scholarly journals Geostrophic momentum approximation Q-vector and its application in synoptic charts

2014 ◽  
Vol 63 (6) ◽  
pp. 069201
Author(s):  
Zhou Xiao-Gang ◽  
Zhu He ◽  
Wang Xiu-Ming
Keyword(s):  
Momentum Approximation ◽  
Q Vector

The multiple q-vector incommensurate magnetic structure of TbGe3

2007 ◽  
Vol 19 (23) ◽  
pp. 236201 ◽  
Author(s):  
P Schobinger-Papamantellos ◽  
J Rodríguez-Carvajal ◽  
K H J Buschow
Keyword(s):  
Magnetic Structure ◽  
Incommensurate Magnetic Structure ◽  
Q Vector

The role of hydrogen bonds in order-disorder transition of a new incommensurate low temperature phase β-[Zn-(C7H4NO4)2]·3H2O

2018 ◽  
Vol 233 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Masoumeh Tabatabaee ◽  
Morgane Poupon ◽  
Václav Eigner ◽  
Přemysl Vaněk ◽  
Michal Dušek
Keyword(s):  
Low Temperature ◽  
Hydrogen Bonds ◽  
Dicarboxylic Acid ◽  
Room Temperature ◽  
Temperature Phase ◽  
Temperature Structure ◽  
Modulated Structure ◽  
Q Vector ◽  
Low Temperature Phase

AbstractThe room temperature structure withP21/csymmetry of the zinc(II) complex of pyridine-2,6-dicarboxylic acid was published by Okabe and Oya (N. Okabe, N. Oya, Copper(II) and zinc(II) complexes of pyridine-2,6-dicarboxylic acid.Acta Crystallogr. C.2000,56, 305). Here we report crystal structure of the low temperature phaseβ-[Zn(pydcH)2]·3H2O, pydc=C7H3NO4, resulting from the phase transition around 200K. The diffraction pattern of the low temperature phase revealed satellite reflections, which could be indexed with q-vector 0.4051(10)b* corresponding to (3+1)Dincommensurately modulated structure. The modulated structure was solved in the superspace groupX21/c(0b0)s0, whereXstands for a non-standard centring vector (½, 0, 0, ½), and compared with the room temperature phase. It is shown that hydrogen bonds are the main driving force of modulation.

scholarly journals Development of a One-Month-Long, Westward-Propagating Subtropical Low in Boreal Summer

2018 ◽  
Vol 146 (1) ◽  
pp. 231-242 ◽  
Author(s):  
John Molinari ◽  
David Vollaro
Keyword(s):  
Wave Breaking ◽  
Northeast Asia ◽  
Wave Structure ◽  
Boreal Summer ◽  
Central Pacific ◽  
The Pacific ◽  
Monsoon Gyre ◽  
Jet Streak ◽  
Q Vector ◽  
Equatorial Rossby Wave

Abstract A strong MJO event produced an upper-tropospheric jet streak in northeast Asia and repeated wave breaking in the jet exit region along 150°E during July 1988. A midlatitude low moved equatorward and intensified in the presence of bandpass-filtered (15–100 day) Q vector forcing for upward motion associated with the wave breaking. This forced ascent helped to moisten the atmosphere enough to increase the column water vapor to above 55 mm. This value was sufficiently large to support a self-sustaining low even after the upper forcing weakened. The horizontal scale of the Q vector forcing was about 1500 km, consistent with the scale of most favorable convective response to quasigeostrophic forcing in the subtropics described by Nie and Sobel. The low lasted one month as it moved southwestward, then westward, while remaining north of 20°N. Maximum precipitation along the track of the low exceeded 700 mm, with an anomaly more than 400 mm. A climatology of long-lasting lows was carried out for the monsoon gyre cases studied previously. During El Niño, long-lasting lows often began near the equator in the central Pacific, and were likely to have a mixed Rossby–gravity wave or equatorial Rossby wave structure. It is speculated that the quasi-biweekly mode, the submonthly oscillation, the 20–25-day mode, and the Pacific–Japan pattern are each variations on this kind of event. During La Niña, long-lasting lows that originated in midlatitudes were more common. It is argued that these lows from midlatitudes represent a unique disturbance type in boreal summer.

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