Unit Overview - The learner will gain both theoretical and a phenomenological understanding of the weather, looking at contemporary meteorological interpretations and instrumentation whilst connecting this to daily practical observations. This will be contextualised to the trainees holding by reflecting on local weather patterns and their effect on the farm or garden.
1.1 Demonstrate the ability to read a surface pressure chart
Features of a surface pressure chart
1.2 Describe basic meteorological concepts
Temperature is a degree of hotness or coldness that can be measured using a thermometer. There are a number of scales used to measure temperature, for example, Fahrenheit, Celcius and Kelvin scales.
'The atmosphere is a river of air flowing above our heads in ceaseless meandering currents and eddies. The patient observer can come to recognize what are known as singularities in the deceptively chaotic flow of this great river of air.' Dennis Klocek
Atmospheric pressure or barometric pressure is the pressure caused by the weight of the air above us. It can be affected by several factors for example the weather and the the altitude of the measurement. As we rise up through the atmosphere the barometric pressure drops, until at a certain point - up in space - there is a perfect vacuum with no air molecules left.
Rain, drizzle, hail, snow and sleet are all forms of precipitation. In other words precipitation is any form of either liquid or solid water particles that fall from the Earth's atmosphere and land on the Earth. The cause of precipitation is the meeting of warm and cold air masses high above us.
These are the winds which blow most frequently at a given location. At the Eyam site the most potent winds are North Westerlies although in 2020 we have experienced a great variety of winds from many directions, swirling and blowing around the site, causing damage and frustration for the grower.
There are 10 basic cloud types and they are grouped according to the way they look - for example are they in a clump, do they have layers or are they streaked? They are further classified by how high they are, for example are they high, mid-level or low. The following images and descriptions show the main cloud types.
Low Level Clouds
Known as 'fair weather clouds' they rarely produce rain and they are frequently float across the sky on a sunny day. They are know to break up fairly quickly and their shape is usually flat bottomed and coton wool topped.
The most common type of cloud, usually carrying only light rain and usually making a very good job of blocking out the sun. The colours usually vary between white and dark grey.
Reaching upto 10 miles into the atmosphere and signalling the coming of heavy rains and storms these clouds are very powerful and dramatic. They can be veru dark in colour and carry a huge amount of rain. Usually this type of cloud will deliver a heavy downpour of rain.
Mid Level Clouds
These bumpy clouds may not themselves carry rain but they can be an indicator of rain to come.
These are the clouds that present themselves as flat, grey and solid. They are the clouds which create overcast weather.
High Level Clouds
These beautiful high clouds are composed of ice crystals. As the ice crystals fall they can create wavy stripes but the ice crystals just evaporate as they fall through the sky and they never impact Earth.
Vapour trails from aeroplanes.
Rounded cloud forms which have smooth and quite crisp edges. They normally form over higher hilly or mountainous ground.
Shaped like cows udders these can indicate an approaching storm.
Cirrus Clouds dissipating at sundown over the sheep fields at the back of the site.
Cumulonimbus forming on the horizon at Eyam
Warm and Cold Weather Fronts
The air on Earth has different properties. Air from the north is cold. Air from the south is warm. There is a sharp boundary between warm and cold air. A weather front is the boundary between the air masses. Air fronts can be more easily understood when visualised on a surface pressure chart. The warm fronts are red, the cold fronts are blue. When these weather fronts meet, a band of rainfall is the usual result.
Cloud Sequences Associated with Fronts
When a warm front meets a cold front the warm air slides over the top of the cold air. This is because cold air is more dense than warm air so it sinks. When the warm air rises above the cold air it begins to cool and then clouds form.
Warm fronts create many types of cloud, for example altocumulus, alto stratus, cirrocumulus and cumulonimbus.
Cold air generally produces cumulus clouds. These often grow into cumulonimbus clouds which cause thunderstorms. Cold fronts can produce nimbostratus and stratocumulus clouds.
2.1 Demonstrate the ability to make phenomenological observations
Predicting the weather has been of critical importance to humanity for probably in excess of 15000 years. Various cultures have had different approaches to weather observation and weather folklore is built into all cultures. Songs, sayings and rhymes are commonplace and many have a close relation to reality. Consider the following:
'Red sky at night sailor's delight, Red sky in the morning sailor's warning'
There is some good weather science standing behind the quotation. In general weather systems move from west to east in the UK. High pressure traps dust and particles which refract to create a red sky. So a red sky means that there is high pressure moving in from the west, so a calm and sunny day will follow.
In contrast when a red sky appears in the morning it generally means that the high pressure system has passed us by, making room for a cold front to come in, with the attendant poor weather that occurs upon the boundary between a warm and a cold front.
There are other examples of weather folklore that have some validity. Cows lying down is an indicator for imminent rainfall. Is it possible that these creatures are more adept at sensing air pressure changes? It seems that the ruminant with it's huge stomachs may indeed be 'sensing' the imminent weather change through its internal organs.
African cultures have multiple indiginous methods for telling the weather, many based on natural events and processes and all predating subjugation by westerners. For example, the behviour of trees, eg fruiting levels could indicate high or low rainfall patterns. Certain behaviours of birds can indicate the arrival of the rainy season, frogs 'hissing' indicates the arrival of rains.
Wind direction is another key factor in determining imminent rain. In many cultures there are embedded ideas about what might be the sign or symbol for future meteorological events.
Phenomenology is concerned with the study of experiences from the perspective of the individual. When I observe the behaviour of the animals on the farm I see that they animals have a deeper understanding of prospective changes in the weather such as wind direction. They respond to cooler easterly winds by retreating to the field shelter, long before a human being would detect the change.
2.2 Describe one phenomenological approach to understanding the weather.
Key thinkers in phenomenology such as Dennis Klocek have developed interesting ideas about planetary motion and weather patterns. His research is presented in a number of lectures on his website. From this he believes he can make long term predictions about weather based on planetary motion.
Aonghus Gordon has described the druid weather station of Dun Aonghosa on the isle of Aran County Galway. This ancient settlement is believed to be a weather station for looking out and feeling and experiencing the oncoming weather.
3.1 Collate weather data on own holding over a given period
For the last three years I have been measuring maximum and minimum temperature and precipitation using traditional instruments. I intend to refine this data further in the future and include windspeed and barometric pressure. I am particularly interested in trying to formulate 'feels like' temperature on the holding to give further insights into the conditions on the site for the students and staff.
3.2 Reflect on local weather patterns that affect own holding
An aerial view of the Southern section of the site
Eyam Edge Farm, at 1300ft experiences extreme weather. It sits on the geological feature known as Eyam Edge, which is a steep escarpment. This feature marks the division between the Dark Peak area and The White Peak area of The Peak District National Park. The White Peak, south of the holding, is composed of limestone bedrock, The Dark Peak area is composed of gritstone, a form of sandstone containing larger particles.
This is important, because the presence of this steep escarpment, lying to the south, causes thermals to rise up and then circulate above the edge, creating a micro climate. The airflows discussed, mean that the presence of birds of prey such as buzzards is a daily occurrence. Indeed the road leading to the site is named 'Hawkhill Road'
The exposed South West corner of the site on a beautiful still day
Although there is a tract of woodland to the South of the site, which provides a certain degree of shelter, there is an exposed corner to the South West of the site which is where the prevailing winds come from. These winds can have high speeds and can cause damage to crops, trees and buildings. Anything built on site needs to be built to withstand these high winds.
High winds can also be a problem in the winter, because moderate levels of snow can be whipped up into snow drifts as seem in the following images taken in 2018.
The road to the site on 4th March 2018. Dense freezing fog, together with strong Easterly winds (The Beast from the East)
The truck caught in a snow drift. Picture taken after the snow plough cleared the road.
3.3 Reflect on the effects of weather on the land based activities of the holding
In 2018, particularly during March we received tremendous quantities of snow and freezing weather. This was the weather phenomenon known as The Beast from the East. The water supply froze and remained frozen for 5 weeks. I had to fetch water from the village to keep the animals alive and this would subsequently refreeze within a couple of hours. The wind chill factor was making the temperatures feel like -15 and even lower. I got the truck stuck in a snowdrift and had to abandon it and walk home. By the time I had got back the driving sleet had frozen in my beard and took time to defrost.
By the end of April the adjacent farm had lost 30 ewes to the low temperatures and as they were carrying lambs it was even more of a tragedy. Fortunately we were able to keep most of the ewes warm and dry in the woodland shelter, but had we not had this facility we would have been in a terrible situation too. These levels of snow were difficult to deal with but also brought some problem solving skills to the fore with one student getting around the frozen water supply rather cleverly during a natural dye session.
A student suggests melting snow for the dye pot. Open fires - usually 3 or 4 around the site - were obligatory.
In 2019 we received a ridiculous quantity of rain in a relatively short period. The rainfall data taken from my records shows that in 2019 1267mm of rain fell. This is more than double the average yearly rainfall. Almost half of the rainfall for the year fell in the months of September, October, November and December.
These levels of rain were extremely difficult to contend with. The following problems were all too frequent on the holding:
A extremely dry May has been followed by high rainfall levels ever since, right up until July as I write this we have been faced with very frequent rain, often unforecast, and often persisting. Because of the Covid 19 lockdown, Brantwood Specialist School was shut. The students have continued to come to the Eyam Site for the education and they have experienced the huge variety of weather patterns that have occurred. This year has been characterised by dramatic shifts in temperature, rainfall, wind patterns and low light levels caused by thick clouds.
3.4 Reflect on the relationship of RMT students with weather and its effect on garden/farm activities
At 1300ft we exist in a location which is challenging and difficult for the RMT student. The purpose of many of the garden spaces is to provide suitable protection for the student against the harsh and often extreme conditions. The Sensory Garden was built to protect from the elements, containing as it does the wall to stop the wind and the central firepit to provide warmth. Everything has been designed with a purpose, and that purpose is often to enclose and protect. In addition we have had to take measure to protect crops (and students) from high winds and the wind chill factor that they bring. I have observed and felt wind chill equating to -15 degrees on frequent occasions
4. Understand the importance of water and flow in the context of Biodynamic practice
The first and most importance of water and flow might be seen in the way that a preparation is 'enlivened' or 'dynamised' through the stirring process in water. (rain water is always best)
Steiner described the stirring or dynamising process he intended when discussing horn manure 500: “You must make sure…that the entire contents of the horn have been thoroughly exposed to the water. To do this, you have to start stirring it quickly around the edge of the bucket, on the periphery, until a crater forms that reaches nearly to the bottom, so that everything is rotating rapidly. Then you reverse the direction quickly, so that everything seethes and starts to swirl in the opposite direction. If you continue doing this for an hour, you will get it thoroughly mixed.”
A further example of the importance of water and flow is the 'Flow Form' this structure encourages the flow of water into a vortex within the pools that form the structure. At Ruskin Mill, flowforms are everywhere. They are used to introduce fresh water into the fishponds and they are used elsewhere to dynamise the water.
© Brantwood Specialist School
Created by Jim Hildyard