Spatiotemporal variation of the ozone QBO in MLS data by wavelet analysis

Abstract. Spatiotemporal characteristics of the ozone quasi-biennial oscillation (QBO) over the tropical-subtropical stratosphere (40° S–40° N) have been examined by analyzing data from the Microwave Limb Sounder (MLS) aboard Upper Atmospheric Research Satellite (UARS) for the period 1992–1999. A combination of regression analysis and wavelet analysis combines to act as an accurate QBO filter. Wavelet analysis provides inter-annual variability of amplitude and phase of the ozone QBO in the vertical structure of tropical-subtropical stratosphere. It gives minute details of phase propagation and descend rates, which can be used as input to models. Latitude-height structure shows evidence of a secondary meridional circulation induced by the QBO as double peak structure at the equator with maximum amplitude at two pressure levels 30 hPa and 9 hPa and a node at 14 hPa. The equatorial maxima are out of phase with each other. The maximum amplitude (~1.4 ppmv) of the ozone QBO was observed near the equator at 10 hPa. Descent rate of the easterly phase is greater than westerly. The lag correlation of the ozone QBO with circulation and variation of descent rates in the vertical structure of the stratosphere are examined in detail. In the equatorial upper stratosphere ozone anomalies descent with the rate ~1.5 km/month but in tropics and subtropics (above 2 hPa) they propagate upward.

Download Full-text

Double Peak Structure of Electron Energy Distribution in Ramsauer Gases by Monte Carlo Simulation

IEEJ Transactions on Fundamentals and Materials ◽

10.1541/ieejfms1990.121.3_256 ◽

2001 ◽

Vol 121 (3) ◽

pp. 256-262 ◽

Cited By ~ 2

Author(s):

Teruhiro Suzuki ◽

Tatsuya Fukuyama ◽

Haruo Itoh

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Energy Distribution ◽

Electron Energy ◽

Electron Energy Distribution ◽

Double Peak ◽

Double Peak Structure ◽

Peak Structure

Download Full-text

Double-peak structure of the dynamical structure factor in diluted Heisenberg antiferromagnets

Physical Review B ◽

10.1103/physrevb.51.11479 ◽

1995 ◽

Vol 51 (17) ◽

pp. 11479-11483 ◽

Cited By ~ 5

Author(s):

Takamichi Terao ◽

Tsuneyoshi Nakayama

Keyword(s):

Structure Factor ◽

Dynamical Structure ◽

Dynamical Structure Factor ◽

Double Peak ◽

Double Peak Structure ◽

Peak Structure ◽

Heisenberg Antiferromagnets

Download Full-text

Double Peak Structure in the Density of States of a Kondo Lattice

NATO ASI Series - Microscopic Aspects of Nonlinearity in Condensed Matter ◽

10.1007/978-1-4684-5961-6_29 ◽

1991 ◽

pp. 283-288

Author(s):

Maria Marinaro ◽

Canio Noce ◽

Alfonso Romano

Keyword(s):

Density Of States ◽

Kondo Lattice ◽

Double Peak ◽

Double Peak Structure ◽

Peak Structure

Download Full-text

Variability in the speed of the Brewer–Dobson circulation as observed by Aura/MLS

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-4563-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 4563-4575 ◽

Cited By ~ 34

Author(s):

T. Flury ◽

D. L. Wu ◽

W. G. Read

Keyword(s):

Time Series ◽

Interannual Variability ◽

Lower Stratosphere ◽

Meridional Circulation ◽

Time Lag ◽

Quasi Biennial Oscillation ◽

One Year ◽

The Tropics ◽

Biennial Oscillation ◽

Stratospheric Water Vapour

Abstract. We use Aura/MLS stratospheric water vapour (H2O) measurements as tracer for dynamics and infer interannual variations in the speed of the Brewer–Dobson circulation (BDC) from 2004 to 2011. We correlate one-year time series of H2O in the lower stratosphere at two subsequent pressure levels (68 hPa, ~18.8 km and 56 hPa, ~19.9 km at the Equator) and determine the time lag for best correlation. The same calculation is made on the horizontal on the 100 hPa (~16.6 km) level by correlating the H2O time series at the Equator with the ones at 40° N and 40° S. From these lag coefficients we derive the vertical and horizontal speeds of the BDC in the tropics and extra-tropics, respectively. We observe a clear interannual variability of the vertical and horizontal branch. The variability reflects signatures of the Quasi Biennial Oscillation (QBO). Our measurements confirm the QBO meridional circulation anomalies and show that the speed variations in the two branches of the BDC are out of phase and fairly well anti-correlated. Maximum ascent rates are found during the QBO easterly phase. We also find that transport of H2O towards the Northern Hemisphere (NH) is on the average two times faster than to the Southern Hemisphere (SH) with a mean speed of 1.15 m s−1 at 100 hPa. Furthermore, the speed towards the NH shows much more interannual variability with an amplitude of about 21% whilst the speed towards the SH varies by only 10%. An amplitude of 21% is also observed in the variability of the ascent rate at the Equator which is on the average 0.2 mm s−1.

Download Full-text