[Question]: How to download met data for use in back trajectories

[Anuragsahucuraj]

library(openair)

setwd('C:/Users/Anurag Sahu/Downloads/NP') 

getMet <- function(year = 2018:2023, month = 1:12, path_met = 'TrajData/') 
{
  for (i in seq_along(year)) 
    {
    for (j in seq_along(month)) 
      {
      download.file(url=paste0('ftp://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP',
                               year[i],sprintf('%02d',month[j]),'.gbl'),
                    destfile=paste0(path_met,'RP',year[i],sprintf('%02d',month[j]),'.gbl'),
                    mode='wb')
    }
  }
}

getMet(year=2018,month=2:12,path_met='TrajData/')

I am trying to download the back trajectory data but its not make 23mb the .gbl file which is not completed

Error:trying URL 'http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP201802.gbl'
Error in download.file(url = paste0("http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP",  : 
  cannot open URL 'http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP201802.gbl'
In addition: Warning message:
In download.file(url = paste0("http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP",  :
  URL 'http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP201802.gbl': Timeout of 60 seconds was reached 

[jack-davison]

I can't seem to recreate your issue on my end, everything seems to install successfully.

Perhaps there was a temporary issue with NOAA, is it still failing now?

getMet <- function(year = 2018:2023, month = 1:12, path_met = 'TrajData/') 
{
  for (i in seq_along(year)) 
  {
    for (j in seq_along(month)) 
    {
      download.file(url=paste0('ftp://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP',
                               year[i],sprintf('%02d',month[j]),'.gbl'),
                    destfile=paste0(path_met,'RP',year[i],sprintf('%02d',month[j]),'.gbl'),
                    mode='wb')
    }
  }
}

getMet(year = 2018,
       month = 2:12,
       path_met = 'temp/')

fs::dir_ls("temp")
#> temp/RP201802.gbl temp/RP201803.gbl temp/RP201804.gbl temp/RP201805.gbl 
#> temp/RP201806.gbl temp/RP201807.gbl temp/RP201808.gbl temp/RP201809.gbl 
#> temp/RP201810.gbl temp/RP201811.gbl temp/RP201812.gbl

^{Created on 2023-09-18 with reprex v2.0.2}

[Anuragsahucuraj]

Yes,
I try your code also i am getting same error "Timeout of 60 seconds was reached "
In my TrajData folder some file are start downloading
but its only 28 mb
#> TrajData/RP201801.gbl
#> TrajData/RP201802.gbl
after 60 sec its showing same error
Error:trying URL 'http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP201802.gbl'
Error in download.file(url = paste0("http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP", :
cannot open URL 'http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP201802.gbl'
In addition: Warning message:
In download.file(url = paste0("http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP", :
URL 'http://arlftp.arlhq.noaa.gov/pub/archives/reanalysis/RP201802.gbl': Timeout of 60 seconds was reached

[jack-davison]

Ah - if your WiFi is poor, or if the NOAA servers are being slow, it is likely that R's in-built "timeout" time is being reached.

You can increase it as in this SO thread: https://stackoverflow.com/questions/35282928/how-do-i-set-a-timeout-for-utilsdownload-file-in-r

getOption('timeout')
# [1] 60

options(timeout=100)

[Anuragsahucuraj]

Ok i downloaded this file from another sources but not when i am trying to make the .gbl file in .Rdate using this code

Code
add.met <- function(month,Year,met,bat.file)
{

if (month==0)
{
month<- 12
Year<- as.numeric(Year) -1
}
if(month <11) month <- paste('0',month,sep='')

Add first line

write.table(paste('echo',met,' >>CONTROL'),
bat.file,col.names=FALSE,
row.names=FALSE,quote=FALSE,append=TRUE)
x <- paste('echo RP',Year,month,'.gbl >>CONTROL',sep='')
write.table(x,bat.file,col.names=FALSE,row.names=FALSE,quote=FALSE,append=TRUE)
}

procTraj <- function(lat=25.8154,lon=79.9187, year= 2021,name='IGP_CARE',
met='./TrajData/',out='./TrajProc/',hours=120,height=500,
hy.path='/hysplit/')
{

lapply(c('openair','plyr','reshape2'),require,character.only=TRUE)

setwd(paste0(hy.path,'/working/'))

Remove existing 'tdump' files//

path.files <- paste0(hy.path,'/working/')
bat.file <- paste0(hy.path,'working/test.bat') ## Name of BAT file to add to/run
files <- list.files(path=path.files,pattern='tdump')
lapply(files,function(x) file.remove(x))

start <- paste(year,'-01-01',sep='')
end <- paste(year,'-3-31 18:00',sep='')
dates <- seq(as.POSIXct(start,'GMT'),as.POSIXct(end,'GMT'),by='3 hour')

for (i in 1:length(dates))
{
year <- format(dates[i],'%y')
Year <- format(dates[i],'%Y') # Long format
month <- format(dates[i],'%m')
day <- format(dates[i],'%d')
hour <- format(dates[i],'%H')

x <- paste('echo',year,month,day,hour,'          >CONTROL')
write.table(x,bat.file,col.names=FALSE,row.names=FALSE,quote=FALSE)

x <- 'echo 1          >>CONTROL'
write.table(x,bat.file,col.names=FALSE,row.names=FALSE,quote=FALSE,append=TRUE)

x <- paste('echo',lat,lon,height, '          >>CONTROL')
write.table(x,bat.file,col.names=FALSE,row.names = FALSE,quote=FALSE,append=TRUE)

x <- paste('echo ','-',hours, '   >>CONTROL',sep='')
write.table(x,bat.file,col.names=FALSE,row.names=FALSE,quote=FALSE,append=TRUE)

x <- 'echo 0          >>CONTROL
echo 10000.0    >>CONTROL
echo 3          >>CONTROL'

write.table(x,bat.file,col.names=FALSE,row.names=FALSE,quote=FALSE,append=TRUE)


months <- as.numeric(unique(format(dates[i],'%m')))
months <- c(months,months + 1:2)
months <- months -1
months <- months[months <= 12]
if (length(months) ==2) months <- c(min(months) - 1,months)

for (i in 1:3)
  add.met(months[i],Year,met,bat.file)

x <- 'echo ./          >>CONTROL'
write.table(x,bat.file,col.names=FALSE,row.names=FALSE,quote=FALSE,append=TRUE)

x <- paste('echo tdump', year, month,day,hour, '          >>CONTROL',sep='')
write.table(x,bat.file,col.names=FALSE,row.names=FALSE,quote=FALSE,append=TRUE)

x <- '\\hysplit4\\exec\\hyts_std'
write.table(x,bat.file,col.names=FALSE,row.names=FALSE,quote=FALSE,append=TRUE)


system(paste0(hy.path,'working/test.bat'))

}
traj_NS <- read.files(hours,hy.path)

file.name <- paste(out,name,Year,'.RData',sep='')
save(traj_NS,file=file.name)
}

read.files <- function(hours = 120, hy.path)
{

files <- Sys.glob('tdump*')
output <- file('Rcombined.txt','w')

for (i in files) {
input <- readLines(i)
input <- input[-c(1:7)] # Delete header
writeLines(input,output)
}
close(output)

traj_NS <- read.table(paste0(hy.path,'working/Rcombined.txt'),header=FALSE)
traj_NS <- subset(traj_NS,select = -c(V2, V7, V8))

traj_NS <- rename(traj_NS, c(V1='receptor',V3='year',V4='month',V5='day',
V6='hour',V9='hour.inc',V10='lat',V11='lon',
V12='height',V13='pressure'))

year <- traj_NS$year[1]
if (year < 50) traj_NS$year <- traj_NS$year + 2000 else traj_NS$year <- traj_NS$year + 1900

traj_NS$date2 <- with(traj_NS, ISOdatetime(year,month,day,hour,min=0,sec=0,tz="Asia/Calcutta"))

traj_NS$date <- traj_NS$date - 3600 * traj_NS$hour.inc
traj_NS
}

for(i in 2020){
procTraj(lat=25.8154,lon=79.9187, year=i,
name='IGP_CARE',hours=120,
met='/Users/Anurag Sahu/Documents/TrajData/',
out='/Users/Anurag Sahu/Documents/TrajData/',
hy.path='/hysplit/')
}

load("~/TrajProc/IGP_CARE2021.Rdata")
view(traj_NS)

I am getting this error
Error in setwd(paste0(hy.path, "/working/")) :
cannot change working directory