The sea breeze/land breeze diurnal circulation within the Los Angeles Basin and adjacent waters transports marine air into the basin during the day and urban air to Santa Monica Bay during the night. Nitryl chloride, ClNO2 is a nocturnal trace gas formed from the heterogeneous reaction of dinitrogen pentaoxide (N2O5) with chloride containing aerosol. Its photolysis after sunrise produces atomic chlorine radicals and regenerates NO2, both of which may increase ozone production. Mixing of the chloride source from marine sea salt with the urban NOx source in Los Angeles provides conditions ideal for the production of ClNO2. This paper presents an analysis using a wind profiler on the coast and measurements of ClNO2 and its precursors made from both ship and aircraft to assess the prevailing meteorological conditions important for ClNO2 production in this region, with a particular focus on the production over water within the land breeze phase of the circulation. A box model is used to calculate an upper limit to the amount of ClNO2 capable of being produced strictly over Santa Monica Bay during the land breeze. On three out of the four nights of ClNO2 measurements in Santa Monica Bay, the ClNO2 exceeds the upper limit calculated using the box model and shows that the majority of the ClNO2 is produced over the city and transported to Santa Monica Bay by the land breeze. This ClNO2 transport suggests the sea breeze more efficiently transports aerosol chloride inland than land breeze transports NOx offshore.
High-spin states in 157 Yb have been populated in the 144 Sm( 16 O, 3n) 157 Yb fusion-evaporation reaction at a beam energy of 85 MeV, and two rotational bands have been established for the first time. Within the framework of the triaxial particle-rotor model, the energy spectra and single-particle configurations of 157 Yb are investigated. The calculated energy spectra agree well with the experimental data. The newly observed ν f 7/2 band, and the previously known ν i 13/2 band in 157 Yb, are also discussed by means of Total-Routhian-Surface methods. The structural characters observed in 157 Yb provide evidence for the shape coexistence of three distinct shapes: prolate, triaxial and oblate. At higher spins, both the ν f 7/2 band and the ν i 13/2 band in 157 Yb undergo a shape evolution with sizable alignments occurring.