Monday, April 27, 2015

Saturday, April 25, 2015

Ancient stormy weather: World's oldest weather report could revise bronze age chronology

An inscription on a 3,500-year-old stone block from Egypt may be one of the world's oldest weather reports -- and could provide new evidence about the chronology of events in the ancient Middle East.
A new translation of a 40-line inscription on the 6-foot-tall calcite block called the Tempest Stela describes rain, darkness and "the sky being in storm without cessation, louder than the cries of the masses."
Two scholars at the University of Chicago's Oriental Institute believe the unusual weather patterns described on the slab were the result of a massive volcano explosion at Thera -- the present-day island of Santorini in the Mediterranean Sea. Because volcano eruptions can have a widespread impact on weather, the Thera explosion likely would have caused significant disruptions in Egypt.
The new translation suggests the Egyptian pharaoh Ahmose ruled at a time closer to the Thera eruption than previously thought -- a finding that could change scholars' understanding of a critical juncture in human history as Bronze Age empires realigned. The research from the Oriental Institute's Nadine Moeller and Robert Ritner appears in the spring issue of the Journal of Near Eastern Studies.
The Tempest Stela dates back to the reign of the pharaoh Ahmose, the first pharaoh of the 18th Dynasty. His rule marked the beginning of the New Kingdom, a time when Egypt's power reached its height. The block was found in pieces in Thebes, modern Luxor, where Ahmose ruled.
If the stela does describe the aftermath of the Thera catastrophe, the correct dating of the stela itself and Ahmose's reign, currently thought to be about 1550 B.C., could actually be 30 to 50 years earlier.
"This is important to scholars of the ancient Near East and eastern Mediterranean, generally because the chronology that archaeologists use is based on the lists of Egyptian pharaohs, and this new information could adjust those dates," said Moeller, assistant professor of Egyptian archaeology at the Oriental Institute, who specializes in research on ancient urbanism and chronology.
In 2006, radiocarbon testing of an olive tree buried under volcanic residue placed the date of the Thera eruption at 1621-1605 B.C. Until now, the archeological evidence for the date of the Thera eruption seemed at odds with the radiocarbon dating, explained Oriental Institute postdoctoral scholar Felix Hoeflmayer, who has studied the chronological implications related to the eruption. However, if the date of Ahmose's reign is earlier than previously believed, the resulting shift in chronology "might solve the whole problem," Hoeflmayer said.
The revised dating of Ahmose's reign could mean the dates of other events in the ancient Near East fit together more logically, scholars said. For example, it realigns the dates of important events such as the fall of the power of the Canaanites and the collapse of the Babylonian Empire, said David Schloen, associate professor in the Oriental Institute and Near Eastern Languages & Civilizations on ancient cultures in the Middle East.
"This new information would provide a better understanding of the role of the environment in the development and destruction of empires in the ancient Middle East," he said. For example, the new chronology helps to explain how Ahmose rose to power and supplanted the Canaanite rulers of Egypt -- the Hyksos -- according to Schloen. The Thera eruption and resulting tsunami would have destroyed the Hyksos' ports and significantly weakened their sea power.
In addition, the disruption to trade and agriculture caused by the eruption would have undermined the power of the Babylonian Empire and could explain why the Babylonians were unable to fend off an invasion of the Hittites, another ancient culture that flourished in what is now Turkey.
A tempest of rain
Some researchers consider the text on the Tempest Stela to be a metaphorical document that described the impact of the Hyksos invasion. However, Ritner's translation shows that the text was more likely a description of weather events consistent with the disruption caused by the massive Thera explosion.
Ritner said the text reports that Ahmose witnessed the disaster -- the description of events in the stela text is frightening.
The stela's text describes the "sky being in storm" with "a tempest of rain" for a period of days. The passages also describe bodies floating down the Nile like "skiffs of papyrus." Importantly, the text refers to events affecting both the delta region and the area of Egypt further south along the Nile. "This was clearly a major storm, and different from the kinds of heavy rains that Egypt periodically receives," Ritner said.
In addition to the Tempest Stela, a text known as the Rhind Mathematical Papyrus from the reign of Ahmose also makes a special point of mentioning thunder and rain, "which is further proof that the scholars under Ahmose paid close and particular attention to matters of weather," Ritner said.
Marina Baldi, a scientist in climatology and meteorology at the Institute of Biometeorology of the National Research Council in Italy, has analyzed the information on the stela along with her colleagues and compared it to known weather patterns in Egypt.
A dominant weather pattern in the area is a system called "the Red Sea Trough," which brings hot, dry air to the area from East Africa. When disrupted, that system can bring severe weather, heavy precipitation and flash flooding, similar to what is reported on the Tempest Stela.
"A modification in the atmospheric circulation after the eruption could have driven a change in the precipitation regime of the region. Therefore the episode in the Tempest Stela could be a consequence of these climatological changes," Baldi explained.
Other work is underway to get a clearer idea of accurate dating around the time of Ahmose, who ruled after the Second Intermediate period when the Hyksos people seized power in Egypt. That work also has pushed back the dates of his reign closer to the explosion on Thera, Moeller explained.

Story Source:
The above story is based on materials provided by University of Chicago. The original article was written by Susie Allen and William Harms. Note: Materials may be edited for content and length.

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Notes on weather...

In the Shang Dynasty, it was amazing to predict weather with the sensory system including the eyes and ears. People with such ability would find it easy to claim a high position in the government. Later during the Zhou Dynasty, people already learned to forecast weather through the behavior of animals.
If people can clearly hear the cricket chirp at night, it can be predicted that the weather next day will be fairly good.
If the dragonfly flies up and down in the sky, there will be a heavy rain.
If the anthill is closed, a thunder storm is on the way.
In ancient times, people could predict weather despite the lack of precise instruments. The ancient wisdom has been passed down from generation to generation in the form of proverbs. Usually the proverbs are very reliable. 

Proverbs Concerning Weather
There will be rain if it is wet at the foot of a pillar.
Morning glow presages rain while evening glow indicates a fine sunny day.
Tower-shaped alto-cumulus or stratocumulus usually precedes trough of low pressure. The unstable air is very likely to lead to rain.
In the Qin and Han Dynasties, people succeeded in establishing the 24 solar terms. Afterwards, the birth of the lunar calendar further embodied the wisdom of generations of ancestors.

Notes on weather...

Early History
The art of weather forecasting began with early civilizations using reoccurring astronomical and meteorological events to help them monitor seasonal changes in the weather. Around 650 B.C., the Babylonians tried to predict short-term weather changes based on the appearance of clouds and optical phenomena such as haloes. By 300 B.C., Chinese astronomers had developed a calendar that divided the year into 24 festivals, each festival associated with a different type of weather.
Around 340 B.C., the Greek philosopher Aristotle wroteMeteorologica, a philosophical treatise that included theories about the formation of rain, clouds, hail, wind, thunder, lightning, and hurricanes. In addition, topics such as astronomy, geography, and chemistry were also addressed. Aristotle made some remarkably acute observations concerning the weather, along with some significant errors, and his four-volume text was considered by many to be the authority on weather theory for almost 2000 years. Although many of Aristotle’s claims were erroneous, it was not until about the 17th century that many of his ideas were overthrown.
Throughout the centuries, attempts have been made to produce forecasts based on weather lore and personal observations. However, by the end of the Renaissance, it had become increasingly evident that the speculations of the natural philosophers were inadequate and that greater knowledge was necessary to further our understanding of the atmosphere. In order to do this, instruments were needed to measure the properties of the atmosphere, such as moisture, temperature, and pressure. The first known design in western civilization for a hygrometer, an instrument to measure the humidity of air, was described by Nicholas Cusa (c.1401-1464, German) in the mid-fifteenth century. Galileo Galilei (1564-1642, Italian) invented an early thermometer in 1592 or shortly thereafter; and Evangelista Torricelli (1608-1647, Italian) invented the barometer for measuring atmospheric pressure in 1643.

Forecasting from the Beginning
Our brief exploration into forecasting pretty much follows the techniques and methods developed by early weather wizards. From the earliest of times, hunters, farmers, warriors, shepherds, and sailors learned the importance of being able to tell what the weather might be up to next. Ancient civilizations appealed to the gods of the sky. The Egyptians looked to Ra, the sun god. The Greeks sought out the all-powerful Zeus. Then there was Thor, the god of thunder and lightning in ancient Nordic times. Some societies, such as the Aztecs, used human sacrifice to satisfy the rain god, Tlaloc. Native American and Australian aborigines performed rain dances. Those who were able to predict the weather and seemed to influence its production were held in highest esteem. After all, they appeared to be very well connected.

One of the earliest scientific approaches to weather prediction occurred around 300 B.C.E., documented in Aristotle's work, "Meteorologica." The ancient Greeks invented the term meteorology, which means the study of atmospheric disturbances or meteors. Aristotle tried to explain the weather through the interaction of earth, fire, air, and water. His pupil Theophrastus really went to work and wrote the ultimate weather text The Book of Signs, which contained a collection of weather lore and forecast signs. Amazingly it served as the definitive weather book for 2,000 years! (What if they're still reading this 2,000 years from now?)
Theophrastus's weather lore included colors of the sky, rings and halos, and even sound. Hippocrates—also known as "the Father of Medicine"—was also very much involved with the weather. His work On Airs, Waters, and Places became a medical classic, linking good health with favorable weather conditions. The opening of his work begins with the advice that those who wish to investigate medicine must first begin with an understanding of seasons and weather.

Weather forecasting advanced little from these ancient times to the Renaissance. Then beginning in the fifteenth century, Leonardo da Vinci designed an instrument for measuring humidity called a hygrometer. Later Galileo Galilei invented the thermometer and his student Evangelista Torricelli came up with the barometer for measuring air pressure. With these tools, people could monitor the atmosphere. Then Sir Isaac Newton derived the physics and mathematics that accurately described the atmosphere. Newton's work on motion remains The Book of Signs of modern meteorology. To this day, his principles form the foundation of all computer analyses and predictions.

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