sfbay: San Francisco Bay water quality data

Description

Selected observations and variables from U.S. Geological Survey water quality stations in south San Francisco Bay. Data include CTD and nutrient measurements.

Usage

sfbay

Arguments

Format

sfbay is a data frame with 23207 observations (rows) of 12 variables (columns):

`[, 1]`	`date`
date	`[, 2]`
`time`	time
`[, 3]`	`stn`
station code	`[, 4]`
`depth`	measurement depth
`[, 5]`	`chl`
chlorophyll a	`[, 6]`
`dox.pct`	dissolved oxygen
`[, 7]`	`spm`
suspended particulate matter	`[, 8]`
`ext`	extinction coefficient
`[, 9]`	`sal`
salinity	`[, 10]`
`temp`	water temperature
`[, 11]`	`nox`
nitrate + nitrite	`[, 12]`
`nhx`	ammonium

sfbayStns is a data frame with 16 observations of 6 variables:

`[, 1]`	`site`
station code	`[, 2]`
`description`	station description
`[, 3]`	`lat`
latitude	`[, 4]`
`long`	longitude
`[, 5]`	`depthMax`
maximum depth, in m	`[, 6]`
`distFrom36`	distance from station 36, in km

sfbayVars is a data frame with 7 observations of 3 variables:

`[, 1]`	`variable`
water quality variable code	`[, 2]`
`description`	description
`[, 3]`	`units`
measurement units	`[, 1]`

sfbayChla is a time series matrix (380 months x 16 stations) of average 0-5 m chlorophyll a concentrations calculated from the data in sfbay.

Source

Downloaded from http://sfbay.wr.usgs.gov/access/wqdata on 2009-11-17.

Details

The original downloaded dataset was modified by taking a subset of six well-sampled stations and the period 1985--2004. Variable names were also simplified. The data frames sfbayStns and sfbayVars describe the stations and water quality variables in more detail; they were created from information at the same web site. Note that the station numbers in sfbayStns have been prefixed with s to make station codes into legal R variable names. sfbayChla was constructed from the entire downloaded sfbay dataset and encompasses the period 1969--2009.

Examples

Run this code

data(sfbay)
str(sfbay)
str(sfbayStns)
str(sfbayVars)
plot(sfbayChla[, 1:10], main = "SF Bay Chl-a")

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