surfacePressure: Compute near-surface pressure

In environmentalinformatics-marburg/satelliteTools: What the package does (short line)

Description

Compute the near-surface air pressure from the barometric formula using the geopotential height of certain pressure levels, the referring temperature profile and the underlying digital elevation model as input data.

Usage

## S4 method for signature 'Raster'
surfacePressure(gp, ta, dem, p, ...)

## S4 method for signature 'numeric'
surfacePressure(gp, ta, dem, p)

Arguments

gp	Geopotential heights as Raster* or, if a spatially distinct location is processed, as numeric vector.
ta	Temperature profile of the same class as gp.
dem	If gp is a Raster* object, a digital elevation model as RasterLayer or numeric vector (e.g. derived from getValues); else a single numeric elevation value.
p	numeric pressure levels associated with gp.
...	If gp is a Raster* object, further arguments passed on to writeRaster.

Value

If gp is a Raster* object, a RasterLayer with near-surface air pressure; else a single numeric value.

References

Roedel W, Wagner T (2011) Physik unserer Umwelt: Die Atmosphaere. Springer: Heidelberg, Dordrecht, London, New York, ISBN: 978-3-642-15728-8. Available online at http://cost733class.geo.uni-augsburg.de/moin/iguawiki/data/pages/KursmaterialWS1213_HsKlivar/attachments/Roedel_Die_Atmosphaere.pdf.

Examples

### example from MYD07_L2 (20 levels) ---

## pressure levels             
p <- c(5, 10, 20, 30, 50, 70, 100, 150, 200, 250, 300, 400, 500, 620, 700, 
       780, 850, 920, 950, 1000) 
       
## geopotential heights
gp <- c(35005.573, 30329.573, 25786.936, 23204.563, 20074.706, 18113.499, 
        16109.901, 13765.185, 11966.857, 10484.984, 9218.005, 7115.921, 
        5399.528, 3679.846, 2676.816, 1760.488, 1018.150, NA, NA, NA)
        
## temperature profile         
ta <- c(234.6088, 226.9892, 220.2491, 214.4910, 203.8553, 194.2660, 191.1759, 
        205.9155, 220.9708, 232.4576, 241.8924, 256.9488, 267.5008, 277.0947, 
        283.7734, 289.8672, 294.1234, NA, NA, NA)   
    
## pixel elevation     
z <- 3625.708                                                    

## compute near-surface air pressure
surfacePressure(gp, ta, z, p)

environmentalinformatics-marburg/satelliteTools documentation built on May 16, 2019, 8:16 a.m.