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- Author or Editor: Lin H. Chambers x
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Abstract
New data products from the Clouds and the Earth's Radiant Energy System (CERES) instrument on the Tropical Rainfall Measuring Mission Satellite have been examined in the context of the recently proposed adaptive tropical infrared Iris hypothesis. The CERES Single Scanner Footprint data products combine radiative fluxes with cloud properties obtained from a co-orbiting imaging instrument. This enables the use of cloud property–based definitions of the various regions in the simple Iris climate model. Regardless of definition, the radiative properties are found to be different from those assigned in the original Iris hypothesis. As a result, the strength of the feedback effect is reduced by a factor of 10 or more. Contrary to the initial Iris hypothesis, most of the definitions tested in this paper result in a small positive feedback. Thus, the existence of an effective infrared iris to counter greenhouse warming is not supported by the CERES data.
Abstract
New data products from the Clouds and the Earth's Radiant Energy System (CERES) instrument on the Tropical Rainfall Measuring Mission Satellite have been examined in the context of the recently proposed adaptive tropical infrared Iris hypothesis. The CERES Single Scanner Footprint data products combine radiative fluxes with cloud properties obtained from a co-orbiting imaging instrument. This enables the use of cloud property–based definitions of the various regions in the simple Iris climate model. Regardless of definition, the radiative properties are found to be different from those assigned in the original Iris hypothesis. As a result, the strength of the feedback effect is reduced by a factor of 10 or more. Contrary to the initial Iris hypothesis, most of the definitions tested in this paper result in a small positive feedback. Thus, the existence of an effective infrared iris to counter greenhouse warming is not supported by the CERES data.
Abstract
Using the Tropical Rainfall Measuring Mission (TRMM) satellite measurements over tropical oceans, this study evaluates the iris hypothesis recently proposed by Lindzen et al. that tropical upper-tropospheric anvils act as a strong negative feedback in the global climate system. The modeled radiative fluxes of Lindzen et al. are replaced by the Clouds and the Earth's Radiant Energy System (CERES) directly observed broadband radiation fields. The observations show that the clouds have much higher albedos and moderately larger longwave fluxes than those assumed by Lindzen et al. As a result, decreases in these clouds would cause a significant but weak positive feedback to the climate system, instead of providing a strong negative feedback.
Abstract
Using the Tropical Rainfall Measuring Mission (TRMM) satellite measurements over tropical oceans, this study evaluates the iris hypothesis recently proposed by Lindzen et al. that tropical upper-tropospheric anvils act as a strong negative feedback in the global climate system. The modeled radiative fluxes of Lindzen et al. are replaced by the Clouds and the Earth's Radiant Energy System (CERES) directly observed broadband radiation fields. The observations show that the clouds have much higher albedos and moderately larger longwave fluxes than those assumed by Lindzen et al. As a result, decreases in these clouds would cause a significant but weak positive feedback to the climate system, instead of providing a strong negative feedback.
Abstract
In January 1997, the Students’ Cloud Observations Online (S’COOL; http://scool.larc.nasa.gov) project began with NASA scientists visiting rural Gloucester, Virginia, to observe clouds with middle school students. In the nearly 20 years since, this educational outreach component of NASA’s Clouds and the Earth’s Radiant Energy System (CERES) mission has collected ∼144,500 observations from every continent and ocean basin around the world. Thousands of students, educators, and cloud-watching enthusiasts have participated in S’COOL.
More than half of S’COOL observation reports correspond to one or more CERES overpasses. A thorough analysis of collocated S’COOL and satellite data were conducted during summer 2015. Results showed that the S’COOL community reports high-quality observations providing useful insights on the strengths and shortcomings of passive cloud remote sensing from space. This reconfirms the utility of S’COOL observations to the scientific community and enables deeper insight into challenges associated with validation of space-based cloud property retrievals.
To maintain long-term participation, S’COOL has added components that involve participants directly with science data analysis, strengthening ties to CERES research and deepening engagement. Whenever possible, the S’COOL team sends corresponding subsets of CERES data for the participant to compare to their report. Observations can now be matched to images and cloud retrievals from multiple satellites and instruments. Recent connections to geostationary data make cloud observations at almost any time of day over nonpolar regions useful for validation. This attention to inviting participants into an authentic science experience is key to the long-term success of the project.
Abstract
In January 1997, the Students’ Cloud Observations Online (S’COOL; http://scool.larc.nasa.gov) project began with NASA scientists visiting rural Gloucester, Virginia, to observe clouds with middle school students. In the nearly 20 years since, this educational outreach component of NASA’s Clouds and the Earth’s Radiant Energy System (CERES) mission has collected ∼144,500 observations from every continent and ocean basin around the world. Thousands of students, educators, and cloud-watching enthusiasts have participated in S’COOL.
More than half of S’COOL observation reports correspond to one or more CERES overpasses. A thorough analysis of collocated S’COOL and satellite data were conducted during summer 2015. Results showed that the S’COOL community reports high-quality observations providing useful insights on the strengths and shortcomings of passive cloud remote sensing from space. This reconfirms the utility of S’COOL observations to the scientific community and enables deeper insight into challenges associated with validation of space-based cloud property retrievals.
To maintain long-term participation, S’COOL has added components that involve participants directly with science data analysis, strengthening ties to CERES research and deepening engagement. Whenever possible, the S’COOL team sends corresponding subsets of CERES data for the participant to compare to their report. Observations can now be matched to images and cloud retrievals from multiple satellites and instruments. Recent connections to geostationary data make cloud observations at almost any time of day over nonpolar regions useful for validation. This attention to inviting participants into an authentic science experience is key to the long-term success of the project.
In recent years, an education plan has been a required part of most proposals for new scientific research funding from NASA. Likewise, the National Science Foundation considers “integration of research and education” as one of its principal strategies. As a result, many scientists are seeking effective ways to incorporate education into their work. This article shares important lessons learned by one group of scientists embarking on outreach efforts. Experience with the Students' Cloud Observations On-line (S'COOL) Project, the educational outreach portion of the Clouds and the Earth's Radiant Energy System (CERES) investigation, yields lessons that may help other scientists to develop useful outreach efforts.
CERES scientists developed S'COOL over a 15-month period, with direct involvement and feedback from teachers. S'COOL has continued to evolve, thanks to ongoing feedback from participants. As a result, the project has been quite successful, currently involving over 1400 registered participants in 61 countries around the world. Student reports of cloud conditions help scientists verify their cloud property retrieval algorithms and allow students to obtain and analyze real scientific data. A number of educational materials, including an extensive multilingual Web site, have been developed to help teachers and students understand the research questions and the challenges of working with global remote-sensing datasets.
In recent years, an education plan has been a required part of most proposals for new scientific research funding from NASA. Likewise, the National Science Foundation considers “integration of research and education” as one of its principal strategies. As a result, many scientists are seeking effective ways to incorporate education into their work. This article shares important lessons learned by one group of scientists embarking on outreach efforts. Experience with the Students' Cloud Observations On-line (S'COOL) Project, the educational outreach portion of the Clouds and the Earth's Radiant Energy System (CERES) investigation, yields lessons that may help other scientists to develop useful outreach efforts.
CERES scientists developed S'COOL over a 15-month period, with direct involvement and feedback from teachers. S'COOL has continued to evolve, thanks to ongoing feedback from participants. As a result, the project has been quite successful, currently involving over 1400 registered participants in 61 countries around the world. Student reports of cloud conditions help scientists verify their cloud property retrieval algorithms and allow students to obtain and analyze real scientific data. A number of educational materials, including an extensive multilingual Web site, have been developed to help teachers and students understand the research questions and the challenges of working with global remote-sensing datasets.
Abstract
Citizen science is often recognized for its potential to directly engage the public in science, and is uniquely positioned to support and extend participants’ learning in science. In March 2018, the Global Learning and Observations to Benefit the Environment (GLOBE) Program, NASA’s largest and longest-lasting citizen science program about Earth, organized a month-long event that asked people around the world to contribute daily cloud observations and photographs of the sky (15 March–15 April 2018). What was considered a simple engagement activity turned into an unprecedented worldwide event that garnered major public interest and media recognition, collecting over 55,000 observations from 99 different countries, in more than 15,000 locations, on every continent including Antarctica. The event was called the “Spring Cloud Challenge” and was created to 1) engage the general public in the scientific process and promote the use of the GLOBE Observer app, 2) collect ground-based visual observations of varying cloud types during boreal spring, and 3) increase the number and locations of ground-based visual cloud observations collocated with cloud-observing satellites. The event resulted in roughly 3 times more observations than during the historic and highly publicized 2017 North American total solar eclipse. The dataset also includes observations over the Drake Passage in Antarctica and reports from intense Saharan dust events. This article describes how the challenge was crafted, outreach to volunteer scientists around the world, details of the data collected, and impact of the data.
Abstract
Citizen science is often recognized for its potential to directly engage the public in science, and is uniquely positioned to support and extend participants’ learning in science. In March 2018, the Global Learning and Observations to Benefit the Environment (GLOBE) Program, NASA’s largest and longest-lasting citizen science program about Earth, organized a month-long event that asked people around the world to contribute daily cloud observations and photographs of the sky (15 March–15 April 2018). What was considered a simple engagement activity turned into an unprecedented worldwide event that garnered major public interest and media recognition, collecting over 55,000 observations from 99 different countries, in more than 15,000 locations, on every continent including Antarctica. The event was called the “Spring Cloud Challenge” and was created to 1) engage the general public in the scientific process and promote the use of the GLOBE Observer app, 2) collect ground-based visual observations of varying cloud types during boreal spring, and 3) increase the number and locations of ground-based visual cloud observations collocated with cloud-observing satellites. The event resulted in roughly 3 times more observations than during the historic and highly publicized 2017 North American total solar eclipse. The dataset also includes observations over the Drake Passage in Antarctica and reports from intense Saharan dust events. This article describes how the challenge was crafted, outreach to volunteer scientists around the world, details of the data collected, and impact of the data.
Abstract
New objectively balanced observation-based reconstructions of global and continental energy budgets and their seasonal variability are presented that span the golden decade of Earth-observing satellites at the start of the twenty-first century. In the absence of balance constraints, various combinations of modern flux datasets reveal that current estimates of net radiation into Earth’s surface exceed corresponding turbulent heat fluxes by 13–24 W m−2. The largest imbalances occur over oceanic regions where the component algorithms operate independent of closure constraints. Recent uncertainty assessments suggest that these imbalances fall within anticipated error bounds for each dataset, but the systematic nature of required adjustments across different regions confirm the existence of biases in the component fluxes. To reintroduce energy and water cycle closure information lost in the development of independent flux datasets, a variational method is introduced that explicitly accounts for the relative accuracies in all component fluxes. Applying the technique to a 10-yr record of satellite observations yields new energy budget estimates that simultaneously satisfy all energy and water cycle balance constraints. Globally, 180 W m−2 of atmospheric longwave cooling is balanced by 74 W m−2 of shortwave absorption and 106 W m−2 of latent and sensible heat release. At the surface, 106 W m−2 of downwelling radiation is balanced by turbulent heat transfer to within a residual heat flux into the oceans of 0.45 W m−2, consistent with recent observations of changes in ocean heat content. Annual mean energy budgets and their seasonal cycles for each of seven continents and nine ocean basins are also presented.
Abstract
New objectively balanced observation-based reconstructions of global and continental energy budgets and their seasonal variability are presented that span the golden decade of Earth-observing satellites at the start of the twenty-first century. In the absence of balance constraints, various combinations of modern flux datasets reveal that current estimates of net radiation into Earth’s surface exceed corresponding turbulent heat fluxes by 13–24 W m−2. The largest imbalances occur over oceanic regions where the component algorithms operate independent of closure constraints. Recent uncertainty assessments suggest that these imbalances fall within anticipated error bounds for each dataset, but the systematic nature of required adjustments across different regions confirm the existence of biases in the component fluxes. To reintroduce energy and water cycle closure information lost in the development of independent flux datasets, a variational method is introduced that explicitly accounts for the relative accuracies in all component fluxes. Applying the technique to a 10-yr record of satellite observations yields new energy budget estimates that simultaneously satisfy all energy and water cycle balance constraints. Globally, 180 W m−2 of atmospheric longwave cooling is balanced by 74 W m−2 of shortwave absorption and 106 W m−2 of latent and sensible heat release. At the surface, 106 W m−2 of downwelling radiation is balanced by turbulent heat transfer to within a residual heat flux into the oceans of 0.45 W m−2, consistent with recent observations of changes in ocean heat content. Annual mean energy budgets and their seasonal cycles for each of seven continents and nine ocean basins are also presented.
