Several Vigna species were used to determine the role of pod trichomes and pod toughness in the resistance of cowpea to feeding damage by the coreid bug Clavigralla tomentosicollis Stal. The scanning electron microscopy study revealed the presence of glandular and non-glandular trichomes on the pod wall of all test genotypes. The cultivated genotypes TVu 1890, TVu 3354 and IT84S-2246 of the V. unguiculata ssp. unguiculata showed significantly lower (P<0.05) densities of glandular trichomes than accessions of the wild Vigna species (TVnu 72, TVnu 151, and TVnu 707). All pods were similar with respect to the density and length of non-glandular trichomes. The two wild accessions TVnu 151 and TVnu 707 of the V. unguiculata ssp. dekindtiana had low pod strength similar to that of the susceptible genotype IT84S-2246, and also showed high seed damage levels comparable to that of this susceptible genotype. These accessions of the subspecies dekindtiana contrasted with the wild and resistant accession TVnu 72 of the V. vexillata species which suffered minor seed damage in

Polar cap mesospheric winds observed with a Fabry-Perot interferometer with a circle-to-line interferometer optical (FPI/CLIO) system have been compared with measurements from a field-widened Michelson interferometer optimized for E-region winds (ERWIN). Both instruments observed the Meinel OH emission emanating from the mesopause region (approximately 86 km) at Resolute Bay, Canada (74.9 degrees N, 94.9 degrees W). This is the first time, to our knowledge, that winds measured simultaneously from a ground-based Fabry-Perot interferometer and a ground-based Michelson interferometer have been compared at the same location. The FPI/CLIO and ERWIN instruments both have a capability for high temporal resolution (less than 10 min for a full scan in the four cardinal directions and the zenith). Statistical comparisons of hourly mean winds for both instruments by scatterplots show excellent agreement, indicating that the two optical techniques provide equivalent observations of mesopause winds. Small deviations in the measured wind can be ascribed to the different zenith angles used by the two instruments. The combined measurements illustrate the dominance of the 12-h wave in the mesopause winds at Resolute Bay, with additional evidence for strong gravity wave activity with much shorter periods (tens of minutes). Future operations of the two instruments will focus on observation of complementary emissions, providing a unique passive optical capability for the determination of neutral winds in the geomagnetic polar cap at various altitudes near the mesopause.

Abstract. Earth's radiation budget is affected by new particle formation (NPF) and the growth of these nanometer-scale particles to larger sizes where they can directly scatter light or act as cloud condensation nuclei (CCN). Large uncertainties remain in the magnitude and spatiotemporal distribution of nucleation (less than 10 nm diameter) and Aitken (10–60 nm diameter) mode particles. Acquiring size-distribution measurements of these particles over large regions of the free troposphere is most easily accomplished with research aircraft. We report on the design and performance of an airborne instrument, the nucleation mode aerosol size spectrometer (NMASS), which provides size-selected aerosol concentration measurements that can be differenced to identify aerosol properties and processes or inverted to obtain a full size-distribution between 3 and 60 nm. By maintaining constant downstream pressure the instrument operates reliably over a large range of ambient pressures and during rapid changes in altitude, making it ideal for aircraft measurements from the boundary layer to the stratosphere. We describe the modifications, operating principles, extensive calibrations, and laboratory and in-flight performance of two NMASS instruments operated in parallel as a 10-channel battery of condensation particle counters (CPCs) in the NASA Atmospheric Tomography Mission (ATom) to investigate NPF and growth to cloud-active sizes in the remote free troposphere. An inversion technique to obtain a size distributions from the discrete channels of the NMASS is described and evaluated. Concentrations measured by the two NMASS instruments flying in parallel are self-consistent and also consistent with measurements made with an Optical Particle Counter. Extensive laboratory calibrations with a range of particle sizes and compositions show repeatability of the response function of the instrument to within 5–8 % and no sensitivity in sizing performance to particle composition. Particle number, surface area, and volume concentrations from the data inversion are determined to better than 20 % for typical particle size distributions. The excellent performance of the NMASS systems provides a strong analytical foundation to explore NPF around the globe in the ATom dataset.

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Observations of the OH neutral winds show variations indicating strong tidal wave activity at the mesopause.