JCDP

Meteorological records observed by Perry’s fleet during late Edo era

Hisayuki Kubota (Hokkaido University)

Meteorological observation in Japan was first started in Hakodate in 1872. The weather was also measured in Japan by using meteorological instruments before 1872, but it was conducted by individuals and the observation period was short (Zaiki et al. 2006). Therefore, we need to rely on historical diaries and documents to recover the climate during the Edo era (Yamakawa 1993).

On the other hand, the barometer was invented in the 17^th century and meteorological observations were conducted in European countries. It was the age of exploration in European countries and many ships sailed to Asian countries, but Japan was a closed country during that time. Many European ships arrived near Japan in the 19^th century with meteorological instruments on board. Historical ship logs are stored in libraries in each country and they attempted to rescue meteorological observation data recorded in ship logs (Brohan et al. 2006). Here we focus on Perry’s fleet who came to Japan in 1853 and 1854 in the late Edo era to open the country (Fig.1). Their ship logs are stored in the US National Archive. Here we introduce meteorological observation data recorded in their ship logs while sailing around Japan.

Fig.1：Matthew Perry (Wikipedia）

Figure 2 shows a ship log of USS Mississippi, one of Perry’s fleet on the 8^th of July 1853 when she arrived in Tokyo Bay. Hourly meteorological observations were conducted. USS Mississippi left the east coast of the US in 1852, sailed eastward and arrived in Japan in July 1853. After that, she spent Christmas in Hong Kong and arrived in Japan again in February 1854. She then sailed eastward and reached the east coast of the US. Meteorological observation data are digitized and recovered from the records of USS Mississippi ship logs.

Fig. 2：Ship log of USS Mississippi on 8^th July 1853 when she arrived in Tokyo Bay

Fig. 3：Ship track of USS Mississippi during 1852-1855

Figure 4 shows the ship track USS Mississippi sailed along East Asia. Fig. 5 shows pressure, wind and existence of rain during 6-8th June when she anchored off the coast of Shimoda. Pressure dropped, associated with rain during 6-7th June, and then northerly wind intensified which indicates a low-pressure passage. Lightning stroke at Edo was recorded on 7th June 1854 in Bukou chronology (Taguchi 1943). It might be related to this low-pressure passage.

Fig.4：Ship track of USS Mississippi sailed along East Asia

Fig.5：Pressure (green dots), wind (arrows), and existence of rain (blue dots) during 6-8 June 1854

It is known that ships of more than 10 countries sailed along East Asia during the 18^th to 19^th centuries. For example, more than 10,000 ship logs were found and stored in the UK library. We expect to elucidate the climate around Japan during the Edo era in the future by using meteorological observation data recorded in European and American ship logs (Kubota 2018, Kubota et al. 2018a,b).

References

Brohan, P., R. Allan, J. E. Freeman, A. M. Waple, D. Wheeler, C. Wilkinson and S. Woodruff, 2009: Marine observations of old weather, Bull. Amer. Meteor. Soc., 90, 219-230.

Kubota, H., 2018: Meteorological observation records in Hokkaido during the 18^th to 19^th century, “Saihyo”, 84, 3.

Kubota, H., R. Allan, C. Wilkinson, P. Brohan, K. Wood, M. Mollan, 2018a: Recovery of climate around Japan during the late Edo era using meteorological observation data recorded in foreign ship logs sailed to Japan, Meteorological Society of Japan Fall meeting 2018, B366.

Kubota, H., R. Allan, C. Wilkinson, P. Brohan, K. Wood, M. Mollan, 2018b: Recovery of Japan climate during late Edo era by foreign ship logs, The association of Japanese Geographers Spring meeting, 532.

Taguchi, T., 1943： Overview of historical weather events in Japan, Central Meteorological Observatory of Tokyo Japan, Chijin Shokan Co. Ltd.

Yamakawa, S., 1993: Natural disaster and climate change during little ice age, Chigaku Zasshi, 102, 183-195.

Zaiki, M., G. P. Konnen, T. Tsukahara, P. D. Jones, T. Mikami and K. Matsumoto, 2006: Recovery of nineteenth-century Tokyo/Osaka meteorological data in Japan, Int. J. Climatol. 26: 399–423.

12/08/2018

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.