BC The Greek geographer Strabo of Amaseia (now in Turkey) divides the Earth into frigid, temperate, and torrid zones.

c. 10 BC The Greek geographer Strabo of Amaseia (now in Turkey) divides the Earth into frigid, temperate, and torrid zones.

Theodoric of Friebourg (now in Germany) writes De iride (On the Rainbow) describing his experiments with bulbs filled with water.

The English mathematician Thomas Harriot (1560–1621) notes that snowflakes have six sides.

c. 1592

The Italian scientist Galileo (1564–1642) invents a simple form of thermometer (the ‘thermoscope’) based on the expansion of air.

The German astronomer Johannes Kepler (1571–1630) publishes A New Year’s Gift, or On the Six-Cornered Snowflake.

The Dutch physicist Willebrord Snell (1591–1626) discovers his law of refraction of light (which he did not publish).

The French philosopher René Descartes publishes Discours de la méthode, which includes an appendix Les Météores containing his ideas about the rainbow and the formation of clouds.

The refraction law discovered by Snell is independently published by Descartes in another appendix, La Dioptrique.

Ferdinand II of Tuscany constructs a thermometer containing liquid.

Appendix I 1643

The Italian physicist Evangelista Torricelli (1608–1647) constructs the first barometer by inverting a tube, closed at one end and con- taining mercury, in a dish of mercury.

The French mathematician and philosopher Blaise Pascal (1623–1662) investigates Torricelli’s barometer. He arranges for his brother-in-law to take an instrument to different heights up a moun- tain, thereby demonstrating that the height of the column decreased with altitude.

The English astronomer and physicist Edmond Halley (1656–1742) formulates the law relating height to pressure.

Halley gives a partial explanation of the trade winds, suggesting that hot equatorial air rises and is replaced by cooler air moving in from the tropics.

The French physician Guillaume Amontons (1663–1705) invents a hygrometer.

Amontons constructs an improved barometer.

Amontons constructs a constant-volume air thermometer.

The German physicist Gabriel Daniel Fahrenheit (1686–1736) con- structs a thermometer with alcohol as the working fluid.

Fahrenheit uses mercury as the working fluid in thermometers for the first time and defines a temperature scale based on the freezing point of ice and salt (0°) and the temperature of the human body (96°).

The French entomologist and physicist René Réamur (1683–1757) introduces a thermometer using a water/alcohol mixture and devises

a temperature scale based on the freezing point of water (0°) and its boiling point (set at 80°).

The German explorer Johann Gmelin discovers the permafrost in Siberia.

The English meteorologist George Hadley (1685–1768) explains the direction of the trade winds (by reference to the Earth’s rotation) in his paper Concerning the Cause of the General Trade Winds. This introduces the idea of the Hadley cell.

The Swedish astronomer Anders Celsius (1701–1744) devises a tem- perature scale in which he sets the freezing point of water at 100° and the boiling point of water at 0°.

Jean Pierre Christin inverts the fixed points on Celsius’ scale, to pro- duce the scale used today.

The American statesman and inventor Benjamin Franklin

Appendix I

(1706–1790) begins a series of experiments on electricity. His dis- covery that charge could be drawn by a pointed metal conductor led to the use of the lightning rod.

Franklin fixes a lightning rod to his house in Philadelphia.

Franklin performs a now famous experiment in which he flies a kite in a thunderstorm to demonstrate that lightning is a form of electric- ity.

The English chemist John Dalton (1766–1844) publishes Meteoro- logical Observations and Essays – an account of his weather obser- vations, which he started in 1787 (and continued for the rest of his life).

The British pharmacist and amateur meteorologist Luke Howard (1722–1846) proposes the first classification of cloud types (still the basis of the present classification).

The French physicist Jean Baptiste Biot (1774–1862) and the French chemist Joseph-Louis Gay-Lussac (1778–1850) make a balloon as- cent to a height of three miles to investigate whether the composi- tion of the atmosphere or the Earth’s magnetic field changes at this height.

The British admiral Sir Francis Beaufort (1774–1857) proposes a scale of wind speeds (now known as the Beaufort scale).

The English chemist John Frederic Daniell (1790–1845) invents the dew-point hygrometer.

The Swiss geologist Ignatz Venetz (b. 1788) proposes that glaciers formerly occurred throughout Europe.

Daniell publishes Meteorological Essays and Observations, in which

he puts forward theories of wind movement and the atmosphere.

The French physicist Jean-Baptiste Fourier (1768–1830) suggests that human activity may have effects on the Earth’s climate.

The French mathematician Gaspard Coriolis (1792–1843) publishes Mémoire sur les équations du mouvement relatif des systèmes de corps (Memoir on the Equations of Relative Motion of Systems of Bodies), in which he describes what is now known as the Coriolis effect.

The Swiss-born American naturalist Jean Louis Agassiz (1807–1873) first begins to use the term Eiszeit (Ice Age).

Agassiz publishes his findings in Etudes des glaciers (Studies on Glaciers).

P. Adie designs the Kew barometer.

Appendix I 1857

The Dutch meteorologist Christopher Buys Ballot (1817–90) pro- poses a rule relating wind direction to the location of the pressure center (Buys Ballot’s law).

The Scottish meteorologist Alexander Buchan (1829–1907) attempts to identify recurring periods of similar weather (Buchan spells).

James Coffin suggests that there are three distinct wind zones in the northern hemisphere.

The British explorer and anthropologist Francis Galton (1822–1911) publishes Meteographica (Weather Mapping), which introduces the term ‘anticyclone’ and describes modern techniques of weather mapping.

The American meteorologist Cleveland Abbe (1838–1916) is ap- pointed chief meteorologist with the Weather Service (part of the US Army).

The American geologist Thomas Chowder Chamberlin (1843–1928) suggests that there were several Ice Ages separated by nonglacial epochs. He published his ideas in a chapter contributed to The Great Ice Age (1874–84) by James Geikie.

The International Meteorological Committee adopts the Beaufort scale for use in weather telegraphs

Gustavus Hinrichs, an Iowa weather researcher, first uses the word ‘derecho’ for a widespread type of windstorm.

1890s

The British astronomer E. Walter Maunder (1851–1928) identifies a period of low solar activity (the Maunder minimum).

The German geographer and climatologist Eduard Brückner (1862–1927) investigates the cycle of cold and damp weather alter- nating with warm and dry weather in northwestern Europe (the Brückner cycle).

Luis Carranza, President of the Lima Geographical Society, con- tributes a small article to the Bulletin of the society in which he de- scribes a countercurrent flowing N to S from Paita to Pacasmayo occurring annually after Christmas. He reports that fishermen call this El Niño.

The US Weather Bureau separates from the Army and becomes an independent organization under the direction of Cleveland Abbe.

The Swedish chemist Svante Arrhenius (1859–1927) points out that increased carbon dioxide in the atmosphere can cause the green- house effect. He suggests that past Ice Ages may have been caused by decreased amounts of carbon dioxide.

Appendix I 1900

The Russian-born German climatologist Wladimir Peter Köppen (1846–1940) first publishes his classification of climatic types (which he modifies several times before 1936).

The British physicist Oliver Heaviside (1850–1925) and the Ameri- can Arthur Edwin Kennelly (1861–1939) independently suggest the existence of the ionosphere to explain transatlantic radio transmis- sions.

The French meteorologist Léon Philippe Teisserenc de Bort (1855–1913) identifies and names the troposphere and the strato- sphere as distinct layers of the atmosphere.

The Swedish physicist Vagn Walfrid Ekman (1874–1954) produces

a mathematical model for the result of winds blowing over the ocean (the Ekman spiral).

The Norwegian meteorologist Jacob Aall Bonnevie Bjerknes (1897–1975) publishes one of the first scientific accounts of meteo- rology in his Weather Forecasting as a Problem in Mechanics.

Jacob Bjerknes publishes Dynamical Meteorology and Hydrography.

The Serbian astronomer and mathematician Milutin Milankovitch (1879–1958) proposes a theory of long-term cyclic climate change (Milankovitch cycles).

The United Nations Framework Convention on Climate Change (UNFCCC) is drawn up.

The British meteorologist William Napier Shaw introduces a type of thermodynamic diagram (the tephigram).

Sir Gilbert Walker, Director of Observations in India, notes “when pressure is high in the Pacific Ocean it tends to be low in the Indian Ocean from Africa to Australia”. He calls the effect the Southern Oscillation.

The British physicist Edward Victor Appleton (1892–1965) discovers a layer in the ionosphere (now called the Appleton layer).

G. Stüve introduces a type of thermodynamic diagram (the Stüve diagram).

Universal Time is adopted as the name for Greenwich Mean Time when used for scientific purposes.

The American climatologist Charles Warren Thornthwaite (1889–1963) devises a precipitation-efficiency index.

Appendix I 1932

The Swedish-born American meteorologist Carl-Gustaf Arvid Rossby (1898–1957) introduces diagrams for indicating the proper- ties of air masses (now known as Rossby diagrams).

The Swedish meteorologist Tor Harold Percival Bergeron (1891–1977) publishes a paper On the Physics of Clouds and Pre- cipitation, in which he argues that ice crystals in clouds are involved in the mechanism of rain formation.

Work by Walker Findeisen supports Bergeron’s theory (later known as the Bergeron–Findeisen process).

The American physicist Vincent Joseph Shaefer (1906–1993) in- duces rainfall by seeding clouds with pellets of solid carbon dioxide.

The American chemist Willard Frank Libby (1908–1980) invents radiocarbon dating, which is used in paleoclimatology.

The American climatologist Charles Warren Thornthwaite (1899–1963) introduces the concept of moisture index.

The German climatologist Hermann Flohn (1912–97) proposes a climate classification based on global wind belts and precipitation (the Flohn classification).

A team led by the Hungarian-born American mathematician John Von Neumann (1903–1957) produces the first computer-generated weather forecasts using the ENIAC computer.

The World Meteorological Organization (WMO) commences opera- tion.

The American geographer and climatologist Arthur N. Strahler (1918–2002) introduces a climate classification based on air masses (the Strahler classification).

The World Meteorological Organization publishes the International Cloud Atlas.

The British government introduces an Act of Parliament to limit smoke emissions with the aim of reducing smog.

The American oceanographer Roger Revelle (1909–91) instigates the start of measurements on the amount of carbon dioxide in the atmosphere.

The American physicist James Van Allen (1914– ) discovers two bands of ionized particles in the atmosphere as a result of satellite data (the Van Allen belts).

The temperature–humidity index is first introduced by the US Weather Bureau.

Appendix I 1960

The National Oceanic and Atmospheric Administration (NOAA) launches the weather satellite TIROS-1.

The American meteorologist Edward Norton Lorenz (1917– ) no- tices that computer predictions of weather are highly sensitive to small differences in initial conditions. This eventually leads to the development of chaos theory.

Lorenz publishes his ideas in a paper, Deterministic Nonperiodic Flow.

The British climatologist Hubert Horace Lamb (1913–97) intro- duces the dust veil index.

The US government introduces the first Clean Air Act to set national air pollution standards.

The American geographer Werner H. Terjung proposes a climate classification based on comfort.

Jacob Bjerknes in California University, Los Angeles, explains the El Niño Southern Oscillation (ENSO).

1970s

The American engineer Herbert Saffir (1917– ) and the meteorolo- gist Robert Simpson (1912– ) devise a scale for measuring hurri- cane strength (the Saffir–Simpson scale).

The second US Clean Air Act.

The Japanese-born American meteorologist Tetsuya Fujita (1920–98) with Allen Pearson introduces a scale for measuring tor- nado intensities (the Fujita or Fujita–Pearson scale).

Earth Resources Technology Satellite 1 (later called Landsat-1) is launched.

The Global Atmospheric Research Program (GARP) conducts the GARP Atlantic Tropical experiment (GATE) to further understand- ing of the tropical atmosphere.

The American chemist Sherwood Rowland (1927– ) and Marco Molina suggest that CFCs (chlorofluorocarbons) could cause long- term depletion of the ozone layer.

The first GOES (Geostationary Operational Environmental Satellite) is launched.

The European Space Agency is formed.

The US National Academy of Sciences publishes a report supporting Rowland’s theory concerning CFCs and ozone depletion.

Appendix I 1977

The first Meteosat weather satellite is launched by the European Space Agency.

The use of CFCs is banned in the US.

The British scientist James Ephraim Lovelock (1919– ) publishes Gaia, expounding the idea that the Earth is a self-regulating ecosys- tem (the so-called Gaia hypothesis).

The World Climate Research Program (WCRP) is established.

The British Antarctic Survey obtains conclusive evidence of a hole in the ozone layer.

The Vienna Convention for the Protection of the Ozone Layer takes place.

The Tropical Ocean-Global Atmosphere Program (TOGA) is started.

The Montreal Protocol – an international agreement to regulate the use of CFCs – is drawn up.

The Joint Global Ocean Flux Study (JGOFS) is initiated to study the fluxes of carbon in the oceans.

The Global Energy and Water Cycle Experiment (GEWEX) is launched to observe the hydrologic cycle.

The German scientist Helmut Heinrich obtains evidence for the marked discharge of large numbers of icebergs from the eastern North American ice sheet during glacial periods (Heinrich events).

The Global Atmospheric Watch (GAW) is established to collect data on the atmosphere’s physical characteristics.

Projects start to analyze the Greenland ice sheet. The Greenland Ice Core Project (GRIP) is run by the European Science Foundation. The Greenland Ice Sheet Project 2 (GISP 2) is a US project.

Nations meeting in Berlin agree the Berlin mandate to take action on climate change beyond the year 2000.

The Kyoto Protocol is agreed to achieve reductions in greenhouse- gas emissions.

Landsat-7 is launched.

The US refuses to ratify the Kyoto Protocol.

Russia ratifies the Kyoto Protocol.

The Kyoto Protocol comes into force.

Appendix II