Infrared Radiation in the Thermosphere Near the End of Solar Cycle 24.

Observations of thermospheric infrared radiative cooling by carbon dioxide (CO2) and nitric oxide (NO) from 2002 to 2018 are presented. The time span covers more than 6,000 days including most of solar cycle (SC) 23 and the entirety of SC 24 to date. Maxima of infrared cooling rate profiles (nW/m3) are smaller during SC 24 than SC 23, indicating a cooler thermosphere. Rates of global infrared power (W) from CO2 are now at levels observed during the deep solar minimum of 2009. Rates of NO power are still larger than those observed during 2009 and are being maintained at an elevated level by geomagnetic activity. During SC 24 to date, the thermosphere has radiated 70% of the energy of the mean of the past five cycles and would require an additional 1,690 days at current infrared radiation rates to reach that amount.

Space-Based Sentinels for Measurement of Infrared Cooling in the Thermosphere for Space Weather Nowcasting and Forecasting.

Infrared radiative cooling by nitric oxide (NO) and carbon dioxide (CO2) modulates the thermosphere's density and thermal response to geomagnetic storms. Satellite tracking and collision avoidance planning require accurate density forecasts during these events. Over the past several years, failed density forecasts have been tied to the onset of rapid and significant cooling due to production of NO and its associated radiative cooling via emission of infrared radiation at 5.3 µm. These results have been diagnosed, after the fact, through analyses of measurements of infrared cooling made by the Sounding of the Atmosphere using Broadband Emission Radiometry instrument now in orbit over 16 years on the National Aeronautics and Space Administration Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics satellite. Radiative cooling rates for NO and CO2 have been further shown to be directly correlated with composition and exospheric temperature changes during geomagnetic storms. These results strongly suggest that a network of smallsats observing the infrared radiative cooling of the thermosphere could serve as space weather sentinels. These sentinels would observe and provide radiative cooling rate data in real time to generate nowcasts of density and aerodynamic drag on space vehicles. Currently, radiative cooling is not directly considered in operational space weather forecast models. In addition, recent research has shown that different geomagnetic storm types generate substantially different infrared radiative response, and hence, substantially different thermospheric density response. The ability to identify these storms, and to measure and predict the Earth's response to them, should enable substantial improvement in thermospheric density forecasts.

The global infrared energy budget of the thermosphere from 1947 to 2016 and implications for solar variability.

We present an empirical model of the global infrared energy budget of the thermosphere over the past 70 years. The F 10.7, Ap, and Dst indices are used in linear regression fits to the 14.5 year time series of radiative cooling by carbon dioxide and nitric oxide measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the TIMED satellite. Databases of these indices are used to develop the radiative cooling time series from 1947. No consistent relation between the occurrence of peak sunspot number and peak infrared cooling is found over the past six solar cycles. The total infrared energy radiated by the thermosphere, integrated over a solar cycle, is nearly constant over five complete solar cycles studied. This is a direct consequence of the geoeffective solar energy also being nearly constant over the same intervals. These results provide a new metric for assessing the terrestrial context of the long-term record of solar-related indices.

The spectroscopic foundation of radiative forcing of climate by carbon dioxide.

The radiative forcing (RF) of carbon dioxide (CO2) is the leading contribution to climate change from anthropogenic activities. Calculating CO2 RF requires detailed knowledge of spectral line parameters for thousands of infrared absorption lines. A reliable spectroscopic characterization of CO2 forcing is critical to scientific and policy assessments of present climate and climate change. Our results show that CO2 RF in a variety of atmospheres is remarkably insensitive to known uncertainties in the three main CO2 spectroscopic parameters: the line shapes, line strengths, and half widths. We specifically examine uncertainty in RF due to line mixing as this process is critical in determining line shapes in the far wings of CO2 absorption lines. RF computed with a Voigt line shape is also examined. Overall, the spectroscopic uncertainty in present-day CO2 RF is less than 1%, indicating a robust foundation in our understanding of how rising CO2 warms the climate system.

A combined solar and geomagnetic index for thermospheric climate.

Infrared radiation from nitric oxide (NO) at 5.3 µm is a primary mechanism by which the thermosphere cools to space. The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the NASA Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite has been measuring thermospheric cooling by NO for over 13 years. In this letter we show that the SABER time series of globally integrated infrared power (watts) radiated by NO can be replicated accurately by a multiple linear regression fit using the F10.7, Ap, and Dst indices. This allows reconstruction of the NO power time series back nearly 70 years with extant databases of these indices. The relative roles of solar ultraviolet and geomagnetic processes in determining the NO cooling are derived and shown to vary significantly over the solar cycle. The NO power is a fundamental integral constraint on the thermospheric climate, and the time series presented here can be used to test upper atmosphere models over seven different solar cycles. KEY POINTS: F10.7, Ap, and Dst replicate time series of radiative cooling by nitric oxide Quantified relative roles of solar irradiance, geomagnetism in radiative cooling Establish a new index and extend record of thermospheric cooling back 70 years.

Influence of solar variability on the infrared radiative cooling of the thermosphere from 2002 to 2014.

Infrared radiative cooling of the thermosphere by carbon dioxide (CO2, 15 µm) and by nitric oxide (NO, 5.3 µm) has been observed for 12 years by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite. For the first time we present a record of the two most important thermospheric infrared cooling agents over a complete solar cycle. SABER has documented dramatic variability in the radiative cooling on time scales ranging from days to the 11 year solar cycle. Deep minima in global mean vertical profiles of radiative cooling are observed in 2008-2009. Current solar maximum conditions, evidenced in the rates of radiative cooling, are substantially weaker than prior maximum conditions in 2002-2003. The observed changes in thermospheric cooling correlate well with changes in solar ultraviolet irradiance and geomagnetic activity during the prior maximum conditions. NO and CO2 combine to emit 7 × 1018 more Joules annually at solar maximum than at solar minimum. KEY POINTS: First record of thermospheric IR cooling rates over a complete solar cycleIR cooling in current solar maximum conditions much weaker than prior maximumVariability in thermospheric IR cooling observed on scale of days to 11 years.

Cooling and Contraction of the Mesosphere and Lower Thermosphere From 2002 to 2021.

We examine the thermal structure of the mesosphere and lower thermosphere (MLT) using observations from 2002 through 2021 from the SABER instrument on the NASA TIMED satellite. These observations show that the MLT has significantly cooled and contracted between the years 2002 and 2019 (the year of the most recent solar minimum) due to a combination of a decline in the intensity of the 11-year solar cycle and increasing carbon dioxide (CO2.) During this time the thickness of atmosphere between the 1  and 10-4 hPa pressure surfaces (approximately 48 and 105 km) has contracted by 1,333 m, of which 342 m is attributed to increasing CO2. All other pressure surfaces in the MLT have similarly contracted. We further postulate that the MLT in the two most recent solar minima (2008-2009 and 2019-2020) was very likely the coldest and thinnest since the beginning of the Industrial Age. The sensitivity of the MLT to a doubling of CO2 is shown to be -7.5 K based on observed trends in temperature and growth rates of CO2. Colder temperatures observed at 10-4 hPa in 2019 than in the prior solar minimum in 2009 may be due to a decrease of 5% in solar irradiance in the Schumann-Runge band spectral region (175-200 nm).

Near-vision acuity levels and performance on neuropsychological assessments used in occupational therapy.

We investigated how induced blur affects performance on the Trail Making Test and Digit Symbol Test routinely used in occupational therapy cognitive evaluations. The study used a factorial design with both age (young and old adults) and simulated blur levels of near visual acuity (20/50 and 20/100) manipulated between participants. A sample of 124 healthy, community-living adults was used in the final analysis. Significant differences (p<.05) were found in performance for young participants between 20/50 and 20/100 blur level as well as between 20/20 and 20/100 blur level for the Digit Symbol Test. Scores for old participants decreased as a function of blur but were not significant. This study illustrates that cognitive evaluations used throughout the lifespan may require the appropriate visual acuity level to maximize performance. Occupational therapists' understanding of client factors and their effect on performance is fundamental to the client evaluation process.

Drivers with dementia and outcomes of becoming lost while driving.

Researchers of driving and dementia have reported that drivers with early Alzheimer's disease (AD) may continue to drive for extended periods of time, as long as their driving is evaluated or monitored. The earliest symptoms of AD are known to include loss of recent memory and the inability to recognize familiar environments. In an exploratory study, we examined 207 reports of lost drivers with dementia over 10 yr reported by newspapers and media. Seventy AD drivers were not found, 32 drivers were found dead, and 116 drivers were found alive, although of those found alive, 35 people were found injured. Miles driven and days missing were also reported in some cases, in addition to cause of death (such as drowning or exposure to weather). Becoming lost may have serious consequences. Additional research is needed in this area to more clearly understand the consequences of becoming lost while driving.

A study of the usefulness of the HESI Exit Exam in predicting NCLEX-RN failure.

Schools of nursing across the country are implementing progression policies that prohibit students from graduating or from taking the nursing licensure examination, sometimes based solely on a single predictive test score. In addition, little empirical evidence exists that supports progression policies as effective in increasing a school's NCLEX-RN pass rates. This article reports on a study conducted when one school did not achieve the results they expected after implementing a progression policy. With use of logistic regression, diagnostic indexes, and other methods, reasons for the disparity between expected and observed NCLEX-RN pass rates were examined. Results revealed that the Health Education Systems, Inc. (HESI) Exit Exam was not able to accurately predict NCLEX-RN outcomes for graduates and, further, that progression policies that allow retest after retest so as to achieve a minimum score on the HESI Exit Exam are not supported empirically. Conclusions and suggestions for schools using or considering progression policies are provided.

Evidence-based and occupational perspective of effective interventions for older clients that remediate or support improved driving performance.

To assess the effectiveness of person-related interventions on driving ability in older adults, this literature review was completed as a part of the Evidence-Based Literature Review Project of the American Occupational Therapy Association. Nineteen articles were incorporated into the systematic review and include interventions in the following areas: visual, cognitive, and motor; educational; passengers; and medical. The results provide inconclusive evidence for the use of interventions such as the Useful Field of View training, home exercise programs, and passenger interactions. Conclusive evidence shows that older adults respond positively to programs stressing self-awareness of driving skills and that some medical interventions affect the ability to drive. Despite limitations, the studies reviewed provide useful information that deserves further exploration. Reading the literature provides therapists with knowledge that might improve client care. Learning about cutting-edge interventions and educating peers and students about evidence-based interventions may lead to safer community mobility for older adults.

Teaching a Person with Memory Impairment Smartphone Use for Emergencies during Outdoors Walking: Case Report.

Safety issues arise during the performance of activities as dementia advances. Occupational therapists collaborate with dementia clients and their caregivers to find solutions and strategies to prolong safe activity participation. Additionally, occupational therapists teach through demonstration showing engagement in specific activities may no longer be safe. We present the case of a 70-year-old male with mild dementia. His caregiver believes he needs to use a smartphone for safety during outdoors walking; the client's enjoyed and valued occupation. This case report illustrates smartphone use may be difficult to learn for a person with mild dementia. It highlights the need for the caregiver and person with dementia to receive education together for best understanding. New technologies for community mobility such as outdoors walking are considered.