Interesting temperature field structure during the SOLVE-2/VINTERSOL Winter
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mesoscale temperature structure↗
Engineering topics
Gary, Bruce
Publications and source records attributed to Gary, Bruce.
Geophysica MTP observations during the EUPLEX campaign
The Jet Propulsion Laboratory (JPL) Microwave Temperature Profiler (MTP) was the first United States instrument to fly on the Russian Geophysica high-altitude research aircraft. Careful comparison of MTP measurements with radiosondes launched near the Geophysica flight track has allowed us to establish the flight level temperature to an accuracy of 0.2K.
MTP↗
Convectively Generated Gravity Waves In The Tropical Stratosphere: Case Studies And Importance For The Circulation Of The Middle Atmosphere
The advent of high altitude aircraft measurements in the stratosphere over tropical convective systems has made it possible to observe the mesoscale disturbances in the temperature field that these systems excite. Such measurements show that these disturbances have horizontal scales comparable to those of the underlying anvils (about 50-100 km) with peak to peak theta surface variations of about 300-400 meters. Moreover, correlative wind measurements from the tropical phase of the Stratosphere-Troposphere Exchange Project (STEP) clearly show that these disturbances are gravity waves. We present two case studies of anvil-scale gravity waves over convective systems. Using steady and time-dependent linear models of gravity wave propagation in the stratosphere, we show: (1) that the underlying convective systems are indeed the source of the observed phenomena; and (2) that their generating mechanism can be crudely represented as flow over a time-dependent mountain. We will then discuss the effects gravity waves of the observed amplitudes have on the circulation of the middle atmosphere, particularly the quasi-biennial, and semiannual oscillations.
Pfister, Leonhard↗
An Algorithm for Forecasting Mountain Wave Related Turbulence in the Stratosphere
A global mountain wave parameterization for prediction of wave related displacements and turbulence is described. The parameterization is used with input from NMC analyses of wind and temperature to examine small-scale disturbances encountered by the NASA high-altitude ER-2 during the Second Airborne Arctic Stratosphere Experiment (AASE-II). The magnitude and location of observed large wave events are well reproduced. A strong correlation is suggested between patches of moderate turbulence encountered by the ER-2 and locations where breaking mountain waves are predicted by the parameterization. These facts suggest that useful forecasts of global mountain wave activity, including wave related CAT, can be made quickly and inexpensively using our mountain wave parameterization with input from current numerical forecast models.
Chan, Roland↗
Small-scale waves encountered during AASE
Variability on scales of 200 km or less in the lower stratosphere is examined using potential temperature data collected during the AASE campaign. Enhanced variability is found over regions containing topography presumably due to gravity waves. The effect of gravity wave critical levels on topographically induced variability is examined. A significant reduction in variability is found when a critical level is present.
Bacmeister, Julio T.↗
Reconstruction of O3 and N2O fields from ER-2, DC-8, and balloon observations
Measurements of N2O and O3 during the Airborne Arctic Stratospheric Expedition have been composited using the potential vorticity and potential temperature of each measurement as coordinates. For ozone, data sources included the ER-2 and balloon ozonesonde in situ measurements, DC-8 DIAL lidar, and Stratospheric Aerosol and Gas Experiment satellite profiles. For N2O, only ER-2 data were used. These chemical composites have been reconstructed onto average meteorological fields for the mission in a latitude-altitude cross section, yielding a picture of the chemical composition of the polar vortex during this period. Tracers inside the vortex show an apparent descent of about 2 km relative to those outside, resulting in an apparent chemical edge on isentropic and isobaric surfaces.
Schoeberl, Mark R.↗
ER-2 mountain wave encounter over Antarctica - Evidence for blocking
Orographically forced large-amplitude gravity waves (mountain waves) encountered during the AAOE experiment by ER-2 on September 22, 1987 over Alexander Island (73-70 deg W, 69-72 deg S) were analyzed using a three-dimensional steady-state model of stratified flow over realistic topography, similar to the model used by Smith (1980). Taking into account the effects of low-level flow blocking, reasonable agreement was obtained between the model and observations, indicating that blocking may be an important feature of real flow over topography.
Bacmeister, Julio T.↗
Reconstruction of the constituent distribution and trends in the Antarctic polar vortex from ER-2 flight observations
The measurements of ozone, ClO, and N2O concentrations in the south polar region taken aboard the ER-2 aircraft during the Airborne Antarctic Ozone Experiment are analyzed using conservative coordinate transformations to potential temperature-N2O and potential temperature-potential vorticity space. The latter transformation is equivalent to interpreting trace species observations within the modified Lagrangian mean (MLM) coordinate system. The results show that the MLM transformed ozone concentration decreases at about 0.06 ppmv per day between 20- and 16-km altitude inside the polar vortex during the mid-August to mid-September period. These ozone changes are collocated with the region of high ClO concentration. Outside the chemically perturbed region, at the highest aircraft altitudes, ozone concentration systematically increases, suggesting a diabatic cooling of the order 0.3-0.6 K/day.
Schoeberl, Mark R.↗