JCDP

Daily Diary Weather Records

Diaries of Local Governments during the Historical Period

A huge number of official diaries kept by local governments during the Edo period (1603-1878), which include daily weather descriptions, have been preserved in libraries, museums, etc in all over Japan. JCDP has released a part of the weather record in the diary in EXCEL files (Japanese only). If you like to use undisclosed data for academic research etc., please apply to JCDP by Contact Form.
Please quote the source (JCDP and the URL of the site) or citation when publishing academic papers and articles using these data.

“Hirosaki Clan Government Diary” (Hirosaki City Library collection)

All the original weather descriptions in the diaries were digitized by Mr.Yoshimi Fukuma (Former Head of JMA Akita Observatory), and the CD-ROM containing all the data has been published by “Hoppou Shinsha（北方新社）”.

Hirosaki Clan Government Diary Weather Records: 1661-1868 (40.61N 140.46E)

All the data files (CSV) and explanatory note file (PDF) in Japanese can be downloaded from Japanese page.

Diaries of the Nagasaki-Dejima Chief 1700-1860, 1817-1823

Extracted weather data of Nagasaki (Japan) from the Diaries of the Dejima Chief 1700-1860, 1817-1823 and from the Von Siebold Documents 1825-1828: Project description and file descriptions

A.P.M. Baede and G.P. Konnen (both retired)
Royal Netherlands Meteorological Institute KNMI

In the framework of a long-term joint co-operation between Japan and KNMI aimed at climate reconstruction of Japan in its pre-instrumental era, we now explored the availability of the mostly visual weather data in the daily Diary of the Chief of the Dutch trading post on the island Dejima near Nagasaki. A Pilot project extracted the Januaries of the years 1700-1860; the Follow-up project extracted all months during the period 1817-1823, the term of office of the Chief Jan Cock Blomhoff. Together with the subsequently extracted Von Siebold data 1825-1828 (a supplementary project), the Cock Blomhoff series provides a detailed picture of the Kyushu daily weather in the early 19th century. With this report all data are made systematically accessible and available for further analysis.

Extracted weather data of Nagasaki (Japan) from the Diaries of the Dejima Chief 1700-1860, 1817-1823 and from the Von Siebold Documents 1825-1828: Project description and file descriptions PDF

1826_TEMP_PR_Siebold_lists.xls DATA
1826_WEATHER_Siebold_lists.xls DATA
1827_TEMP_PR_Siebold_lists.xls DATA
1827_WEATHER_Siebold_lists.xls DATA
1828_TEMP_PR_Siebold_lists.xls DATA
1828_WEATHER_Siebold_lists.xls DATA
Dictionary of archaic weather terms.docx DATA
Dictionary of common weather terms.doc DATA
1700-1860_Januaries_Text.doc DATA
1700-1860_Januaries_Weather_#entries_per_month.doc DATA
1700-1860_WEATHER_Januaries.xls DATA
1817_WEATHER_Blomhoff_Diary.xls DATA
1817-1823_Blomhoff_Diary_Texts.docm DATA
1818_TEMP_Blomhoff-Siebold lists.xls DATA
1818_WEATHER_Blomhoff_Diary.xls DATA
1819_TEMP_Blomhoff-Siebold lists.xls DATA
1819_WEATHER_Blomhoff_Diary.xls DATA
1820_TEMP_Blomhoff-Siebold lists.xls DATA
1820_WEATHER_Blomhoff_Diary.xls DATA
1821_TEMP_Blomhoff-Siebold lists.xls DATA
1821_WEATHER_Blomhoff_Diary.xls DATA
1822_TEMP_Blomhoff-Siebold lists.xls DATA
1822_WEATHER_Blomhoff_Diary.xls DATA
1823_TEMP_Blomhoff-Siebold lists.xls DATA
1823_WEATHER_Blomhoff_Diary.xls DATA
1825_TEMP_Siebold_lists.xls DATA
1825_WEATHER_Siebold_lists.xls DATA

Topics

Anomaly maps in “Climate Atlas”

　　　　　　　　　　　　　　　　　　　　　　　
Junpei Hirano

In climatology, we use values called “anomalies” to understand the average state of climatic elements (atmospheric pressure, temperature, precipitation, sunshine duration, and solar radiation, etc.). The “normal” is defined as the average value of climatic factors during the past 30 years. Since the average value changes due to climate change such as global warming, the normal is updated every ten years. For example, for the 10-year period from 2011 to 2020, the 1981-2010 average was used as the “normal,” but it was updated in 2021, and for the 10-year period from 2021 to 2030, the 1991-2020 average will be used as the “new normal.

In weather forecasting, the term “warmer (colder) than normal” is sometimes used, but in this case, “normal” refers to the “normal” value of temperature. In other words, the “normal value” of temperature is the standard for evaluating the warmth (coldness), etc. of each year. The difference between the temperature of each year and the normal is called the ” anomaly”. In the case of temperature, a positive anomaly indicates a warmer than normal year, while a negative anomaly indicates a colder than normal year. A map of temperature anomalies shows the distribution of areas with warmer-than-normal temperatures (positive anomaly areas) and areas with colder-than-normal temperatures (negative anomaly areas).

Similar to temperature, precipitation can also be plotted based on the “normal” value. However, in the case of precipitation, anomalies are generally expressed as the ratio of precipitation to the normal (ratio of normal to precipitation). For example, if you draw a precipitation anomaly map for a year with an El Niño or La Niña event, you can see areas with more or less rainfall than normal. Global precipitation anomaly maps for summer (June-August) and winter (December-February) of El Niño events are available on the Climate Atlas “World” page. However, as the basis for the anomalies, we have used the 43-year average for the period 1979-2021, for which precipitation data are available, instead of the 30-year “normal. Green-colored areas indicate areas of higher-than-normal rainfall, while brown-colored areas indicate areas of lower-than-normal rainfall. It can be seen that in El Niño years, there is more rainfall in the eastern tropical Pacific and less in the western tropical Pacific.

Furthermore, by comparing the precipitation anomaly map with the SST anomaly map, we can see the relationship between SST anomalies and precipitation anomalies. For example, in the “Winter DJF SST anomaly map for El Niño years”, the eastern tropical Pacific is colored red, indicating that SSTs are higher than normal. In an El Niño year, the sea surface temperature in this region is high, which activates cumulus convection and leads to heavy rainfall.

Global precipitation anomaly maps for summer (June – August) and winter (December – February) La Niña years show the opposite pattern (heavy rainfall in the eastern tropical Pacific and less rainfall in the western tropical Pacific). In La Niña years, sea surface temperatures (SSTs) drop below normal in the eastern tropical Pacific (see SST anomaly distribution in La Niña years), which suppresses cumulus convection and results in less rainfall.

The JCDP “Climate Atlas” will include various climate anomaly maps in the future. We recommend that you use the anomaly maps in the JCDP Climate Atlas when explaining “extreme weather” and its spatial distribution in high school geography and geology courses and in university liberal arts courses.