OBSERVATIONS of EARTH'S ATMOSPHERE ATM OCN 100 - Fall 2000 LECTURE 1B OBSERVATIONS of EARTH'S ATMOSPHERE A. INTRODUCTION: Practical Questions What constitutes the atmosphere? What can we learn about the atmosphere? Why do we want to know about it?

B. THE PLANET EARTH Uniqueness of Planet Earth Water Planet The planet with life Components of Planet Earth System Lithosphere Atmosphere Hydrosphere Cryosphere Biosphere Interactions within System Weathering Hydrological cycle

From Geog. 101 UW-Stevens Point

C. SURVEY of PLANET EARTH’S ATMOSPHERE Importance of Earth's atmosphere Moderates temperature of planet; Shields life from harsh space environment; Provides life with water, oxygen, etc. Overall Dimensions of Earth's atmosphere About 100 km (62 mi) thick; Compare with 6370 km (3950 mi) earth radius; but ....

VERTICAL VARIATION in ATMOSPHERIC DENSITIES [Source U. S. Std VERTICAL VARIATION in ATMOSPHERIC DENSITIES [Source U.S. Std. Atmosphere, 1976]

C. SURVEY OF PLANET EARTH’S ATMOSPHERE (con’t) Importance of Earth's atmosphere Overall Dimensions of Earth's atmosphere Comparison with other components of Earth System

ESTIMATED VOLUMES & MASSES of EARTH SYSTEM COMPONENTS [Source: J. Y ESTIMATED VOLUMES & MASSES of EARTH SYSTEM COMPONENTS [Source: J.Y. Wang, 1975]

D. WEATHER-CLIMATE ELEMENTS What we need to Know Weight (mass), Energy, Constituents, Motion. Observed Weather-Climate Elements AIR PRESSURE AIR TEMPERATURE ATMOSPHERIC HUMIDITY PRECIPITATION CLOUD TYPE, AMOUNT WINDS (SPEED & DIRECTION)

E. PROBING THE ATMOSPHERE Surface vs. Aloft Locations Problems Surface Weather Station Human observer, Thermometers, barometers, rain gauges, wind instruments, etc.

Traditional Surface Weather Station

Automated Weather Station (ASOS)

NWS & FAA Automatic Weather Stations

Automated Weather Buoy

E. PROBING THE ATMOSPHERE (con’t.) Other Observation Tools/Platforms Radiosondes Weather Radar Weather Satellites Meteorological Rockets Wind Profilers

Radiosonde

Radiosonde (con’t)

RADIOSONDE LOCATIONS

Weather Radar

Weather Radar (con’t.)

Weather Radar (con’t.)

NWS DOPPLER RADAR SITES

GOES Satellite

Geosynchronous Satellite Field of View

ATS-III in 1968

GOES-11 in 2000

Visible vs. IR Images

Man Computer Data Acquisition System (McIDAS)

TIROS in 1960s

F. VISUALIZING THE WEATHER: THE SURFACE WEATHER MAP Meaning of synoptic weather analysis synoptic: “syn” = same + “optic” = to see Goal of synoptic weather analysis Requirements for synoptic weather analysis Same time of observation Uniform instruments & observation techniques

MAP of TIME ZONES U.S. Naval Observatory, 1996

F. THE SURFACE WEATHER MAP (con’t.) Historical perspective First weather map in 1819 of 1783 Storm; Early U.S. Weather maps in 1870’s.

Surface weather map Sep. 1872

F. THE SURFACE WEATHER MAP (con’t.) Interpretation of modern surface weather maps where...

ON THE SURFACE WEATHER MAP Pressure systems Isobars (“iso” + “bar”) Highs & Lows Winds Circulation around Highs & Lows The “Hand-twist Model” Clouds Fronts Cold fronts, warm fronts & stationary fronts

Warm Front

Cold Front

Stationary Fronts