Quasi-biennial Oscillation and Solar Cycle Response of SABER H2O in the Mesosphere
Abstract
This work presents the Quasi-biennial Oscillation (QBO) and Solar Cycle Response of SABER H2O in the mesosphere. SABER H2O is a recently released dataset and its interannual variations have not yet been analyzed. These SABER H2O are binned into bi-monthly zonal-means and then analyzed. This work first does a conventional EOF analysis and complex EOF analysis on the detrended and deseasonalized datasets. A conventional EOF analysis decomposes the data into orthogonal modes of variation. However, a conventional EOF analysis is only good for stationary modes. It is not good for propagating modes. For propagating modes, we utilize the complex EOF analysis. We then do a correlation and multiple linear regression between the dataset and the QBO index and the F10.7 index to further check whether the modes are indeed consistent with these variations. For comparison, we did the same analyses to simulations from the Specified Dynamics - Whole Atmosphere Community Climate Model (SD-WACCM). Preliminary results show that the most dominant stationary mode of interannual variation in SABER H2O is consistent with the 11-year solar cycle while the most dominant propagating mode of variation is consistent with the QBO. The QBO response in both datasets have similar general structures characterized by an anti-phase relationship with the QBO index between altitudes 50 km and 70 km and by an in-phase relationship with the QBO index between altitudes 70 km and 80 km. SD-WACCM though simulates a very weak response in the region between altitudes 70 km and 80 km. For preliminary results on the solar cycle responses, both datasets show an anti-phase relationship with the F10.7 index between altitudes 60 km and 80 km. However, the solar cycle response in SABER H2O is almost twice as large as the solar cycle responses in SD-WACCM H2O. These results show that the general discrepancy between the SABER H2O and SD-WACCM H2O in their QBO and solar cycle responses is that the model simulates a weaker QBO and solar cycle response than observed. Fortunately, the spatial variation is satisfactorily similar and so we can do a tendency analysis on the model to explain what photochemical reactions or transport processes drive these signatures. These tendency analyses will explain the physical mechanisms behind how the QBO and solar cycle affect mesospheric H2O.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSA23A..03S
- Keywords:
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- 0340 Middle atmosphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0355 Thermosphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3369 Thermospheric dynamics;
- ATMOSPHERIC PROCESSES;
- 2447 Modeling and forecasting;
- IONOSPHERE