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DATE |
HEADLINE |
STORY |
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September 2007 |
Attribution of Decadal Variability in Lower Stratospheric Tropical Ozone |
Marsh and Garcia show results that suggest that some of the decadal variability in tropical ozone previously attributed to solar variability is in fact related to the occurence of ENSO events. |
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July 2007 |
Energetic particle precipitation effects on the Southern Hemisphere stratosphere in 1992-2005 |
This study represents the first estimation of EPP-NOx contributions to the stratospheric odd nitrogen budget using observations over an entire cycle. [read paper] |
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March 2007 |
Simulation of secular trends in the middle atmosphere, 1950-2003! |
Garcia et al. have compared WACCM3 simulations to observations for the period 1950-2003. They show that WACCM3 is able to faithfully simulate most changes in middle atmosphere composition over the last 50 years. [read paper] |
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March 2007 |
Mesospheric dynamical changes induced by solar protons assessed! |
C. Jackman et al. have shown using the TIME-GCM that the fourth largest solar proton event in 40-years, which occurred Oct-Nov 2003, produced odd hydrogen and odd nitrogen that led to significant short-lived ozone decreases. [read paper] |
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November 2006 |
New ozone modified refractive index! |
T. Nathan and E. Cordero have shown that the refractive index (RI) for vertically propagating planetary waves, as traditionally cited, is incomplete - it neglects the wave-induced heating that arises from the interactions between stratospheric ozone and planetary wave fields. The new ozone-modified RI provides important insights into how solar-modulated changes in stratospheric ozone affect planetary wave propagation and drag on the zonal mean flow, processes vital to the driving of the global atmospheric circualtion. [read paper]
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November 2006 |
Stratospheric variability and trends in models used in the IPCC AR4 are assessed! |
E. Cordero and P. M. Forster have analyzed atmospheric and oceanic GCMs for the IPCC fourth assessment report in order to better understand model variability and assess the importance of various forcing mechanisms on stratospheric trends during the 20th century. [read paper] |
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October 2006 |
Improved regression analysis of solar cycle modulation of ozone! |
B. Soukharev and L. Hood have performed multiple regression analyses of long-term satellite data sets and compared the results with models. They show that the amplitude of the solar cycle variation in the tropical upper stratosphere is somewhat reduced in comparison with earlier results. [read paper] |
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October , 2006 |
Conditions for predicting unique low frequency wave fields are derived! |
D. Hodyss and T. Nathan show that explicit knowledge of the type of forcing that produces the stationary long waves in the atmosphere is vital to predicting a unique low frequency (LF) field. Forcing structures for which the LF dyanamics are Hamiltonian are shown to yield conservation laws that provide necessary conditions for instability and a constraint on the LF structures that can develop. [read paper] |
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September, 2006 |
Generalized stability criteria derived! |
D. Hodyss and T. Nathan derived generalized stability criteria for long waves in variable media. The new stability criteria have application to Rossby waves in geophysical fluids and magetoacoustic waves in the solar wind. [read paper] |
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December 2005 |
Empirical model of solar UV radiance developed! |
J. Morrill has developed an empirical model of solar UV spectral irradiance. The model identifies three surface features: quiet sun, active sun and sunspots. [read paper] |
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December 2005 |
New pathway identified for communicating the 11-year solar cycle to the QBO! |
Cordero and Nathan show that wave-ozone feedbacks provide a new nonlinear pathway for communicating solar variability to the QBO. [read paper] |
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