Introduction to pRecipe

Mijael Rodrigo Vargas Godoy, Yannis Markonis

2024-01-31


pRecipe was conceived back in 2020 as part of MRVG’s doctoral dissertation at the Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Czechia. Designed with reproducible science in mind, pRecipe facilitates the download, exploration, visualization, and analysis of multiple precipitation data products across various spatiotemporal scales (Vargas Godoy and Markonis 2023).


~The Global Water Cycle Budget | Vargas Godoy et al. (2021)

“Like civilization and technology, our understanding of the global water cycle has been continuously evolving, and we have adapted our quantification methods to better exploit new technological resources. The accurate quantification of global water fluxes and storage is crucial in studying the global water cycle.”


Before We Start

Like many other R packages, pRecipe has some system requirements:

Data

pRecipe database hosts 27 different precipitation data sets; seven gauge-based, eight satellite-based, seven reanalysis, and five hydrological model precipitation products. Their native specifications, as well as links to their providers, and their respective references are detailed in the following subsections. We have already homogenized, compacted to a single file, and stored them in a Zenodo repository under the following naming convention:

<data set>_<variable>_<units>_<coverage>_<start date>_<end date>_<resolution>_<time step>.nc

The pRecipe data collection was homogenized to these specifications:

E.g., GPCP v2.3 (Adler et al. 2018) would be:

gpcp_tp_mm_global_197901_202205_025_monthly.nc

Gauge-Based Products

Spatial Coverage
Data Set Spatial Resolution Global Land Ocean Temporal Resolution Record Length Get Data Reference
CPC-Global 0.5° x Daily 1979/01-2022/08 Download P. Xie, Chen, and Shi (2010)
CRU TS v4.06 0.5° x Monthly 1901/01-2021/12 Download Harris et al. (2020)
EM-EARTH 0.1° x Daily 1950/01-2019/12 Download Tang, Clark, and Papalexiou (2022)
GHCN v2 x Monthly 1900/01-2015/05 Download Peterson and Vose (1997)
GPCC v2020 0.25° x Monthly 1891/01-2022/08 Download Schneider et al. (2011)
PREC/L 0.5° x Monthly 1948/01-2022/08 Download Chen et al. (2002)
UDel v5.01 0.5° x Monthly 1901/01-2017/12 Download Willmott and Matsuura (2001)

Satellite-Based Products

Spatial Coverage
Data Set Spatial Resolution Global Land Ocean Temporal Resolution Record Length Get Data Reference
CHIRPS v2.0 0.05° 50°SN Monthly 1981/01-2022/07 Download Funk et al. (2015)
CMAP 2.5° x x x Monthly 1979/01-2022/07 Download Pingping Xie and Arkin (1997)
CMORPH 0.25° 60°SN 60°SN 60°SN Daily 1998/01-2021/12 Download Joyce et al. (2004)
GPCP v2.3 0.5° x x x Monthly 1979/01-2022/05 Download Adler et al. (2018)
GPM IMERGM v06 0.1° x x x Monthly 2000/06-2020/12 Download G. J. Huffman et al. (2019)
MSWEP v2.8 0.1° x x x Monthly 1979/02-2022/06 Download Beck et al. (2019)
PERSIANN-CDR 0.25° 60°SN 60°SN 60°SN Monthly 1983/01-2022/06 Download Ashouri et al. (2015)
TRMM 3B43 v7 0.25° 50°SN 50°SN 50°SN Monthly 1998/01-2019/12 Download George J. Huffman et al. (2010)

Reanalysis Products

Spatial Coverage
Data Set Spatial Resolution Global Land Ocean Temporal Resolution Record Length Get Data Reference
20CR v3 x x x Monthly 1836/01-2015/12 Download Slivinski et al. (2019)
ERA-20C 1.125° x x x Monthly 1900/01-2010/12 Download Poli et al. (2016)
ERA5 0.25° x x x Monthly 1959/01-2021/12 Download Hersbach et al. (2020)
JRA-55 1.25° x x x Monthly 1958/01-2021/12 Download Kobayashi et al. (2015)
MERRA-2 0.5° x 0.625° x x x Monthly 1980/01-2023/01 Download Gelaro et al. (2017)
NCEP/NCAR R1 1.875° x x x Monthly 1948/01-2022/08 Download Kalnay et al. (1996)
NCEP/DOE R2 1.875° x x x Monthly 1979/01-2022/08 Download Kanamitsu et al. (2002)

Hydrological Model Forcing

Spatial Coverage
Data Set Spatial Resolution Global Land Ocean Temporal Resolution Record Length Get Data Reference
FLDAS 0.1° x Monthly 1982/01-2021/12 Download McNally et al. (2017)
GLDAS CLSM v2.0 0.25° x Daily 1948/01-2014/12 Download Rodell et al. (2004)
GLDAS NOAH v2.0 0.25° x Monthly 1948/01-2014/12 Download Rodell et al. (2004)
GLDAS VIC v2.0 x Monthly 1948/01-2014/12 Download Rodell et al. (2004)
TerraClimate 4\(km\) x Monthly 1958/01-2021/12 Download Abatzoglou et al. (2018)

Introduction to pRecipe

In this introductory demo we will first download the GPM-IMERGM data set. We will then subset the downloaded data over South America for the 2001-2015 period, and crop it to the national scale for Bolivia. In the next step, we will generate time series for our data sets and conclude with the visualization of our data.

NOTE: While the functions in pRecipe are intended to work directly with its data inventory. pRecipe can handle most other data sets in “.nc” format, as well as any other “.nc” file generated by its functions.

Installation

install.packages('pRecipe')
library(pRecipe)

Data Download

Downloading the entire data collection or only a few data sets is quite straightforward. You just call the download_data function, which has four arguments dataset, path, domain, and timestep.

Let’s download the GPM-IMERGM data set and inspect its content with infoNC:

download_data(dataset = 'gpm-imerg')
gpm_global <- raster::brick('gpm-imerg_tp_mm_global_200006_202012_025_monthly.nc')
infoNC(gpm_global)
[1] "class      : RasterBrick "
[2] "dimensions : 720, 1440, 1036800, 256  (nrow, ncol, ncell, nlayers)"
[3] "resolution : 0.25, 0.25  (x, y)"
[4] "extent     : -180, 180, -90, 90  (xmin, xmax, ymin, ymax)"
[5] "crs        : +proj=longlat +datum=WGS84 +no_defs "
[6] "source     : gpm-imerg_tp_mm_global_200006_202012_025_monthly.nc "
[7] "names      : X2000.06.01, X2000.07.01, X2000.08.01, X2000.09.01, X2000.10.01, X2000.11.01, X2000.12.01, X2001.01.01, X2001.02.01, X2001.03.01, X2001.04.01, X2001.05.01, X2001.06.01, X2001.07.01, X2001.08.01, ... "
[8] "Date/time  : 2000-06-01, 2021-09-01 (min, max)"
[9] "varname    : tp " 

Processing

Once we have downloaded our database, we can start processing the data with:

Subset

To subset our data to a desired region and period of interest, we use the subset_data function, which has three arguments x, box, and yrs.

  • x Raster* object or a data.table or a filename (character).
  • box is the bounding box of the region of interest with the coordinates in degrees in the form (xmin, xmax, ymin, ymax).
  • yrs is the period of interest with years in the form (start_year, end_year).

Let’s subset the GPM-IMERGM data set over South America (-96, -30, -56, 24) for the 2001-2015 period, and inspect its content with infoNC:

gpm_subset <- subset_data(gpm_global, box = c(-96, -30, -56, 24), yrs = c(2001, 2015))
infoNC(gpm_subset)
[1] "class      : RasterBrick "
[2] "dimensions : 320, 264, 84480, 180  (nrow, ncol, ncell, nlayers)"
[3] "resolution : 0.25, 0.25  (x, y)"
[4] "extent     : -96, -30, -56, 24  (xmin, xmax, ymin, ymax)"
[5] "crs        : memory"
[6] "source     : r_tmp_2023-07-07_185756.586009_13478_99533.grd "
[7] "names      :  X2001.01.01,  X2001.02.01,  X2001.03.01,  X2001.04.01,  X2001.05.01,  X2001.06.01,  X2001.07.01,  X2001.08.01,  X2001.09.01,  X2001.10.01,  X2001.11.01,  X2001.12.01,  X2002.01.01,  X2002.02.01,  X2002.03.01, ... "
[8] "min values : 0.000000e+00, 0.000000e+00, 0.000000e+00, 0.000000e+00, 0.000000e+00, 0.000000e+00, 0.000000e+00, 0.000000e+00, 2.393141e-04, 0.000000e+00, 0.000000e+00, 0.000000e+00, 0.000000e+00, 0.000000e+00, 0.000000e+00, ... "
[9] "max values :    1069.6940,     917.3006,    1102.5068,     915.1335,    1549.5077,    1169.6469,    1483.0360,    1453.4453,    1624.6550,    1233.0613,    1715.0280,    1285.7706,     881.6859,     874.7393,     883.4313, ... "
[10] "time       : 2001-01-01, 2015-12-01 (min, max)"  

Crop

To further crop our data to a desired polygon other than a rectangle, we use the crop_data function, which has two arguments x, and y.

  • x Raster* object or a data.table or a *.nc filename (character).
  • y is a “.shp” filename (character).

Let’s crop our GPM-IMERG subset to cover only Bolivia with the respective shape file, and inspect its content with infoNC:

gpm_bol <- crop_data(gpm_subset, "gadm41_BOL_0.shp")
infoNC(gpm_bol)
[1] "class      : RasterBrick "
[2] "dimensions : 54, 50, 2700, 180  (nrow, ncol, ncell, nlayers)"
[3] "resolution : 0.25, 0.25  (x, y)"
[4] "extent     : -69.75, -57.25, -23, -9.5  (xmin, xmax, ymin, ymax)"
[5] "crs        : +proj=longlat +datum=WGS84 +no_defs "
[6] "source     : memory"
[7] "names      :  X2001.01.01,  X2001.02.01,  X2001.03.01,  X2001.04.01,  X2001.05.01,  X2001.06.01,  X2001.07.01,  X2001.08.01,  X2001.09.01,  X2001.10.01,  X2001.11.01,  X2001.12.01,  X2002.01.01,  X2002.02.01,  X2002.03.01, ... "
[8] "min values : 4.359420e+01, 5.965404e+01, 9.195424e+00, 2.650523e+00, 4.473422e-01, 4.649702e-03, 3.581941e-04, 1.511060e-02, 3.136731e-01, 5.168897e-01, 3.443884e-01, 1.019173e+01, 3.299495e+00, 2.491986e+01, 1.160967e+01, ... "
[9] "max values :    613.21777,    530.11438,    497.65503,    371.26581,    216.29959,    136.70122,    209.37540,    124.56583,    166.48785,    313.69836,    472.29553,    487.41364,    613.77014,    673.70099,    549.12671, ... "
[10] "time       : 2001-01-01, 2015-12-01 (min, max)" 

Generate Time series

To make a time series out of our data, we use the fldmean function, which has one argument x.

  • x Raster* object or a data.table or a *.nc filename (character).

Let’s generate the time series for our three different GPM-IMERGM data sets (Global, South America, and Bolivia), and inspect its first 12 rows:

gpm_global_ts <- fldmean(gpm_global)
head(gpm_global_ts, 12)
          date     value
        <Date>     <num>
 1: 2000-06-01  93.64844
 2: 2000-07-01  96.05852
 3: 2000-08-01  94.18216
 4: 2000-09-01  90.43190
 5: 2000-10-01  93.91238
 6: 2000-11-01  93.61439
 7: 2000-12-01  96.70333
 8: 2001-01-01  94.67989
 9: 2001-02-01  86.00950
10: 2001-03-01  96.15177
11: 2001-04-01  97.05069
12: 2001-05-01 100.53676
gpm_subset_ts <- fldmean(gpm_subset)
head(gpm_subset_ts, 12)
          date     value
        <Date>     <num>
 1: 2001-01-01 106.52438
 2: 2001-02-01  89.98158
 3: 2001-03-01 113.35350
 4: 2001-04-01 107.26019
 5: 2001-05-01 123.50707
 6: 2001-06-01  94.20347
 7: 2001-07-01 102.07352
 8: 2001-08-01  94.62878
 9: 2001-09-01  96.31932
10: 2001-10-01 112.90529
11: 2001-11-01 102.68565
12: 2001-12-01 113.49551
gpm_bol_ts <- fldmean(gpm_bol)
head(gpm_bol_ts, 12)
          date     value
        <Date>     <num>
 1: 2001-01-01 233.87604
 2: 2001-02-01 183.34294
 3: 2001-03-01 165.97789
 4: 2001-04-01  85.02165
 5: 2001-05-01  63.68961
 6: 2001-06-01  24.68989
 7: 2001-07-01  31.89638
 8: 2001-08-01  17.94735
 9: 2001-09-01  55.87102
10: 2001-10-01 103.33750
11: 2001-11-01 163.95180
12: 2001-12-01 156.72036

Visualize

Either after we have processed our data as required or right after downloaded, we have different options to visualize our data:

Let’s plot our three different GPM-IMERGM data sets (Global, South America, and Bolivia)

Maps

To see a map of any data set raw or processed, we use plot_map.

plot_map(gpm_global)

plot_map(gpm_subset)

plot_map(gpm_bol)

Time Series Visuals

Line

plot_line(gpm_global_ts)