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The presenting chest radiographs of 27 newborn patients with D-transposition of the great vessels (D-TGV) were evaluated for the degree of pulmonary flow as well as other findings classically described in D-TGV (narrow superior mediastinum, radiographically absent thymus, inapparent main pulmonary artery, nonvisualization of the malpositioned aortic arch, asymmetric pulmonary blood flow, and cardiomegaly). Of the 27 patients, 22 (82%) demonstrated normal or decreased flow. The majority of the D-TGV patients also failed to demonstrate any of the other classically described radiographic findings. A normal chest radiograph is the most common presenting scenario in the neonate with D-TGV.

Measurements of atmospheric N2O spanning altitudes from the surface to 14 km, and latitudes from 67°S to 85°N, show high concentrations in the tropics and subtropics, with strong maxima in the middle and upper troposphere. The pattern varies significantly over time scales of a few weeks. Global simulations do not accurately capture observed distributions with latitude, altitude, or time. Inversion results indicate strong, episodic inputs of nitrous oxide from tropical regions (as large as 1 Tg N‐N2O over 9 weeks) are necessary to produce observed vertical and latitudinal distributions. These findings highlight strong tropical sources of N2O with high temporal variability, and the necessity of using full vertical profile observations in deriving emissions from atmospheric measurements. Measurements of N2O show high concentrations at altitude in the tropicsAnalysis finds strong, temporally variant N2O emissions from tropical regionsInverse analysis using remote surface observations miss large tropical emissions

Observations of three stratospheric species (N2O, CH4, and NOy) are examined for their suitability as mixing tracers in the inner Arctic vortex region between late February and mid‐March 2000. NOyis highly inhomogeneous on isentropic surfaces and has little systematic vertical gradient between the 420 and 470 K potential temperature surfaces due to severe and extensive denitrification. Probability distribution functions of NOycalculated from in situ measurements do not show systematic and significant change as a function of time, indicating that mixing was too slow to substantially homogenize NOydistribution and therefore to strongly affect photochemical O3destruction rates during the period. We propose that the NOyinhomogeneity is useful for diagnosing small‐scale, irreversible mixing rates during the measurement period. A simple kinematic model is used to show that the NOystandard deviation on an isentropic level in the vortex has desirable properties for quantifying these rates. A practical method for deriving mixing rates for chemistry and transport models has been proposed for future studies.