A high spatial resolution observation of an emerging flux region ( EFR) was made using a vector magnetograph and a H Lyot filtergraph with the Domeless Solar Telescope at Hida Observatory on 2006 October 22. In H wing images, we could see many Ellerman bombs ( EBs) in the EFR. Observations in two modes, slit scan and slit fixed, were performed with the vector magnetograph, along with the H filtergraph. Using the H wing images, we detected 12 EBs during the slit scan observation period and 9 EBs during the slit fixed observation period. With the slit scan observation, we found that all the EBs were distributed in the area where the spatial gradient of vertical field intensity was large, which indicates the possibility of rapid topological change in the magnetic field in the area of EBs. With the slit fixed observation, we found that EBs were distributed in the areas of undulatory magnetic fields, in both the vertical and horizontal components. This paper is the first to report the undulatory pattern in the horizontal components of the magnetic field, which is also evidence for emerging magnetic flux triggered by the Parker instability. These results allow us to confirm the association between EBs and emerging flux tubes. Three triggering mechanisms for EBs are discussed with respect to emerging flux tubes: 9 out of 21 EBs occurred at the footpoints of emerging flux tubes, 8 occurred at the top of emerging flux tubes, and 4 occurred in the unipolar region. Each case can be explained by magnetic reconnection in the low chromosphere.

[1] The Brewer-Dobson circulation (BDC) is approximately expressed by the residual circulation (RC) and considered to be driven by the body force induced by the breaking and/or dissipation of atmospheric waves. The contribution of different types of waves to the RC in the Center for Climate System Research/National Institute for Environmental Studies (CCSR/NIES) Chemistry Climate Model (CCM) is diagnosed using the "downward control principle (DC)." Gravity wave drag (GWD) including orographic gravity wave drag (OGWD) has a great influence on the RC in the low and middle latitudes of the lower stratosphere. In particular, the summer hemispheric low-latitude part of winter circulation is mainly formed by the GWD. These results are consistent with the estimates of the GWD contribution using reanalysis data by subtracting the resolved wave contribution from the RC with DC principle. In addition, it is seen that the net upward mass flux on the 70 hPa surface is strengthened during the 21st century because of the upward shift of the OGWD, which is consistent with previous studies. These conclusions indicate that gravity waves play an important role in maintaining the BDC.Citation: Okamoto, K., K. Sato, and H. Akiyoshi (2011), A study on the formation and trend of the Brewer-Dobson circulation,

A new method is proposed to estimate three-dimensional (3D) material circulation driven by waves based on recently derived formulas by Kinoshita and Sato that are applicable to both Rossby waves and gravity waves. The residual-mean flow is divided into three, that is, balanced flow, unbalanced flow, and Stokes drift. The latter two are wave-induced components estimated from momentum flux divergence and heat flux divergence, respectively. The unbalanced mean flow is equivalent to the zonal-mean flow in the two-dimensional (2D) transformed Eulerian mean (TEM) system. Although these formulas were derived using the “time mean,” the underlying assumption is the separation of spatial or temporal scales between the mean and wave fields. Thus, the formulas can be used for both transient and stationary waves. Considering that the average is inherently needed to remove an oscillatory component of unaveraged quadratic functions, the 3D wave activity flux and wave-induced residual-mean flow are estimated by an extended Hilbert transform. In this case, the scale of mean flow corresponds to the whole scale of the wave packet. Using simulation data from a gravity wave–resolving general circulation model, the 3D structure of the residual-mean circulation in the stratosphere and mesosphere is examined for January and July. The zonal-mean field of the estimated 3D circulation is consistent with the 2D circulation in the TEM system. An important result is that the residual-mean circulation is not zonally uniform in both the stratosphere and mesosphere. This is likely caused by longitudinally dependent wave sources and propagation characteristics. The contribution of planetary waves and gravity waves to these residual-mean flows is discussed.

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A new method is described for the regioselective synthesis of multisubstituted pyridine derivatives. Treatment of N-acetyl β-enamino ketones with alkynes in the presence of the rhenium catalyst, Re(2)(CO)(10), gives multisubstituted pyridines regioselectively. In this reaction, the N-acetyl moieties are important for the selective formation of the multisubstituted pyridines. This reaction proceeds via insertion of alkynes into a carbon-carbon single bond of β-enamino ketones, intramolecular nucleophilic cyclization, and elimination of acetic acid.