A DATA SET a series of observations collected by the same methodology. Each data set should have documentation sufficient for someone unfamiliar with the research to replicate the study. Data sets may be broken into subsets (data files) that are discrete in space and time, in that order. The documentation for a data set should include all spatial and temporal subdivisions of the data.

DATA SET IDENTIFIER: El Verde atmospheric deposition data from Nov. 21, 1983 to Sep. 22, 1987

PROJECT TITLE: El Verde Weather data
LTER core area: Inorganic inputs and nutrient movements
LEF research area : Environmental Monitoring

DATA SET FILES (SUBSETS):
El Verde atmospheric deposition data (mcdevrai.txt)

RESEARCH LOCATION:
El Verde Tower (Bulk data) and NADP, El Verde Tower (Wet data) at the Luquillo Experimental Forest(LEF) (18 15'N, 65 50'W)

INVESTIGATORS:
PRINCIPAL INVESTIGATOR: William H. McDowell
OTHER RESEARCHERS:
CONTACT PERSON & PHONE:
William H. McDowell
Tel.#: (603)862-2249;
FAX: (603)862-4976;
E-MAIL: bill.mcdowell@unh.edu

PROJECT DESCRIPTION:
SOURCE OF FUNDING (SPONSOR) : NSF-LTER

ABSTRACT:
The chemistry of bulk precipitation was measured from November 1983 to September 1987 at El Verde in the Luquillo Experimental Forest, Puerto Rico. Wet-only precipitation was also analyzed as part of the National Atmospheric Deposition Program from 1984 to 1987. Volume-weighted mean pH was 5.14 in bulk precipitation and 5.12 in wet precipitation. Concentrations of most species were correlated negatively with weekly rainfall. Sea salt aerosols contributed most of the Na+,Cl-,Mg2+ and K+ found in wet and bulk precipitation; sulfate and calcium, however, were derived primarily from non-sea salt source. Due to the high rainfall (3.4m annually during the study period) and close proximity of the study site to the ocean, deposition rates of the major cations and anions were high relative to many other tropical site. Precipitation chemistry at El Verde appears to be affected by several factors. During summers, Saharan dusts contribute a significant portion of the excess Ca2+,K+ and Mg2+. During winter months cold fronts may transport SO24- and NO3- from North America and the western part of Puerto Rico to the sampling sites.

METHODS:
Bulk and wet precipitation were collected from the top of a 25-m walk-up tower which is located within the rain forest and extends above the canopy. Elevation at ground level is 400 m above MSL. Bulk and wet precipitation were sampled at weekly intervals from November 1983 to September 1987 (bulk) and from February 1985 to September 1987 (wet).
Bulk precipitation was collected using a Hubbard Brook-type collector (Likens et al., 1967) which consisted of a plastic funnel connected by plastic tubbing to a 2 l reservoir. An all-glass bulk collector was also installed for the sampling of dissolved organic carbon (DOC). Wet and dry precipitation were collected in polyethylene buckets as part of the National Atmospheric Deposition Program (NADP) using an Aerochem Metrics Automatic Precipitation Collector (Model 301) and NADP protocol (NADP, 1984).

DATA COLLECTION TIME PERIOD:
STARTING DATE: November 21, 1983
PERIODICITY OF SAMPLE : approximately weekly
END PERIOD : September 22, 1987

REFERENCES : 

CROSS-REFERENCES (other data sets related to this one): LTERDBAS #20: Chemistry of rainfall, throughfall, and stream water from El Verde and Bisley Verde and Bisley stations

SAMPLE LOCATION:

STORAGE SITES: ITES, Data Manager's File DM-002 , Drawer #1

KEYWORDS: water chemistry, biogeochemistry, atmospheric deposition, El Verde

PUBLICATIONS:
McDowell, W.H., et al. 1990. Influence of sasalt aerosols and long range transport on precipitaion chmistry at El Verde, Puerto Rico. Atmospheric Environment 24A: 2813-2821

DISSEMINATION:
UNRESTRICTED

CHECKLIST:
Documentation for Data Files and Data Variables will be completed by the beginning of the project.
* Documentation for Data Set
* Documentation for Data Files
Documentation for Variables

FILING MEDIA
On-line data

DATE OF LAST REVIEW : 10/24/1996
DATE OF LAST ENTRY : 10/22/1996
STAGE OF DATA SET MANAGEMENT (dates) :
RECEIVED: 10/21/1996
CATALOGUED: 1/16/1997
ON-LINE: 1/16/1997
REVIEWED BY RESEARCHER:
FILING MEDIA:
NAME OF DOCUMENTATION FILE : LEFDS195.FM*
NAME OF DATA FILE : MCDEVRAI.WQ1
NAME OF ON - LINE CATALOG : LEFDSET1 RECORD #: 95
DOCUMENT TYPE : data base (magnetic media)
PRIORITY TO BE ENTERED : N/A

SITE DESCRIPTION :
The study site was Luquillo Experimental Forest at the eastern part end of Puerto Rico(18° 15'N, 65° 50'W). The Luquillo Experimental Forest is synonymous with the Caribbean National Forest and has been administered by the U.S. Forest Service for ~70 yrs. Elevation ranges from 200 to 1,000m. The plan community is dominated by tabonuco (Dacryodes excelsa) forest typeat elevations of 200-600m adn the colorado (Cyrilla racemiflora) forest type at elevations of 600-750 m. On ridges and peaks above 750 m, vegetation consistes of short-saturated elfin forest. Palms (most commonly Prestoea montana) are found throughout the forest but are especially common along streams channels and in poorly drained areas. Human disturbance, consisting of small farms and selective tree harvesting (mostly at lower elevations), preceded Forest Service administration. Scattered plantation forests have been established since designation of the area as an esperimental forest (Brown et al. 1983).
Precipitation ranges from 250 to >500 cm yr^-1 in the Luquillo Forest area and increases with elevation. Precipitation peaks in May and from August to November (McDowell and Estrada-Pinto 1988). Hurricanes and tropical depressions produce individual rainfall events that are highly unpredictable and very intense, and hurricanes are thought to play a major role in structuring plant community dynamics (Brown et al. 1983).

DESCRIPTION OF DATA SET FORMAT (MAGNETIC MEDIA):

Column		Type of datum		Name of Variable		Abbreviation(s)
1		DD-MMM-YY		Date		DATE$
2		DD-MMM-YY		Date		DATE
3		Number of year of collection		{0=1983, ...,4=1987}		YEAR
4		Precipitation		centigrades		MM
5		Bulk pH (lab)		percent		BPH
6		Bulk Dissolved organic Carbon		mg/L		BDOC
7		Bulk Ammonium Nitrogen		µ g/L		BNH4N
8		Bulk Nitrate Nitrogen		µ g/L		BNO3N
9		Bulk Sulfate		mg/L		BSO4
10		Bulk Chloride		mg/L		BCL
11		Bulk Sodium		mg/L		BNA
12		Bulk Potassium		mg/L		BK
13		Bulk Magnesium		mg/L		BMG
14		Bulk Calcium		mg/L		BCA
15		Wet pH (lab)		percent		WPH
16		Wet Calcium		mg/L		WCA
17		Wet Magnesium		mg/L		WMG
18		Wet Potassium		mg/L		WK
19		Wet Sodium		mg/L		WNA
20		Wet Chloride		mg/L		WCL
21		Wet Sulfate		mg/L		WSO4
22		Wet Ammonium Nitrogen		µ g/L		WNH4N
23		Wet Nitrate Nitrogen		µ g/L		WNO3N

Observations

FILE NAME (IF MAGNETIC MEDIA): mcdevrai.wq1, .txt

PREVIOUS VERSIONS OF DATA : EVRAI.wB1

SUMMARY STATISTICS :

Type		Formula

Rev. 10/24/96