b42fbac8-nca3-ghcn-daily-r201305-process

Decadal average anomalies for the number of 2-day, 5-year precipitation events (difference between the decade and the 1951-1980 average precipitation) for the Alaska region were plotted as a bar graph. Note: the far right bar contains data for 12 years (2001-2012).

First, COOP stations with less than 10% missing daily precipitation data for the period 1901-2012 were identified. For each station, the accumulated precipitation values for 2-day periods were determined and then ranked for the entire period of record. Next, the top N values were identified, where N equals the number of years of available data, divided by 5. These events were considered extreme. Then, the number of extreme events in each year was computed. Next, grid box average values were calculated for each year, by averaging the values for each station available in that grid box. The annual values were then averaged for all grid boxes containing data in Alaska. Decadal averages were then calculated. Finally, the 1951-1980 average value was subtracted from the decadal average value, and a percentage change was calculated.

The duration of this activity was 6 hours.

Output artifacts generated by this activity :

getprcpextremes_AK_May03_2013.f95
prcpextremes_2dy_5yr_1951_2012_AK_May03_2013.txt
counteventsAlaska_May03_2013.f95
timeseries_prcp_AK_19512012_2dy_5yr_May01_2013.txt
gridprcpextremes_regions_2dy_5yr_19012012_May01_2013.csv
precip_2dy5yr_decadal_barchart.pro
precip_2dy5yr_anom_decadal_values_1901-2012.txt
precip_2dy5yr_anom_min_max_values_1901-2012.txt
AK_precip_2dy5yr_anom_pct_1901_2012.eps
APP_extreme precipitation_v8.png

This activity resulted in the following :

• image b42fbac8-e257-4089-941a-5aa3774b7476 was derived from dataset Global Historical Climatology Network - Daily

Computing environment : Linux (CentOS release 6.4); Mac OS X (darwin x86_64 m64)

Software used : Fortran 95; lf95 compiler (Lahey/Fujitsu Linux64 Fortran compiler release L8.10b); IDL (version 8.0)

Visualization software used : IDL (version 8.0)

Notes : Fortran 95 was used to perform numerical calculations. IDL was used to visualize the data.