An Assessment of Uncertainty in Atmospheric State Measurements on Airborne Platforms

Several federal agencies, including NASA, maintain a fleet of highly specialized research aircraft which are routinely used in airborne science field studies. Well characterized measurements of atmospheric state parameters, such as pressure, ambient temperature, and wind speed are paramount in the ability to perform higher level analysis towards complex research questions. Even though measurements have been made over several decades, they remain a challenge given the compressibility of air along the aircraft axis, instrument placement along the aircraft skin, and the potential for probe contamination. Therefore, a set of redundant measurements is often acquired to ensure a complete instrument time series. This uncertainty assessment takes advantage of various inter-comparison techniques devised to diagnose the temporal and spatial fidelity of atmospheric state parameters, often between different instrumentation sources and aircraft assets. To be discussed are the impacts of this ongoing study, current limitations to the airborne probes, and plans for future work

Horizontal wavenumber spectra of winds, temperature, and trace gases during the Pacific Exploratory Missions: 2. Gravity waves, quasi-two-dimensional turbulence, and vortical modes

We examine the horizontal wavenumber spectra of horizontal velocity and potential temperature collected by aircraft above the Pacific Ocean to determine whether gravity waves, quasi-two-dimensional (Q-2-D) turbulence, or vortical modes dominate atmospheric fluctuations at scale sizes of 1–100 km and altitudes of 2–12 km. We conclude from the study of Doppler-shifting effects that Q-2-D turbulence and/or vortical modes are more prevalent than gravity waves over the ocean, except in the equatorial zone. The results are consistent with recent numerical simulations of Q-2-D turbulence, which show that the characteristic inverse cascade of energy is greatly facilitated by the presence of background rotation. Furthermore, a Stokes-parameter analysis reveals the general paucity of coherent wavelike motions, although specific cases of gravity-wave propagation are observed. Finally, a case study of a long flight segment displays a k⁻³ horizontal velocity variance spectrum at scales longer than about 100 km. A Stokes-parameter analysis indicates that these large-scale fluctuations were likely due to vortical modes rather than inertio-gravity waves.United States. National Aeronautics and Space Administration (Grant NAG1-1758)United States. National Aeronautics and Space Administration (Grant NAG1-1901

Perfectionism and efficiency: Accuracy, response bias, and invested time in proof-reading performance

Investigating problem-solving performance, Ishida, H. (2005: College students’ perfectionism and task-strategy inefficience: Why their efforts go unrewarded? Japanese Journal of Social Psychology, 20, 208–215) found high levels of perfectionism were associated with lower efficiency. Aiming to replicate and further explore this finding, the present study investigated how two dimensions of perfectionism (high standards, discrepancy between expectations and performance) predicted efficiency in proof-reading performance. N = 96 students completed a proof-reading task involving the detection of spelling, grammar, and format errors. When error-detection performance was subjected to signal detection analysis, high standards correlated positively with the number of incorrectly detected errors (false alarms). Moreover, when task-completion time was taken into account, high standards were negatively correlated with efficiency (accuracy/time). In comparison, discrepancy correlated negatively with the number of correctly detected errors (hits) and positively with a conservative response bias. The findings show that perfectionistic standards are associated with reduced efficiency demonstrating the importance of considering invested time, errors, and response bias when investigating the relationship between perfectionism and performance

Characterizations of tropospheric turbulence and stability layers from aircraft observations

[1] Velocity, temperature, and specific humidity data collected by aircraft at 20-Hz resolution are analyzed for stability and turbulence parameters. Over 100 vertical profiles (mostly over the ocean) with a total of over 300 km in vertical airspace sampled are used. The compiled statistics show that anisotropy in the velocity fluctuations prevail down to the smallest spatial separations measured. A partitioning of convective versus dynamical instability indicates that in the free troposphere, the ratio of shear-produced turbulence to convectively produced turbulence increases from roughly 2:1 for weak turbulence (ϵ 10⁻⁴ m² s⁻³). For the boundary layer, this ratio is close to 1:1 for weak turbulence and roughly 2:1 for strong turbulence. There is also a correlation between the strength of the vertical shear in horizontal winds and the turbulence intensity. In the free troposphere the turbulence intensity is independent of the degree of static stability, whereas in the boundary layer the turbulence intensity increases with a fall in static stability. Vertical humidity gradients correlate with static stability for strong humidity gradients, which supports the basic notion that stable layers impede vertical mixing of trace gases and aerosols. Vertical shear correlates with vertical humidity gradient, so it appears that the effect of differential advection creating tracer gradients dominates the effect of differential advection destroying tracer gradients through shear-induced turbulence.United States. National Aeronautics and Space Administration (Grant NCC1-415)United States. National Aeronautics and Space Administration (Grant NAG1-2306

Japan Tsunami Current Flows Observed by HF Radars on Two Continents

Quantitative real-time observations of a tsunami have been limited to deep-water, pressure-sensor observations of changes in the sea surface elevation and observations of sea level fluctuations at the coast, which are essentially point measurements. Constrained by these data, models have been used for predictions and warning of the arrival of a tsunami, but to date no detailed verification of flow patterns nor area measurements have been possible. Here we present unique HF-radar area observations of the tsunami signal seen in current velocities as the wave train approaches the coast. Networks of coastal HF-radars are now routinely observing surface currents in many countries and we report clear results from five HF radar sites spanning a distance of 8,200 km on two continents following the magnitude 9.0 earthquake off Sendai, Japan, on 11 March 2011. We confirm the tsunami signal with three different methodologies and compare the currents observed with coastal sea level fluctuations at tide gauges. The distance offshore at which the tsunami can be detected, and hence the warning time provided, depends on the bathymetry: the wider the shallow continental shelf, the greater this time. Data from these and other radars around the Pacific rim can be used to further develop radar as an important tool to aid in tsunami observation and warning as well as post-processing comparisons between observation and model predictions

Standing Genetic Variation in Contingency Loci Drives the Rapid Adaptation of Campylobacter jejuni to a Novel Host

The genome of the food-borne pathogen Campylobacter jejuni contains multiple highly mutable sites, or contingency loci. It has been suggested that standing variation at these loci is a mechanism for rapid adaptation to a novel environment, but this phenomenon has not been shown experimentally. In previous work we showed that the virulence of C. jejuni NCTC11168 increased after serial passage through a C57BL/6 IL-10-/- mouse model of campylobacteriosis. Here we sought to determine the genetic basis of this adaptation during passage. Re-sequencing of the 1.64Mb genome to 200-500X coverage allowed us to define variation in 23 contingency loci to an unprecedented depth both before and after in vivo adaptation. Mutations in the mouse-adapted C. jejuni were largely restricted to the homopolymeric tracts of thirteen contingency loci. These changes cause significant alterations in open reading frames of genes in surface structure biosynthesis loci and in genes with only putative functions. Several loci with open reading frame changes also had altered transcript abundance. The increase in specific phases of contingency loci during in vivo passage of C. jejuni, coupled with the observed virulence increase and the lack of other types of genetic changes, is the first experimental evidence that these variable regions play a significant role in C. jejuni adaptation and virulence in a novel host

Horizontal wavenumber spectra of winds, temperature, and trace gases during the Pacific Exploratory Missions: 1. Climatology

Aircraft-based meteorological and chemical measurements from NASA's Pacific Exploratory Missions provide a suitable database for studying the climatology of horizontal wavenumber spectra in the troposphere overlying an ocean. The wavenumber spectra of trace gas and meteorological quantities aid in identifying the physical processes producing atmospheric structures as well as provide diagnostics for general circulation models. Flight segments were distributed over altitudes ranging from about ∼50 m to 13 km and 70°S to 60°N in latitude. The spectra were averaged according to altitude and latitude regions. The wavelength range covered was typically ∼0.5–100 km. Quantities processed in this way were horizontal velocity, potential temperature, specific humidity, and the mixing ratios of ozone, methane, carbon monoxide, and carbon dioxide. Spectral power and slope (in log-log coordinates) corresponding to the wavelength regime of 6–60 km were tabulated for those measured quantities. The spectral slopes of horizontal velocity and potential temperature were generally close to −5/3 with no transition to a steeper slope at short wavelengths as seen in some other studies. Spectral slopes of the tracer species also ranged around −5/3. This agreement in form of the dynamical and tracer spectra is consistent with both the gravity-wave advection and quasi two-dimensional turbulence models. In the upper troposphere the spectral power for all quantities except specific humidity tended to be greater at latitudes higher than 30° compared to latitudes lower than 30°. This latitudinal trend confirms the earlier results of the Global Atmospheric Sampling Program.United States. National Aeronautics and Space Administration (Grant NAG1-1758)United States. National Aeronautics and Space Administration (Grant NAG1-1901

Pennsylvania Folklife Vol. 19, No. 1

• The Moravian Settlements of Pennsylvania in 1757: The Nicholas Garrison Views • The San Rocco Festival at Aliquippa, Pennsylvania: A Transplanted Tradition • Amish Genealogy: A Progress Report • Pulpit Humor in Central Pennsylvania • The Pre-Metric Foot and its Use in Pennsylvania German Architecture • Mennonite Contacts Across the Atlantic: The Van der Smissen Letter of 1838 • Bread, Baking, and the Bakeoven: Folk-Cultural Questionnaire No. 13https://digitalcommons.ursinus.edu/pafolklifemag/1037/thumbnail.jp

Pennsylvania Folklife Vol. 26, No. 2

• Battalion Day: Militia Exercise and Frolic in Pennsylvania Before the Civil War • Folklore in the Library: Cherished Memories of Old Lancaster • Widows\u27 Wills for Philadelphia County, 1750-1784: A Study of Pennsylvania German Folklife • Forest County Lore • The Big Valley Amish of Central Pennsylvania: A Community of Cultural Contrasts • Maurice A. Mook (1904-1973): An Appreciation • Collectanea: Ore-Mining and Basket-Making in Maxatawny ; The Sharadin Tannery at Kutztown ; Occult Lore Recorded in Cumberland County • German Immigrants in America as Presented in Travel Accounts • The Pie and Related Forms in Pennsylvania Cuisine: Folk-Cultural Questionnaire No. 46https://digitalcommons.ursinus.edu/pafolklifemag/1071/thumbnail.jp