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ABSTRACT
We introduce a simple method for detecting changes, both transient and persistent, in reanalysis and merged satellite products due to both natural climate variability and changes to the data sources/analyses used as input. This note demonstrates this Histogram Anomaly Time Series (HATS) method using tropical ocean daily precipitation from MERRA-2 and from GPCP One-Degree Daily (1DD) precipitation estimates. Rather than averaging over space or time, we create a time series display of histograms for each increment of data (such as a day or month). Regional masks such as land–ocean can be used to isolate particular domains. While the histograms reveal subtle structures in the time series, we can amplify the signal by computing the histogram’s anomalies from its climatological seasonal cycle. The qualitative analysis provided by this scheme can then form the basis for more quantitative analyses of specific features, both real and analysis induced. As an example, in the tropical oceans the analysis clearly identifies changes in the time series of both reanalysis and observations that may be related to changing inputs.
ABSTRACT
We introduce a simple method for detecting changes, both transient and persistent, in reanalysis and merged satellite products due to both natural climate variability and changes to the data sources/analyses used as input. This note demonstrates this Histogram Anomaly Time Series (HATS) method using tropical ocean daily precipitation from MERRA-2 and from GPCP One-Degree Daily (1DD) precipitation estimates. Rather than averaging over space or time, we create a time series display of histograms for each increment of data (such as a day or month). Regional masks such as land–ocean can be used to isolate particular domains. While the histograms reveal subtle structures in the time series, we can amplify the signal by computing the histogram’s anomalies from its climatological seasonal cycle. The qualitative analysis provided by this scheme can then form the basis for more quantitative analyses of specific features, both real and analysis induced. As an example, in the tropical oceans the analysis clearly identifies changes in the time series of both reanalysis and observations that may be related to changing inputs.
Abstract
Hurricane Harvey and other recent weather extremes stimulated extensive public discourse about the role of anthropogenic climate change in amplifying, or otherwise modifying, such events. In tandem, the scientific community has made considerable progress on statistical “climate attribution.” However, explaining these statistical methods to the public has posed challenges. Using appropriately designed “spinner boards,” we find that even members of the general public who do not understand the difference between weather and climate are readily able to understand basic concepts of attribution and explain those concepts to others. This includes both understanding and explaining the way in which the probability of an extreme weather event may increase as a result of climate change and explaining how the intensity of hurricanes can be increased. If properly developed and used by TV weather forecasters and news reporters, this method holds the potential to significantly improve public understanding of climate attribution.
Abstract
Hurricane Harvey and other recent weather extremes stimulated extensive public discourse about the role of anthropogenic climate change in amplifying, or otherwise modifying, such events. In tandem, the scientific community has made considerable progress on statistical “climate attribution.” However, explaining these statistical methods to the public has posed challenges. Using appropriately designed “spinner boards,” we find that even members of the general public who do not understand the difference between weather and climate are readily able to understand basic concepts of attribution and explain those concepts to others. This includes both understanding and explaining the way in which the probability of an extreme weather event may increase as a result of climate change and explaining how the intensity of hurricanes can be increased. If properly developed and used by TV weather forecasters and news reporters, this method holds the potential to significantly improve public understanding of climate attribution.
Abstract
Over the past 15 years, numerous studies have suggested that the sinking branches of Earth’s Hadley circulation and the associated subtropical dry zones have shifted poleward over the late twentieth century and early twenty-first century. Early estimates of this tropical widening from satellite observations and reanalyses varied from 0.25° to 3° latitude per decade, while estimates from global climate models show widening at the lower end of the observed range. In 2016, two working groups, the U.S. Climate Variability and Predictability (CLIVAR) working group on the Changing Width of the Tropical Belt and the International Space Science Institute (ISSI) Tropical Width Diagnostics Intercomparison Project, were formed to synthesize current understanding of the magnitude, causes, and impacts of the recent tropical widening evident in observations. These working groups concluded that the large rates of observed tropical widening noted by earlier studies resulted from their use of metrics that poorly capture changes in the Hadley circulation, or from the use of reanalyses that contained spurious trends. Accounting for these issues reduces the range of observed expansion rates to 0.25°–0.5° latitude decade‒1—within the range from model simulations. Models indicate that most of the recent Northern Hemisphere tropical widening is consistent with natural variability, whereas increasing greenhouse gases and decreasing stratospheric ozone likely played an important role in Southern Hemisphere widening. Whatever the cause or rate of expansion, understanding the regional impacts of tropical widening requires additional work, as different forcings can produce different regional patterns of widening.
Abstract
Over the past 15 years, numerous studies have suggested that the sinking branches of Earth’s Hadley circulation and the associated subtropical dry zones have shifted poleward over the late twentieth century and early twenty-first century. Early estimates of this tropical widening from satellite observations and reanalyses varied from 0.25° to 3° latitude per decade, while estimates from global climate models show widening at the lower end of the observed range. In 2016, two working groups, the U.S. Climate Variability and Predictability (CLIVAR) working group on the Changing Width of the Tropical Belt and the International Space Science Institute (ISSI) Tropical Width Diagnostics Intercomparison Project, were formed to synthesize current understanding of the magnitude, causes, and impacts of the recent tropical widening evident in observations. These working groups concluded that the large rates of observed tropical widening noted by earlier studies resulted from their use of metrics that poorly capture changes in the Hadley circulation, or from the use of reanalyses that contained spurious trends. Accounting for these issues reduces the range of observed expansion rates to 0.25°–0.5° latitude decade‒1—within the range from model simulations. Models indicate that most of the recent Northern Hemisphere tropical widening is consistent with natural variability, whereas increasing greenhouse gases and decreasing stratospheric ozone likely played an important role in Southern Hemisphere widening. Whatever the cause or rate of expansion, understanding the regional impacts of tropical widening requires additional work, as different forcings can produce different regional patterns of widening.
Abstract
The goal of the U.S. Climate Resilience Toolkit’s (CRT) Climate Explorer (CE) is to provide information at appropriate spatial and temporal scales to help practitioners gain insights into the risks posed by climate change. Ultimately, these insights can lead to groups of local stakeholders taking action to build their resilience to a changing climate. Using CE, decision-makers can visualize decade-by-decade changes in climate conditions in their county and the magnitude of changes projected for the end of this century under two plausible emissions pathways. They can also check how projected changes relate to user-defined thresholds that represent points at which valued assets may become stressed, damaged, or destroyed. By providing easy access to authoritative information in an elegant interface, the Climate Explorer can help communities recognize—and prepare to avoid or respond to—emerging climate hazards. Another important step in the evolution of CE builds on the purposeful alignment of the CRT with the U.S. Global Change Research Program’s (USGCRP) National Climate Assessment (NCA). By closely linking these two authoritative resources, we envision that users can easily transition from static maps and graphs within NCA reports to dynamic, interactive versions of the same data within CE and other resources within the CRT, which they can explore at higher spatial scales or customize for their own purposes. The provision of consistent climate data and information—a result of collaboration among USGCRP’s federal agencies—will assist decision-making by other governmental entities, nongovernmental organizations, businesses, and individuals.
Abstract
The goal of the U.S. Climate Resilience Toolkit’s (CRT) Climate Explorer (CE) is to provide information at appropriate spatial and temporal scales to help practitioners gain insights into the risks posed by climate change. Ultimately, these insights can lead to groups of local stakeholders taking action to build their resilience to a changing climate. Using CE, decision-makers can visualize decade-by-decade changes in climate conditions in their county and the magnitude of changes projected for the end of this century under two plausible emissions pathways. They can also check how projected changes relate to user-defined thresholds that represent points at which valued assets may become stressed, damaged, or destroyed. By providing easy access to authoritative information in an elegant interface, the Climate Explorer can help communities recognize—and prepare to avoid or respond to—emerging climate hazards. Another important step in the evolution of CE builds on the purposeful alignment of the CRT with the U.S. Global Change Research Program’s (USGCRP) National Climate Assessment (NCA). By closely linking these two authoritative resources, we envision that users can easily transition from static maps and graphs within NCA reports to dynamic, interactive versions of the same data within CE and other resources within the CRT, which they can explore at higher spatial scales or customize for their own purposes. The provision of consistent climate data and information—a result of collaboration among USGCRP’s federal agencies—will assist decision-making by other governmental entities, nongovernmental organizations, businesses, and individuals.
Abstract
A technology revolution in Earth observation sensor design is occurring. This revolution in part is associated with the emergence of CubeSat platforms that have forced a de facto standardization on the volume and power into which sensors have to fit. The extent that small sensors can indeed provide similar or replacement capabilities compared to larger and more expensive counterparts has barely been demonstrated and any loss of capability of smaller systems weighed against the gains in costs and new potential capabilities offered by implementing them with a more distributed observing strategy also has not yet been embraced. This paper provides four examples of observations made with prototype miniaturized observing systems, including from CubeSats, that offer a glimpse of this emerging sensor revolution and a hint at future observing system design.
Abstract
A technology revolution in Earth observation sensor design is occurring. This revolution in part is associated with the emergence of CubeSat platforms that have forced a de facto standardization on the volume and power into which sensors have to fit. The extent that small sensors can indeed provide similar or replacement capabilities compared to larger and more expensive counterparts has barely been demonstrated and any loss of capability of smaller systems weighed against the gains in costs and new potential capabilities offered by implementing them with a more distributed observing strategy also has not yet been embraced. This paper provides four examples of observations made with prototype miniaturized observing systems, including from CubeSats, that offer a glimpse of this emerging sensor revolution and a hint at future observing system design.
Abstract
Since 2003, the High Plains Regional Climate Center (HPRCC) has been producing the Applied Climate Information System (ACIS) Climate Summary Maps for users all across the country. The maps allow users to quickly and easily assess climate conditions for various time scales that range from weeks to months to years, as well as spatial scales varying from state to regional and national levels. Although popular among the climate and drought monitoring community, the maps are utilized by a number of sectors, including academia, agriculture, government, resource management, and utilities. Over the years, the HPRCC has received a number of requests from users looking to customize and enhance the ACIS Climate Summary Maps. With funding provided by the National Integrated Drought Information System (NIDIS), the Center is now able to produce and distribute GIS versions of the ACIS Climate Summary Maps. Maps in GIS formats help to meet user needs by allowing them the opportunity to create custom color scales, choose specific regions, and combine information from various sources with the data available in the mapped products. The GIS data are available via a GIS Portal and GeoServer, which are accessible from the HPRCC website.
Abstract
Since 2003, the High Plains Regional Climate Center (HPRCC) has been producing the Applied Climate Information System (ACIS) Climate Summary Maps for users all across the country. The maps allow users to quickly and easily assess climate conditions for various time scales that range from weeks to months to years, as well as spatial scales varying from state to regional and national levels. Although popular among the climate and drought monitoring community, the maps are utilized by a number of sectors, including academia, agriculture, government, resource management, and utilities. Over the years, the HPRCC has received a number of requests from users looking to customize and enhance the ACIS Climate Summary Maps. With funding provided by the National Integrated Drought Information System (NIDIS), the Center is now able to produce and distribute GIS versions of the ACIS Climate Summary Maps. Maps in GIS formats help to meet user needs by allowing them the opportunity to create custom color scales, choose specific regions, and combine information from various sources with the data available in the mapped products. The GIS data are available via a GIS Portal and GeoServer, which are accessible from the HPRCC website.
Abstract
Global and national climate assessments are comprehensive, authoritative sources of information about observed and projected climate changes and their impacts on society. These assessments follow well-known, accepted procedures to create credible, legitimate, salient sources of information for policy- and decision-making, build capacity for action, and educate the public. While there is a great deal of research on assessments at global and national scales, there is little research or guidance for assessment at the U.S. state scale. To address the need for guidance for state climate assessments (SCAs), the authors combined insights from the literature, firsthand experience with four SCAs, and interviews with individuals involved in 10 other SCAs to identify challenges, draw lessons, and point out future research needs to guide SCAs. SCAs are challenged by sparseness of literature and data, insufficient support for ongoing assessment, short time lines, limited funding, and surprisingly, little deliberate effort to address legitimacy as a concern. Lessons learned suggest SCAs should consider credibility, legitimacy, and salience as core criteria; happen at regular intervals; identify assessment scope, resource allocation, and trade-offs between generation of new knowledge, engagement, and communication up front; and leverage boundary organizations. Future research should build on ongoing efforts to advance assessments, examine the effectiveness of different SCA approaches, and seek to inform both broad and specific guidance for SCAs.
Abstract
Global and national climate assessments are comprehensive, authoritative sources of information about observed and projected climate changes and their impacts on society. These assessments follow well-known, accepted procedures to create credible, legitimate, salient sources of information for policy- and decision-making, build capacity for action, and educate the public. While there is a great deal of research on assessments at global and national scales, there is little research or guidance for assessment at the U.S. state scale. To address the need for guidance for state climate assessments (SCAs), the authors combined insights from the literature, firsthand experience with four SCAs, and interviews with individuals involved in 10 other SCAs to identify challenges, draw lessons, and point out future research needs to guide SCAs. SCAs are challenged by sparseness of literature and data, insufficient support for ongoing assessment, short time lines, limited funding, and surprisingly, little deliberate effort to address legitimacy as a concern. Lessons learned suggest SCAs should consider credibility, legitimacy, and salience as core criteria; happen at regular intervals; identify assessment scope, resource allocation, and trade-offs between generation of new knowledge, engagement, and communication up front; and leverage boundary organizations. Future research should build on ongoing efforts to advance assessments, examine the effectiveness of different SCA approaches, and seek to inform both broad and specific guidance for SCAs.
