WEATHER FORECAST THROUGH HISTORY

AN INTRODUCTION

José Luis Pascual Blázquez                   ã  June, 2006                        

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            Introduction. Empirical stage (Meteorognomy). First scientific stage of exclusively astronomical-aristotelian base. Second scientific stage:  laws, apparatuses, recording data... Vindicating Astrometeorology in century XXI.

Introduction       

In the history of the weather forecast we have to distinguish three great stages: 

              1) Empirical stage or of signs, cradle in the experience (repetition of facts), still well-known in rural ambiences.  We cannot speak strictly here of scientific methodology in the present sense of the term, but we should reject this class of knowledge, typical of a way of life and culture that deserve our consideration. 

              2) First scientific stage. Here, the atmospheric phenomena are interpreted, or tried to give them a logical-rational explanation that, in addition, allows the prediction of future events. In western cultures the basic theoretical support was the aristotelian Physics.  This stage have fundamentally astronomical base, that is to say, here, the celestial events (referring to stars and planets) not only were distinguished of terrestrial (rain, wind, rainbow, rays and thunders, etc.), but were considered intimately bound as cause (movement of the spheres and stars) and effect (meteorological phenomena).

              3) Second scientific stage, as from centuries XVI and XVII;  it was then when they were demonstrated by means of experimentation and calculation some insufficiencies and heavy errors of Aristotle Physics, giving birth to science as we know now.  The rupture with the aristotelian ideas brought a new conception of Nature (heliocentric system of the world, Kepler’s Laws, Galileo’s Kinematics, Newton ’s Mechanics, etc.). New emergent science needed not at all the celestial connection to describe terrestrial facts; astrologers continued patches to the Aristotle’s ideas, being anchored and sunk in the ostracism along the years. Then arose the experimental investigations, the design and the accomplishment of apparatuses to measure atmospheric parameters (pressure, temperatures, amount of rains, etc.), scientist began to consider the circulation general of the atmosphere, etc., until arriving at present time with the use of numerical models made by means of powerful computers and the pursuit of atmospheric dynamics with meteorological satellites. 

We are specially interested here, for two first stages and how happened the transition to the third, that we will not study in a exhaustive way, being such subject sufficiently treated by diverse authors and works. 

Empirical stage (Meteorognomy)

We can consider here the first written testimony of this class of knowledge, the omens  of Babylonia : 

If 15 Sabatu Venus disappears by the west, remaining invisible 3 days, and the 18 Sabatu it appears by the east, catastrophes for the kings;  Adad will bring rains, Ea underground waters;  the king will send greetings to the king.  Tablets of Venus de Ammisaduqa nº 63.  [ Mentioned by B.L. van der Waerden in " On babylonian astronomy ", The tablets of Ammisaduqa.  Beroso magazine nº 7, page  47.   Barcelona , 2002 ].                   

We found similar prognoses in pre-Columbian mesoamericans Annals and other cultures in analogous stage of development.  In the Mediterranean area we have ample written certainty of which it was common knowledge of the population to guide themselves in the annual time and for the short and long term weather forecast. It deals with observations that allow to know the climate standard of some dates, or if it is going to rain or snow, to be cold or warm, windy, stormy, etc. coming from the experience and of the systematic observation (in the country observation is an automatic function, unlike which it happens for the city inhabitants). 

Still now, the indigenous populations of the Altiplano de los Andes sow potatoes in the soil later or more early according to the appearance of the Pleiades during the month of June;  if they seems numerous and shining (eleven) they plant them in normal date, expecting good rains and favourable time for potatoes growing;  if they are dim and in little number, they expect for delayed rains and delay the plantation (in Agriculture the moment of rains usually is more important that its amount). 

The indigenous populations, unlike the scientists, ignore that the appearance of the Pleiades in its rise of June is bound to the type of winds flow in the Altiplano, determined by “El Niño” phenomenon; but it does not prevent them to optimize the moment of seedtime fitting it to a stellar observation, alien to the development of the climatic sequences in that zone.  [ See Etnoclimatology of the Andes ,  S. Orlove, John C.H. Chiang and Mark Cane.   Scientific American  nº 330,  2004 March. Spanish edition. ] 

As much the ancient cultures grecolatin and Arab had that rural knowledge orally transmitted of parents to children, rhymed widespread.  Nevertheless, its authentic corpus  has arrived until us written by authors of urban culture, who compiled it and were transmitting later (today something similar has happened with the proverbs, mainly those of meteorological content). 

The way to locate itself in the annual time, fundamental to know the moment of farming, seedtime, trashumance, etc. was solved in neolithic times by means of the association of the appearances and disappearances of certain groups of stars to the annual cycle of Nature, that basically depends on the Sun and its swings along the sky. If we did without the precession of the equinoxes (1º every 72 years of displacement) the succession of all stars of the celestial sphere by the horizons East and West has the same period that the solar year (main cause of the stations). 

We find in the cuneiform Babylonian documents the first lists of this annual star succession (we know as lists of astrolabs)  and the first written establishment of the association star-work farming in Hesiod: 

When the Pleiades, daughters of Atlas are rising, begin the harvest, the plowing when theyset.   [ Works and days, 385 ]. 

Greek astronomers gathered and systematized this empirical knowledge (Eudoxus, Calipus, Euctemon, etc.)  in a collection of text called parapegmata,  stone calendars that were exposed in the streets for public informationl.  They gave the dates of the main astronomical and meteorological events along the year, taking as reference the risings and settings of certain stellar groups.

We have complete  the Geminus Parapegma, of enormous astronomical and meteorological interest. Through this text we can understand the origin of our term " dog days " to designate the algid moments of summer heat, because a little before the beginnings of ours Era the rising of Sirius happened at dawn over the East horizon (Canis major), that is to say, the Greater Dog; with the precession of equinoxes the bigining of summer heat was announced by the rising of Procyon  (Canis Minor, the Small dog), some centuries later. 

The Greek Claudius Ptolemy (II century), whose astronomical and astrological work dominated the western scientific panorama until century XVI, made himself weather observations in Alexandria and elaborated its own description of the annual time in the work named Phaseis (that we have rather to understand as “strip” or “bands” of stars which ascend and descend through the horizon, which Ptolemy uses to know the moment of the year and climate associate). 

This author also gathered some signs of weather forecast (halos, Sun and Moon colours, etc.)  in his famous astrological treated  Quadripartitum  or Tetrabible.    

The Geminus Parapegma, as others contemporaneous works, and later the Arab books of  anwá, describe the standard time of the year in their places of origin ( Greece and Arabia ).  Chronologically nearer to us in time, the medieval Arab calendars have arrived complete at present time with an information of enormous interest, because to the meteorological subject they add  agricultural contents, advice of dietetic and hygiene bound to hippocratic Medicine, customs and folklore medieval, as much Christian as Muslim, etc. 

People interested can read at the moment in Castilian language the Andalusian anonymous Calendar, the Treatise of months of Ibn Asim,  and Liber regius (Latin language), or a version in Arab, Latin and French of Calendar of Cordova,  etc.

This type of information located country inhabitants in the annual time, but it was not enough to survive to surprises of the inclemency; the other great question was:  what class of weather can we expect today, or tomorrow?  There will be storm, stable weather, heat, wind or cold?  And the next season, how will be?  And the next year?  Better to seed or to leave fallow?  Can we expect good or little grass?  There will be sufficient water in wells or rivers for the kitchen gardens?  We enter here in empirical associations usually called " signs ".

From our modern perspective that short of information pretends a primitive stage of knowledge, but only from the limited point of view of the urban and uprooted culture of the environment that we have;  in a unique Nature where everything is organized and interacts permanently, like in any complex system, it is very difficult that something cab happens without leaving any track in the rest.  In the same way which a headache can warn of a gastric ailment, the type of weather in a while of the year can announce how comes whole the climatic cycle, or the abundance of acorns in the oaks can be a good augury of the coming time.  This type of knowledge is not an exact science (present Meteorology is not either), but there is no doubt, was useful and continues offering interest and attention, at least curiosity in the modern man.

Valuable information of this type we can find nowadays in Phenomena  of Aratus, in Georgics  of Virgilius, Peri semeion (De signis),  written c.a. 300 a .C. and attributed to Teofrastus, and also in agricultural texts that the Romans Varron and Columela wrote (De re rustica).   Separate mention deserves Natural History  of Pliny (century I) in books II and XVIII, where it compiles, as in the rest of this encyclopedic work, all the knowledge of his time on the matter.  This part dedicated to Empirical Meteorology appeared in Middle Ages as an independent treaty, with similar materials of diverse origin; its title was De praesagiis tempestatum.   

This type of texts had a great successful, that still is present nowadays. This class of omens of weather for the day that begins, for morning, for the lunation, the month, the station or the year, was copied and repeated by numerous authors as from the medieval period;  they already appeared in some almanacs after the invention of the press, later in works on Chronology.  For example, in Chronology and repertoire of the reason of the times, by Rodrigo Zamorano, published in Seville in 1585;  in Repertoire of the times and Natural History of this New Spain,  by Henrico Martinez, appeared in Mexico in 1606;  in General Agriculture by Alonso Hererra, published in Madrid in 1645;  in Rustic Record, phisica visible and undeniable astrology:  Pastoral lessons of agriculture and judgments to make scholar to the peasant of Diego de Torres Villarroel, appeared for the first time in  1727, and of course, in the more important Spanish almanac. His author, Jerónimo Cortés, who from the end of century XVI continued publishing up to 1936. 

This class of useful signs for weather forecast we can classify them in diverse types: 

a) Observation of the Sun, the Moon and the stars, including fotometeors. 

b) The weather and the prevalence of the types of wind on certain days of the year and the moon (lunar month). 

c) Observation of plants and animals. 

d) Observation of non alive materials (grounds, walls, soot, rivers, wells, etc.). 

         e)Types of clouds and place of appearance. 

        f)In general, the texts that bring this class of information classify it in fair weather signals, of hail, colds and heats, rain, as well as the way to make seasonal prognoses and for the complete year. 

Let us comment a little all this meteorognomic hotchpoch, that is the suitable term to denominate this class of knowledge. 

On what they indicate the color of the Sun, the Moon and the aspect of stars already speaks Aratus  in Phenomena  and little have added later other authors, which is logical, since the progressive urbanization of societies does not favour the meteorognomic knowledge, but only its written conservation. Aratus talks about the prognoses that indicate the aspect of both stellar groups that there are around the Manger, in the constellation of Cancer (if they are seen or not, if they pretend to come near or they vanish), which is a fine empiric diagnosis of the presence, or no, of humidity in height atmosphere (cirrostratus, announcing a disturbance);  Aratus also gathers the predictions that was current in their time by means of two typically Mediterranean plants, the “lentisco” and the oak (amount, number of flowerings, etc.). 

The European proverbs keep in rhymed version most indications from the color and aspect of the Sun, as well as from all class of fotometeors (halos, rainbow, “parhelios” , etc.). 

Proverbs also keeps sentences on the weather forecast, either in the long term, according to the lunar day or the year;  we enter here in prognoses such as “cabañuelas ", " témporas ", " caniculares", " canablas ", " barruntos ", " aberruntos ", " surtimientos ", zotal egunak, cabanelles, andtwelve nights”, etc., of exclusive rural and popular origin, as well as of oral tradition (there is no written text on the subject until the end of century XX, when the culture of survival in Spanish countries is extinguished). 

The observation of the flight and the behavior of birds, flies and mosquitos, spiders, toads, frogs, cattle and ovine, hens and roosters, fish in the rivers and a long list of others, as well as dandelions, saffron, “carlina”, etc., in relation to the changes of weather, is world-wide well-known, and its continuity is ensured in multiple sentences of proverbs. 

Ancients observed accurately the appearance of humidity in grounds and walls, bad scents in the pipes, upwellings or turbulences in waters of wells and pools, the soot fall in the chimneys, way of crackle of live coals, or the flame in oil lamps, observation of ashes of fireplaces and chimneys, etc.

Local names for certain cloud appearance, or its location on certain places, proliferate along all Europe so that the meteorological condition to come is significant and quite sure; so it is the case of “nubes paciendo” (clouds grazing), “hats”, “monteras” or “toquillas” (hadscarfs) on the tops of some mountains, the Andalusian vaca esollá,  sign of south winds or " llovedores", the ampurdanian  núvol cerdà  that appears with the “tramontana” wind and indicates rain in France, etc.  In general they come with very defined meteorological conditions, well known by the inhabitants of the place where they are characteristic. 

Between the more estimable indications are the seasonal and annual; we have made a complete study compilation in our work  “Cabañuelas” and Empirical Meteorology.  The short and long  term weather forecast in rural world  (2005).   Before, there is a nourished group of investigators and authors who dedicated to their time and its attention to gather this type of knowledge (in Spain José María Iribarren, Julio Caro Baroja, Cels Gomis, Joan Amades, Enrique Gaspar Casas, Antonio Allue Morer, Julia Sevilla, Jesús Cantero, etc.). 

Do you think that this class of beliefs and this type of knowledge are typical of a closed rural world without communication with the outside?  On the contrary, it is the expression of a common cultural substrate spread all along Europe and North Africa (at least in which we have been able to verify), as it demonstrates the fact that many sentences of the proverbs are repeated from a country to another, from a language to another, without another difference that the translation. Such establishment could be interpreted as plagiarism, copy or simple circulation along the time of oral traditions; there is no doubt this is a part of the truth, but not everything.  The surprising uniformity of the European and North African meteorognomic knowledge also finds justification in the fact of the population of Europe after the thaw that conducted to the Neolithic and subsequent drying of the Sahara;  Europe literally was invaded by populations that fled from that climatic catastrophe searching for more favourable zones to the life, carrying themselves the culture and language, which we may to suppose enough uniforms at that time, to disperse later with time. 

That happened with languages, but not with meteorognomics knowledge, particularly during the last climatic period, the subatlantic, that lasts from -500 approximately;  that uniformity allows to think about its maintenance and conservation along the time.

We cannot close this part of our study without gathering ancient ways to foretell the weather, although we enter here into the divinatory techniques (do not forget the etymology of the term, " to speak with the Gods"), which is to be understood in the mentality of ancient peoples (we also have ours, with their weakness, which we do not discern, we also have veils of our culture). 

Between the divinatory procedures it was the escapulimancy, still used in Middle Ages; the interpretation of the aspect of a lamb shoulder blade, once roasted, had one double character, public and private.  The private set standards on the government of the family and home; the public deal with subjects as the state, harvests, prices and, of course, the coming climate. 

Arab manuscripts are conserved teaching the way to interpret the signs of lamb shoulder blade, gathered surely in the phase of progressive urbanization of the Arab culture (the tradition was rural, there is no doubt, and orally transmitted, as all teachings in this world). 

In countries of celtic influence we found a similar divinatory method, but with the breastbone of goose that traditionally is eaten in Saint Martin day (November 11th, we find here the custom already christianized).  If the bone colour is white announces a cold winter and abundant snows;  speckled variable weather, whereas if half is white and other  half black a part of the winter will be severe and the other relatively temperate. 

In the ancient world, where the deads were next to the alive and any sign was considered as ominous (uniqueness of Nature, current use of the symbolic language) the sacred and the profane formed an inseparable  contiuum.  The religious celebration was inseparable of the knowledge of future; thus we see it in the observation of the altars smoke, where the ritual sacrifices were carried out, indicating the wind that was going to dominate in the coming cycle (in each place, the type of wind determines the heat or the cold, rain or drought, etc.). 

Christianizeds, these beliefs have been conserved up to present time; still in century XX was thought in the North Iberian Peninsula that the wind that blew in the mass of the Sunday of Branches during the Ofertory was going to be the dominant of the year, and sailors and farmers went out to observe it.  In France also it is the wind of that day, and in a part of Europe and Africa the one of Saint John’s day (in fact the one of solstice or  Al Ansara).   What indicates the vane in the new year’s eve was determining for the medieval universe, and, with Christian influence, we have the winds of Saint Martin, Saint Matthew, Saint Mark and many more dates of the calendar that were determined in Antiquity by the risings and settings of the constellations, got dressed with the tunic of the new religious cycle all along Europe.

Let us see the use of this class of knowledge in Kepler’s days:

.. Here however, I do not reject the [well known] observations of the ancient authors, Hesiod, Strates, Virgil, Plutus nor other modern [observations] of agriculturist, who draw conclusions as to the future temperature of the air from the annual rising of the stars and phase of the Moon at the time they observe these phenomena (not a long time beforehand.   [ Johannes Kepler   On the very certain foundations of Astrology.   Clancy Publications. New York , 1942.  Thesis 50, pág.  20 ]. 

One of the key-points of meteorognomic knowledge (shared with the astrological one) is the importance given at certain moments of the year (we could talk now of critical important points).  The collections of proverbs are full of sentences saying that if in such day it happens such thing during so many weeks, months, in present station or all along the year will dominate such-and-such wind, rain, drought, etc.  The same intrinsic idea dominates in the long term technique of “cabañuelas” and other similar procedures in weather forecast.  The concept goes united to the " propitious moments " of magic and divination (nights of Saint John , Christmas Eve, equinoxes, etc., that nowadays only comprises a part of  festive folklore). 

As an example, in the well-known text The myth of eternal return  Mircea Eliade deals with the importance of the days that separate the end of the beginning of year:

Analogous custom of the "destines fixation " of the Babylonian New Year, that has been transmitted until present times in the New Year ceremonial between the mandeans and the yezids ones.  Also the twelve days that separate the Christmas Eve of the Epiphany continue being considered at the moment a prefiguration of the twelve months of the year, because the New Year repeats the cosmogonic act.  Farmers of all Europe have no other reason when they determine the weather of every month and its dose of rain by means of meteorological signs of those twelve days [ Emecé/Alianza Editorial.   Madrid , 2000.  Pág.  69. Spanish edition.]

The Babylonian New Year ceremonial of akitu  lasted twelve days, and within those days was the "celebration of Lots ", zahmuk,  in which the omens for each of the twelve months of the year were determined.  So, the general pattern of the “cabañuelas” can have its origin in the first historical cultures, the Mesopotamian ones.  Mircea Eliade also calims that the mythical-ritual set of the New Year already was well-known of the sumeroacads, long before Babylonian summit-time.  In it, the twelve intermediate days that separate the old year of the new one also preappeared the twelve months.

First scientific stage of exclusively astronomical-aristotelian base

In order to understand this historical phase on meteorological knowledge we have to leave our present academic and cultural formation, trying to get the ancient thought; unusually and paradoxically our ancestors did not distinguish meteorology of astronomy, nor the celestial phenomena of the atmospheric ones, something extremely astonishing for modern mentalities. Comets and rainbows, the epochs of rains or heats, everything what we can make out watching upwards, comprised a continuum for ancient peoples. And, since in deepest of the firmament stood God or the divinities, it does not have to be strange that all these phenomena, astronomical and atmospheric, were taken as manifestations or signs from the divine will that sometimes awarded to humankind with fecund rains, or it punished them by his bad actions with droughts, plagues and catastrophes. 

The departure point for this first stage of scientific development in European and North African cultures was three texts of Aristotle (century IV b.C.):  Meteora  (Meteorologics), De caelo  (On the heavens) and De generatione et corruptione  (On generation and corruption).  In the three texts a radical division is settled between the sky (immutable, incorruptible, not formed by matter but the fifth Element or quintessence, in that only can be circular uniform  movement of the orbs or planetary spheres dragging the corresponding star) and the material Earth (formed by four Elements, that is to say, Fire, Air, Water and Earth), susceptible to changes, mutations, accidents, “passions” and, therefore, generation and corruption.  The sky (in fact, the skies, the celestial orbs or spheres), are active and causes; on the contrary, the Earth is passive and undergoes the effect of celestial turns.  In this system of thought all phenomena of the material world  -inferior- have by cause the turn and movement of the superior or celestial world. 

There was a physical-mathematician development of these ideas by means of Geometry, harmonic proportions and Music, that in Antiquity consisted of Acoustics or Sound’s Physics, as he can see in several extant (The Manual of harmonics  by Nicomacus of Gerasa, Harmonicas  by Claudius Ptolemy, etc.), and  in near times Harmonices mundi  by Kepler, in which he tries to justify the facts –then unquestionable, of relation between celestial and the terrestrial facts- by means of mathematical apparatus of  " music of the spheres " or " celestial music ", one inaudible melody, although anybody doubted about its existence.  As relic of these times we have the astronomical origin of notes of the present musical scale. 

In Antiquity the word  meteorology did not exist to deal with the weather nor its prognosis; during the Middle Ages, in Latin language it was spoken De accidentibus aeris and in Arab of al-athar al-'ulwiya.  Aristotle’s Meteora was translated as " On the impressions [ of the superior bodies ] ", that is to say, the stars.  We must consider the great catastrophe, in all levels, that the fail of Roman Empire supposed for Europe; it is not exaggerated at all to affirm that the culture, literally, disappeared, giving force to all kind of beliefs and superstitions. " Dark Age " has been called the next centuries after Rome failure. Science did not begin to be revived up to four centuries later, with the fusion that made the Arabs of greco-roman, Persian and Hindu traditional knowledge, which penetrated in Europe by three routes, bizantine, Italian and Spanish. 

They made up the cultural and scientific summit of Middle Ages, so is the reason that their writings were so desired for the Christians, that remained underdeveloped in all orders of  knowledge.  Specially, Arab astronomy dazzled on the other side of the borders (as all scientific and philosophical knowledge in general), and astronomical were the Arabs tools of weather forecast.

All this thought came from East and dominated in Europe and North Africa until the end of Renaissance, and it was only left with the Modern Age, parallel the birth of Physics, present Chemistry and Geology. 

In the gestation of medieval meteorology two routes with an unique origin came together (Middleaster, that is to say, Babylonian): the Greek (Aristotle and an important part of the hellenistic thought) and the Indian (stellar astrology, lunar mansions, etc., with Persian and hermetic influences). 

This flow and ebb of ideas travelled after the dispersion of Babylonian culture, where surely it reached the highest levels of development; there the knowledge were transmitted of parents to children, who learned from the first years of life, and perhaps in this system of transmission was the key of its great success, as we know through Diodorus Siculus. From there Eastern science travelled towards the West, fertilizing hellenistic Greece , and towards East, overlapping itself in the Hindu systems. 

We found the reunification of both branches in an Arab medieval well known, Al Kindi, author of two Letters and some other pieces that deals, among other many scientific and philosophical works, on atmospheric phenomena and weather forecast. His work was the most important contribution in the transmission of these ideas, because it was translated to Hebrew in century XIV, and also the Latin; it was widely desired and recognized, as we see in the great amount of medieval and even Renaissance European authors who translated him, copied, plagiarized and retranslated Al Kindi’s works. 

Letters I and II were including in a single Latin text divided into 8 chapters, known as De mutatione temporum.   Kitab al-sirr,  Book I (Forty Chapters)  was known in Latin as Iudicia.           

Other authors who dedicated their attention to the subject were Omar b. Al Farrukan Al Tabarí (kitab to mukhtasar al-masái)l,  that also was translated to Latin. Abumassar, Persian astrologer of century IX, wrote On the great conjunctions,  a classical work profusely devoted to relations between planetary configurations and climatic phenomena and (kitab to nukat, Flores astrologiae  in Latin language).

Other texts with similar contents were kitab tahawil sini al-alam  of Sahl b. Bishr (Fatidica  in Latin).  Most of these texts were translated to the Latin in century XII; this century was the begining of the entrance of these knowledge in Europe . 

From century XII  also comes the Latin version Epistola in pluviis et ventis,  written by the Jew named Messahallah.  Chapters with meteorological contents we can see in " The Book of Three Judges " and " The  Book of Nine Judges ".  The Jew born in Tudela ( Navarre ) named Abraham Ben Ezra wrote Sefer ha -'Olam,  translated at the end of century XIII as Liber coniunctionum that dicitur of world vel seculo.  There is some meteorological material (among them two " lots " of rain, one of them attributed to Enoc) in The Book of the Judgments of Stars, published  recently in Spanish from the Catalan version (School of Translators of Sirventa), a manuscript that is conserved in the Monasterio de El Escorial (Madrid). 

The Libro conplido en los iudizios de las estrellas  by Aly Ben Ragel, translated to medieval Castilian in century XIII, ordered by Alfonso X The Wise of Castile, contains a part of Book VIII devoted to weather forecast. Its sources are Omar b. Al Farrukan Al Tabari like and Abumasar.  We have to point out that during centuries XX and XXI this text was transliterated by the hispanist scholar Gerold Hilty (1954 and 2005) and adapted twice to modern spanish one (1995, School of Translators of Sirventa and Gracentro). 

Another fundamental work in this field by its notables contents of meteorological matter was translated to medieval Castilian in the Court of Alfonso X (century XIII), Book of the Crosses,  attributed to Obeydallah.  The system seems to be of very ancient application, because he was already well-known in visigotic Spain and probably the Low Latin period. Peculiarly, this text also has been published during century XX, (Lloyd Kasten and Lawrence B. Kiddle, Madrid, 1961). 

The European medieval translators, in addition to make their work of adaptation, took control of an important part of these materials, putting their name in them as authors. Juan of Seville, or “The Hispanic”, or “The Hispalense”, wrote Tractatus pluviarum et aeris mutationis;  also there are meteorological contents in his Epitome totius  astrologiae.   Hermann of Carinthia wrote Liber imbrium;   Grosseteste Ad precognoscendam diversam aeris dsipositionem; Firminus of Bellavalle  De mutatione aeris;  John of Ashenden Summa iudicialis de accidentibus mundi;   also there is information on this subject in Liber decem astrologiae  by Guido Bonatti and in the sixth part of Compilatio de astrorum scientia  by Leopold of Austria, very present in the most popular Spanish Almanc, that of the Valencian Jerónimo Cortés.

We found at the end of century XV an important astronomer, the Jew of Salamanca Abraham Zacut, known mainly by its improvement in astronomical tables for the navigation towards the recently discovered New World ;  but he also wrote a remarkable work on Astrology,  Brief Treaty on celestial influences.  It contains a chapter devoted exclusively to weather forecast, that is, by means of elements of astronomical type (planetary configurations and aspects between planets).  Zacut summarizes in few pages, with a great synthesis capacity,  most of the ancient knowledge.  And not only that, but demonstrates to have exercised in astrological prognosis of weather and, unlike most of authors, gives data confirming the doctrine (the deluge of 1503 with 5 retrograde planets, rains of  Sagitarius conjunctions during the winter, colds with Saturn passage by Capricorn, etc.). 

In written documents there is a revealing detail that speaks clearly about the conceptions of medieval and Renaissance men:  many astronomical tables have in the margins annotations with weather observations, illustrating that, more than to carry out systematic registries, looked only for correlations between concrete celestial configurations and certain phenomena or atmospheric conditions. Nevertheless, the rule, has its exception:  William Merle carried out systematic registries from 1337 to 1344 (manuscript conserved in Oxford , Bodleian Library, Digby 176).  In Spain it is not rare to find valuable climatic, meteorological and fenologic information, in ecclesiastical archives. 

Zacut lived in the first years of the press, simultaneously with the conquest of America .  From now, Astronomy is going to have a basic role in navigation, for ships orientation in marine journeys, so that astronomical interest had a preponderant role to improve ephemerides, to locate with Maxima possible precision courses and ships positions.  Nevertheless, between the navigators, weather forecast, and mainly in the long term, will not decrease, on the contrary;  to posses good astronomical tables will allow navigators to make its calculations and to know the weather in advance, as it can be verified in Columbus astronomical ephemerides, who still used astrological science in weather forecast. 

Almanacs with all kind of predictions, and among them, climatic and meteorological, began to proliferate all through Europe . In century XVI about 3000 different almanacs with weather forecasts circulated around Europe , made by about 600 different authors.  But this almanacs not only were written by yokels;  Kepler, one of the creators of modern Physics, published almanacs, and also Benjamin Franklin, the inventor of lightning conductors, predicted the weather during 25 years from 1732 in Poor Richard’s Almanac. 

They are also characteristic of the century XVI end and beginnings of the XVII some works devoted to Chronology, including abundant astrological and meteorognomic material (Chronology and repertoire of the reason of  times,  by Rodrigo Zamorano, cosmographer of Felipe II, Seville, 1585;  Repertoire of times and Natural History of this New Spain,  Henrico Martinez, Mexico, 1606).  This work includes weather prognoses from 1606, by quarters of Moon, to 1620, as well as abundant meteorognomic information;  it comments the effects of Mars-Saturn conjunctions on Mexico in century XV and also gives very diverse astrological contents. 

In this epoch we also have an important author that dedicated his time to try to give account of the effects of planets on the Earth, and among them meteorological influences; we are talking of Johannes Kepler, convinced neoplatonic and Pythagorean, one of the modern science builders (defending Copernicus heliocentrism, friend of Galileo, discoverer of the three laws that take their name, exquisite mathematician and author of Astronomia nova,  which remarkably improves in  Mars astronomical knowledge, Mysterium Cosmographicum  ("The Secret of the Universe ", where tries to justify the relations between the distances and the planetary periods) and Harmonices mundi,  in which it gives his interpretation of the planetary influence resorting to mathematical tools of his epoch (Music and Geometry).  It is specially interesting for us On the very certain foundations of astrology, containing some of his own criteria prediction (Kepler only worked with the " planetary aspects ", not with horoscopes) and weather forecast for entire year 1602.  This work has been published in Spanish recently (2003). 

Kepler did not follow the way of other astrologers; unlike most of them, who limited themselves to repeat previous authors without critic nor verification of the doctrine, Kepler investigated the subject both in theoretical order as in practitioner;  He really was the last finder of the truth in an epoch that the old ideas, and mainly the apparently unconquerable aristotelian and Ptolemaic buildings, staggered before the new model of the world (heliocentric copernican) and the new Physics (Kepler, Galileo and Newton in the beginning, followed later of numerous new creators of science).

Therefore, century XVII marks the definitive crisis, the border between the doctrines that sink and the new emergent ones;  in the middle of such stagnation the more extensive and complete astrological work dedicated exclusively to weather forecast appears in Lisbon during 1632:  Astrological Summa and art to teach to make weather forecasts,  written by Antonio de Nájera, who, as Zacut, is more known between the historians by his astronomical works related to navigation, in the epoch of American colonization.  This work also has been reedited recently, in 1996. 

The Summa,  as already its name announces, develops the contributions of Ptolemy, with all its elements, to which it adds the doctrines of lunar mansions and " openings of the doors " coming from Indian Astrology, with practical examples, quantification of planetary forces, treatment of eclipses and, mainly, a great number of aphorisms accumulated in previous books, throughout centuries.  Antonio de Nájera quotes Abu Massar and Al Kindi, that, with Ptolemy, are their main sources. 

But the astrological winter knocked to the doors;  in 1677, the Valencian augustine Leonardo Ferrer composes his peculiar Curious Astronomica and description of the world superior, and inferior,  that contains a part devoted to weather forecast with some contribution of him (it defends, for example, the doctrine of symmetrical points –“antiscios” in respect to cardinal points of the Zodiac and that the aspects between Mercury and Jupiter move the “tramontana” wind). 

The last Spanish astrologer of great reputation that treated the subject was Diego de Torres Villarroel, known as The Great Piscator of Salamanca  and university professor of Mathematics in this Castilian University ; Torres also was the last in teaching astrology there. His Rustic Record, phisica, visible and undeniable astrology: Pastoral lessons of agriculture and judgments to make scholar to the peasant (1727)  contains a meteorognomic section that does not contribute anything new and constitutes one more copy of so many other previous ones coming from the grecolatin culture. Their prognoses scarcely talks about climate; nevertheless, we can verify documentarily that in 1756 had the great success to predict the French revolution. 

In this epoch was born a new vision of the world and astrologers began to be object of jokes; Torres had to defend himself of some of them with their acid and quevedesc characteristic style. He refuted Newton ’s theories with a scholastic simplicity that today makes us smile compassionately. 

Second scientific stage:  laws, apparatuses, recording data...

The birth of modern science, as we know it at the moment, had a long gestation.  In the same way which in Greece there were defenders of the heliocentric system of the world (Hiparcus) and materialistic thinkers, at the present time exist defending of the ancient thought. That is what we could expect, because there are two reasonable ways to contemplate the reality for our human thought and brain. 

For that reason there were first people during the Middle Ages that glimpsed another way to approach the interpretation of the reality –the subject of science- different to Scholastics, this one of christianized aristotelian base, initiated by Saint Thomas of Aquino.  For that reason, weather forecast by means of astronomical markers never underwent any annoyance of the ecclesiastic power (Saint Isidore, in Etimologias,  defended the practice and kindness of " natural astrology ", that is, the one devoted to time measurement and weather forecast, as opposed to " divinatory ", dangerous in moral realm). 

Between these advanced people  emphasizes the English franciscan Roger Bacon, author of Opus Maius (1268); he praises here the necessity of experiment and induction in phenomena interpretation.  As it is known, he went into the jail and his final life was dark, maybe tragic.

In the Renaissance we found Galileo Galilei (1564-1642), considered as official founder of experimental method.  At present it would seem a simpleness, but we must consider that, in the summit of power of Christian historical cycle, the investigation with material bodies was not admitted by some ecclesiastical authorities, pertaining the matter to the tempting devil –wealth of the world, physical knowledge, opposed to the spirit -; only just Kepler was able to dare to watch through the telescope, recently invented, to see Jupiter moons, Moon craters or Saturn rings.  Neither the Sun spots (the Sun was the symbol of Christ in the world, so it could not have defects that disfigured the perfection of the King Stars). Galileo was pioneering in the use of Algebra (equations) to describe the bodies movement (fallen of graves, launching of projectiles, etc.); Algebra in addition, coming from the Muslim world, the Christian mathematics were much more underdeveloped.  If at present time this may seem a triviality, then, not only was revolutionary, but dangerous, due to the almost absolute power of ecclesiastical hierarchy. 

Galileo wrote in a quite satirical style his defender of the heliocentric system of the world, Dialogues on both maximum systems of the world, ptolemaic and copernican,  defying aristotelian Physics not only with philosophical argumentation, but with experience too (fallen of graves from Pisa’s Tower);  only a genius and quick-tempered person like him could dare to as much... and it is known that he had to retract itself of his ideas before the Pope of Rome. 

We assign to Galileo the invention of the first thermometer, a key instrument in the development of the new way to investigate and to interpret atmospheric phenomena. 

We found in 1623 the appearance of a text that changed our minds about the world:  Instauratio magna  by Francis Bacon, and a few years later (1637) The Speech of the method,  by René Descartes, another work that destroyed the ancient ideas. 

The intellectual climate of that epoch conducted to make in 1639 the first pluviometer and in 1641 the first thermometer with certain reliability.  In 1644 the Italian Evangelista Torricelli carried out its well-known experiment of the mercury column, being able to demonstrate that the air had some weight and exerted a pressure on all the bodies; the experience, in addition, allowed to measure the value of atmospheric pressure. 

To Pascal is attributed an ascent to the Puy de Dôme revealing that the barometric mercury column diminished with height;  it can seem a triviliality now, but then it supposed to face an amount of dogmas and obsolete beliefs living their final days. 

We must think that in century XVII the existence of the air as something material was not clear at all;  pneuma is the Greek ethimology of the term,  from where our car “pneumatics” or " tyres ". It also means " gas " and " spirit ". Still now distilled are called "spirits "; for example, etilic alcohol is known as "spirit of wine ", that is, the subtlest part of that drink.  The air chemical composition was not known until 1781, when the French Lavoisier found that he contained  20% of oxygen and 80% of nitrogen.  For many people the winds were consequence of  Eolo’s whims, a Greek God  (nevertheless aristotelian Physics recognized that the air dilated with the heat and contracted with the cold, originating the wind). 

Otto von Guericke (1602-86) was pioneer in using the water barometer to predict the weather; it exists a document of 1660 in which von Guericke predicts a strong storm because of the great reduction observed in the water column. 

In 1659 was made the first hygrometer of condensation; in 1669 was carried out the well-known experience of Magdeburg ’s hemispheres, giving account of the enormous power of atmospheric pressure (being adapted to its presence we have no sensation at all about the air weight). 

In 1714 Fahrenheit used mercury as thermometric liquid, attaining unknown reliability in temperature’s measurement. 

In 1714 we found the first Traité de Météorolgoie,  written by the French Louis de Cotte, priest of Montmorency, taking a term nonused until then in the rising science.  In 1788 was published South Mémoires sur Météorologie  by the same author. 

Bejamin Franklin (1706-90) managed to capture atmospheric electricity by means of one commits during storms, being able to demonstrate that rays and thunders had an electrical nature. 

In 1688 the British astronomer Edmund Halley proposed for the first time the necessity to make a wind map on planetary scale, an advanced and bold idea from our historical perspective.  This proposal did not find positive echo until 1735, when George Hadley proposed a general model of atmospheric circulation; thus Meteorology came near to its present patterns. 

But this is another history. 

Vindicating Astrometeorology in century XXI

The new way to contemplate the world has given great results, one of them, Meteorology as we know it now.  Meteorology gives excellent proposals in short term weather forecast; but also it is well known that, beyond of two days, the solutions of numerical models are little trustworthy and the hopes to improve in middle and long term are limited. We already have generic seasonal predictions (temperatures and precipitations average), and that supposes a remarkable qualitative improvement; but even so, the long term weather forecast is a problem without satisfactory solution. 

One of the main difficulties consists on in which the atmosphere behaves as a chaotic system, and that limits drastically the reliability of the equations that are introduced in the great computers. Some people think that the more exact data and the more are those that are given to the machines, the more close we will be of the final solution.  In Meteorology we are in front of a determinism question, as it already happened to the investigators of the atomic world at the beginning of century XX

As opposed to this bleak panorama, in respect to the climatic variability, we think that the problem can be attacked by other different ways from used by the meteorologists at the moment.  The evolution of Physics and science in general during the last decades allows us to make some proposals that some years ago would been considered bold or absurd.  In fact we are talking of to attack the problem of long term prediction by means of global considerations, that is to say, astronomical. We will justify immediately the reason. 

We have a previous success in Milankovitch’s Theory, that interprets the great climatic changes - freezings, defrostings, etc. – by means of the variations of the Earth orbit (axis inclination, movement of the  apsids line and precession of the equinoxes, all of them long period factors and apparently separated of the causes of climate).  It is possible to ask ourselves if the climatic variability is not interpretable also through connected astronomical markers with the Earth, as they are planetary cycles within the Solar System (corresponding resonant periods).  The quantitative weakness of the planetary influence suggests at first it can be negligible and we can ignore it without any consequence for mathematical models; in fact, astronomical parameters have been introduced in the equations of the numerical models and given to the great computers; as we could expect, so weak factors actually do not vary the value of the final solutions. 

Nevertheless, to conclude of this fact that the planetary effect does not exist, or that really we can ignore it, would be a fatal error; we think that it would be an enormous error in all the orders - philosophical,  logical, scientific, etc. -.  We are going to try to explain the reason. 

Are we so sure enough that the cause of the annual climatic cycle and its supra annual variability is supported exclusively in the Earth orbital motion?  We know that to propose lunar and planetary influences it sounds to astrology, to popular beliefs and superstition.  We want to remember here that in years 30 and 40 of century XX meteorologists put great hopes in the study of this type of influences - solar activity, planetary and lunar gravitation-. To deal with the problem of climatic variability they celebrated the International Congress of Cosmobiology in Nize in June of 1938, that reunited to astronomers, meteorologists, physicists, engineers, etc. And, nevertheless...  can we take the scissors and cut to our whim the Nature by where we want like a negligent surgeon?  Will not we be denaturing the problem when separating the Earth and the Sun of the rest of elements of the Solar System, that behaves as an unique and a whole entitiy?  When reducing  the climate to an interaction between only two bodies of that machinery that works integrated, shared in common and interactively, will not we be losing something really decisive, simplifying the problem and leaving turned it a simple cartoon? We can separate the parts mentally, conceptually, but the real fact is that the parts are not isolated nor separated, but they are joined and working in a unique reality.

         We have a point of comparison in the role which the oligoelements have in the soil (Agronomy), or the catalysts in chemical reactions and enzymes in alive beings (Biochemical).  The presence of oligoelements in the soil, although in lowest amounts, is fundamental in agriculture, and also in nutrition. Deficiencies of boron, manganese, etc. in the soils can determine the ruin of the harvests; although the fundamental elements for plants are nitrogen, phosphorus and potassium, in Agronomy exists the minimum’s law:   the production is limited by the element that is in smaller amount, even if this one is a oligoelement.  And the same it happens in the superior animals:  although the basic nutrients are proteins, lipids and glucids, the presence in lowest amounts of zinc, cupper, vitamins, etc. is fundamental and its deficiency can cause serious alterations of the health in no proportional relation with the necessary daily minimum doses of these substances.

Something suggests that similar circumstances can also occur in the development of climatic variability respect to some planetary cycles, by weak that can be the luminosity or the gravity from a planet respect to other parameters (annual solar cycle, etc.). 

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