JMSJ, 2016, Vol. 94, No. 6 (December)
Ota et al (2016)
Ota, Y., and R. Imasu, 2016: CO2 Retrieval using thermal infrared radiation observation by Interferometric Monitor for Greenhouse Gases (IMG) onboard Advanced Earth Observing Satellite (ADEOS). J. Meteor. Soc. Japan, 94, 471-490.
http://doi.org/10.2151/jmsj.2016-027 Graphical Abstract
- CO2 concentrations in the upper troposphere were retrieved from thermal infrared spectra as observed by the only spaceborne hyperspectral sounder launched in the 1990s: the Interferometric Monitor for Greenhouse gases (IMG) onboard the Advanced Earth Observing Satellite (ADEOS).
- The effective optical path difference (EOPD) of IMG was evaluated in order to optimize the actual instrumental line shape function of IMG in orbit.
- CO2 retrieval method was based on maximum a posteriori (MAP) retrieval method and on a priori temperature field of ERA-40 re-analysis meteorological data. CO2 retrieval noises of the MAP retrieval were estimated respectively as 2.5% and 2.0% at pressure levels of 500 hPa and 300 hPa.
- The CO2 retrieval method was applied to IMG data measured in April, 1997. Although assuming uniform CO2 concentration as a priori, the results showed that latitudinal gradient of zonal mean concentration was consistent with climatological features presented by previous studies at pressure levels of 500 hPa and 300 hPa.
Kitamura, Y., 2016: Improving a turbulence scheme for the terra incognita in a dry convective boundary layer. J. Meteor. Soc. Japan, 94, 491-506.
http://doi.org/10.2151/jmsj.2016-028 Graphical Abstract
- A new formulation for eddy viscosity and thermal eddy diffusivity is presented to constitute a turbulence closure model applicable to the terra incognita range in which neither the Reynolds Averaged Navier-Stokes Simulation (RANS) nor the Large-Eddy Simulation (LES) is appropriate.
- The anisotropic length scales are empirically determined as a function of the model resolution using the results of the a priori LES analysis and are applied to the Deardorff model.
- The proposed model improves the representation of the vertical heat flux and the magnitude of the resolved convection even for the resolutions including the terra incognita range, while the original Deardorff model tends to underestimate the subgrid heat flux with increasing the grid size.
Inoue et al (2016)
Inoue, H. Y., K. Kusunoki, K. Arai, N. Ishitsu, T. Adachi, S. Yoshida, and C. Fujiwara, 2016: Structure and evolution of misovortices observed within a convective snowband in the Japan Sea coastal region during a cold-air outbreak on 31 December 2007. J. Meteor. Soc. Japan, 94, 507-524.
http://doi.org/10.2151/jmsj.2016-029 Graphical Abstract
- The structure and temporal evolution of the misovortices within a convective snowband during landfall were investigated using high-resolution data obtained from two X-band Doppler radars in the Japan Sea coastal region.
- The vortices developed along a low-level convergence line with horizontal shear, suggesting that horizontal shearing instability was responsible for their initial development.
- The vortex extended upward with time as it approached the coast. During landfall, its core diameter contracted markedly and its peak tangential velocity and vertical vorticity increased at lower altitudes (Fig.1).
- Such a temporal change of low-level vortex was associated with an intensification of low-level convergence around the vortex and the convergence line, suggesting that stretching of the low-level vortex was responsible for it (Fig.2).
Notes and Correspondence
Yatagai et al (2016)
Yatagai, A., and S. Oyama, 2016: Thermospheric nocturnal wind climatology observed by Fabry-Perot interferometers over the Asia-Oceania region. J. Meteor. Soc. Japan, 94, 525-536.
http://doi.org/10.2151/jmsj.2016-026 Graphical Abstract
- This study shows the horizontal structure of climatology of thermospheric nocturnal winds at a height of about 250 km in the Asia–Oceania region for the first time using observations made with Fabry–Perot interferometers (FPIs)
- The observation data were evaluated in the quality control process that involved consideration of cloud information, wind speed value, and the standard deviation of results obtained from synchronous fringe images. As the result, about 30% of observation data from all the four stations were analyzed to make the figures.
- The seasonal climatology reported here can be used to provide a background average wind status and distinguish modulations for anomalous events.