Atmospheric Deposition Monitoring

 

 

  DRYFALL

In 1997, the Clean Air Status and Trends Network (CASTNet) monitored atmospheric concentrations of sulfur dioxide, nitric acid, and particulate sulfate and nitrate at six PRIMENet sites; Big Bend, Canyonlands, Glacier, Rocky Mountain, Sequoia/Kings Canyon, and Shenandoah NPs. CASTNet filter pack systems have subsequently been installed in the remaining PRIMENet parks, with the exception of Hawaii Volcanoes, which is scheduled for July 1999.

CASTNet Filter Pack and Meteorological Station Site Information. Data available HERE.

Site

Site ID

Latitude (N)

Longitude (W)

Elevation (m)

Filter Pack

Met. Station

Acadia

ACAD

44.37

68.26

122

11/98-present

06/91-present

Big Bend

BIBE

29.31

103.18

1052

01/95-present

09/90-present

Canyonlands

CANY

38.45

109.82

1814

01/95-present

07/92-present

Denali

DENA

63.73

148.96

661

07/98-present

07/87-present

Everglades

EVER

25.39

80.68

2

11/98-present

01/89-present

Glacier

GLAC

48.51

113.10

967

01/95-present

01/95-present

Great Smoky Mtns.

GRSM

35.63

83.94

793

10/98-present

07/88-present

Hawaii Volcanoes

HAVO

19.43

155.26

1215

 11/99

11/86 - present

Olympic

OLYM

48.10

123.43

125

11/98-present

05/91-present

Rocky Mountain

ROMO

40.28

105.55

2743

01/95-present

12/94-present

Sequoia/Kings Canyon

SEKI

36.57

118.78

1902

01/97-present

09/88-present

Shenandoah

SHEN

38.52

78.44

1073

06/88-present

01/88-present

Theodore Roosevelt

THRO

49.60

108.27

700

10/98-present

09/98-present

Virgin Islands

VIIS

18.34

64.80

80

05/98-present

05/98-present

*Virgin Islands NP was not presented in Figure 3 because it was not in operation in 1997.

*Only sites with continuous data for 1997, Big Bend, Canyonlands, Glacier, Rocky Mountain, Sequoia/Kings Canyon, and Shenandoah NPs

were included in Figures 5 and 6.

*Theodore Roosevelt and Virgin Islands NPs were not included in Table 1 because they were not in operation in 1997.

 

 

Atmospheric concentration data are collected at each site with open-faced, 3-stage filter packs. The filter pack contains a teflon filter for collection of particulate species, a nylon filter for nitric acid and a base-impregnated cellulose filter for sulfur dioxide. Filter packs are exposed for 1-week intervals at a flow rate of 1.5 liters per minute (3.0 liters per minute for western sites), and sent to the laboratory for chemical analysis.

 

The following graphs, compare atmospheric concentrations of sulfur dioxide and particulate sulfate, and nitric acid and particulate nitrate, respectively. Again only one year of data is presented because operation dates were highly variable. Shenandoah NP had the highest sulfur concentrations, while Shenandoah and Sequoia/Kings Canyon NPs had the highest nitrogen concentrations.

Atmospheric Concentration of Sulfur Dioxide and Particulate Sulfate in 1997.

 

 

Atmospheric Concentrations of Nitric Acid and Particulate Nitrate in 1997.

 

 

To estimate total deposition to a park site, both wet and dry deposition must be monitored. As part of CASTNet, dry deposition rates will be calculated using a multi-layer version of the NOAA "big leaf" model, with the parameters of atmospheric concentration, meteorological data and information on land use, vegetation, and surface conditions. Dry deposition estimates for each site will be available when runs of the model are complete. Updated information on CASTNet is available.

 

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