Orographic Primary and Secondary Gravity Waves in the Middle Atmosphere From 16‐Year SABER Observations

Xiao, Li; Xu, Jiyao; Yue, Jia; Vadas, Sharon L.; Becker, Erich

doi:10.1029/2019gl082256

Cited by 40 publications

(45 citation statements)

References 73 publications

(116 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also examined the mean potential energy density PE during this event and found that it departed significantly from exponential at z ∼ 55-80 km as a result of MW attenuation. This agrees with SABER and lidar observations (Lu et al, 2015, Liu et al, 2019Preusse et al, 2006;Trinh et al, 2018). We found that the PE increased exponentially from z ∼ 95 to 115 km because of the growth of the secondary and tertiary GWs, decreased at z ≃ 115-125 km because of the dissipation of most of the secondary GWs, and increased at z ∼ 125-160 km because of the growth of the tertiary GWs.…”

Section: Discussionsupporting

confidence: 91%

Numerical Modeling of the Generation of Tertiary Gravity Waves in the Mesosphere and Thermosphere During Strong Mountain Wave Events Over the Southern Andes

2019

Self Cite

View full text Add to dashboard Cite

We investigate the effects on the mesosphere and thermosphere from a strong mountain wave (MW) event over the wintertime Southern Andes using a gravity wave (GW)‐resolving global circulation model. During this event, MWs break and attenuate at z∼50–80 km, thereby creating local body forces that generate large‐scale secondary GWs having concentric ring structure with horizontal wavelengths λH=500–2,000 km, horizontal phase speeds cH=70–100 m/s, and periods τr∼3–10 hr. These secondary GWs dissipate in the upper mesosphere and thermosphere, thereby creating local body forces. These forces have horizontal sizes of 180–800 km, depending on the constructive/destructive interference between wave packets and the overall sizes of the wave packets. The largest body force is at z=80–130 km, has an amplitude of ∼2,400 m/s/day, and is located ∼1,000 km east of the Southern Andes. This force excites medium‐ and large‐scale “tertiary GWs” having concentric ring structure, with λH increasing with radius from the centers of the rings. Near the Southern Andes, these tertiary GWs have cH=120–160 m/s, λH=350–2,000 km, and τr∼4–9 hr. Some of the larger‐λH tertiary GWs propagate to the west coast of Africa with very large phase speeds of cH≃420 m/s. The GW potential energy density increases exponentially at z∼95–115 km, decreases at z∼115–125 km where most of the secondary GWs dissipate, and increases again at z>125 km from the tertiary GWs. Thus, strong MW events result in the generation of medium‐ to large‐scale fast tertiary GWs in the mesosphere and thermosphere via this multistep vertical coupling mechanism.

show abstract

Section: Discussionsupporting

confidence: 91%

Numerical Modeling of the Generation of Tertiary Gravity Waves in the Mesosphere and Thermosphere During Strong Mountain Wave Events Over the Southern Andes

2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…This energy increase cannot be justified by the slight decrease of balloon altitude after the Andes, because only 4% amplitude increase of pressure variations are expected. The hypothesis of detection of mountain gravity waves is strengthened by the seasonal observations of high activity in gravity waves domain above Andes from March to October (Hoffmann et al, 2013;Liu et al, 2019).…”

Section: Mountain Gravity Wavesmentioning

confidence: 99%

Infrasound and Gravity Waves Over the Andes Observed by a Pressure Sensor on Board a Stratospheric Balloon

et al. 2020

View full text Add to dashboard Cite

The study of infrasound (acoustic) and gravity waves sources and propagation in the atmosphere of a planet gives us precious insight on atmosphere dynamics, climate, and even internal structure. The implementation of modern pressure sensors with high rate sampling on stratospheric balloons is improving their study. We analyzed the data from the National Aeronautics and Space Administration Ultra Long Duration Balloon mission (16 May to 30 June 2016). Here, we focus on the balloon's transit of the Andes Mountains. We detected gravity waves that are associated to troposphere convective activity and mountain waves. An increase of the horizontal wavelengths from 50 to 70 km with increasing distance to the mountains is favoring the presence of mountain waves. We also report on the detection of infrasounds generated by the mountains in the 0.01–0.1 Hz range with a pressure amplitude increase by a factor 2 relative background signal. Besides, we characterized the decrease of microbaroms power when the balloon was flying away from the ocean coast. These observations suggest, in a way similar to microseisms for seismometers, that microbaroms are the main background noise sources recorded in the stratosphere even far from the ocean sources. Finally, we observed a broadband signal above the Andes, between 0.45 and 2 Hz, probably associated with a thunderstorm. The diversity of geophysical phenomena captured in less than a day of observation stresses the interest of high rate pressure sensors on board long‐duration balloon missions.

show abstract

“…Using temperature data from the SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument onboard the TIMED (Thermosphere Ionosphere Mesosphere Energetics Dynamics) satellite, Trinh et al (2018) and X. Liu et al (2019) found that this hot spot is visible in the stratosphere and lower mesosphere, but not near the mesopause (e.g., at z ∼ 85-90 km in Figure 2 of Trinh et al, 2018). A possible explanation is that the hot spot is partially smoothed out around the mesopause because of horizontal propagation of (secondary) GWs.…”

Section: 1029/2020ja028034mentioning

confidence: 99%

Explicit Global Simulation of Gravity Waves in the Thermosphere

2020

Self Cite

View full text Add to dashboard Cite

We present a new version of the high-resolution Kühlungsborn Mechanistic general Circulation Model (KMCM) extended to z ∼ 450 km. This model is called HIAMCM (HI Altitude Mechanistic general Circulation Model) and explicitly simulates gravity waves (GWs) down to horizontal wavelengths of λ h ∼ 165 km. We find predominant tertiary GWs in the winter thermosphere at middle/high latitudes. These GWs typically have horizontal wavelengths λ h ∼ 300-1,100 km, ground-based periods ∼ 25-90 min, and intrinsic horizontal phase speeds c Ih ∼ 250-350 m s −1. Above z ∼ 200 km, the predominant GW horizontal propagation directions are roughly against the background winds from the diurnal tide; the GWs propagate mainly poleward at midnight, eastward at 6 local time (LT), equatorward at noon, and westward at 18 LT. Wintertime GWs at z ∼ 300 km having 165 km ≤ λ h ≤ 330 km create a large hot spot over the Southern Andes/Antarctic Peninsula that agrees well with quiet time satellite measurements. Due to cancelation effects, the time-averaged zonal mean Eliassen-Palm flux divergence from the resolved GWs in the thermosphere is negligible compared to that of the tides and compared to the zonal component of the time-averaged zonal mean ion drag. We also find that the thermospheric GWs dissipate mainly from macroturbulent diffusion and, above z ∼ 200 km, from molecular diffusion, whereas the tides dissipate mainly from ion drag. The averaged dissipative heating in the thermosphere due to tides is much stronger than that due to GWs.

show abstract

Orographic Primary and Secondary Gravity Waves in the Middle Atmosphere From 16‐Year SABER Observations

Cited by 40 publications

References 73 publications

Numerical Modeling of the Generation of Tertiary Gravity Waves in the Mesosphere and Thermosphere During Strong Mountain Wave Events Over the Southern Andes

Numerical Modeling of the Generation of Tertiary Gravity Waves in the Mesosphere and Thermosphere During Strong Mountain Wave Events Over the Southern Andes

Infrasound and Gravity Waves Over the Andes Observed by a Pressure Sensor on Board a Stratospheric Balloon

Explicit Global Simulation of Gravity Waves in the Thermosphere

Contact Info

Product

Resources

About