scholarly journals Gravity waves in the tropical lower stratosphere: A model study of seasonal and interannual variability

2000 ◽  
Vol 105 (D14) ◽  
pp. 17983-17993 ◽  
Author(s):  
M. Joan Alexander ◽  
Robert A. Vincent
Keyword(s):  
Interannual Variability ◽  
Gravity Waves ◽  
Lower Stratosphere ◽  
Seasonal And Interannual Variability ◽  
Model Study

scholarly journals A Model Study of Gravity Waves over Hurricane Humberto (2001)

2008 ◽  
Vol 65 (10) ◽  
pp. 3231-3246 ◽  
Author(s):  
M. A. Kuester ◽  
M. J. Alexander ◽  
E. A. Ray
Keyword(s):  
Wavelet Analysis ◽  
Gravity Waves ◽  
Lower Stratosphere ◽  
Weather Forecasting ◽  
Mesoscale Model ◽  
Deep Convection ◽  
State University ◽  
Fifth Generation ◽  
Model Study ◽  
Atmospheric Gravity

Atmospheric gravity waves are known to influence global circulations. Understanding these waves and their sources help to develop parameterizations that include their effects in climate and weather forecasting models. Deep convection is believed to be a major source for these waves and hurricanes may be particularly intense sources. Simulations of Hurricane Humberto (2001) are studied using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5). Humberto is simulated at both tropical storm and hurricane stages. Fourier transform and wavelet analysis are employed to investigate wave characteristics and their behavior in the lower stratosphere. The Fourier analysis gives a regional view of storm affects, whereas wavelet analysis gives a local picture of isolated events. Analysis of the movement of convective sources and local winds gives further insight into the mechanisms that can cause gravity waves. Convectively generated gravity waves are observed in the lower stratosphere of this model with horizontal scales of 15–300 km, vertical scales of 4–8 km, and intrinsic periods of approximately 20–100 min.

Seasonal and interannual variability in13C composition of ecosystem carbon fluxes in the U.S. Southern Great Plains

Tellus B ◽  
2011 ◽  
Vol 63 (2) ◽  
Author(s):  
Margaret S. Torn ◽  
Sebastien C. Biraud ◽  
Christopher J. Still ◽  
William J. Riley ◽  
Joe A. Berry
Keyword(s):  
Interannual Variability ◽  
Great Plains ◽  
Carbon Fluxes ◽  
Southern Great Plains ◽  
Seasonal And Interannual Variability ◽  
Ecosystem Carbon ◽  
Ecosystem Carbon Fluxes ◽  
The U.S

scholarly journals Aircraft measurements of gravity waves in the upper troposphere and lower stratosphere during the START08 field experiment

2015 ◽  
Vol 15 (13) ◽  
pp. 7667-7684 ◽  
Author(s):  
Fuqing Zhang ◽  
Junhong Wei ◽  
Meng Zhang ◽  
K. P. Bowman ◽  
L. L. Pan ◽  
...  
Keyword(s):  
Power Law ◽  
Gravity Waves ◽  
Lower Stratosphere ◽  
Potential Temperature ◽  
Shear Instability ◽  
Aircraft Measurements ◽  
Upper Troposphere ◽  
Airborne Measurements ◽  
Wide Range

Abstract. This study analyzes in situ airborne measurements from the 2008 Stratosphere–Troposphere Analyses of Regional Transport (START08) experiment to characterize gravity waves in the extratropical upper troposphere and lower stratosphere (ExUTLS). The focus is on the second research flight (RF02), which took place on 21–22 April 2008. This was the first airborne mission dedicated to probing gravity waves associated with strong upper-tropospheric jet–front systems. Based on spectral and wavelet analyses of the in situ observations, along with a diagnosis of the polarization relationships, clear signals of mesoscale variations with wavelengths ~ 50–500 km are found in almost every segment of the 8 h flight, which took place mostly in the lower stratosphere. The aircraft sampled a wide range of background conditions including the region near the jet core, the jet exit and over the Rocky Mountains with clear evidence of vertically propagating gravity waves of along-track wavelength between 100 and 120 km. The power spectra of the horizontal velocity components and potential temperature for the scale approximately between ~ 8 and ~ 256 km display an approximate −5/3 power law in agreement with past studies on aircraft measurements, while the fluctuations roll over to a −3 power law for the scale approximately between ~ 0.5 and ~ 8 km (except when this part of the spectrum is activated, as recorded clearly by one of the flight segments). However, at least part of the high-frequency signals with sampled periods of ~ 20–~ 60 s and wavelengths of ~ 5–~ 15 km might be due to intrinsic observational errors in the aircraft measurements, even though the possibilities that these fluctuations may be due to other physical phenomena (e.g., nonlinear dynamics, shear instability and/or turbulence) cannot be completely ruled out.

Seasonal and Interannual Variability of NDVI in the Republic of Adygea

2021 ◽  
Author(s):  
Sergey A. Lebedev ◽  
Andrey G. Kostianoy ◽  
Pavel N. Kravchenko ◽  
Olga P. Shevyakova
Keyword(s):  
Interannual Variability ◽  
Seasonal And Interannual Variability ◽  
The Republic
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