How did Weather Monitoring Develop

Figure 1. Aristotle's understanding shaped European thought on weather observations for over two millennia.

We have increasingly become accustomed to seeing the impact of major hurricanes and weather phenomena on communities. Fortunately, over the 20th and 21st centuries, weather monitoring technologies, such as radar, have allowed us to obtain much more warning before events occur. However, weather monitoring has had a long historical road, as past and modern societies have always had a desire to know what would happen to their crops, homes and livelihoods.

Early Development

By the 3rd millennium BCE, seasonality and its regularity was recorded. Early weather recording often related to astronomical observations, as seasonal changes, celestial phenomena, and timekeeping were seen as being related. Some of the earliest detailed records of meteorological data derive from ancient Mesopotamia from the 8th century BCE. During that time, a record spanning some six hundred years seems to have been collected that described weather phenomena, often focusing on difficult or bad weather. While the texts often focus on omens, particularly what might happen after a weather phenomenon such as storms occured, the compiling of the data suggests a type of forecasting was intended by the compilation. In effect, the records may have been an attempt to correlate weather events with other events using long-term data, including political, economic and other important matters. Early records from Mesopotamia also indicate how celestial objects often foreshadowed weather events. For instance, a halo around the moon portends rain and flooding.

In China, records often seemed neutral as to the types of weather data kept. By the 13th century BCE, the Chinese were attempting to record amount of rainfall, types of precipitation (sleet vs. rain) and temperature. The Chinese, similar to Mesopotamia, also saw their weather as being related with the whims of the gods or their behavior that the gods decided to punish or reward. Records also indicate understanding of the hydrologic cycle and how distant events such as rainfall in the mountains could influence flooding. The concept of Yin and Yang was related to weather, where a balance between hot and cold and other opposites in weather were necessary for society to be balanced. In effect, this is early evidence of how weather began to also shape philosophy and concepts of spiritual as well as physical balance in life.

Aristotle has often been considered a pioneer in meteorology with his book Meteorlogica, with the title suggesting that our present English term deriving from the ancient Greek. Aristotle saw that weather was affected by the four bodies, namely fire, air, earth, water. Many of his views involved the supernatural, similar to Mesopotamia and China; however, he made some important observations. For instance, the rising of hot air and the descent of cold air. He also understood that the atmosphere was complex, consisting of multiple layers (Figure 1).

Later Development

Figure 2. Pomponius Mala was one of the first to indicate that the world was divisible into climatic zones.

In the Roman Period, at around 25-50 CE, Pomponius Mela, who was a geographer, formulates a more comprehensive understanding of climatic zones. This includes zones that are comparable to our division of regions into temperate, arctic, desert, and tropical zones. His writings also suggest that these zones were related to the latitude in which someone was in, as more northerly zones generally were colder and more southerly zones had tropical zones. However, within the northern and southern zones, comparable climatic zones could be found and these affect the weather noticeable in those regions (Figure 2).

Other Late Antiquity and early Medieval developments also occurred in India, a region that had developed a strong meteorological tradition already by around 3000 BCE. Varahamihira wrote at around 500 CE about the importance of early rains and it is clear, similar to Chinese knowledge, that rain did not just come from the sky but related to the sun and evaporation. There were also attempts to correlate revenue, or the wider economy, with rainfall, as the timing of the rains was seen as being critical to affecting the wider economy. The types of clouds were seen as being a strong indication of the types of rains one could expect.

While some observation and understanding of weather phenomena improved in the Middle Ages, there were improvements in optical instruments and observation techniques that allowed better understanding of observations such as rainbows and lightening. It was with Galileo Galilei in the 17th century through the thermoscope, which was a series of glass containers and gases that would rise and fall based on temperature, that more significant changes began to emerge in the understanding of weather. This instrument allowed him and others to make more accurate measurements of temperature, improving understanding of temperature fluctuations. This also now meant that European scientists could move away from Aristotle's concepts of fire, air, water, and earth as driving temperature. While it is not fully clear if Galileo was the inventor of this device, it is clear that such 17th century innovations did help the understanding of weather to now develop in something more similar to what we would call scientific observation.

Modern Technologies

By the 18th century, recording of weather became more standard, with Gabriel Fahrenheit and Anders Celsius giving us some standard ways we measure temperature that are still with us today. By the early 1800s, Luke Howard began to formulate cloud types in a standard form that allowed better understand of subsequent patterns in rainfall or atmospheric moisture. By 1817, Alexander Humboldt came up with the idea of climatic maps to indicate average global temperature. This began the modern measurement and monitoring of global temperatures that have affected our own understanding of change such as global climate change. The 1830s and 1840s also saw many new types of equipment being utilized for weather monitoring, including measuring barometric pressure, use of storm clocks to measure meteorological data, and use of early cameras for weather observation. By 1849, the United States had developed a series of stations to monitor weather with data sent via telegraph. This long-distance recording and coordination of data allowed the understanding of the relationship between vapor pressure and temperature.

In the late 19th century, more complex and larger weather phenomena were better understood, such as hurricanes. Weather monitoring stations were utilized in the Atlantic to begin to record and provide warning about hurricane developments. By 1904, Australia developed a unified meteorological service to better standardize and monitor national weather. However, the next major game-changer for understanding and monitoring weather occurred with the development of radar in the 1940s. The Great Atlantic Hurricane of 1944 was the first hurricane recorded and monitored using radar. While radar technologies have changed, this has remained among the key ways in which we still can monitor and use data from to forecast where hurricanes can go.

Since the 1970s, while technologies have improved, there has been also more devotion by institutions for weather monitoring. This has included the military, the National Oceanic and Atmospheric Administration, NASA, as well as many local entities that provide near constant weather observations.

Summary

Weather monitoring has been observed since the early development of writing. Although many early observations appear to be superstitious, from our perspective, it is also evident that scientific knowledge developed over time as relationships between observed weather phenomena and what preceded the event became better established. Weather monitoring has always been a major concern for societies that have been fixed to the land because of their urban or agricultural systems or simply because the tremendous destruction that ill weather could cause large-scale human systems. Although our instrumentation and scientific understanding has advanced rapidly since the 19th century, simple observations also allowed sometimes accurate predictions to be made and even allowed better preparation. This includes the understanding of the volatility of climate and its potentially detrimental long-term consequences over decades and centuries. The records from Mesopotamia, for example, indicate the appreciation of how long-term monitoring of the climate could be of benefit for future generations.