Interpretation of cirrus cloud properties using coincident satellite and lidar data during the FIRE cirrus IFO

The First ISCCP Regional Experiment (FIRE) Cirrus Intensive Field Observations (IFO) provide an opportunity to examine the relationships between the satellite observed radiances and various parameters which describe the bulk properties of clouds, such as cloud amount and cloud top height. Lidar derived cloud altitude data, radiosonde data, and satellite observed radiances are used to examine the relationships between visible reflectance, infrared emittance, and cloud top temperatures for cirrus clouds

The 27-28 October 1986 FIRE IFO cirrus case study: Cirrus parameter relationships derived from satellite and lidar data

Cirrus cloud radiative and physical characteristics are determined using a combination of ground-based, aircraft, and satellite measurements taken as part of the First ISCCP Regional Experiment (FIRE) Cirrus Intensive Field Observations (IFO) during October and November 1986. Lidar backscatter data are used to define cloud base, center, and top heights and the corresponding temperatures. Coincident GOES 4 km visible (0.65 microns) and 8 km infrared window (11.5 microns) radiances are analyzed to determine cloud emittances and reflectances. Infrared optical depth is computed from the emittance results. Visible optical depth is derived from reflectance using a theoretical ice crystal scattering model and an empirical bidirectional reflectance mode. No clouds with visible optical depths greater than 5 or infrared optical depths less than 0.1 were used in the analysis. Average cloud thickness ranged from 0.5 km to 8 km for the 71 scenes. An average visible scattering efficiency of 2.1 was found for this data set. The results reveal a significant dependence of scattering efficiency on cloud temperature

The 27-28 October 1986 FIRE IFO Cirrus Case Study: Cirrus Parameter Relationships Derived from Satellite and Lidar Data

Cirrus cloud radiative and physical characteristics are determined using a combination of ground-based, aircraft, and satellite measurements taken as part of the FIRE Cirrus Intensive Field Observations (IFO) during October and November 1986. Lidar backscatter data are used with rawinsonde data to define cloud base, center, and top heights and the corresponding temperatures. Coincident GOES 4-km visible (0.65 micro-m) and 8-km infrared window (11.5 micro-m) radiances are analyzed to determine cloud emittances and reflectances. Infrared optical depth is computed from the emittance results. Visible optical depth is derived from reflectance using a theoretical ice crystal scattering model and an empirical bidirectional reflectance model. No clouds with visible optical depths greater than 5 or infrared optical depths less than 0.1 were used in the analysis. Average cloud thickness ranged from 0.5 km to 8.0 km for the 71 scenes. Mean vertical beam emittances derived from cloud-center temperatures were 0.62 for all scenes compared to 0.33 for the case study (27-28 October) reflecting the thinner clouds observed for the latter scenes. Relationships between cloud emittance, extinction coefficients, and temperature for the case study are very similar to those derived from earlier surface- based studies. The thicker clouds seen during the other IFO days yield different results. Emittances derived using cloud-top temperature were ratioed to those determined from cloud-center temperature. A nearly linear relationship between these ratios and cloud-center temperature holds promise for determining actual cloud-top temperatures and cloud thicknesses from visible and infrared radiance pairs. The mean ratio of the visible scattering optical depth to the infrared absorption optical depth was 2.13 for these data. This scattering efficiency ratio shows a significant dependence on cloud temperature. Values of mean scattering efficiency as high as 2.6 suggest the presence of small ice particles at temperatures below 230 K. The parameterization of visible reflectance in terms of cloud optical depth and clear-sky reflectance shows promise as a simplified method for interpreting visible satellite data reflected from cirrus clouds. Large uncertainties in the optical parameters due to cloud reflectance anisotropy and shading were found by analyzing data for various solar zenith angles and for simultaneous AVHRR data. Inhomogeneities in the cloud fields result in uneven cloud shading that apparently causes the occurrence of anomalously dark, cloudy pixels in the GOES data. These shading effects complicate the interpretation of the satellite data. The results highlight the need for additional study of cirrus cloud scattering processes and remote sensing techniques

The 27-28 October 1986 FIRE IFO Cirrus Case Study: Cirrus Parameter Relationships Derived from Satellite and Lidar Data

Cirrus cloud radiative and physical characteristics are determined using a combination of ground based, aircraft, and satellite measurements taken as part of the First ISCCP Region Experiment (FIRE) cirrus intensive field observations (IFO) during October and November 1986. Lidar backscatter data are used with rawinsonde data to define cloud base, center and top heights and the corresponding temperatures. Coincident GOES-4 4-km visible (0.65 micrometer) and 8-km infrared window (11.5 micrometer) radiances are analyzed to determine cloud emittances and reflectances. Infrared optical depth is computed from the emittance results. Visible optical depth is derived from reflectance using a theoretical ice crystal scattering model and an empirical bidirectional reflectance model. No clouds with visible optical depths greater than 5 or infrared optical depths less than 0.1 were used in the analysis. Average cloud thickness ranged from 0.5 km to 8.0 km for the 71 scenes. Mean vertical beam emittances derived from cloud-center temperatures were 062 for all scenes compared to 0.33 for the case study (27-28 October) reflecting the thinner clouds observed for the latter scenes. Relationships between cloud emittance , extinction coefficients, and temperature for the case study are very similar to those derived from earlier surface-based studies. The thicker clouds seen during the other IFO days yield different results. Emittances derived using cloud-top temperature wer ratioed to those determined from cloud-center temperature. A nearly linear relationship between these ratios and cloud-center temperature holds promise for determining actual cloud-top temperature and cloud thickness from visible and infrared radiance pairs. The mean ratio of the visible scattering optical depth to the infrared absorption optical depth was 2.13 for these data. This scattering efficiency ratio shows a significant dependence on cloud temperature. Values of mean scattering efficiency as high as 2.6 suggest the presence of small ice particles at temperatures below 230 K. the parameterization of visible reflectance in terms of cloud optical depth and clear sky reflectance shows promise as a simplified method for interpreting visible satellite data reflected from cirrus clouds. Large uncertainties in the optical parameters due to cloud reflectance anisotropy and shading were found by analyzing data for various solar zenith angles and for simultaneous advanced very high resolution radiometer (AVHRR) data. Inhomogeneities in the cloud fields result in uneven cloud shading that apparently causes the occurrence of anomalously dark, cloud pixels in the GOES data. These shading effects complicate the interpretation of the satellite data. The results highlight the need for additional study or cirrus cloud scattering processes and remote sensing techniques

Summing Over Inequivalent Maps in the String Theory Interpretation of Two Dimensional QCD

Following some recent work by Gross, we consider the partition function for QCD on a two dimensional torus and study its stringiness. We present strong evidence that the free energy corresponds to a sum over branched surfaces with small handles mapped into the target space. The sum is modded out by all diffeomorphisms on the world-sheet. This leaves a sum over disconnected classes of maps. We prove that the free energy gives a consistent result for all smooth maps of the torus into the torus which cover the target space $p$ times, where $p$ is prime, and conjecture that this is true for all coverings. Each class can also contain integrations over the positions of branch points and small handles which act as ``moduli'' on the surface. We show that the free energy is consistent for any number of handles and that the first few leading terms are consistent with contributions from maps with branch points.Comment: 17 pages, 5 eps figures contained in a uuencoded file, UVA-HET-92-1

Optimizing Perioperative Decision Making: Improved Information for Clinical Workflow Planning

Perioperative care is complex and involves multiple interconnected subsystems. Delayed starts, prolonged cases and overtime are common. Surgical procedures account for 40–70% of hospital revenues and 30–40% of total costs. Most planning and scheduling in healthcare is done without modern planning tools, which have potential for improving access by assisting in operations planning support. We identified key planning scenarios of interest to perioperative leaders, in order to examine the feasibility of applying combinatorial optimization software solving some of those planning issues in the operative setting. Perioperative leaders desire a broad range of tools for planning and assessing alternate solutions. Our modeled solutions generated feasible solutions that varied as expected, based on resource and policy assumptions and found better utilization of scarce resources. Combinatorial optimization modeling can effectively evaluate alternatives to support key decisions for planning clinical workflow and improving care efficiency and satisfaction

An Exploratory Analysis of Relationships between Physical Activity, General Health and Fitness, and Job-Specific Fitness in Law Enforcement Officers

The physical fitness of law enforcement officers (LEO) generally declines over their career. Sedentary behaviors contribute to these declines, which could impact job performance. Wellness programs often encourage physical activity (PA) participation in officers with the belief that this will benefit general and job-specific fitness. Greater evidence for this assertion could support wellness program implementation. PURPOSE: To derive relationships between PA with general and job-specific fitness in LEO. METHODS: Data from 60 LEO (48 males, 12 females) from one agency were analyzed. Officers completed a questionnaire assessing PA (weekly strenuous, moderate, and mild exercise sessions; activity score), with 3 added items for resistance training (RT) (likelihood of RT; average RT sessions per week over past 3 months; number of RT sessions in past 7 days). General health and fitness tests included resting heart rate (RHR), blood pressure, waist-to-hip ratio (WHR), sit-and-reach, grip strength, 60-s push-ups, 60-s sit-ups, and YMCA step test. Job-specific fitness was measured by a 99-yard obstacle course, 165-lb body drag, 6-foot chain link fence climb, 6-foot solid wall climb, and 500-yard run. Partial correlations controlling for sex calculated relationships between PA with general and job-specific fitness (p<0.05). The sample was also split into quartiles based on PA activity score. Univariate analyses, with sex as a covariate and Bonferroni post hoc analyses, derived between-quartile fitness differences. RESULTS: Weekly strenuous PA sessions related to RHR (r=-0.36), WHR (r=-0.29), push-ups (r=0.31), and sit-ups (r=0.33). Activity score related to RHR (r=-0.27) and sit-ups (r=0.35). RT likelihood related to RHR (r=-0.40), WHR (r=-0.33), push-ups (r=0.39), and sit-ups (r=0.40); 3-month RT frequency related to RHR (r=-0.41), push-ups (r=0.43), and sit-ups (r=0.31); weekly RT frequency related to push-ups (r=0.39) and sit-ups (r=0.35). There were no significant relationships for PA and job-specific fitness. The top quartile had a lower RHR than the bottom quartile (p=0.03) and completed more sit-ups than the bottom two quartiles (p≤0.03). While there were no significant between-quartile differences in job-specific fitness, there was a tendency for higher quartiles to be faster (Figure 1). CONCLUSIONS: Officers who completed more weekly strenuous PA had a lower RHR and WHR, and better muscular endurance (push-ups/sit-ups). Greater RT frequency related to lower RHR and better muscular endurance. While there were no significant relationships or between-group differences when officers were split into PA quartiles, officers in higher quartiles tended to be faster in the job tasks. However, general PA alone may not be enough to maintain job-specific fitness. PRACTICAL APPLICATIONS: Greater PA and RT frequency may benefit RHR, WHR, and muscular endurance. Some positive impacts to job performance may occur, but LEO may require job-specific fitness training

The N=1 Supersymmetric Landau Problem and its Supersymmetric Landau Level Projections: the N=1 Supersymmetric Moyal-Voros Superplane

The N=1 supersymmetric invariant Landau problem is constructed and solved. By considering Landau level projections remaining non trivial under N=1 supersymmetry transformations, the algebraic structures of the N=1 supersymmetric covariant non(anti)commutative superplane analogue of the ordinary N=0 noncommutative Moyal-Voros plane are identified