Latitudinal and Seasonal Asymmetries of the Helium Bulge in the Martian Upper Atmosphere
dc.contributor.author | Gupta, Neha | |
dc.contributor.author | Rao, N. V. | |
dc.contributor.author | Bougher, S. | |
dc.contributor.author | Elrod, M. K. | |
dc.date.accessioned | 2021-10-05T15:06:20Z | |
dc.date.available | 2022-11-05 11:06:18 | en |
dc.date.available | 2021-10-05T15:06:20Z | |
dc.date.issued | 2021-10 | |
dc.identifier.citation | Gupta, Neha; Rao, N. V.; Bougher, S.; Elrod, M. K. (2021). "Latitudinal and Seasonal Asymmetries of the Helium Bulge in the Martian Upper Atmosphere." Journal of Geophysical Research: Planets 126(10): n/a-n/a. | |
dc.identifier.issn | 2169-9097 | |
dc.identifier.issn | 2169-9100 | |
dc.identifier.uri | https://hdl.handle.net/2027.42/170228 | |
dc.description.abstract | In the present study, we investigate the characteristics of helium (He) bulges in the Martian upper atmosphere using He densities and winds measured by the Neutral Gas and Ion Mass Spectrometer (NGIMS) aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. The observations are compared with those predicted by the Mars Global Ionosphere Thermosphere Model (M‐GITM). The results of the present study show that the nightside He bulge is a persistent feature of the Martian upper atmosphere in all seasons. The He densities inside the bulges are 1–2 orders of magnitude greater than those on the dayside. In solstices, the bulges are observed in the winter polar region which is in accordance with the model predictions. In equinoxes, however, the bulges are observed to extend from mid‐latitudes into the southern polar regions (>60°S), which is contrary to the model predictions at mid‐latitudes. These anomalous bulges are predominantly observed in the northern spring equinox and are 10–30 × greater than the modeled ones. During the autumnal equinox, the observed winds depart from the modeled winds. Furthermore, the observed winds point to the southern polar regions where the bulges are observed. Thus, the results of the present study indicate that in equinoxes the regions of local vertical advection, that are responsible for the formation of the bulges, are displaced toward the southern polar regions. The results of the present study point to the need of a larger wind database from NGIMS in southern polar region, particularly during equinoxes.Plain Language SummaryHelium in the upper atmospheres of Earth, Venus, and Mars is known to accumulate on the nightside which is often referred as “He bulge.” The upwelling of winds on the dayside and their downwelling on the nightside, combined with large‐scale circulation, is the primary driver of the bulge formation. The densities inside the He bulge are, in general, 1–2 orders of magnitude greater than those on the dayside. In the present study, the He bulge in the Mars upper atmosphere is investigated using the neutral densities measured by the Mars Atmosphere and Volatile EvolutioN spacecraft and those of a global model. In the northern summer, the He bulge occurs in the winter polar nightside which is in accordance with the model predictions. In spring and autumn, however, the observed He bulges extend from mid‐latitudes into the southern polar region whereas the model predicts their presence at mid‐latitudes. The southern polar bulges in autumn are observed in regions where the observed winds point toward the southern pole. Inclusion of the effects of the upward propagating small‐scale waves on the Martian upper atmosphere in the model, along with a larger observational wind database, is likely to address the data‐model differences.Key PointsIn equinoxes, helium bulges are observed to extend from mid‐latitudes in to the southern polar regions (>60°S)The observed helium densities in the southern polar regions in equinoxes are 10–30 × greater than the modeled onesThe observed winds seem to support the formation of helium bulge in the southern polar region during the autumnal equinox | |
dc.publisher | Wiley Periodicals, Inc. | |
dc.publisher | University of Michigan ‐ Deep Blue Data | |
dc.subject.other | Mars thermosphere | |
dc.subject.other | MAVEN | |
dc.subject.other | NGIMS | |
dc.subject.other | MGITM | |
dc.subject.other | thermospheric winds | |
dc.subject.other | helium bulge | |
dc.title | Latitudinal and Seasonal Asymmetries of the Helium Bulge in the Martian Upper Atmosphere | |
dc.type | Article | |
dc.rights.robots | IndexNoFollow | |
dc.subject.hlbsecondlevel | Geological Sciences | |
dc.subject.hlbtoplevel | Science | |
dc.description.peerreviewed | Peer Reviewed | |
dc.description.bitstreamurl | http://deepblue.lib.umich.edu/bitstream/2027.42/170228/1/jgre21736.pdf | |
dc.description.bitstreamurl | http://deepblue.lib.umich.edu/bitstream/2027.42/170228/2/jgre21736_am.pdf | |
dc.identifier.doi | 10.1029/2021JE006976 | |
dc.identifier.source | Journal of Geophysical Research: Planets | |
dc.identifier.citedreference | Montabone, L., Forget, F., Millour, E., Wilson, R. J., Lewis, S. R., Cantor, B., et al. ( 2015 ). Eight‐year climatology of dust optical depth on Mars. Icarus, 251, 65 – 95. https://doi.org/10.1016/j.icarus.2014.12.034 | |
dc.identifier.citedreference | Leelavathi, V., Venkateswara Rao, N., & Rao, S. V. B. ( 2020 ). Inter‐annual variability of atmospheric gravity waves in the Martian thermosphere: Effects of the 2018 planet‐encircling dust event. Journal of Geophysical Research: Planets, 125, E2020JE006649. https://doi.org/10.1029/2020je006649 | |
dc.identifier.citedreference | Liu, G., England, S., Lillis, R. J., Mahaffy, P. R., Elrod, M., Benna, M., & Jakosky, B. ( 2017 ). Longitudinal structures in Mars’ upper atmosphere as observed by MAVEN/NGIMS. Journal of Geophysical Research: Space Physics, 122, 1258 – 1268. https://doi.org/10.1002/2016JA023455 | |
dc.identifier.citedreference | Liu, G., England, S. L., Lillis, R. J., Withers, P., Mahaffy, P. R., Rowland, D. E., et al. ( 2018 ). Thermospheric expansion associated with dust increase in the lower atmosphere on Mars observed by MAVEN/NGIMS. Geophysical Research Letters, 45, 2901 – 2910. https://doi.org/10.1002/2018GL077525 | |
dc.identifier.citedreference | Liu, X., Wang, W., Thayer, J. P., Burns, A., Sutton, E., Solomon, S. C., et al. ( 2014 ). The winter helium bulge revisited. Geophysical Research Letters, 41, 6603 – 6609. https://doi.org/10.1002/2014GL061471 | |
dc.identifier.citedreference | Mahaffy, P. R., Benna, M., King, T., Harpold, D. N., Arvey, R., Barciniak, M., et al. ( 2014 ). The neutral gas and ion mass spectrometer on the Mars atmosphere and volatile evolution mission. Space Science Reviews, 195, 49 – 73. https://doi.org/10.1007/s11214-014-0091-1 | |
dc.identifier.citedreference | Mahaffy, P. R., Benna, M., Elrod, M., Yelle, R. V., Bougher, S. W., Stone, S. W., & Jakosky, B. M. ( 2015 ). Structure and composition of the neutral upper atmosphere of Mars from the MAVEN NGIMS investigation. Geophysical Research Letters, 42, 8951 – 8957. https://doi.org/10.1002/2015GL065329 | |
dc.identifier.citedreference | Mauersberger, K., Potter, W., & Kayser, D. ( 1976 ). A direct measurement of the winter helium bulge. Geophysical Research Letters, 3, 269 – 271. https://doi.org/10.1029/gl003i005p00269 | |
dc.identifier.citedreference | Medvedev, A. S., & Yiğit, E. ( 2012 ). Thermal effects of internal gravity waves in the Martian upper atmosphere. Geophysical Research Letters, 39, L05201. https://doi.org/10.1029/2012GL050852 | |
dc.identifier.citedreference | Moudden, Y., & Forbes, J. ( 2010 ). A new interpretation of Mars aerobraking variability: Planetary wave‐tide interactions. Journal of Geophysical Research, 115, E09005. https://doi.org/10.1029/2009JE003542 | |
dc.identifier.citedreference | Niemann, H. B., Kasprzak, W. T., Hedin, A. E., Hunten, D. M., & Spencer, N. W. ( 1980 ). Mass spectrometric measurements of the neutral gas composition of the thermosphere and exosphere of Venus. Journal of Geophysical Research, 85, 7817 – 7827. https://doi.org/10.1029/JA085iA13p07817 | |
dc.identifier.citedreference | Pilinski, M., Bougher, S. W., Greer, K., Thiemann, E., Andersson, L., Benna, M., & Elrod, M. ( 2018 ). First evidence of persistent night‐time temperature structures in the neutral thermosphere of Mars. Geophysical Research Letters, 45, 8819 – 8825. https://doi.org/10.1029/2018GL078761 | |
dc.identifier.citedreference | Reber, C., Cooley, J., & Harpold, D. ( 1968 ). Upper atmosphere hydrogen and helium measurements from the Explorer 32 satellite. Space Research, 8, 993. | |
dc.identifier.citedreference | Reber, C. A., & Hays, P. B. ( 1973 ). Thermospheric wind effects on the distribution of helium and argon in the Earth’s upper atmosphere. Journal of Geophysical Research, 78, 2977 – 2991. https://doi.org/10.1029/JA078i016p02977 | |
dc.identifier.citedreference | Roeten, K. J., Bougher, S. W., Benna, M., Mahaffy, P. R., Lee, Y., Pawlowski, D., et al. ( 2019 ). MAVEN/NGIMS thermospheric neutral wind observations: Interpretation using the M‐GITM general circulation model. Journal of Geophysical Research: Planets, 124, 3283 – 3303. https://doi.org/10.1029/2019je005957 | |
dc.identifier.citedreference | Stone, S. W., Yelle, R. V., Benna, M., Elrod, M. K., & Mahaffy, P. R. ( 2018 ). Thermal structure of the Martian upper atmosphere from MAVEN NGIMS. Journal of Geophysical Research: Planets, 123, 2842 – 2867. https://doi.org/10.1029/2018JE005559 | |
dc.identifier.citedreference | Sutton, E. K., Thayer, J. P., Wang, W., Solomon, S. C., Liu, X., & Foster, B. T. ( 2015 ). A self‐consistent model of helium in the thermosphere. Journal of Geophysical Research: Space Physics, 120, 6884 – 6900. https://doi.org/10.1002/2015JA021223 | |
dc.identifier.citedreference | Terada, N., Leblanc, F., Nakagawa, H., Medvedev, A. S., Yiğit, E., Kuroda, T., et al. ( 2017 ). Global distribution and parameter dependences of gravity wave activity in the Martian upper thermosphere derived from MAVEN/NGIMS observations. Journal of Geophysical Research: Space Physics, 122, 2374 – 2397. https://doi.org/10.1002/2016JA023476 | |
dc.identifier.citedreference | Thayer, J., Liu, X., Lei, J., Pilinski, M., & Burns, A. ( 2012 ). The impact of helium on thermosphere mass density response to geomagnetic activity during the recent solar minimum. Journal of Geophysical Research, 117, A07315. https://doi.org/10.1029/2012JA017832 | |
dc.identifier.citedreference | Thiemann, E. M. B., Andersson, L., Lillis, R., Withers, P., Xu, S., Elrod, M., et al. ( 2018 ). The Mars topside ionosphere response to the X8.2 solar flare of 10 September 2017. Geophysical Research Letters, 45, 8005 – 8013. https://doi.org/10.1029/2018gl077730 | |
dc.identifier.citedreference | Thiemann, E. M. B., Chamberlin, P. C., Eparvier, F., Woods, T., Bougher, S. W., Jakosky, B. M., & Templeman, B. ( 2017 ). The MAVEN EUVM spectral irradiance model for solar variability at Mars: Algorithms and results. Journal of Geophysical Research: Space Physics, 122, 2748 – 2767. https://doi.org/10.1002/2016JA023512 | |
dc.identifier.citedreference | Thiemann, E. M. B., Eparvier, F. G., Andersson, L. A., Fowler, C. M., Peterson, W. K., Mahaffy, P. R., et al. ( 2015 ). Neutral density response to solar flares at Mars. Geophysical Research Letters, 42, 8986 – 8992. https://doi.org/10.1002/2015GL066334 | |
dc.identifier.citedreference | Venkateswara Rao, N., Gupta, N., & Kadhane, U. R. ( 2020 ). Enhanced densities in the Martian thermosphere associated with the 2018 planet‐encircling dust event: Results from MENCA/MOM and NGIMS/MAVEN. Journal of Geophysical Research: Planets, 125, e2020JE006430. https://doi.org/10.1029/2020je006430 | |
dc.identifier.citedreference | Williamson, H. N., Johnson, R. E., Leclercq, L., & Elrod, M. K. ( 2019 ). Large amplitude perturbations in the Martian exosphere seen in MAVEN NGIMS data. Icarus, 331, 110 – 115. https://doi.org/10.1016/j.icarus.2019.05.020 | |
dc.identifier.citedreference | Wilson, R. J. ( 2002 ). Evidence for nonmigrating thermal tides in the Mars upper atmosphere from the Mars global surveyor accelerometer experiment. Geophysical Research Letters, 29 ( 7 ), 1120. https://doi.org/10.1029/2001GL013975 | |
dc.identifier.citedreference | Zurek, R. W., Tolson, R. A., Bougher, S. W., Lugo, R. A., Baird, D. T., Bell, J. M., & Jakosky, B. M. ( 2017 ). Mars thermosphere as seen in MAVEN accelerometer data. Journal of Geophysical Research: Space Physics, 122 ( 3 ), 3798 – 3814. https://doi.org/10.1002/2016ja023641 | |
dc.identifier.citedreference | Smith, M. D. ( 2004 ). Interannual variability in TES atmospheric observations of Mars during 1999–2003. Icarus, 167 ( 1 ), 148 – 165. https://doi.org/10.1016/j.icarus.2003.09.010 | |
dc.identifier.citedreference | Benna, M., Bougher, S. W., Lee, Y., Roeten, K. J., Yiğit, E., Mahaffy, P. R., & Jakosky, B. M. ( 2019 ). Global circulation of Mars upper atmosphere. Science, 366, 1363 – 1366. https://doi.org/10.1126/science.aax1553 | |
dc.identifier.citedreference | Benna, M., & Elrod, M. ( 2019 ). NGIMS PDS software interface specification MAVEN‐NGIMS‐SIS‐0001, PDS atmospheres node. Retrieved from http://atmos.pds.nasa.gov/data_and_services/atmospheresdata/MAVEN/ngims.html | |
dc.identifier.citedreference | Bhardwaj, A., Thampi, S. V., Das, T. P., Dhanya, M. B., Naik, N., Vajja, D. P., et al. ( 2016 ). On the evening time exosphere of Mars: Result from MENCA aboard Mars Orbiter Mission. Geophysical Research Letters, 43, 1862 – 1867. https://doi.org/10.1002/2016GL067707 | |
dc.identifier.citedreference | Bougher, S. ( 2021 ). Mars thermospheric helium distributions: M‐GITM simulated datasets for comparison to MAVEN/NGIMS measurements [data set]. University of Michigan ‐ Deep Blue Data. https://doi.org/10.7302/36zc-y350 | |
dc.identifier.citedreference | Bougher, S. W., Blelly, P.‐L., Combi, M., Fox, J. L., Mueller‐Wodarg, I., Ridley, A., & Roble, R. G. ( 2008 ). Neutral upper atmosphere and ionosphere modeling. In A. F. Nagy, A. Balogh, T. E. Cravens, M. Mendillo, & I. Mueller‐Wodarg (Eds.), Comparative aeronomy. Space Sciences Series of ISSI (Vol. 29, pp. 107 – 141 ). Springer. https://doi.org/10.1007/978-0-387-87825-6_4 | |
dc.identifier.citedreference | Bougher, S. W., Cravens, T. E., Grebowksy, J., & Luhmann, J. ( 2015 ). The aeronomy of Mars: Characterization by MAVEN of the upper atmosphere reservoir that regulates volatile escape. Space Science Reviews, 195, 423 – 456. https://doi.org/10.1007/s11214-014-0053-7 | |
dc.identifier.citedreference | Bougher, S. W., Jakosky, B. M., Halekas, J., Grebowsky, J., Luhmann, J., Mahaffy, P., et al. ( 2015 ). Early MAVEN dip deep campaign reveals thermosphere and ionosphere variability. Science, 350, aad0459. https://doi.org/10.1126/science.aad0459 | |
dc.identifier.citedreference | Bougher, S. W., Pawlowski, D., Bell, J. M., Nelli, S., McDunn, T., Murphy, J. R., et al. ( 2015 ). Mars global ionosphere‐thermosphere model: Solar cycle, seasonal, and diurnal variations of the Mars upper atmosphere. Journal of Geophysical Research: Planets, 120, 311 – 342. https://doi.org/10.1002/2014JE004715 | |
dc.identifier.citedreference | Bougher, S. W., Roeten, K. J., Olsen, K., Mahaffy, P. R., Benna, M., Elrod, M., et al. ( 2017 ). The structure and variability of Mars dayside thermosphere from MAVEN NGIMS and IUVS measurements: Seasonal and solar activity trends in scale heights and temperatures. Journal of Geophysical Research: Space Physics, 122, 1296 – 1313. https://doi.org/10.1002/2016JA023454 | |
dc.identifier.citedreference | Cageao, R. P., & Kerr, R. B. ( 1984 ). Global distribution of helium in the upper atmosphere during solar minimum. Planetary and Space Science, 32 ( 12 ), 1523 – 1529. https://doi.org/10.1016/0032-0633(84)90019-9 | |
dc.identifier.citedreference | Elrod, M. K., Bougher, S., Bell, J., Mahaffy, P. R., Benna, M., Stone, S., et al. ( 2017 ). He bulge revealed: He and CO 2 diurnal and seasonal variations in the upper atmosphere of Mars as detected by MAVEN NGIMS. Journal of Geophysical Research: Space Physics, 122, 2564 – 2573. https://doi.org/10.1002/2016JA023482 | |
dc.identifier.citedreference | Elrod, M. K., Bougher, S. W., Roeten, K., Sharrar, R., & Murphy, J. ( 2020 ). Structural and compositional changes in the upper atmosphere related to the PEDE‐2018 dust event on Mars as observed by MAVEN NGIMS. Geophysical Research Letters, 47 ( 4 ), e2019GL084378. https://doi.org/10.1029/2019GL084378 | |
dc.identifier.citedreference | England, S. L., Liu, G., Yiğit, E., Mahaffy, P. R., Elrod, M., Benna, M., et al. ( 2017 ). MAVEN NGIMS observations of atmospheric gravity waves in the Martian thermosphere. Journal of Geophysical Research: Space Physics, 122, 2310 – 2335. https://doi.org/10.1002/2016JA023475 | |
dc.identifier.citedreference | Fritts, D. C., Wang, L., & Tolson, R. H. ( 2006 ). Mean and gravity wave structures and variability in the Mars upper atmosphere inferred from Mars Global Surveyor and Mars Odyssey aerobraking densities. Journal of Geophysical Research, 111, A12304. https://doi.org/10.1029/2006JA011897 | |
dc.identifier.citedreference | Gonzalez‐Galindo, F., Chaufray, J.‐Y., Lopez‐Valverde, M. A., Gilli, G., Forget, F., Leblanc, F., et al. ( 2013 ). Three‐dimensional Martian ionosphere model: The photochemical ionosphere below 180 km. Journal of Geophysical Research, 118, 2105 – 2123. https://doi.org/10.1002/jgre.20150 | |
dc.identifier.citedreference | González‐Galindo, F., López‐Valverde, M. A., Forget, F., García‐Comas, M., Millour, E., & Montabone, L. ( 2015 ). Variability of the Martian thermosphere during eight Martian years as simulated by a ground‐to‐exosphere global circulation model. Journal of Geophysical Research: Planets, 120, 2020 – 2035. https://doi.org/10.1002/2015JE004925 | |
dc.identifier.citedreference | Gupta, N., & Venkateswara Rao, N. ( 2021 ). Latitudinal and seasonal Asymmetries of the helium bulge in the Martian upper atmosphere (version 1). Mendeley Data. https://doi.org/10.17632/jvzcpt65mh.1 | |
dc.identifier.citedreference | Gupta, N., Venkateswara Rao, N., & Kadhane, U. R. ( 2019 ). Dawn‐dusk asymmetries in the Martian upper atmosphere. Journal of Geophysical Research: Planets, 124, 3219 – 3230. https://doi.org/10.1029/2019JE006151 | |
dc.identifier.citedreference | Haberle, R. M., Joshi, M. M., Murphy, J. R., Barnes, J. R., Schofield, J. T., Wilson, G., et al. ( 1999 ). General circulation model simulations of the Mars Pathfinder atmospheric structure investigation/meteorology data. Journal of Geophysical Research, 104, 8957 – 8974. https://doi.org/10.1029/1998JE900040 | |
dc.identifier.citedreference | Hinson, D. P., Wilson, R. J., Smith, M. D., & Conrath, B. J. ( 2003 ). Stationary planetary waves in the atmosphere of Mars during southern winter. Journal of Geophysical Research, 108 ( E1 ), 5004. https://doi.org/10.1029/2002JE001949 | |
dc.identifier.citedreference | Jain, S. K., Bougher, S. W., Deighan, J., Schneider, N. M., Gonzalez‐Galindo, F., Stewart, A. I. F., et al. ( 2020 ). Martian thermospheric warming associated with the Planet Encircling Dust Event of 2018. Geophysical Research Letters, 47 ( 3 ), E2019GL085302. https://doi.org/10.1029/2019GL085302 | |
dc.identifier.citedreference | Johnson, F. S., & Gottlieb, B. ( 1970 ). Eddy mixing and circulation at ionospheric levels. Planetary and Space Science, 18, 1707 – 1718. https://doi.org/10.1016/0032-0633(70)90004-8 | |
dc.identifier.citedreference | Kasprzak, W. T. ( 1969 ). Evidence for a helium flux in the lower thermosphere. Journal of Geophysical Research, 74, 894 – 896. https://doi.org/10.1029/JA074I003P00894 | |
dc.identifier.citedreference | Smith, M. D. ( 2009 ). THEMIS observations of Mars aerosol optical depth from 2002–2008. Icarus, 202 ( 2 ), 444 – 452. https://doi.org/10.1016/j.icarus.2009.03.027 | |
dc.identifier.citedreference | Kasprzak, W. T., Neiman, H. B., Hedin, A. E., Bougher, S. W., & Hunten, D. M. ( 1993 ). Neutral composition measurements by the pioneer Venus neutral mass spectrometer during orbiter re‐entry. Geophysical Research Letters, 20, 2747 – 2750. https://doi.org/10.1029/93GL02241 | |
dc.identifier.citedreference | Keating, G., & Prior, E. ( 1968 ). The winter helium bulge. Space Research, 8, 982. | |
dc.identifier.citedreference | Krasnopolsky, V. A., Bowyer, S., Chakrabarti, S., Gladstone, G. R., & McDonald, J. S. ( 1994 ). First measurement of helium on Mars: Implications for the problem of radiogenic gases on the terrestrial planets. Icarus, 109, 337 – 351. https://doi.org/10.1006/icar.1994.1098 | |
dc.identifier.citedreference | Krasnopolsky, V. A., & Gladstone, G. R. ( 2005 ). Helium on Mars and Venus: EUVE observations and modeling. Icarus, 176, 395 – 407. https://doi.org/10.1016/j.icarus.2005.02.005 | |
dc.identifier.citedreference | Kuroda, T., Medvedev, A. S., & Yiğit, E. ( 2020 ). Gravity wave activity in the atmosphere of Mars during the 2018 global dust storm: Simulations with a high‐resolution model. Journal of Geophysical Research: Planets, 125 ( 11 ), E2020JE006556. https://doi.org/10.1029/2020JE006556a | |
dc.identifier.citedreference | Leblanc, F., Benna, M., Chaufray, J. Y., Martinez, A., Lillis, R., Curry, S., et al. ( 2019 ). First in situ evidence of Mars nonthermal exosphere. Geophysical Research Letters, 46, 4144 – 4150. https://doi.org/10.1029/2019GL082192 | |
dc.identifier.citedreference | Lee, C., Lawson, W. G., Richardson, M. I., Heavens, N. G., Kleinböhl, A., Banfield, D., et al. ( 2009 ). Thermal tides in the Martian middle atmosphere as seen by the Mars Climate Sounder. Journal of Geophysical Research, 114, E03005. https://doi.org/10.1029/2008JE003285 | |
dc.working.doi | NO | en |
dc.owningcollname | Interdisciplinary and Peer-Reviewed |
Files in this item
Remediation of Harmful Language
The University of Michigan Library aims to describe library materials in a way that respects the people and communities who create, use, and are represented in our collections. Report harmful or offensive language in catalog records, finding aids, or elsewhere in our collections anonymously through our metadata feedback form. More information at Remediation of Harmful Language.
Accessibility
If you are unable to use this file in its current format, please select the Contact Us link and we can modify it to make it more accessible to you.