Learning from History

1. Learning from History • So impossible is to keep our heads above the rising tide of the new meteorological literature that we are neglecting, to our loss, the rich stores which lie buried in the books of a generation ago. • Robert De C. Ward (Harvard U.) • Monthly Weather Review, Jan. 1914 p.23()

2. Hazy Weather in the Autumn: Indian Summer • Dry haze is undoubtedly due to fine particles of dust composed of: • fine particles soil • smoke and ashes from fires • salt from ocean spray • germs and fungi • Mo. Weather Rev. Aug. 1901(1243)

3. Vertical Transport and Dispersion • During the daylight the sun warms the soinl which heats the adjacent air and the rising currents carry the dust up to 300, 5000 and 7000 feet with well defined upper surface. • Mo. Weather Rev. Aug. 1901(1243)

4. Horizontal Transport and Dispersion • If a general wind is blowing this will bring abundance of fresh air and the haze is diminished but spread over a larger area. • If there is no general wind as for instance in the midst of areas of high pressure, then the layer of dust reaches higher each successive day. This is the general explanation of the dry haze weather ‘Indian Summer’ • Mo. Weather Rev. Aug. 1901(1243)

5. Removal • The amount of dust in the air depends on the balance between the settling by night and rising by day [implication dust settles out every night] (1243)

6. Dust in Fiume, March 1901 • Examination under polarizing microscope (640x) showed mostly colorless and some colored, irregular fragments of crystals together with skeletons of microorganisms and small particles of soot. The color of the collected dust was bright reddish brown. • The dust fall averaged between 260 and 1400 g/m2 in Fiume. • Dust of Fiume belong to the same class as the Trade Wind dust which blows from Africa over the Atlantic and the one collected on May 30 1892 in Sweden. • The dust produced a reddish haze, to diminish the insolation and thereby doubless increasing the air temperature in the upper strata. [no backscattering?]1242

7. Sahara Dust Transport • One can easily see that we have here to do with a severe storm in the Sahara region, and by the attending winds the finer dust was raised and transported northward. • In January 1890 the steamship Queensmore arriving at Baltimore from England, reported red rain and red dust off the coast of Newfoundland. It would be very remarkable if this was Sahara dust. • The dust was examined by Prof. Perhanz both microscopically and chemically and found to be perfectly similar to the sands of the Desert of Sahara, described by many authors.(1240)

8. Volcanic Aerosol: Dust or Droplets?(1251) • The beautiful sky colors produced by volcanic aerosol from Krakatoa and Pelee must have been produced by droplets of condensation. • It would require a long mechanical grinding to make a uniformly fine impalpable powder

9. Editor, Mo. Weather Rev. Jul 1990 CA 1234 • During the mid 1800s, dust was of interest more to the geologists than to meteorologists. • By the late 1800s meteorologists recognized that aerosols are essential parts of the atmosphere. • The presence of dust facilitates rain and snow formation • Influences the visible and thermal radiation. • Specifying the composition of the air should be expanded from gaseous chemical composition to include the aerosol

10. Rafinesque:Thoughts on Atmospheric Dust (1818)1234 • Dust is falling from the atmosphere all the time • Dust exists on the tops of the highest mountains • A portion is formed chemically in the atmosphere by combination of gases and elementary particles dissolved in in the air, sometimes rapidly • Its accumulation is is thick in the lower strata of the atmosphere • It settles slowly to the ground in clear weather but is quickly washed down by rain and snow • Some dust is from the pulverization of of road and field surfaces • Other dust comes from materials in the activity of mankind but whence arises the dust observed by means of sunbeams? • Just as the sea deposits particles that eventually form rocks so the air deposits a more delicate pulverulent matter.

11. Dialog of Rafinesque: • Anonymous comment(1920): All dust comes from the action of the wind, even the dust seen at sea has the same origin, being carried 1500 miles over the Atlantic • Rafinesque: I do not deny that the winds raise terrestrial dust and often carry it to distance; but I assert that … as dust exists in the atmosphere as far as the clouds at all time, I venture to believe, with Virey, Patrin, Deluc, and other philosophers, that there must be another independent formation of dust in the besides the scanty terrestial supply wafted by the winds.

12. Rafinesque: The Rays of Sun • The sun rays are not an optical reflection from the atmosphere since it is brighter and not so azure. It must be dust. • The phenomenon can be seen even after long and heavy rains which must have precipitated all the terrestrial dust to the ground. • Whence the dust must be continually formed formed in the atmosphere.

13. Rafinesque, 1820: Gas-Particle Conversion • The insights given by modern chemistry into the gaseous formations of solid substances will be amply sufficient to to account for this spontaneous formation. • We know that sulfur, muriate of ammonia, etc. can be formed by sublimation of gases • That smoke soot, manna, volcanic productions, meteorites, earths, and even stones or metals may be spontaneously combined by a casual meeting of gaseous emanations. • It is not, therefore, difficult to conceive how dusty particles may be formed in the great chemical laboratory of our atmosphere.

14. Aitken, 1894: Photo-Nucleation in Britain • On cloudy days the nuclei count remained low • The number increased with sunshine, in proportion to the sunshine which occur during anticyclonic conditions. • Sunshine may produce some change in the constituents of the atmosphere which gives rise to nuclei formation in saturated air. • The high nuclei days were not hazy which suggests that the nuclei were of molecular dimensions

15. Aitken, 1894: Nuclei-Visibility Relationship • It has been the custom to record the limit of visibility. • Observations on rainy days were discarded (Kingairloch) • The data were classified according to humidity • The amount of haze was proportional to the number of particles • Hence (Nuclei x Visual Range) = Cont. • In dry air C is 2x the the value for moist air

16. Aitken, 1894: On Aerosol Sources and Removal • Densely-inhabited areas lose their purity • Purifying areas of the world are those regions that lose more impurity than they gain. • Much of the dusty impurity discharged into our atmosphere falls to the ground but much is so fine that it will hardly settle. • The deposition of vapor on these particles seems to be the method adopted by nature for clensing them away. • Hence cloudy and rainy regions are the most purifying areas

17. Meteoric • It is well recognized that permanent addition to our globe, doue to showers and myrids of meteors is probably equivalent to not less than 1 inch/century for the globe.. And all this is carried to the bottom of the ocean.(1234)

18. Kempf, 1914 Regional Haze Die Entwicklung der Therorien uber Hochenrauch The Development of Theories on Regional Haze up to 1870 Dissertation by N. Kempf (1914) Regional haze is a strong haziness of relatively dry air with large spatial extent and longer duration.

19. Kempf, 1914: Theories on the Cause of Regional Haze 1. Emissions of non-aqueous vapors from the Earth surface (earthquakes) 2. Volcanic Ash 3. Cosmic Ash 4. Windblown Dust 5. Combustion Processes 6. Electricity +

20. Prestel, 1861: Peat Smoke Episode

21. Egen, 1828: Establishing Source-Receptor Relationship • Smell: If it smells like smoke..[chemical composition] • Temporal Trend: • Decay with Distance: • Wind Direction: • Direct evidence: • Time-Space correlation

22. The 19th Century Atmospheric Aerosol Science:From Confusion to Modern Science • There was a confusion as to what aerosols were and where do they come from. By the late 1800 the major aerosol source types, windblown dust, sea salt, combustion smoke and soot, secondary fine particles, were identified, but not quantified • Aerosol properties • Unique air pollution problem of North Central Europe: Regional smoke palls from peat burning

23. 1700-1900: From Enlightenment to Modern Science • 1700 - 1800: Era of Enlightenment. Emergence of naturalists, architects, engineers, geographers and many new ideas, good and poor. • 1800-1850: Transition form theory-driven to observation and later data-driven atmospheric aerosol science • 1850-1900: Consolidation of theories by weeding out the unsubstantiated ideas.

24. Haze form Gaseous Emissions from the Earth • Mostly attributed to bursts of emissions during earthquakes. • I. Kant (1756) in Locarno, IT: In two hours a hot reddish haze has spread over the valley which turned into red rain, which beyond doubt, is linked to earthquake activity. • Marconelle (1783): Rapid springtime warming of the earth caused the emission of fermentation products to the atmosphere. Once the water was evaporated by the sunshine, only the solid particles remained which formed the ‘dry fog’. The dry fog covers large geographic areas due to the large extent of the missions [not due to long range transport].

25. Haze from Volcanic Emissions • Seneca (ca. 60 AD) has noted that Volcanic gases and ash cause atmospheric turbidity. • However, only in the 1700s was is suspected that volcanic aerosol is spread over large area. • B. Franklin has noted that the haze in 1783 may have been due to an eruption in Island.

26. Volcanic Aerosol and Global Circulation • The 1883 Krakatoa eruption • Kiessling • Global Ciculation