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Animation 1

Size: 34 MB (intended for high-speed connections or download)

Format: MOV

Required for viewing: latest version of Quicktime

Caption: The 925 and 500 hPa synoptic presents the contours of the height relative to sea level at which pressures of 925 and 500 hPa were present in NCEP analyzes based on analyzed radiosonde measurements. At all levels the wind flow is counterclockwise around low height anomalies (cyclones) and clockwise around high height anomalies (anticyclones), and the wind velocity is proportional to the height gradient. At 925 hPa the flow is somewhat ageostrophic, so winds blow roughly parallel to the isolines of height but slightly inward toward height minima and slightly outward from height maxima. At 500 hPa the flow is nearly geostrophic, so winds blow parallel to the isolines of height. The height at which a given pressure occurs is related to the temperature of the column beneath; the lower the height at 925 and 500 hPa, the colder the air in the column from that height to the sea level pressure surface. If the sea level pressure surface lies below the surface (for example, in mountainous regions) an approximation about the temperature profile is required to compute the 925 and 500 hPa heights. Therefore inaccuracies in the height fields are likely to be the largest in mountainous regions.

Animation 2

Size: 13.5 MB (intended for high-speed connections or download)

Format: MOV

Required for viewing: latest version of Quicktime

Caption: Maps of the modeled sulfate at 6-hour intervals. Continental boundaries are represented by black (white) lines and the superimposed colors indicate the sulfate or SO2 column burden (sulfate wet deposition) according to the color bar at the right of each frame, with a logarithmic scale spanning 3 orders of magnitude for sulfate and 4 orders of magnitude for SO2 (many orders of magnitude for sulfate wet deposition). The date and time of each frame are found in the lower left corner using the format YYYY MM DD HH (YYMMDDHH for sulfate wet deposition), where YYYY (YY) is the year, MM is the month, DD is the day, and HH is the UT time in hours (1200 UT is denoted 12 UT).

Animation 3

Size: 15 MB (intended for high-speed connections or download)

Format: MOV

Required for viewing: latest version of Quicktime

Caption: Map of the SO2 column burden at 6 hour intervals. See Animation 2 caption for further explanation.

Animation 4

Size: 4.5 MB (intended for high-speed connections or download)

Format: MOV

Required for viewing: latest version of Quicktime

Caption: Map of the sulfate wet deposition at 6 hour intervals. See Animation 2 caption for further explanation.