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Abstract
How Great Plains climate will respond under global warming continues to be a key unresolved question. There has been, for instance, considerable speculation that the Great Plains is embarking upon a period of increasing drought frequency and intensity that will lead to a semipermanent Dust Bowl in the coming decades. This view draws on a single line of inference of how climate change may affect surface water balance based on sensitivity of the Palmer drought severity index (PDSI). A different view foresees a more modest climate change impact on Great Plains surface moisture balances. This draws on direct lines of analysis using land surface models to predict runoff and soil moisture, the results of which do not reveal an ominous fate for the Great Plains. The authors’ study presents a parallel diagnosis of projected changes in drought as inferred from PDSI and soil moisture indicators in order to understand causes for such a disparity and to shed light on the uncertainties. PDSI is shown to be an excellent proxy indicator for Great Plains soil moisture in the twentieth century; however, its suitability breaks down in the twenty-first century, with the PDSI severely overstating surface water imbalances and implied agricultural stresses. Several lines of evidence and physical considerations indicate that simplifying assumptions regarding temperature effects on water balances, especially concerning evapotranspiration in Palmer’s formulation, compromise its suitability as drought indicator in a warming climate. The authors conclude that projections of acute and chronic PDSI decline in the twenty-first century are likely an exaggerated indicator for future Great Plains drought severity.
Abstract
How Great Plains climate will respond under global warming continues to be a key unresolved question. There has been, for instance, considerable speculation that the Great Plains is embarking upon a period of increasing drought frequency and intensity that will lead to a semipermanent Dust Bowl in the coming decades. This view draws on a single line of inference of how climate change may affect surface water balance based on sensitivity of the Palmer drought severity index (PDSI). A different view foresees a more modest climate change impact on Great Plains surface moisture balances. This draws on direct lines of analysis using land surface models to predict runoff and soil moisture, the results of which do not reveal an ominous fate for the Great Plains. The authors’ study presents a parallel diagnosis of projected changes in drought as inferred from PDSI and soil moisture indicators in order to understand causes for such a disparity and to shed light on the uncertainties. PDSI is shown to be an excellent proxy indicator for Great Plains soil moisture in the twentieth century; however, its suitability breaks down in the twenty-first century, with the PDSI severely overstating surface water imbalances and implied agricultural stresses. Several lines of evidence and physical considerations indicate that simplifying assumptions regarding temperature effects on water balances, especially concerning evapotranspiration in Palmer’s formulation, compromise its suitability as drought indicator in a warming climate. The authors conclude that projections of acute and chronic PDSI decline in the twenty-first century are likely an exaggerated indicator for future Great Plains drought severity.
The Intergovernmental Panel on Climate Change concluded that there is “discernible evidence” that humans—through accelerating changes in multiple forcing factors—have begun to alter the earth's climate regime. Such conclusions are based primarily upon so-called “fingerprint” studies, namely the warming pattern in the midtroposphere in the Southern Hemisphere, the disproportionate rise in nighttime and winter temperatures, and the statistical increase in extreme weather events in many nations. All three aspects of climate change and climate variability have biological implications.
Detection of climate change has also drawn upon data from glacial records that indicate a general retreat of tropical summit glaciers. Here the authors examine biological (plant and insect) data, glacial findings, and temperature records taken at high-elevation, mountainous regions. It is concluded that, at high elevations, the overall trends regarding glaciers, plants, insect range, and shifting isotherms show remarkable internal consistency, and that there is consistency between model projections and the ongoing changes. There are implications for public health as well as for developing an interdisciplinary approach to the detection of climate change.
The Intergovernmental Panel on Climate Change concluded that there is “discernible evidence” that humans—through accelerating changes in multiple forcing factors—have begun to alter the earth's climate regime. Such conclusions are based primarily upon so-called “fingerprint” studies, namely the warming pattern in the midtroposphere in the Southern Hemisphere, the disproportionate rise in nighttime and winter temperatures, and the statistical increase in extreme weather events in many nations. All three aspects of climate change and climate variability have biological implications.
Detection of climate change has also drawn upon data from glacial records that indicate a general retreat of tropical summit glaciers. Here the authors examine biological (plant and insect) data, glacial findings, and temperature records taken at high-elevation, mountainous regions. It is concluded that, at high elevations, the overall trends regarding glaciers, plants, insect range, and shifting isotherms show remarkable internal consistency, and that there is consistency between model projections and the ongoing changes. There are implications for public health as well as for developing an interdisciplinary approach to the detection of climate change.
Spanish historical archives contain a vast store of information about Spain and its former colonies in America and Asia. Some searches for climate-related information within these archives have been undertaken recently, but they have been by no means exhaustive. This paper discusses the principal archives and shows, by means of several examples, that they exhibit a high potential for inferring past climate over a wide range of timescales and geographical areas. Extraction of such information is often time consuming, and requires a combination of archival, historical, and climatological expertise, and the development of individualized methodologies to fit each situation and type of data. In spite of these difficulties, the archives can be particularly useful in many cases where there are no alternative sources of climate data. Thus, the complexities of the multidisciplinary effort required should not discourage other researchers from undertaking similar studies.
Spanish historical archives contain a vast store of information about Spain and its former colonies in America and Asia. Some searches for climate-related information within these archives have been undertaken recently, but they have been by no means exhaustive. This paper discusses the principal archives and shows, by means of several examples, that they exhibit a high potential for inferring past climate over a wide range of timescales and geographical areas. Extraction of such information is often time consuming, and requires a combination of archival, historical, and climatological expertise, and the development of individualized methodologies to fit each situation and type of data. In spite of these difficulties, the archives can be particularly useful in many cases where there are no alternative sources of climate data. Thus, the complexities of the multidisciplinary effort required should not discourage other researchers from undertaking similar studies.
Abstract
Hurricane Lane (2018) was an impactful event for the Hawaiian Islands and provided a textbook example of the compounding hazards that can be produced from a single storm. Over a 4-day period, the island of Hawaiʻi received an island-wide average of 424 mm (17 in.) of rainfall, with a 4-day single-station maximum of 1,444 mm (57 in.), making Hurricane Lane the wettest tropical cyclone ever recorded in Hawaiʻi (based on all available quantitative records). Simultaneously, fires on the islands of nearby Maui and Oʻahu burned 1,043 ha (2,577 ac) and 162 ha (400 ac), respectively. Land-use characteristics and antecedent moisture conditions exacerbated fire hazard, and both fire and rain severity were influenced by the storm environment and local topographical features. Broadscale subsidence around the storm periphery and downslope winds resulted in dry and windy conditions conducive to fire, while in a different region of the same storm, preexisting convection, incredibly moist atmospheric conditions, and upslope flow brought intense, long-duration rainfall. The simultaneous occurrence of rain-driven flooding and landslides, high-intensity winds, and multiple fires complicated emergency response. The compounding nature of the hazards produced during the Hurricane Lane event highlights the need to improve anticipation of complex feedback mechanisms among climate- and weather-related phenomena.
Abstract
Hurricane Lane (2018) was an impactful event for the Hawaiian Islands and provided a textbook example of the compounding hazards that can be produced from a single storm. Over a 4-day period, the island of Hawaiʻi received an island-wide average of 424 mm (17 in.) of rainfall, with a 4-day single-station maximum of 1,444 mm (57 in.), making Hurricane Lane the wettest tropical cyclone ever recorded in Hawaiʻi (based on all available quantitative records). Simultaneously, fires on the islands of nearby Maui and Oʻahu burned 1,043 ha (2,577 ac) and 162 ha (400 ac), respectively. Land-use characteristics and antecedent moisture conditions exacerbated fire hazard, and both fire and rain severity were influenced by the storm environment and local topographical features. Broadscale subsidence around the storm periphery and downslope winds resulted in dry and windy conditions conducive to fire, while in a different region of the same storm, preexisting convection, incredibly moist atmospheric conditions, and upslope flow brought intense, long-duration rainfall. The simultaneous occurrence of rain-driven flooding and landslides, high-intensity winds, and multiple fires complicated emergency response. The compounding nature of the hazards produced during the Hurricane Lane event highlights the need to improve anticipation of complex feedback mechanisms among climate- and weather-related phenomena.
Anthropogenically forced-warming and La Niña forced-precipitation deficits caused at least a sixfold risk increase for compound extreme low precipitation and high temperature in California–Nevada from October 2020 to September 2021.
Anthropogenically forced-warming and La Niña forced-precipitation deficits caused at least a sixfold risk increase for compound extreme low precipitation and high temperature in California–Nevada from October 2020 to September 2021.
Monsoon Region Climate Applications
Integrating Climate Science with Regional Planning and Policy
Historical accounts of the voyages of the Manila galleons derived from the Archivo General de Indias (General Archive of the Indies, Seville, Spain) are used to infer past changes in the atmospheric circulation of the tropical Pacific Ocean. It is shown that the length of the voyage between Acapulco, Mexico, and the Philippine Islands during the period 1590–1750 exhibits large secular trends, such that voyages in the middle of the seventeenth century are some 40% longer than those at the beginning or at the end of the century, and that these trends are unlikely to have been caused by societal or technological factors. Analysis of a series of “virtual voyages,” constructed from modern wind data, indicates that sailing time to the Philippines depended critically on the strength of the trade winds and the position of the western Pacific monsoon trough. These results suggest that the atmospheric circulation of the western Pacific underwent large, multidecadal fluctuations during the seventeenth century.
Historical accounts of the voyages of the Manila galleons derived from the Archivo General de Indias (General Archive of the Indies, Seville, Spain) are used to infer past changes in the atmospheric circulation of the tropical Pacific Ocean. It is shown that the length of the voyage between Acapulco, Mexico, and the Philippine Islands during the period 1590–1750 exhibits large secular trends, such that voyages in the middle of the seventeenth century are some 40% longer than those at the beginning or at the end of the century, and that these trends are unlikely to have been caused by societal or technological factors. Analysis of a series of “virtual voyages,” constructed from modern wind data, indicates that sailing time to the Philippines depended critically on the strength of the trade winds and the position of the western Pacific monsoon trough. These results suggest that the atmospheric circulation of the western Pacific underwent large, multidecadal fluctuations during the seventeenth century.
