We investigated the interplay between climatic anomalies and economic fluctuations in early modern Japan (1603 − 1867), focusing on the Tenpō Famine of the 1830s. Specifically, we reconstructed solar radiation from 1821 to 1850 using descriptions from 18 historical diaries. This represents a novel approach to analyzing climatic impacts on agriculture and the economy during this period. The results suggest that reduced solar radiation, indicative of poor weather conditions, was followed by a substantial increase in rice prices, which rose to three to four times the normal level (from 50-70 to around 200). This rise occurred particularly during the summer of 1836, when solar radiation in July and August was approximately 10% below normal, and cold conditions persisted for three months. Applying principal component analysis to the reconstructed solar radiation data revealed spatiotemporal patterns that elucidated the link between climatic anomalies and their impacts on market prices during the Tenpō Famine. This indicates the sensitivity of market prices and economic stability to climate fluctuations. Using monthly rather than annual data, this study offers further evidence for the connections between climate, agriculture, and economic fluctuations. Our findings provide historical perspectives that could contribute to broader considerations in climate adaptation and policymaking. Additionally, this study suggests further research directions and encourages continued exploration of the relationship among climate change, agriculture, and economic fluctuations, inspiring future research in this field.

This study explores the impact of variations in solar radiation on historical migration patterns through economic stress, such as severe famines, crop failures, and rice price fluctuations. Using individual-level panel data from annual population registers (Ninbetsu-Aratame-Cho) covering the years 1708 to 1870 CE for three agricultural villages and one commercially active town in central Fukushima, northeastern Japan, we analyzed demographic indicators-total migration, legal migration, absconding, and mortality-recorded in the registers in relation to crop failures, rice prices, and reconstructed solar radiation. Monthly solar radiation reconstructed from historical weather records indicated significant reductions during the severe famines of the 1780s and the 1830s, periods associated with increased migration and absconding. A detailed analysis of the Tenpo famine (1833-1838) demonstrated clear correlations between reduced solar radiation and subsequent sharp increases in rice prices, elevated mortality rates in subsequent years, and, with a lag of approximately two years, increased absconding. This study highlights the importance of integrating solar radiation into migration research, further advancing our understanding of the historical linkages between climate variation and human mobility.

We investigated the interplay between climatic anomalies and economic fluctuations in early modern Japan (1603 − 1867), focusing on the Tenpō Famine of the 1830s. Specifically, we reconstructed the solar radiation from 1821 to 1850 using descriptions from 18 historical diaries. This represents a novel approach to analyzing climatic impacts on agriculture and the economy during this period. The results show that lower solar radiation, indicative of poor weather conditions, was associated with higher rice prices, particularly during the summer of 1836. Applying principal component analysis to the reconstructed solar radiation data revealed spatiotemporal patterns that elucidated the link between climatic anomalies and their impacts on agricultural production and market prices during the Tenpō Famine. This demonstrates the sensitivity of market prices and economic stability to climatic fluctuations. By utilizing high-resolution data, this study reveals more detailed connections between climate, agriculture, and economic fluctuations than previously reported. Our findings provide valuable historical perspectives and significantly impact contemporary climate adaptation strategies and policymaking. Additionally, this study suggests further research directions and encourages continued exploration of the relationship among climate change, agriculture, and economic fluctuations, inspiring future research in this field.

Historically, climate change has played an important role in shaping human societies. Understanding past climate change is essential for human adaptation to future changes. Solar radiation, a key factor in Earth’s energy balance, hydrological cycle, and agricultural productivity, is crucial for understanding these changes. Our study focuses on reconstructing solar radiation from historical documents, shedding light on the historical impacts of climate variation and how past societies were influenced by and adapted to changing climate conditions. In Japan, many historical documents, including daily weather records from the 17th to 19th centuries, have been key to understanding historical climate variations. Utilizing these descriptions, we developed a method for reconstructing solar radiation. This method enabled us to analyze solar radiation patterns from 1821 to 1850, providing valuable insights into climate variations and their socio-economic impacts during this period. Our analysis, which focused on the 1830s Tempo Famine, revealed a clear relationship between climate variations and economic fluctuations. We found that the decrease in solar radiation during the summers of 1833, 1836, and 1838 corresponded with rising rice prices in Osaka, underscoring the impact on agricultural productivity and market dynamics. These findings suggest that the solar radiation pattern in the summer of 1836 dramatically influenced the severe famine, as evidenced by the unusual rise in rice prices. This study refines the understanding of the historical climate impacts on society and highlights the broader effects of climate variation on agriculture and market economies. This emphasizes the need to integrate climate information into economic analyses and could provide valuable insights for developing contemporary climate change policies and adaptation strategies.

Understanding the effects of past climate change on human societies and their adaptations is vital for both historical studies and modern resilience strategies. Our previous study examined the impacts of seasonal solar radiation variations, reconstructed from diary weather records across 18 locations in Japan, on rice prices and migration during the Tenpō famine (1833–1839). We found that severe weather, as reflected in these solar radiation estimates, led to high rice prices in Osaka. Consequently, higher temporal resolution data, compared to annual or limited-season data, can be more effective for studying the impacts of climate change on society.This study further explores how climate change affects food and economics and how stresses such as famine and grain price fluctuations impact migration, using historical weather descriptions, rice prices, and migration data. The migration data were calculated based on individual-level panel data from local population registers of four communities (current Fukushima prefecture) from 1708 to 1870. The rice price series in the local market of Aizu in the same prefecture was used to measure the annual fluctuations in local agricultural output. The monthly solar radiation was reconstructed from historical weather descriptions for three locations in the target area of Moriyama, one to the north (Yamagata), and two to the south (Nikko). A comparison of the migration data with the reconstructed monthly solar radiation indicated that after the summer solar radiation decreased significantly, the number of migrations, abscondences, and deaths increased, particularly during the Tenmei (1782-1788) and Tenpo famines.

Understanding how climate has changed in the past has contributed to the development of sustainability. Solar radiation plays a fundamental role in the global energy balance, agricultural productivity, and the hydrological cycle. Here, we applied a method for estimating solar radiation—originally developed using modern daily weather descriptions from the Japan Meteorological Agency—to historical weather records. This approach aimed to reconstruct a long-term variation in solar radiation and explore its implications for past climate and society in Japan, including famine events in the latter part of the Little Ice Age. We first reconstructed solar radiation from 1720 to 1912 using daily weather records from historical diaries in Tokyo, Japan and evaluated these reconstructions against solar radiation estimates derived from the Japan Meteorological Agency’s sunshine duration records. Finally, we combined the reconstructed solar radiation with sunshine-duration-based estimates from 1896 to 1985 and direct observations from 1961 to 2022. The three-level classification effectively captured year-round fluctuations and substantiated significant low-insolation episodes coinciding with cool summers and famines in the eighteenth and nineteenth centuries. Compared to other methods or proxy data, the proposed method effectively reconstructed solar radiation for all seasons and provided higher temporal resolution data for historical reconstruction. This study demonstrates the feasibility of translating qualitative diary descriptions into quantitative solar radiation, providing a framework for future spatiotemporal expansions and deeper investigations into the linkages between climate variation and social change.

How do societies respond to varying climates? This query not only piques academic curiosity but also holds the key to how our society can adapt to the ongoing climate change. To shed light on this, we focus on the Tenpō Famine, a pivotal event in the 1830s that was one of the most severe famines due to poor harvests caused by an abnormal climate. By investigating such a significant occurrence, we aim to provide insights into vulnerable areas in the modern era. We chose the Tenpō Famine for the case study because it falls within a period for which analytical data are readily accessible (e.g., old diaries and price records). It occurred nationwide with regional differences, which makes it valuable for gaining a broad picture of the effects of climate variation. To understand the impact of climate change on societies in the past, it is necessary to consider social and economic information from such periods. This involves reconstructing spatial patterns of climate variation at a higher temporal resolution than provided by annual data. Japan has a wealth of historical diaries from 1821 to 1850. Using these records, we developed a method to estimate solar radiation, enabling the successful reconstruction of historical solar radiation for all seasons at a higher temporal resolution than provided in annual data. Weather descriptions were categorised to estimate solar radiation, making possible analyses of climate variability and its effects at the monthly time scale. This represents a novel approach for analysing climate impacts on agriculture and the economy during this period. We then correlated the reconstructed solar radiation to rice prices, revealing a significant relationship between climatic anomalies and economic stability, particularly during the summer growing season. The results show that lower solar radiation, indicative of poor weather conditions, corresponded to higher rice prices, particularly during the summers of 1833 and 1836. The temporal resolution of economic data has also improved recently. Hence, this study contributes to understanding historical climatic impacts on society by providing an even more refined temporal resolution than was previously available. This underscores the need to integrate climate data into economic analyses to better understand the dynamics of societies facing environmental challenges. Our study is particularly relevant in the context of contemporary climate change and provides historical perspectives that can inform current policies and adaptation strategies.

The impact of climate change on human society has been a significant issue in historical studies and is also vital for future adaptation to climate change. To understand climate change before the start of meteorological observations and its devastating impact on societies in the past, the spatial patterns of climate variations must be reconstructed with a higher temporal resolution than those provided by the annual data. Japan has a large volume of records, including those related to daily weather conditions from the 17th to 19th centuries, which can help with this reconstruction. This study applied the method previously developed by Ichino et al. (2001) for estimating solar radiation from the weather records of the Japan Meteorological Agency (JMA) to those collected from historical diaries. Adjusting the classification of descriptions from historical diaries, which are recorded in various expressions, allowed for their application in the method constructed from the current JMA weather descriptions. We estimated solar radiation for 1720–1912 in Japan based on the weather descriptions recorded in historical diaries from Tokyo, pertaining to the Little Ice Age. We validated the estimation compared to solar radiation estimated from the JMA-observed sunshine duration. The reconstruction was combined with the estimation from sunshine duration and the observed solar radiation to create the solar radiation time series data for 1720–2022. The method used in this study successfully reconstructed solar radiation data in an adequate manner for all seasons with a higher temporal resolution, compared to other methods, including the use of proxy data for assessing historical climate variation. In addition, solar radiation is a fundamental factor for not only the energy balance of the Earth but also the hydrological cycle and agricultural productivity. Therefore, this extended reconstruction of time series data could contribute towards discussing climate change and its effects on historical societies. Herein, we discuss the long-term variations of the reconstructed solar radiation data since the 18th century, focusing on its particular effects on famine. Reference Ichino M, Sakamoto N, Masuda K, Mikami T (2001) The method for estimating global solar radiation based on weather records－toward the climatic reconstruction in the historical period－. Tenki 48:823–830. (in Japanese) Keywords Solar radiation, Historical weather descriptions, Historical diaries, Little Ice Age, Climate change, Japan

Japan has plenty of diaries in the 17th to 19th centuries, which include records of daily weather conditions ("fine", "cloudy", "rainy", etc.) It is well known that they have been used for reconstructing climate variation and events, although it provided qualitative data, not instrumental observations. We estimate global solar radiation from weather conditions. Global solar radiation is an important factor for the energy balance of the Earth, and is also fundamental to the hydrological cycle and agricultural productivity. Our method is effective for all seasons and which could produce reconstruction with higher temporal resolution than other proxy data, for example tree rings. Weather descriptions are classified into 3 categories and weather categories convert to solar radiation. The parameters of conversion are calculated by using JMA observations from 1995 to 1999. We reconstructed monthly mean global solar radiation from 1821 to 1850 based on the weather records described in 11 historical diary documents. We focused on the years of Tempo Famine from 1833 to 1839. In 1836, monthly solar radiation in summer in the east-west zone of Japan including Kanto, Kinki, and northern Kyushu was smaller than the provisional normal (average of 1821-1850). It was 10% or more smaller than the normal in July and August. However, it was not particularly small in Tohoku to the north of the zone and in southern Kyushu to the south of the zone. The characteristic of reconstruction in 1836 is that lower solar radiation prolonged from May to September in the central area of Japan. This suggests that climatic condition similar to Baiu was prolonged, and that it was cold in Tohoku. On the other hand, in 1833 and 1838, when famines also occurred, the reconstructed solar radiation was low in Tohoku. We also checked the effect on market economy by observing the daily price of rice, the main crop at that time. For 1836, we can observe the sharp rise of the price in July. It suggests that the market had reacted to the bad climate condition before the harvest season. After this sharp rise, four times higher than usual, rice price reached a plateau then fell in September 1837. While the rice price in 1833 and 1838 also rose up in summer, they were only two or three times higher than usual and, more importantly, they quickly bounced back. Cross check between the reconstructed solar radiation and the rice price data support thus enables us to conclude that there existed a big difference even among the years recorded as “famine years” on the historical documents.

Many historical documents in Japan include daily weather records. To reconstruct historical climates from daily weather records, Ichino et al. (2001) constructed a method for estimating global solar radiation based on daily weather conditions. Presented is an attempt to reconstruct monthly mean solar radiation during the first part of the 19th century based on weather records found in 11 historical documents, with special attention to records in the year 1836, when a famine occurred. Global solar radiation is an important factor in the energy balance of the Earth, and is also fundamental to the hydrological cycle and agricultural productivity. This implies that reconstructing global solar radiation involves investigations into climatic physics and historical human societies. The estimated monthly means of global solar radiation in 1836 are compared to average estimations for 30 years (1821-1850), including the 1830s, at 11 points in Japan where data are generally available. According to our estimation, the values of solar radiation in July and August 1836 were smaller than their provisional normal values, which is the average for 30 years (1821-1850), at all points except those in Tohoku and southern Kyushu, although these differences were not extreme. On the other hand, fluctuations during the 1830s were larger than other decades before and afterwards. Moreover, the estimations in spring (February, March, and April) and autumn (September, October, and November) were no smaller than the average estimations. These results show an anomalously low solar radiation in July and August, which might have been a key climatic condition affecting society in the famine year.

This study identifies intraseasonal oscillations in summer precipitation over northern Eurasia using multi-channel singular spectrum analysis (MSSA) and a gridded daily precipitation data set for northern Eurasia. The analysis period is JuneAugust of 1979-2002. Empirical orthogonal function analysis was first performed on 8-day low-pass-filtered precipitation anomalies at 2.5 degrees grid resolution for northern Eurasia; MSSA was then carried out on the ten leading principal components (PCs). Three quasi-periodic oscillations with timescales of 45, 15, and 9 days were identified. The spatiotemporal structures of precipitation oscillations were defined by composite analysis based on the reconstructed time series of the spatiotemporal PCs obtained from the MSSA. The composite life cycle of each mode was classified into eight phase categories. The 45-day oscillation is characterised by a slow eastward progression of a broad east/west contrastive pattern which is associated with a replacement of elongated dry and wet zones across northern Eurasia. The 15-day oscillation shows a regular eastward phase propagation of precipitation anomalies with a tripole structure across the domain. The eastward displacement of dry and wet zones occurs in association with this oscillation. Spatiotemporal behaviours of the precipitation anomalies associated with the 9-day oscillation are similar to those of the 15-day oscillation, but the spatial scale of this oscillation is somewhat smaller. To explore the connections between the oscillations of precipitation and large-scale atmospheric circulation patterns, a similar composite method was applied to 300-hPa geopotential height anomalies over the Northern Hemisphere. The circulation patterns responsible for the 45-day oscillation are characterised by a wave train extending across the northeastern Atlantic/northern Eurasian sector. The wave train, with zonal wavenumbers of 34, indicates slow eastward moving and quasi-stationary features. The circulation patterns linked to the 15-day oscillation exhibit an eastward propagating wave train extending from northeastern Europe into the North Pacific/North American sector. In spatial scale, this wave train has zonal wavenumbers of 56. The wave trains associated with the 9- and 15-day oscillations have similar behaviour patterns over northern Eurasian. However, the 9-day wave train has a comparatively smaller spatial scale with zonal wavenumbers of 67. Therefore, the intraseasonal oscillations of precipitation are connected to the well-organised wave trains that extend from the Euro-Atlantic region to northern Eurasia, suggesting that the oscillation on each intraseasonal time scale must be produced by propagation of the corresponding wave train. Copyright (C) 2011 Royal Meteorological Society

Downward shortwave flux at the surface over China was derived from sunshine duration data using parameters of Jordan sunshine recorders. The sunshine duration data were obtained as routine meteorological data and adjusted as necessary for the effects of topography, station surroundings, altitude, and atmospheric turbidity. Calculated flux was verified by in situ observations. Daily flux was calculated at more than 190 stations in China, Climatic maps (statistical period: 1971-2000) of surface solar radiation were produced and have been made public.The sunshine duration-based shortwave flux was used to check satellite observation-based datasets. Two versions of satellite-based surface radiation budget datasets (SRB 2.0 and SRB 3.0) from NASA's Langley Research Center were investigated. Compared with the SRB 2.0 dataset, the SRB 3.0 dataset showed improved shortwave flux, especially over western China and the Tibetan Plateau.