Mesospheric Airglow Imaging and Dynamics

cips_thumb The research objective of the Mesospheric Airglow Imaging and Dynamics project is to utilize a suite of instruments, including the acquisition of a new airglow imager, to investigate short-period gravity waves in the Arctic atmosphere over Alaska. Short-period gravity waves are an important component of the larger atmospheric circulation as these waves are believed to transport a large amount of vertical moment flux into the mesosphere and lower thermosphere (MLT) region. The propagation nature and sources of these waves have been studied extensively at low- and mid-latitudes, while their extent and nature at the polar regions are largely unknown. Recently, an effort has been put forth to characterize the waves over the Antarctic continent, although the focus of this effort is on the Arctic region. The project's research will establish a long-term climatology of short-period gravity waves in the Arctic, including their dominant source regions, and influences of large-scale tidal and planetary wave motion. The co-located National Institute of Information and Communications Technology (NICT) Rayleigh lidar will provide essential temperature measurements to provide information regarding the vertical wave propagation, individual wave contribution to the Eliassen-Palm (EP) flux, and coupling between the lower and upper atmosphere during stratospheric warming events.

Raw image data acquired in the OH and O₂ airglow emissions. These images represent the first examples of short-period atmospheric gravity waves observed by the CPI airglow imager located at Poker Flat Research Range in interior Alaska.

Raw images of spectacular aurora captured in the OH airglow emissions on the nights of March 2 & 3, 2011.

Instrument

The CPI airglow imager is a state of the art optical instrument designed to remotely sense the faint airglow emissions with a focus on the MLT region. The imager is hosted (to be deployed mid-December 2010) at Poker Flat Research Range (PFRR) (65° N, 147° W) about 100 miles south of the Arctic Circle. The instrument is equipped with a suite of narrow-band filters to isolate various emissions of interest: the green OI line (557.7 nm), the fainter Na D (589.3 nm) and mesospheric O2 (865.5 nm), and a filter to monitor background (572.5 nm). The strong NIR OH broadband emission is detected using a broadband filter (715-930 nm) with a notch at 865.5 nm to exclude the O2 emission. In addition, a filter is included to monitor the thermospheric O2 emission at 630.0 nm, thus extending the imagers capability beyond the MLT range.

The CCD is a Princeton Instruments Acton Pixis 1024B back-illuminated CCD camera and contains 1024 x 1024 pixels (13 x 13 &mu m) providing a large 13.3 x 13.3 mm image area for high spatial resolution images. Its quantum efficiency (QE) is extremely high (>95%) at the green OI line and the Na doublet, while it maintains a relatively high QE of ~45% at the O2 emission, and range from 30-85% throughout the broad OH band. The camera utilizes Princeton Instruments XP cooling technology, enabling cooling down to as low as -80° C, providing ultra low-noise electronics ideally suitable for low light level imaging applications, such as airglow imaging. The dual speed operation at 100 kHz and 2 MHz (16 bit) allows for both slow (airglow) and fast (aurora) image acquisition. The read-out times at these speeds for raw images are 10.0 and 0.58 seconds, respectively. Higher read-out times can be obtained by performing on-CCD binning (e.g. 8 x 8 binning yields read-out times of 0.85 and 0.14 seconds). The camera utilizes a USB2.0 data interface with plug-n-play capabilities and WinView software package for data acquisition, display, and data processing.

Data
Data obtained as part of this project is available through the CPI Data Center. The data hosted includes nightly summary files acquired by the NICT Lidar and raw image data. The image data consists of several images acquired using a suite of standard airglow filters. In addition to the raw image data, nightly summary files, known as keograms, are also available.

Presentations
Fourier Ray Tracing of Atmospheric Gravity Waves Utilizing a Numerical Weather Prediction System, CEDAR-GEM Workshop, Santa Fe, New Mexico, June 26 - July 1, 2011

Mesospheric Imaging and Dynamics over Poker Flat, Alaska, CEDAR-GEM Workshop, Santa Fe, New Mexico, June 26 - July 1, 2011

References
Clairemidi, J., M. Herse, and G. Moreels (1985) Bi-dimensional observations of waves near the mesopause at auroral latitudes, Planet. Space. Sci., 33, 1013-1022.

Goldberg, R. A., D. C. Fritts, F. J. Schmidlin, B. P. Williams, C. L. Croskey, J. D. Mitchell, M. Friedrich, J. M. Russell III, and U. Blum (2006) The MaCWAVE program to study gravity wave influences on the polar mesosphere, Ann. Geophys., SRef-ID: 1432-0576/ag/2006-24-1159, 24, 1159-1173.

Moffat-Griffin, T., R. E. Hibbins, K. Nielsen , M. J. Jarvis, and M. J. Taylor (2008) Observing mesospheric gravity waves with an imaging riometer, J. Atmos. Terr. Phys., 70, 1327-1335, doi:10.1016/j.jastp.2008.04.009.

Nielsen, K., M. J. Taylor, P.-D. Pautet, N. Mitchell, C. Beldon, W. Singer, D. C. Fritts, F. J. Schmidlin, and R. A. Goldberg (2006) Propagation and ducting of short-period gravity waves at high latitudes during the MaCWAVE winter campaign, Ann. Geophys., SRef-ID: 1432-0576/ag/2006-24-1227, 24, 1227-1243.

Nielsen, K., M. J. Taylor, R. G. Stockwell, and M. J. Jarvis (2006) An unusual mesospheric bore event observed at high latitudes over Antarctica, Geophys. Res. Lett., 33, L07803, doi:10.1029/2005GL025649.

Nielsen, K., M. J. Taylor, and M. J. Jarvis (2009) Climatology of short-period mesospheric gravity waves over Halley, Antarctica (76°S, 27°W), J. Atmos. Terr. Phys., 71(8-9), 991-1000, doi:10.1016/j.jastp.2009.04.005.

Stockwell, R. G., M. J. Taylor, K. Nielsen , and M. J. Jarvis (2006) A novel joint space-wavenumber analysis of an unusual Antarctic gravity wave event, Geophys. Res. Lett., 33, L08805, doi:10.1029/2005GL025660.

Suzuki, S., K. Shiokawa, K. Hosokawa, K. Nakamura, and W. K. Hocking (2009) Statistical characteristics of polar cap mesospheric gravity waves observed by an all-sky airglow imager at Resolute Bay, Canada, J. Geophys. Res., 114, A01311, doi:10.1029/2008JA013652.

Taylor, M. J., and K. Henriksen (1989) Electromagnetic coupling in the polar clefts and caps, P. E. Sandholt and A. Egeland (eds.), Springer, New York.

Thurairajah, B., R. L. Collins, V. L. Harvey, R. S. Lieberman, and K. Mizutani (2010) Rayleigh lidar observations of reduced gravity wave activity during the formation of an elevated stratopause in 2004 at Chatanika, Alaska (65°N, 147°W), J. Geophys. Res., 115, D13109, doi:10.1029/2009JD013036.

Thurairajah, B., R. L. Collins, V. L. Harvey, R. S. Lieberman, M. Gerding, K. Mizutani, and J. M. Livingston (2010) Gravity wave activity in the Arctic stratosphere and mesosphere during the 2007-2008 and 2008-2009 stratospheric sudden warming events, J. Geophys. Res., 115, D00N06, doi:10.1029/2010JD014125.

Wang, L., D. C. Fritts, B. P. Williams, R. A. Goldberg, F. J. Schmidlin, and U. Blum (2006) Gravity waves in the middle atmosphere during the MaCWAVE winter campaign, Ann. Geophys., SRef-ID: 1432-0576/ag/2006-24-1209, 1209-1226.

Williams, B. P., D. C. Fritts, C. Y. She, G. Baumgarten, and R. A. Goldberg (2006) Gravity wave propagation, tidal interaction, and instabilities in the mesosphere and lower thermosphere during the winter 2003 MaCWAVE rocket campaign, MaCWAVE special issue of Ann. Geophys., SRef-ID: 1432-0576/ag/2006-24-1199, 24, 1199-1208.

This project is sponsored by NSF and is a collaboration between Computational Physics Inc. (CPI), Utah State University, and the University of Alaska, Fairbanks (UAF).