Readme document for APHRO_JP_V1207 Last updated 24 July 2012 1. Introduction APHRO_JP is a gridded (0.05x0.05 degree) surface meteorological data over the land in Japan. Daily precipitation and extreme precipitation indices as its derived data are available up to now. Supplemental data of topography/basin information is also prepared in the same grid coordinate as meteorological data for users' convenience on data analysis. APHRO_JP is one of the outcomes by the research project of APHRODITE (Asian Precipitation - Highly-Resolved Observational Data Integration Towards Evaluation of Water Resources) supported by Environment Research and Technology Development Fund of the Ministry of the Environment, Japan. 2. Abstract of each data 2.1 Daily precipitation data (AphroJP_DPREC, AphroJP_DPREC.CSTN) AphroJP_DPREC is a historical daily precipitation data from year 1900, covering whole Japanese land with 0.05x0.05 degree (approx. 5x5 km) grid except some small islands. The gridded data is derived from rain-gauge data observed by Japan Meteorological Agency (JMA) and spatial interpolation method is developed by Meteorological Research Institute (MRI). Owing to the interpolation method considering of precipitation climatology and topographical effect, AphroJP_DPREC can be expected to have relatively good quality even in early 20th century in which the number of rain-gauge is not large. Two products named AphroJP_DPREC and AphroJP_DPREC.CSTN are prepared to meet various research purposes. The former is derived from all collected rain-gauge data while the other uses limited rain-gauge which has been available during the period. Therefore, the former is superior in quality, especially after 1977 when AMeDAS (Automated Meteorological Data Acquisition System) deployed. However, it is not suitable for long-term analysis because its quality is not constant. On the other hand, the latter is better suited for trend analysis and so on, although some problems such as underestimation of heavy rain exist. Details of data processing and characteristics are explained in the paper by Kamiguchi et al., 2010. 2.2 Extreme precipitation indices data AphroJP_EX is an extreme precipitation indices data, calculated from AphroJP_DPREC and AphroJP_DPREC.CSTN. Up to 54 indices of extreme precipitation is available. Details of the data is shown in the paper (Kamiguchi et al., 2011). 2.3 Supplemental data (Topography/Basin/Administrative border) AphroJP_SUPP is the supplemental file containing useful information of topography, river basin as well as administrative area, which helps statistical analysis using APHRO_JP. 3. Specification 3.1 Common specifications 3.1.1 Area and horizontal resolution The data area is rectangle (lat. 123.0E-146.0E; lon. 24.0N-46.0N) surrounding Japan with 0.05x0.05 degree grid (approx. 5x5 km) in Cartesian coordinate. The number of horizontal grid is 460/440 in lon/lat, respectively. Available value is assigned in the land grid except some small islands. 3.1.2 File structure Value in each grid is stored with 4-byte real binary of little endian order. No record length headers are embedded. FORTRAN user can read the file by "direct access". The file consists of 4-dimensions: time, variable, latitude and longitude, and the sequence goes in the following order starting from the fastest varying dimension to the slowest varying dimension: longitude, latitude, variable, and time. The order of longitude is from west to east and that of latitude is from south to north. The order of horizontal plane (123.0E, 46.0N) N (146.0E, 46.0N) ----------------------------------- |...........................|193200| ----------------------------------- |. . | |. . | W ----------------------------------- E |921|922|..........................| ----------------------------------- |461|462|......................|920| ----------------------------------- | 1 | 2 | 3 | 4 |..............|460| ----------------------------------- (123.0E, 24.0N) S (146.0E, 24.0N) The first grid (centered at 123.025E, 24.025N) is located on the left-bottom corner and the second grid is located on the east of the first one. As shown in the above figure, 460th grid is located at the east end of the line and the 461st grid moves to the north of westernmost grid. 4. Details of each file 4.1 Daily precipitation (AphroJP_DPREC, AphroJP_DPREC.CSTN) File name (in case of year 2000) AphroJP_V1207_DPREC.2000 (AphroJP_DPREC) AphroJP_V1207_DPREC.CSTN.2000 (AphroJP_DPREC.CSTN) Number of element: 1 order, element name, definition, unit 1, precip, Daily precipitation amount, mm/day Number of time steps: 365 or 366 (leap year) undefined value: -99.9 4.2 Available observation day File name (in case of year 2000) AphroJP_V1207_DPREC_ody.2000 AphroJP_V1207_DPREC.CSTN_ody.2000 Number of element: 1 order, element name, definition, unit 1, obsday, Number of days with valid observation, day (Number of days with valid observation by rain-gauge in the grid) Number of time step: 1 undefined value: -99.9 4.3 Monthly, seasonal and annual statistics File name (in case of year 2000) AphroJP_V1207_DPREC_mon.2000 AphroJP_V1207_DPREC.CSTN_mon.2000 Number of element: 17 order, element name, definition, unit 1, prJAN, Monthly precipitation amount in January, mm/day 2, prFEB, Monthly precipitation amount in Feburary, mm/day 3, prMAR, Monthly precipitation amount in March, mm/day 4, prAPR, Monthly precipitation amount in April, mm/day 5, prMAY, Monthly precipitation amount in May, mm/day 6, prJUN, Monthly precipitation amount in June, mm/day 7, prJUL, Monthly precipitation amount in July, mm/day 8, prAUG, Monthly precipitation amount in August, mm/day 9, prSEP, Monthly precipitation amount in September, mm/day 10, prOCT, Monthly precipitation amount in October, mm/day 11, prNOV, Monthly precipitation amount in November, mm/day 12, prDEC, Monthly precipitation amount in December, mm/day 13, prANN, Annual precipitation amount, mm/day 14, prDJF, Seasonal precipitation amount in DJF, mm/day 15, prMAM, Seasonal precipitation amount in MAM, mm/day 16, prJJA, Seasonal precipitation amount in JJA, mm/day 17, prSON, Seasonal precipitation amount in SON, mm/day Number of time step: 1 undefined value: -99.9 4.4 Extreme precipitation indices (AphroJP_EX) File name (in case of year 2000) AphroJP_V1207_DPREC_ext.2010 (calculated with AphroJP_DPREC) AphroJP_V1207_DPREC.CSTN_ext.2000 (calculated with AphroJP_DPREC.CSTN) Number of element: 54 order, element name, definition, unit 1, pav, Annual mean precipitation, mm/day 2, pq1, 1st percentile of rain-day amounts, mm/day 3, pq5, 5th percentile of rain-day amounts, mm/day 4, pq10, 10th percentile of rain-day amounts, mm/day 5, pq20, 20th percentile of rain-day amounts, mm/day 6, pq30, 30th percentile of rain-day amounts, mm/day 7, pq40, 40th percentile of rain-day amounts, mm/day 8, pq50, 50th percentile of rain-day amounts, mm/day 9, pq60, 60th percentile of rain-day amounts, mm/day 10, pq70, 70th percentile of rain-day amounts, mm/day 11, pq80, 80th percentile of rain-day amounts, mm/day 12, pq90, 90th percentile of rain-day amounts, mm/day 13, pq95, 95th percentile of rain-day amounts, mm/day 14, pq99, 99th percentile of rain-day amounts, mm/day 15, pmax, The annual maximum of daily precipitation, mm/day 16, pf1, Fraction of total precipitation above annual 1st percentile, 17, pf5, Fraction of total precipitation above annual 5th percentile, 18, pf10, Fraction of total precipitation above annual 10th percentile, 19, pf20, Fraction of total precipitation above annual 20th percentile, 20, pf30, Fraction of total precipitation above annual 30th percentile, 21, pf40, Fraction of total precipitation above annual 40th percentile, 22, pf50, Fraction of total precipitation above annual 50th percentile, 23, pf60, Fraction of total precipitation above annual 60th percentile, 24, pf70, Fraction of total precipitation above annual 70th percentile, 25, pf80, Fraction of total precipitation above annual 80th percentile, 26, pf90, Fraction of total precipitation above annual 90th percentile, 27, pf95, Fraction of total precipitation above annual 95th percentile, 28, r1, Number of days (>= 1mm), day 29, r10, Number of days (>= 10mm), day 30, r20, Number of days (>= 20mm), day 31, r30, Number of days (>= 30mm), day 32, r40, Number of days (>= 40mm), day 33, r50, Number of days (>= 50mm), day 34, r60, Number of days (>= 60mm), day 35, r80, Number of days (>= 80mm), day 36, r100, Number of days (>= 100mm), day 37, r120, Number of days (>= 120mm), day 38, r150, Number of days (>= 150mm), day 39, r200, Number of days (>= 200mm), day 40, r300, Number of days (>= 300mm), day 41, r400, Number of days (>= 400mm), day 42, r500, Number of days (>= 500mm), day 43, sdii, Simple daily intensity, 44, r3d, Greatest 3-day total rainfall, mm 45, r5d, Greatest 5-day total rainfall, mm 46, r10d, Greatest 10-day total rainfall, mm 47, r20d, Greatest 20-day total rainfall, mm 48, r30d, Greatest 30-day total rainfall, mm 49, cdd, Maximum number of consecutive dry-days, day 50, cwd, Maximum number of consecutive wet-days, day 51, ppdd, Mean dry-day persistence, 52, ppww, Mean wet-day persistence, 53, mdd, Mean consecutive day of dry-days, day 54, mwd, Mean consecutive day of wet-days, day Calculation of indices are followed by Stardex (http://www.cru.uea.ac.uk/projects/stardex/deis/indices.tar.gzj Number of time step: 1 undefined value: -99.9 4.5 Supplimental data, geography/basin/administrative border (AphroJP_SUPP) File name APHRO_JP_SUPP.dat Number of elements: 6 order, element name, definition, unit 1, ctycod, Administrative Code of National Land Numerical Information in Japan 2, gdbdid, ID code of unit river basin define in Global Drainage Basin Database(GDBD) 3, basnno, Assigned number to each river basin defined in GDBD 4, height, topographical height defined in GTOPO30, m 5, slpgrd, Gradient of slope (z/d), caluculated with GTOPO30 elevation 6, slpazm, Azimuth of slope (8-directions, 0:N, 1:NE,,,7:NW) Value of administrative code (ctycod) is from the National Land Numerical Information of Japan (exFTsukuba-city, Ibaraki 08220) The data is made with JPGIS-form poligon data distributed in the following site. http://nlftp.mlit.go.jp/ksj/jpgis/jpgis_tool.html GDBD_ID(unit basin ID) and BASIN_ID(Number of Basin) is made with using a data set of Global Drainage Basin Database(GDBD) (ex: GDBD_ID of Tone river: 28). Please refer to GDBD web page at The National Institute of Environment (NIES). (http://www.cger.nies.go.jp/db/gdbd/gdbd_index_j.htmlj basnno is assigned number to unit basin defined by GDBD (http://www.cger.nies.go.jp/db/gdbd/data/Readme_j_20070711.pdf) height is topographical height by GTOPO30 (m) (http://serc.carleton.edu/resources/16409.html) slpgrd is gradient of slope (z/d), calculated with GTOPO30 elevation. slpazm is azimuth of slope (8-directions, 0:N, 1:NE,,,7:NW) toward bottom to top calculated with GTOPO30 elevation. 5. Structure of FTP directory AphroJP_V1207 | |---DPREC---- (daily precipitation data) | |---ODY (number of days with valid observation in year) | |---MON (monthly, seasonal and annual precipitation) | |---EXT (extreme indices of precipitation) | |---DPREC.CSTN----(daily precipitation data) | |---ODY | . same as DPREC | . |---SUPP (supplemental data) 6. Acknowledgment We thank Dr. Kiyoshi Takahashi, National Institute for Environmental Studies who permits to assemble and redistribution of GDBD data. 7. Contact information If you have any inquiries, please contact the following by email. Kenji Kamiguchi Climate Research Department, Meteorological Research Institute email: kkamigu*mri-jma.go.jp (change * to @) APHRODITE project email: aphrodite.precinfo@gmail.com 8. References Kamiguchi, K., O. Arakawa, A. Kitoh, A. Yatagai, A. Hamada, and N. Yasutomi, 2010: Development of APHRO_JP, the first Japanese high-resolution daily precipitation product for more than 100 years, Hydrological Research Letters, 4, 60-64, doi:10.3178/HRL.4.60. Kamiguchi, K., O. Arakawa, and A. Kitoh, 2011: Long-term Changes in Japanese Extreme Precipitation Analyzed with APHRO_JP_EX, Global Environmental Research, 15(2), 91-99.