Historical Indonesian climate data
This inventory lists the Indonesian climate sources available at KNMI and the estimated labour for digitizing each, followed by the post 1970 data held at BMKG that DiDaH set out to rescue.
Sources held at KNMI
| Period | Data | Amount | Estimated effort | Remarks |
|---|---|---|---|---|
| 1866 to 1970 | Hourly observations: air pressure, temperature, moisture and related elements, Batavia and Jakarta | About 105 years of hourly data, roughly 1 million observations at an average of 7 elements each | 1 year of work by a planner, including metadata research, plus 5 man years of typing, so 6 man years in total | More recent data needed for interpretation |
| About 1879 to 1916 | Daily precipitation sums, various stations | An average of 300 precipitation stations, over 4 million observations | 1 year of work by a planner plus 3 man years of typing, so 4 man years in total | More recent data needed for interpretation |
| About 1917 to 1965 | Monthly statistics derived from daily values: precipitation sums, number of wet and dry days, extremes and related figures | An average of 2000 stations with 3 numbers per month, about 3.5 million observations | 1 year of work by a planner plus 3 man years of typing, so 4 man years in total | More recent data needed for interpretation |
| Until 1889, mainly 1848 to 1858 | Periodical observations, various stations | Already digitized | Already digitized | |
| 1910 to 1973 | Monthly and yearly observations, various stations | 74 monthly values with 3 numbers per month across an average of 200 stations, about half a million observations | 1 year of work by a planner plus 1.5 man years of typing, so 2.5 man years in total | It is not clear what is already digitally available |
The labour estimates assume that all numbers are keyed into spreadsheets by hand. Optical character recognition may shorten the estimated time, but this had to be checked at the start of the project. The estimates are based on experience with comparable projects within the KNMI Hisklim programme.
Post 1970 data held at BMKG
The second table was a preliminary inventory of the post 1970 climate data at BMKG that would be digitized within DiDaH. A more elaborate inventory was to be produced during the project.
| Period | Data | Quantity | Approximate effort |
|---|---|---|---|
| 1970 to 2008 | Hourly observed air pressure, temperature, moisture and related elements, Batavia and Jakarta | About 35 years of hourly data, roughly 0.5 million observations at an average of 7 elements each | 5 man years |
| 1970 to 2008 | Monthly statistics derived from daily values, including precipitation sums, number of wet and dry days and extremes | An average of 2000 stations with 3 numbers per month, about 3 million observations | 10 man years |
Once digitized, these records feed directly into the data and indices service and the analyses discussed at the 2012 workshop.