GOES-17 image of Earth’s Western Hemisphere acquired on May 20, 2018, using the Advanced Baseline Imager (ABI). Image courtesy of NOAA/NASA.
Earth observation as a subject isn’t new. Although satellites have taken it to a new level, observations of the planet have been around for hundreds or even thousands of years.
This week two articles on historic Earth observation have caught our attention, first from the nineteen century and secondly from Ancient Rome.
Nineteenth Century EO
Last month, the US National Oceanic & Atmospheric Administration (NOAA) website published an article detailing a mystery involving a dress from the nineteenth century and weather forecasting!
In 2013, Sara Rivers Cofield bought a 1880’s peach coloured silk bustle dress from an antique store in Maine, New England. After getting the dress home, Sara discovered a secret pocket in the seams of the underskirt, and in the pocket were some crumpled bits of paper with lines of text such as – Bismark, omit, leafage, buck, bank – there were also numbers between the lines, times in the margins and each line marked with a different colour. Thinking this was a code of some type, Sara turned to the internet for a solution. However, by 2022, despite a number of people noting it was likely to be some form of telegraphic code, it was considered one of the top 50 unsolvable codes in the world!
In 2023 Wayne Chan, who works as an analyst with the Centre for Earth Observation Science at the University of Manitoba, and solves codes for a hobby decided to try and solve this code. After searching almost two hundred telegraphic codebooks, he found a reference to telegraphic weather codes used by the U.S. Army Signal Corps that were like those from the papers in the dress. After more research, Wayne determined that the book he needed to solve this puzzle was used by the Army Signal Service Division of Telegrams and Reports for the Benefit of Commerce in the 1870 to 1891, a bureau that would eventually become NOAA’s National Weather Service. Contacting NOAA, a librarian at NOAA’s Central Library was able to provide a PDF copy of a weather telegraph code book, published in 1892. It wasn’t the exact book Chan wanted but, with other resources, it helped him determine that the messages were from Signal Service weather stations in the U.S. and Canada.
Each line indicated weather observations at a given location and time of day, which was then telegraphed into a central Signal Service office in Washington. Each message began with the station location, which was unencoded, followed by codewords for temperature/pressure, dew point, precipitation/wind direction, cloud observations, and wind velocity/sunset observations.
So for example – Bismark, omit, leafage, buck, bank – was decoded as
- BISMARK Station name: Bismarck, Dakota Territory
- OMIT Air temperature: 56 F Barometric pressure: 0.08 in Hg
- LEAFAGE Dew point: 32°F Observation time: 10:00 p.m.
- BUCK State of weather: Clear Precipitation: None Wind direction: North
- BANK Current wind velocity: 12 mph Sunset: Clear
Using old daily Signal Service weather maps, provided from the NOAA Central Library also enabled Wayne to determine that these observations were actually recorded on 27 May 1888!
Ancient Rome
The second article goes much further back, in this case to Ancient Rome. The article, published in The Conversation, was written by Dimitri Van Limbergen, a Postdoctoral Researcher at Ghent University, and focuses on winemaking and climate change through the growing system of agroforestry.
This technique for growing grapes required them to be attached to rows of trees in fields, and the vines grew high into the trees. Trees such as poplars, elms, elders, willows, maples, and ash were popular choices as their roots require a lot of water from the soil ensuring the wines did not get too much water. In addition, growing the vines tall mean that rising soil moisture was kept down, solar energy from the sun was increased, and deeper roots means the vines were more resistant to parasites.
Dimitri’s research has highlighted that vine agroforestery expanded significantly between 200 BC and 200 AD, a period of several centuries of markedly warmer temperatures, known as the Roman Climate Optimum. This means the ancient Romans made wine in warmer and more humid conditions than current winemakers. The technique has been assessed in recent experiments, which confirmed that agroforestry offers protection against frosts and the presence of beneficial insects. In addition, shade from the trees appears to delay the grapes ripening without decreasing yields, which is important as higher temperatures mean current winemakers are battling grapes maturing too quickly and having too much sugar, which gives poor quality wine.
The Food and Agriculture Organization of the United Nations has recently stressed the benefits of agroforestry in a warming world, and the need to scale up this technique because it offers environmental and socioeconomic benefits, particularly for smallholder farmers survive.
Summary
These two interesting articles show that Earth observation really isn’t new, and with satellites we’re just using different techniques and approaches!
