Here are a few internet resources for reading related to course material.

The Space Weather Prediction Center has a pdf file
Basic Facts about the Ionosphere from Windows to the Universe
The National Geophysical Data Center's Ionosphere Page
The High Frequency Active Auroral Research Project (HAARP) Ionosphere Page
A perspective of military exploitation from the Global Policy Forum about Argus, Starfish and HAARP
The upper atmosphere (especially section 3) in the Physics of the Aurora webcast
University of Oulu's (Finland) Virtual Library on Aeronomy. A links page to related material.

Discovery of the Ionosphere

1820Hans Christian Oersted discovers that electricity and magnetism are related
1864 - 73James Clerk Maxwell describes theory of electromagnetic radiation and predicts existence of radiowaves
1882 Balfour Stewart suggests winds drive electric currents in the upper atmosphere
1887 Heinrich Hertz proves existence of radiowaves
1895Guglielmo Marconi demonstrates wireless (radio) communication in Bologna, Italy
1899Marconi transmits radio signal across English Channel
Dec. 12, 1901Marconi transmits radio signal across Atlantic Ocean from Cornwall, England to St. John's, Newfoundland
1902Oliver Heaviside; Arthur Kennelly propose existence of conducting layer in upper atmosphere
1909Marconi awarded Nobel Prize
1924Edward Appleton and others develop the ionosonde and begin ground-based soundings; prove existence of ionosphere
1925Appleton discovers second layer (the F region)
1926Robert Watson-Watt (later developer of radar) coins word "ionosphere"
1927Sydney Chapman describes theory for formation of ionosphere
1947Appleton awarded Nobel Prize
1948Rocket probes begin
1950'sRiometer (Relative Ionospheric Opacity Meter using Extra Terrestrial Electromagnetic Radiation) developed
1958Incoherent Scatter Radar developed
1962Alouette 1 satellite makes first topside soundings

Radio Communication

Spaceweather presented by The Windows to the Universe has a section on radio wave propagation and wave modulation (AM vs FM)
The page on the radio spectrum
Even more detail on the allocated uses of the radio and microwave spectrum from 9 kHz to 275 GHz
Albany Amateur Radio Association

Radio Reception

Some Milestones in the History of Radio

Feb 1892William Crookes publishes idea of wireless (radio) communication
May 7, 1895Alexander Popov demonstrates lightning produces radiowaves
March 24, 1896Popov demonstrates wireless communication in Russia.
June 2, 1896Marconi files patent in England for wireless communication
March 3, 1899Earliest reported use of wireless to report naval accident when the Steamship Matthews collides with East Goodwin Lightship
Dec 12, 1901Marconi transmits and receives radio signal (the Morse code for letter S) across the Atlantic
1902U.S. Navy installs radio telephones aboard ships
1906Lee DeForest invents radio amplifier and radio tube triode
1906Reginald Fessenden first broadcast of voice and music
1906Morse code for SOS ...---... adopted as official international distress call
1909First radio "talk show" (topic: women's suffrage)
1909Distress signal saves 1500 lives after the Republic sinks in collision with the Florida
1910Wireless Ship Act requires radio communication aboard U.S. ships
1912Fessenden invents heterodyne receiver
1912U.S. Navy uses adopts term "radio" in place of "wireless"
1912Radio Act - first federal regulation of broadcasters
1916Ernst Alexanderson invents selective radio tuner
1919Shortwave radio invented
1920First regular radio broadcasts; Detroit 8MK(later WWJ),Pittsburgh KDKA
1921First broadcast sporting event; Dempsey-Carpenter bout
1926National Broadcasting Company (NBC) network created
1927Dill-White Act - public ownership of airwaves; forerunner of FCC created
1929Appearance of car radios
1933Edwin Howard Armstrong invents FM broadcasting
1933Luxembourg Effect (cross-modulation) discovered
1934Communications Act of 1934 creates Federal Communications Commission (FCC)
1934Half of U.S. homes have radio
1945FM radio begins operation in the 88-108 MHz band
1961FCC approves stereo FM
1970'sFM overtakes AM as preferred commercial broadcast band

A few internet resources on the history of radio:
Early developments
Timeline of Communication History
Appliances That Changed The Home Forever
Old Time Radio Show Catalog: A website with info and samples of old programs.
Another site for enthusiasts of early radio

A few webites (with some interesting photos of early radio equipment) for radio museums around the world:
U.S. Marconi Museum in Bedford, NH
AWA Electronic Communication Museum in Bloomfield, NY
Marconi Canadian Historic Site in Glace Bay, Nova Scotia, CANADA
Hammond Museum of Radio in Guelph, Ontario, CANADA
The Popov Central Museum of Communication in St. Petersburg, RUSSIA
Popov Museum of Radio in Yekaterinburg, RUSSIA
Marconi Foundation's Historical Museum in Bologna, ITALY

The Big Question: Who invented radio?
I used to think Star Trek's Ensign Chekov's view of history was just comic relief. Little did I know.

Ionospheric Structure

Review of the vertical structure
Currents maps of ionospheric structure: Maximum Usable Frequency, Height of F2 Maximum, and Total Electron Content

The number of electrons (or electron density) varies spatially in altitude and latitude. The structure also varies temporally in a largely regular manner due to:

Some of the regular structure and behavior of the ionosphere was not expected by theory in the 1930's. These phenomena are referred to as Classical anomalies and include:

The ionosphere is also susceptible to largely unpredictable variations due to "weather" from below the ionosphere, intrusions by meteors and solar disturbances. These will be presented under the topic of Ionospheric Storms and "Space Weather".

Formation of the Ionosphere

The concentration of electrons in the ionosphere results from a balance of production and destruction mechanisms. The dominant processes are listed below for each region. The fact that different processes occur at different altitudes is the reason for the vertical structure of the ionosphere.