/sec (32.0 kph)
74 kph 1,313 km 42 hr 8.5 m 136.0 m 11.4 sec 11.91 m/sec (42.9 kph)
92 kph 2,627 km 69 hr 14.8 m 212.2 m 14.3 sec 14.84 m/sec (53.4 kph)
Now we can see that a day of 60 kph winds over the gulf of Thailand (as the fetch) can create 4+m waves (enough to go over the first floor of many beach houses) with the wave speed of 32 kph (imagine being hit by a slow running car). In herricans, wind speed are usually about 120-200 kph (off the scale in the table ;-); the gulf can provide the necessary 'fetch' (clear run);... So it is possible to have 15+m waves pounding coastal areas with speed 60+kph. What more if there is a high tide on a full moon day after a heavy rain... where high waves run into draining fresh water in opposing direction; both fronts have no where to go but up!
I give you flower for your invaluable info on Thailand under Water 4.
I sincerely admire your effort to share this knowledge to save Thailand, thanks.
Thanks for your unwavering support.
I am doing what I can. I hope we could have better information in Thai to learn and to prepare for 'severe weather' on กรมอุตุนิยมวิทยา website (www.tmd.go.th). Our news media had realized the importance of weather, but had not learned to report the weather to most people. Our public servants and our government have yet to show considerations for weather but only after storms and floods. Our school children can learn weather and become our major force in communities for dealing with impacts of severe weather.
Will you look up and watch the weather for me? ;-)
Thank you so much for the information. The Table for estimating wave size is very useful. If I were a geography teacher I would make a lot of use out of this table. As a person born to a a small village nearby the sea, I am quite familiar with the wind , sea, and waves and always enjoy reading about them. Unfortunately, I am not in the capacity to do anything to prevent havoc that is likely tho occur someday in the future. Hopefully our government will seriously think about the climate change and invest to save our land.
Thank you GD : for joining in with the thought to save Thailand from rising sea water. We (salty) know about the sea and know what the force of nature can be overwhelming. I have however a strong belief in not relying on government. Why? In the past as history shows time and time again, governments have different agendas from ordinary people. Governments (or to be more precise 'people in government') concern themselves with power and money (or benefits). They act only when they can gain more power or money.
Common folks stand sandwiched between Nature and Government, often bend with winds to survive, to keep the family and friends. The tasks for common folks are difficult and tiring --day after day--. But they must now also look forewqrd to protect themselves and everything they live on. They cannot wait for government. They cannot wait for charity. They cannot wait for their children (to help them out). They --of course 'all of 'us'-- must work out a plan and start our actions. I am doing mine bit. Will you help?
I have somehow omitted http://www.marine.tmd.go.th/ where a wealth of information about seawater, winds, waves and up-to-date tracking of air pressure systems. Worth a visit for 'lot of food for thought' ;-)
Be prepared to spend time following chains of information links.
News on Hurricane Matthew reminds us of what we too can face
http://thaipost.net/?q=แมทธิวถล่มสหรัฐ-เฮติตายพุ่ง
...ศูนย์เฮอริเคนแห่งชาติ (เอ็นเอชซี) ของสหรัฐได้ลดระดับความรุนแรงของเฮอริเคนแมทธิวจากระดับ 4 เป็นระดับ 3 แล้วเมื่อวันศุกร์ที่ 7 ต.ค. แต่คำเตือนของเอ็นเอชซีกล่าวว่า พายุลูกนี้ยังคงมีความเร็วลมสูงสุด 113 กิโลเมตร/ชั่วโมง ขณะที่มันเคลื่อนตัวถึงแผ่นดินใหญ่และทำให้เกิดฝนตกหนักในหลายชุมชนริมชายฝั่งของรัฐฟลอริดา...
...พายุลูกนี้ได้เข้าถล่มหลายประเทศแถบทะเลแคริบเบียน ระหว่างทางมายังฟลอริดา มันได้เข้าถล่มฝั่งตะวันตกเฉียงเหนือเครือรัฐบาฮามาสด้วยความเร็วลมสูงสุดถึว 195 กิโลเมตร/ชั่วโมงเมื่อวันพฤหัสบดี แต่ยังไม่มีรายงานชัดเจนว่ามีความสูญเสียหรือความเสียหายมากน้อยเพียงใด
ส่วนที่เฮติ ข้อมูลความสูญเสียเริ่มชัดเจนขึ้นใน 2 วันให้หลังพายุถล่มเมื่อวันอังคาร เจ้าหน้าที่กล่าวกันว่า มีผู้เสียชีวิตอย่างน้อย 339 คน อีกนับหมื่นไร้ที่อยู่ ประเทศยากจนที่ประสบภัยพิบัติบ่อยครั้งแห่งนี้ได้รับความเสียหายรุนแรง เส้นทางเชื่อมระหว่างเหนือ-ใต้ถูกน้ำท่วมตัดขาด บ้านเรือนจำนวนมากถูกทำลายราบ ก่อนหน้านี้สาธารณรัฐโดมินิกัน เพื่อนบ้านของเฮติ ก็มีรายงานผู้เสียชีวิตอย่างน้อย 4 ราย ในจำนวนนี้ 3 รายเป็นเด็ก ประชาชนมากกว่า 36,500 คนถูกอพยพ และบ้านเรือนถูกทำลาย 3,000 หลัง
สำหรัฐสหรัฐนั้น ยังต้องรอให้พายุลูกนี้ผ่านพ้นจึงจะสรุปความเสียหายต่อทรัพย์สินหรือชีวิตได้ เอ็นเอชซีเตือนว่า จะมีประชาชนมากกว่า 12 ล้านคนได้รับผลกระทบจากพายุตลอดแนวชายฝั่งแอตแลนติกตั้งแต่ตอนใต้ของฟลอริดา ผ่านจอร์เจีย ถึงเซาท์แคโรไลนา...ตามแนวชายฝั่งอาจเกิดคลื่นพายุซัดฝั่งหรือสตอร์มเซิร์จสูงถึง 3.35 เมตร
"สิ่งที่เรารู้คือ การเสียชีวิตเพราะเฮอริเคนส่วนใหญ่เกิดจากสตอร์มเซิร์จ"