PRESCIENT
PRESCIENT supports long-term, strategically important measurements and capabilities for the wider science community.
I work within the Atmospheric, Ice and Climate team of the British Antarctic Survey (BAS), carrying out research into the processes responsible for climate variability and change in the polar regions, Himalayas, and Andes. This is important because these regions are particularly vulnerable to a wide range of climate change impacts This is predominately achieved using regional atmosphere models and global climate models.
Supervision of students
Postdoctoral research assistants
Previous appointments and Education
Teaching / Training
2026
108) Muszynski, G., A. Orr, I. Roy, G. Di Capua, H. Pritchard, and J. S. Hosking (2026), Using a causal effect network approach to quantify the impact of ENSO teleconnections on summer monsoon precipitation over the Himalayas and key regional circulations, J. Roy. Met. Soc., https://doi.org/10.1002/qj.70114.
107) Zou, X., P. M. Rowe, I. V. Gorodetskaya, A. Orr, D. H. Bromwich, D. Lubin, M. A. Lazzara, Z. Zhang, B. Kawzenuk, J. D. Wille, J. M. Cordeira, N. Hansen, J. Li, P. Gan, and F. M. Ralph, Föhn-Induced Melting over Larsen C Modulated by Atmospheric River Shape, Direction and Landfall Location, Nat. Commun., in press.
106) Pritchard, H., E. C. King, D. J. Goodger, D. Boyle, D. Goldberg, B. Recinos, A. Orr, and D. Regmi (2026), Towards Bedmap Himalayas: a new airborne glacier thickness survey in Khumbu Himal, Nepal, Earth Syst. Sci. Data, 18, 199–217, https://doi.org/10.5194/essd-18-199-2026.
105) Marshall, G. J., R. S. Williams, L. S. Graff, D. Handorf, A. Y. Karpechko, R. H. Köhler, X. Levine, A. Orr, and P. A. Mooney, The Southern Annular Mode and its relationship with Antarctic temperature in contrasting future storylines, Clim. Dyn., 64, https://doi.org/10.1007/s00382-026-08081-8.
104) Davies, B. D., A. Atkinson, A. F. Banwell, M. Brandon, T. Caton Harrison, P. Convey, J. De Rydt, K. Dodds, R. Downie, T. L. Edwards, E. Gilbert, B. Hubbard, K. A. Hughes, G. J. Marshall, A. Orr, J. Rogelj, H. Seroussi, M. Siegert, J. Stroeve, and J. Rumble, The Antarctic Peninsula under present day climate and future low, medium-high and very high emissions scenarios, Front. Environ. Sci., 13, https://doi.org/10.3389/fenvs.2025.1730203.
103) Gumber S., A. Orr, P. Field, F. Covi, H. D. Pritchard, P. Deb, M. Girona-Mata, T. Phillips, E. Potter, C. Thakur, and M. Widmann, Improving snowfall prediction in mountain regions by optimising the high-resolution regional UK Met Office Unified Model with novel lake-based snowfall measurements from supersites in the Alps, Himalayas, and Rockies, Mon. Wea. Rev., under review.
102) Swetha Chittella, S. P., A. Orr, P. Deb and Q. Dalaiden, Recent intensification of extreme precipitation over Antarctica driven by increases in greenhouse gases, The Cryosphere, https://doi.org/10.5194/egusphere-2025-4292, under review.
101) Sangha, I., N. L. Abraham, A. Orr, H. Lu, M. C. Pitts, L. R. Poole, and M. Weimer, Assessment of an updated polar stratospheric cloud parameterisation for the UK Earth System Model (UKESM1.1) within the UK Met Office Unified Model (v13.9) using CALIOP and MLS observations, Geosci. Mod. Dev., https://doi.org/10.5194/egusphere-2026-128, under review.
100) Avilés-Podgurski, L. E., P. Martineau, H. Lu, A. Yamamoto, A. C. Maycock, A. Orr, T. Phillips, T. J. Bracegirdle, A. E. Hogg, G. Muszynski, and A. Fleming, Impact, drivers and pathways of two Arctic atmospheric rivers in April 2020, Weather and Climate Dynamics, https://doi.org/10.5194/egusphere-2025-6285, under review.
99) Tang, H., L. Sihan, J. M. Jones, S. González-Herrero, F. E. L. Otto, A. Orr, J. A. Screen, K. R. Clem, D. Bozkurt, J. L. Catto, C. C. Suitters, M. L. Maclennan, and Y. Sun, Unprecedented 2024 East Antarctic Winter Heatwave Driven by Polar Vortex Weakening and Amplified by Anthropogenic Warming, Nat. Commun., under review.
98) Suitters, C. C., J. A. Screen, J. L. Catto, J. M. Jones, S. Li, A. Orr, A. A. Scaife, and H. Tang, Assessing the Likelihood of Unprecedented Antarctic Heat in the Current Climate, J. Clim., under review.
97) Gilbert, E, J. A. Torres-Alavez, M. G. Hofsteenge, W. J. van de Berg, F. Boberg, O. B. Christensen, C. T. van Dalum, X. Fettweis, S. Gumber, N. Hansen, C. Kittel, C. Lambin, D. Maure, R. Mottram, M. Olesen, A. Orr, T. Phillips, M. van Tiggelen, K. Verro, and P. A. Mooney, The PolarRES dataset: a state-of-the-art regional climate model ensemble for understanding Antarctic climate, The Cryosphere, https://doi.org/10.5194/egusphere-2025-4214, under review.
96) Smith, R. S., T. A. Bilge, T. J. Bracegirdle, P. R. Holland, T. Kuhlbrodt, C. Lang, S. Liddicoat, T. Mitcham, J. Mulcahy, K. A. Naughten, A. Orr, J. Palmieri, A. J. Payne, S. Rumbold, M. Stringer, R. Swaminathan, S. Taylor, J. Walton, and C. Jones, Response of ice sheets, sea-ice and sea level in climate stabilisation and reversibility simulations using a state-of-the-art Earth System Model, Earth System Dynamics, https://doi.org/10.5194/egusphere-2025-4476, under review.
2025
95) Price, R., A. Orr, P. F. Field, G. Mace, and A. Protat (2025), Simulation of Southern Ocean cloud processes using the high-resolution regional UK Met Office Unified Model with interactive aerosols, J. Geophys. Res., 130, https://doi.org/10.1029/2024JD042109.
94) Tazi, K., A. Orr, S. Hosking, and R. E. Turner (2025), Precipitation prediction from large-scale circulation over the Upper Indus Basin using Gaussian processes, Environmental Data Science, 4, https://doi.org/10.1017/eds.2025.10020.
93) Girona-Mata, M., A. Orr, M. Widmann, D. Bannister, D. Ghulam Hussain, S Hosking, J. Norris, D. Ocio, T. Phillips, J. Steiner, and R. E. Turner (2025), Probabilistic precipitation downscaling for ungauged mountain sites: a pilot study for the Hindu Kush Himalaya, Hydrol. Earth Syst. Sci., 29, 3073–3100, https://doi.org/10.5194/hess-29-3073-2025.
92) Swetha Chitella, S. P., A. Orr, and P. Deb (2025), Radiosonde measurements and Polar WRF simulations of low-level wind jets in the Amundsen Sea Embayment, West Antarctica, Adv. Atmos. Sci., https://link.springer.com/article/10.1007/s00376-025-4398-5.
91) Deb, P., D. Bromwich, A. Orr, A. Sena, and K. R. Clem (2025), Recent surge in surface melting of West Antarctic ice shelves linked to Interdecadal Pacific Oscillation, Commun. Earth Environ., 6, 99, https://doi.org/10.1038/s43247-025-02077-8.
90) Gilbert, E., D. Pishniak, J. A. Torres, A. Orr, M. Maclennan, N. Wever, and K. Verro (2025), Extreme precipitation associated with atmospheric rivers over West Antarctic ice shelves: insights from kilometre-scale regional climate modelling, The Cryosphere, 19, 597–618, https://doi.org/10.5194/tc-19-597-2025.
89) Bharati, P., P. Deb, K. M. R. Hunt, A. Orr, M. K. Dash (2025), ENSO-induced latitudinal variation of the subtropical jet modulates extreme winter precipitation over the Western Himalaya, Adv. Atmos. Sci., 42, 427–437, https://doi.org/10.1007/s00376-024-4057-2.
88) Jelmer, J., V. J. Heinrich, M. Lamersc, D. Liggett, and A. Orr (2025), Toward strengthened forecasting services for polar regions, Bull. Amer. Meteor. Soc., https://doi.org/10.1175/BAMS-D-25-0153.1.
87) Fyffe, C. L., E. Potter, E. Miles, T. E. Shaw, M. McCarthy, A. Orr, E. Loarte, K. Medina, S. Fatichi, R. Hellström, M. Baraer, E. Mateo, A. Cochachin, M. Westoby, and F Pellicciotti (2025), Snow is important too: the snowfall dynamics and contribution of snow melt and ice melt to runoff in the Peruvian Andes, Commun. Earth Environ., 6, 434, https://doi.org/10.1038/s43247-025-02379-x.
2024
86) Tazi, K., A. Orr, J. Hernandez-González, S. Hosking, and R. Turner (2024), Downscaling Precipitation in High Mountain Asia using Multi-Fidelity Gaussian Processes: Improved Estimates from ERA5, Hydrol. Earth Syst. Sci., 28, 4903–4925, https://doi.org/10.5194/hess-28-4903-2024.
85) Hansen, N., A. Orr, X. Zou, F. Boberg, T. J. Bracegirdle, E. Gilbert, P. L. Langen, M. A. Lazzara, R. Mottram, T. Phillips, R. Price, S. B. Simonsen, and S. Webster (2024), The importance of cloud phase when assessing surface melting in an offline coupled firn model over Ross Ice shelf, West Antarctica, The Cryosphere, 18, 2897–2916, https://doi.org/10.5194/tc-18-2897-2024.
84) Angus, M., M. Widmann, A. Orr, R. Ashrit, G. C. Leckebusch, and A. Mitra (2024), A comparison of two statistical postprocessing methods for heavy precipitation forecasts over India during the summer monsoon, Q. J. Roy. Met. Soc., 150, 1865–1883, https://doi.org/10.1002/qj.4677.
83) Levine, X., R. Williams, G. Marshall, A. Orr, L. S. Graff, D. Handorf, A. Karpechko, R. Köhler, R. Wijngaard, N. Johnston, H. Lee, L. Nieradzik, and P. Mooney (2024), Storylines of Summer Arctic climate change constrained by Barents-Kara Sea and Arctic tropospheric warming for climate risks assessment, Earth Syst. Dynam., 15, 1161–1177, https://doi.org/10.5194/esd-15-1161-2024.
82) Williams, R. S., G. Marshall, X. Levine, L. S. Graff, D. Handorf, N. Johnston, A. Karpechko, A. Orr, W. J. van de Berg, R. Wijngaard, and P. Mooney (2024), Antarctic climate change from CMIP6 models, based on storylines of future sea ice loss and stratospheric polar strength, J. Clim., 37, 2157–2178, https://doi.org/10.1175/JCLI-D-23-0122.1.
2023
81) Orr, A., P. Deb, K. Clem, E. Gilbert, D. Bromwich, F. Boberg, S. Colwell, N. Hansen, M. Lazzara, P. Mooney, R. Mottram, N. Niwano, T. Phillips, D. Pishniak, C. Riejmer, W. J. van de Berg, S. Webster, and X. Zou (2023), Characteristics of surface “melt potential” over Antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19, J. Clim., 36, 3357–3383, https://doi.org/10.1175/JCLI-D-22-0386.1.
80) Orr, A., Policy-relevant science highlights from the Antarctic CORDEX project, World Meteorological Organisation Antarctic Treaty Paper, 2023, https://www.ats.aq/devAS/Meetings/Documents/95.
79) Lu, H., A. Orr, J. King, T. Phillips, E. Gilbert, S. Colwell, and T. Bracegirdle, Extreme warm events in the South Orkney Islands, Southern Ocean: Compounding influence of atmospheric rivers and fohn conditions, Q. J. Roy. Met. Soc., 149, 3645–3668, http://doi.org/10.1002/qj.4578.
78) Potter, E. R., C. L. Fyffe, A. Orr, D. J. Quincey, A. N. Ross, S. Rangecroft, K. Medina, H. Burns, A. Llacza, G. Jacome, R. A. Hellstrom, J. Castro, A. Cochachin, N. Montoya, E. Loarte, and F. Pellicciotti (2023), Projected increases in climate extremes and droughts in the Peruvian Andes, 1980-2100, npj Clim. Atmos. Sci., 6, 96, https://doi.org/10.1038/s41612-023-00409-z.
77) Zhang, X. D., X. Y. Chen, A. Orr, J. E. Overland, T. Vihma, M. Y. Wang, Q. H. Yang, and R. H. Zhang (2023), Preface to the special issue on Changing Arctic Climate and Low/Mid-latitudes Connections, Adv. Atmos. Sci., 40, 2135−2137, https://doi.org/10.1007/s00376-023-3015-8.
76) Lu, H., S. Colwell, J. King, A. Orr, T. Phillips, E. Dobb, J. Xue, S. Kucieba, G. Phillips, and G. Marshall, Temperature variation in the South Orkney Islands, Southern Ocean, Int. J. Climatol., 43, 7987–8004, https://doi.org/10.1002/joc.8302.
2022
75) Orr, A., B. Ahmad, U. Alam, A. Appadurai, Z. P. Bharucha, H. Biemans, et al. (2022), Knowledge priorities on climate change and water in the Upper Indus Basin: A horizon scanning exercise to identify the Top 100 research questions in social and natural sciences, Earth’s Future, 10, https://doi.org/10.1029/2021EF002619.
74) Gilbert, E., A. Orr, J. King, I. Renfrew, and T. Lachlan-Cope (2022), A 20-year study of melt processes over Larsen C Ice Shelf using a high-resolution regional atmospheric model: Part 1, Model configuration and validation, J. Geophys. Res., 127, https://doi.org/10.1029/2021JD034766.
73) Gilbert, E., A. Orr, I. Renfrew, J. King, and T. Lachlan-Cope (2022), A 20-year study of melt processes over Larsen C Ice Shelf using a high-resolution regional atmospheric model: Part 2, Drivers of surface melt, J. Geophys. Res., 127, https://doi.org/10.1029/2021JD036012.
72) Carter, J., A. Leeson, A. Orr, C. Kittel, J. Melchior van Wessem (2022), Variability in Antarctic surface climatology across region climate models and reanalysis datasets, The Cryosphere, 16, 3815–3841, https://doi.org/10.5194/tc-16-3815-2022.
71) Lee, H., N. Johnston, L. Nieradzik, A. Orr, R. H. Mottram, W. J. van de Berg, and P. A. Mooney (2022), Towards effective collaborations between regional climate modelling and impacts relevant to modelling studies in Polar Regions, Bull. Amer. Meteor. Soc., 103, https://doi.org/10.1175/BAMS-D-22-0102.1.
70) Hansen, N., S. B. Simonsen, F. Boberg, C. Kittel, A. Orr, N. Souverijns, J. M. van Wessem, and R. Mottram (2022), Brief communication: Impact of common ice mask in surface mass balance estimates over the Antarctic ice sheet, The Cryosphere, 16, 711–718, https://doi.org/10.5194/tc-16-711-2022.
2021
69) Orr, A., International Panel on Climate Change (IPCC), AR6 Atlas of Regional Climate Information, Antarctic Chapter, contributing author. In Gutiérrez, J. M., R. G. Jones, G. T. Narisma, L. M. Alves, M. Amjad, I. V. Gorodetskaya, M. Grose, N. A. B. Klutse, S. Krakovska, J. Li, D. Martínez-Castro, L. O. Mearns, S. H. Mernild, T. Ngo-Duc, B. van den Hurk, and J.-H. Yoon, 2021: Atlas. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1927–2058, doi:10.1017/9781009157896.021.
68) Orr, A., A. Kirchgaessner, J. King, T. Phillips, E. Gilbert, A. Elvidge, M. Weeks, A. Gadian, P. Kuipers Munneke, M. van den Broeke, S. Webster, and D. McGrath (2021), Comparison of kilometre and sub-kilometre scale simulations of a foehn wind event over the Larsen C Ice Shelf using the Met Office Unified Model (MetUM), Q. J. Roy. Met. Soc., 147, 3472-3492, https://doi.org/10.1002/qj.4138.
67) Orr, A., H. Lu, P. Martineau, E. P. Gerber, G. Marshall, and T. Bracegirdle (2021), Is our dynamical understanding of the circulation changes associated with the Antarctic ozone hole sensitive to the choice of reanalysis dataset?, Atmos. Chem. Phys., 21, 7451–7472, https://doi.org/10.5194/acp-21-7451-2021.
66) Fyffe, C., E. Potter, S. Fugger, A. Orr, S. Fatichi, K. Medina, R. A. Hellstrom, M. Bernat, C. Aubry-Wake, W. Gurgiser, L. B. Perry, W. Suarez, D. J. Quincey, E. Loarte, and F. Pellicciotti (2021), The energy and mass balance of Peruvian glaciers, J. Geophys. Res., 126, e2021JD034911, https://doi.org/10.1029/2021JD034911.
65) Mottram, R., N. Hansen, C. Kittel, M. van Wessem, C. Agosta, C. Amory, F. Boberg, W. J. van de Berg, X. Fettweis, A. Gossart, N. P. M. van Lipzig, E. van Meijgaard, A. Orr, T. Phillips. S. Webster, S. B. Simonsen, and N. Souverijns (2021), What is the surface mass balance of Antarctica? An intercomparison of regional climate model estimates, The Cryosphere, 15, 3751–3784, https://doi.org/10.5194/tc-15-3751-2021.
64) Tritscher, I., M. C. Pitts, L. R. Poole, S. P. Alexander, F. Cairo, M. P. Chipperfield, J.-U. Groob, M. Hopfner, A. Lambert, B. P. Luo, S. Molleker, A. Orr, R. Salawitch, M. Snels, R. Spang, W. Woiwode, and T. Peter (2021), Polar Stratospheric Clouds: Satellite Observations, Processes, and Role in Ozone Depletion, Rev. Geophys., 59, https://doi.org/10.1029/2020RG000702.
63) Gerber, E. P., P. Martineau, B. Ayarzaguena, D. Barriopedro, T. J. Bracegirdle, A. H. Butler, N. Calvo, S. C. Hardiman, P. Hitchcock, M. Iza, U. Langematz, H. Lua, G. Marshall, A. Orr, F. M. Palmeiro, S.-W. Son, and M. Taguchi (2021), Extratropical Stratosphere–troposphere Coupling, In Stratosphere-troposphere Processes and their Role in Climate (SPARC) Reanalysis Intercomparison Project (S-RIP) (Chap. 6), M. Fujiwara, G. L. Manney, L. Gray, and J. S. Wright, Eds., Oberpfaffenhofen Germany, SPARC, p. 219-262.
62) King, J. C., J. Turner, S. Colwell, H. Lu, A. Orr, T. Phillips, and S. Hosking (2021), Inhomogeneity of the surface air temperature record from Halley, Antarctica, J. Clim., 34, 4771–4783, https://doi.org/10.1175/JCLI-D-20-0748.1.
2020
61) Orr, A., S. Hosking, A. Dellon, L. Hoffmann, R. Spang, T. Moffat-Griffin, J. Keeble, L. Abraham, and P. Braesicke (2020), PSCs initiated by mountain waves in a global chemistry-climate model: A missing piece in fully modelling polar stratospheric ozone depletion, Atmos. Chem. Phys., 20, 12,483-12,497, https://doi.org/10.5194/acp-20-12483-2020.
60) Potter, E., A. Orr, I. Willis, D. Bannister, and P. Wagnon (2020), Meteorological impacts of a novel debris-covered glacier category in a regional climate model across a Himalayan catchment, Atmos. Sci. Lett., 22, https://doi.org/10.1002/asl.1018.
59) Gilbert, E., A. Orr, J. King, I. Renfrew, T. Lachlan-Cope, P. Field, and I. Boutle (2020), Summertime cloud phase strongly influences surface melting on the Larsen C ice shelf Antarctica, Q. J. Roy. Met. Soc., 146, 1575-1589, https://doi.org/10.1002/qj.3753.
58) Pope, J., A. Orr, G. J. Marshall, and N. L. Abraham (2020), Non-additive response of the high-latitude Southern Hemisphere climate to aerosol forcing in a climate model with interactive chemistry, Atmos. Sci. Lett., 21, https://doi.org/10.1002/asl.1004.
57) Sedlar, J., M. Tjernstrom, A. Rinke, A. Orr, J. Cassano, X. Fetweis, G. Heinemann, M. Seefeldt, A. Solomon, H. Matthes, T. Phillips, and S. Webster (2020), Confronting Arctic troposphere, clouds, and surface energy budget representations in regional climate models with observations, J. Geophys. Res., 125, https://doi.org/10.1029/2019JD031783.
56) Inoue, J., K. Sato, A. Rinke, J. J. Cassano, X. Fettweis, G. Heinemann, H. Matthes, A. Orr, T. Phillips, M. Seefeldt, A. Solomon, and S. Webster (2020), Clouds and radiation processes in regional climate models evaluated using observations over the ice-free Arctic Ocean, J. Geophys. Res.,126, https://doi.org/10.1029/2020JD033904.
55) Dell, R., N. Arnold, I. Willis, A. Banwell, A. Williamson, H. Pritchard, and A. Orr (2020), Lateral meltwater transfer across an Antarctic ice shelf’, The Cryosphere, 14, 2313–2330, https://doi.org/10.5194/tc-14-2313-2020.
2019
54) Bannister, D., A. Orr, S. K. Jain, I. P. Holman, A. Momblanch, T. Phillips, A. J. Adeloye, B. Snapir, T. W. Waine, and J. S. Hosking (2019), Bias correction of high‐resolution regional climate model precipitation output gives the best estimates of precipitation in Himalayan catchments, J. Geophys. Res., 124, 14,220–14,239, https://doi.org/10.1029/2019JD030804.
53) Gumber, S., S. Ghosh, A. Orr, S. Kumar, and J. Pope (2019), On the microphysical processing of aged combustion aerosols impacting warm rain microphysics over Asian megacities, Theor. Appl. Climatol., 139, 1479-1491, https://doi.org/10.1007/s00704-019-03042-0.
52) Prasad, V., A. V. Kulkarni, S. Pradeep, S. Pratibha, S. A. Tawde, T. Shirsat, A. R. Arya, A. Orr, and D. Bannister (2019), Large losses in glacier area and water availability by the end of the century under high greenhouse gas emission scenario, Satluj basin, Himalaya, Curr. Sci., 116, 1721-1730, https://doi.org/10.18520/cs/v116/i10/1721-1730.
2018
51) Clem, K., A. Orr, and J. Pope (2018), The Springtime Influence of Natural Tropical Pacific Variability on the Surface Climate of the Ross Ice Shelf, West Antarctica: Implications for Ice Shelf Thinning, Sci. Rep., 8, https://doi.org/10.1038/s41598-018-30496-5.
50) Deb., P., A. Orr, D. H. Bromwich, J. P. Nicholas, J. Turner, and J. S. Hosking (2018), Summer drivers of atmospheric variability affecting ice shelf thinning in the Amundsen Sea Embayment, West Antarctica, Geophys. Res. Lett., 45, 4124-4133, https://doi.org/10.1029/2018GL077092.
49) Potter, E. R., A. Orr, I. C. Willis, D. Bannister, and F. Salerno (2018), Dynamical drivers of the local wind regime in a Himalayan valley, J. Geophys. Res., https://doi.org/10.1029/2018JD029427.
48) Spang, R., L. Hoffmann, R. Muller, J.-U. Groob, I. Tritscher, M. Hopfner, M. Pitts, A. Orr, and M. Riese (2018), A climatology of polar stratospheric cloud composition between 2002 and 2012 based on MIPAS/Envisat observations, Atmos. Chem. Phys., 18, 5089-5113, https://doi.org/10.5194/acp-18-5089-2018.
47) Kuipers Munneke, P., A. J. Luckman, S. L. Bevan, C. J. P. P. Smeets, E. Gilbert, M. R. van den Broeke, W. Wang, C. Zender, B. Hubbard, D. Ashmore, A. Orr, and J. C. King (2018), Intense winter surface melt on an Antarctic ice shelf’, Geophys. Res. Lett., 45, https://doi.org/10.1029/2018GL077899.
46) Widmann, M., R. Blake, K.P. Sooraj, A. Orr, J. Sanjay, A. Karumuri, A. K Mitra, E. N. Rajagopal, A .F. Van Loon, D. M. Hannah, N. Barrand, R. Singh, V. Mishra, F. Sugden, and D. S. Arya (2018), Current Opportunities and Challenges in Developing Hydro-Climatic Services in the Himalayas: Report of India-UK Water Center Pump Priming Project 2017, Center for Ecology & Hydrology, Wallingford and Indian Institute of Tropical Meteorology, Pune.
2017
45) Orr, A., C. Listowski, M. Couttet, E. Collier, W. Immerzeel, P. Deb, and D. Bannister (2017), Sensitivity of simulated summer monsoonal precipitation in Langtang Valley, Himalaya to cloud microphysics schemes in WRF, J. Geophys. Res., 122, 6298-6318, https://doi.org/10.1002/2016JD025801.
43) Orr, A., Regional climate downscaling through the Antarctic CORDEX project, World Meteorological Organisation Antarctic Treaty Paper, 2017, https://www.ats.aq/devAS/Meetings/Documents/82.
44) Turner, J., A. Orr, H. Gudmundsson, A. Jenkins, R. G. Bingham, C.-D. Hilenbrand, and T. J. Bracegirdle (2017), Atmosphere-ocean-ice interactions in the Amundsen Sea Embayment, West Antarctica, Rev. Geophys., 55, 235-276, https://doi.org/10.1002/2016RG000532.
43) Alexander, S., A. Orr, S. Webster, and D. Murphy (2017), Observations and fine-scale model simulations of gravity waves over Davis, East Antarctica (69S, 78E), J. Geophys. Res., 122, 7355-7370, https://doi.org/10.1002/2017JD026615.
42) Hoffman, L., R. Spang, A. Orr, M. J. Alexander, L. A. Holt, and O. Stein (2017), A decadal satellite record of gravity wave activity to study polar stratospheric cloud formation, Atmos. Chem. Phys., 17, 2901-2920, https://doi.org/10.5194/acp-17-2901-2017.
41) Pope, J. O., P. R. Holland, A. Orr, G. J. Marshall, and T. Phillips (2017), The impacts of El Niño on the observed sea ice budget of West Antarctica, Geophys. Res. Lett., 44, 6200-6208, https://doi.org/10.1002/2017GL073414.
40) Zhang, X., T. Jung, M. Wang, Y. Luo, T. Semmler, and A. Orr (2017), Preface to the special issue: Towards improving understanding and prediction of Arctic change and its linkage with Eurasian mid-latitude weather and climate, Adv. Atmos. Sci., 35, 1-4, https://doi.org/10.1007/s00376-017-7004-7.
39) Moffat-Griffin, T., M. J. Taylor, T. Nakamura, A. J. Kavanagh, J. S. Hosking, and A. Orr (2017), 3rd Antarctic Gravity Wave Instrument Network (ANGWIN) science workshop, Adv. Atmos. Sci., 32, 1-3, https://doi.org/10.1007/s00376-016-6197-5.
38) King, J., A. Kirchgaessner, S. Bevan, A. D. Elvidge, P. Kuipers Munneke, A. Luckman, A. Orr, I. A. Renfrew, M. R. van den Broeke (2017), The impacts of fohn winds on surface energy balance during the 2010-2011 melt season over Larsen C Ice Shelf, Antarctica, J. Geophys. Res., 122, 12,062-12,076, https://doi.org/10.1002/2017JD026809.
37) Bramberger, M., A. Dornbrack, K. Bossert, B. Ehard, D. C. Fritts, B. Kaifler, C. Mallaun, A. Orr, P.-D. Pautet, M. Rapp, M. J. Taylor, S. Vosper, B. P. Williams, and B. Witschas (2017), Does strong tropospheric forcing cause large-amplitude mesospheric gravity waves? – A DEEPWAVE case study, J. Geophys. Res., 122, 11,422– 11,443, https://doi.org/10.1002/2017JD027371.
2016
36) Hosking, S., A. Orr, T. Bracegirdle, and J. Turner (2016), Future circulation changes off West Antarctica: Sensitivity of the Amundsen Sea Low to projected anthropogenic forcing, Geophys. Res. Lett., 43, 367-376, https://doi.org/10.1002/2015GL067143.
35) Deb, P., A. Orr, J. S. Hosking, T. Phillips, J. Turner, D. Bannister, J. Pope, and S. Colwell (2016), An assessment of the Polar WRF representation of near-surface meteorological variables over West Antarctica, J. Geophys. Res., 121, 1532-1548, https://doi.org/10.1002/2015JD024037.
34) Jones, R. W., I. A. Renfrew, A. Orr, B. G. M. Webber, D. M. Holland, and M. A. Lazzara (2016), Evaluation of four global reanalysis products using in situ observations in the Amundsen Sea Embayment, Antarctica, J. Geophys. Res., 121, 6240-6257, https://doi.org/10.1002/2015JD024680.
33) Elvidge, A., I. Renfrew, J. King, A. Orr, and T. A. Lachlan-Cope (2016), Foehn warming distributions in non-linear and linear flow regimes: A focus on the Antarctic Peninsula, Q. J. Roy. Met. Soc., 142, 618-631, https://doi.org/10.1002/qj.2489.
32) Spang, R., L. Hoffmann, M. Hopfner, S. Griessbach, R Muller, M. C. Pitts, A. Orr, and M. Riese (2016), A multi-wavelength classification method for polar stratospheric cloud types using infrared limb spectra, Atmos. Meas. Tech., 9, 3619-3639, https://doi.org/10.5194/amt-9-3619.
2015
31) Orr, A., J. S. Hosking, L. Hoffmann, J. Keeble, S. M. Dean, H. K. Roscoe, L. Abraham, S. Vosper, and T. Phillips (2015), Inclusion of mountain wave-induced cooling for the formation of PSCs over the Antarctic Peninsula in a chemistry-climate model, Atmos. Chem. Phys., 15, 1071-1086, https://doi.org/10.5194/acp-15-1071-2015.
30) Orr, A. and J. C. R. Hunt, Wind jets and associated variations in cloudiness along coastlines and in valleys associated with Coriolis effects, Met Office Forecast Handbook, 2015.
29) Elvidge, A., I. Renfrew, J. King, A. Orr, T. A. Lachlan-Cope, M. Weeks, and S. L. Gray (2014), Foehn jets over the Larsen C Ice Shelf, Antarctica, Q. J. Roy. Met. Soc., 141, 698-713, https://doi.org/10.1002/qj.2382.
28) King, J. C., A. Gadian, A. Kirchgaessner, P. Kuipers Munneke, T. A. Lachlan-Cope, A. Orr, C. Reijmer, M. R. van den Broeke, J. M. van Wessem, and M. Weeks (2015), Validation of the summertime surface energy budget of Larsen C Ice Shelf (Antarctica) as represented in three high-resolution atmospheric models, J. Geophys. Res., https://doi.org/10.1002/2014JD022604.
2014
27) Orr, A., T. Phillips, S. Webster, A. Elvidge, M. Weeks, S. J. Hosking, and J. Turner (2014), Met Office Unified Model high resolution simulations of a strong wind event in Antarctica, Q. J. Roy. Met. Soc., 140, 2287-2297, https://doi.org/10.1002/qj.2296.
26) Hosking, J. S., D. Bannister, A. Orr, J. King, E. Young, and T. Phillips (2014), Orographic forcing of surface winds over the shelf waters adjacent to South Georgia, Atmos. Sci. Lett., 16, 50-55, https://doi.org/10.1002/asl2.519.
25) Meredith, M., A. Orr, J. Shanklin, and J. Turner, Assessment for Decision-Makers: Scientific Assessment of Ozone Depletion, World Meteorological Organisation, 46pp, 2014.
2013
24) Orr, A., T. J. Bracegirdle, J. S. Hoskings, W. Feng, H. Roscoe, and J. D. Haigh (2013), Strong dynamical modulation of the cooling of the polar stratosphere associated with the Antarctic ozone hole, J. Climate, 26, 662-668, https://doi.org/10.1175/JCLI-D-12-00480.1.
23) Orr, A., Mesoscale modelling method development in the offshore wind accelerator program: Comparison of UM and HIRLAM models. Cambridge Environmental Research Consultants, Cambridge, UK, 2013.
22) Hosking, J. S., A. Orr, G. J. Marshall, J. Turner, and T. Phillips (2013), The influence of the Amundsen-Bellingshausen Seas Low on the climate of West Antarctica and its representation in coupled climate model simulations, J. Climate, 26, 6633-6648, https://doi.org/10.1175/JCLI-D-12-00813.1.
21) Marshall, G. J., A. Orr, and J. Turner (2013), A predominant reversal in the relationship between the SAM and East Antarctic temperatures during the 21st Century, J. Climate, 26, 5196-5204, https://doi.org/10.1175/JCLI-D-12-00671.1.
2012
20) Orr, A., T. J. Bracegirdle, J. S. Hoskings, T. Jung, J. D. Haigh, T. Phillips, and W. Feng (2012), Possible dynamical mechanisms for Southern Hemisphere climate change due to the ozone hole, J. Atmos. Sci., 69, 2917-2932, https://doi.org/10.1175/JAS-D-11-0210.1.
19) Turner, J., T. Phillips, J. S. Hosking, G. J. Marshall, and A. Orr (2012), The Amundsen Sea low, Int. J. Climatol., https://doi.org/10.1002/joc.3558.
2010
18) Orr, A., P. Bechtold, J. Scinocca, M. Ern, and M. Janiskova (2010), Improved middle atmosphere climate and forecasts in the ECMWF model through a non-orographic gravity wave drag parametrization, J. Climate, 23, 5905-5926, https://doi.org/10.1175/2010JCLI3490.1.
17) Jung, T., G. Balsamo, P. Bechtold, A. C. M. Beljaars, M. Kohler, M. J. Miller, J.-J. Morcrette, A. Orr, M. J. Rodwell, and A. M. Tomkins (2010), The ECMWF model climate: Recent progress through improved physical parametrizations, Q. J. Roy. Met. Soc., 136, 1145-1160, https://doi.org/10.1002/qj.634.
2009
16) Orr, A., and P. Bechtold (2009), Improvement in the capturing of short-range warm season orographic precipitation in the ECMWF model, Meteorol. Atmos. Phys., 103, 15-23, https://doi.org/10.1007/s00703-008-0288-5.
15) Orr, A., The representation of non-orographic gravity waves in the IFS Part II: A physically based spectral parametrization, European Centre for Medium-range Weather Forecasting (ECMWF) technical memo no. 593, ECMWF, Reading, UK, doi: 10.21957/jpko88tx6, https://www.ecmwf.int/node/11446, 2009.
14) Orr, A., and N. Wedi, The representation of non-orographic gravity waves in the IFS Part I: Assessment of the middle atmosphere climate with Rayleigh friction, ECMWF technical memo no. 592, ECMWF, Reading, UK, doi: 10.21957/45nr8vsb, https://www.ecmwf.int/node/11447, 2009.
13) Turner, J., S. N. Chenoli, A. abu Samah, G. Marshall, T. Phillips, and A. Orr (2009), Strong wind events in the Antarctic, J. Geophys. Res., 114, D18103, https://doi.org/10.1029/2008JD011642.
12) Turner, J., J. C. Comiso, G. J. Marshall, T. A. Lachlan-Cope, T. Bracegirdle, T. Maksym, M. P. Meredith, Z. Wang, and A. Orr (2009), Non-annular atmospheric circulation change induced by stratospheric ozone depletion and its role in the recent increase of Antarctic sea ice extent, Geophys. Res. Lett., 36, L08502, https://doi.org/10.1029/2009GL037524.
11) Turner, J., P. Anderson, T. Lachlan-Cope, S. Colwell, T. Phillips, A. Kirchgaessner, G. J. Marshall, J. C. King, T. J. Bracegirdle, D. G. Vaughan, V. Lagun, and A. Orr (2009), Record low surface air temperature at Vostock station, Antarctica’, J. Geophys. Res., 114, D24102, https://doi.org/10.1029/2009JD012104.
2008
10) Orr, A., G. J. Marshall, J. C. R. Hunt, J. Sommeria, C. Wang, N. van Lipzig, D. Cresswell, and J. C. King (2008), Characteristics of airflow over the Antarctic Peninsula and its response to recent strengthening of westerly circumpolar winds, J. Atmos. Sci., 65, 1396-1413, https://doi.org/10.1175/2007JAS2498.1.
9) Van Lipzig, N. P. M., G. J. Marshall, A. Orr, and J. C. King (2008), The relationship between the southern hemisphere annular mode and Antarctic Peninsula summer temperatures: Analysis of a high-resolution model, J. Climate, 21, 1649–1668, https://doi.org/10.1175/2007JCLI1695.1.
2007
8) Orr, A., Evaluation of revised parameterization of sub-grid orographic drag, ECMWF technical memo no. 536, ECMWF, Reading, UK, doi:10.21957/1yye3n6ik, https://www.ecmwf.int/node/11452, 2007.
2006
7) Marshall, G. J., A. Orr, N. van Lipzig, and J. C. King (2006), The impact of a changing Southern Hemisphere Annular Mode on Antarctic Peninsula summer temperatures, J. Climate, 19, 5388-5404, https://doi.org/10.1175/JCLI3844.1.
2005
6) Orr, A., J. C. R. Hunt, R. Capon, J. Sommeria, D. Cresswell, and A. Owinoh (2005), Coriolis effects on wind jets and cloudiness along coasts, Weather, 60, 291-299, https://doi.org/10.1256/wea.219.04.
5) Orr, A., E. Hanna, J. C. R. Hunt, J. Cappelen, K. Steffen, and A. Stephens (2005), Characteristics of stable flows over Southern Greenland, Pure Appl. Geophys., 162, 1747-1778, https://doi.org/10.1007/s00024-005-2691-x.
4) Owinoh, A., J. C. R. Hunt, A. Orr, P. Clark, R. Klein, H. J. S. Fernando, and F. T. N. Nieuwstadt (2005), Effects of changing surface heat flux on the atmospheric boundary layer flow over flat terrain, Bound.-Layer Meteorol., 116, 331-361, https://doi.org/10.1007/s10546-004-2819-z.
2004
3) Orr, A., D. Cresswell, G. J. Marshall, J. C. R. Hunt, J. Sommeria, and C. G. Wang (2004), A ‘low-level’ explanation for the recent large warming trend over the western Antarctic Peninsula involving blocked winds and changes in zonal circulation, Geophys. Res. Lett., 31, L06204, https://doi.org/10.1029/2003GL019160.
2) Hunt, J. C. R., A. Orr, J. W. Rottman, and R. Capon (2004), Coriolis effects in mesoscale flows with sharp changes in surface conditions, Q. J. Roy. Met. Soc., 130, 2703-2731, https://doi.org/10.1256/qj.04.14.
2003
1) Hunt, J. C. R., A. Orr, D. Cresswell, and A. Owinoh (2003), Coriolis effects in mesoscale shallow layer flows, Proceedings of the International Symposium on Shallow Flows (Eds. G. H. Jirka and W. S. J. Uijttewaal), Delft, June 16-18, 117-124.
Pritchard, H., King, E., Goodger, D., Boyle, D., Goldberg, D., Recinos, B., & Orr, A. (2025). Raw and processed helicopter-borne radio-echo sounding ice thickness data from the glaciers of the Khumbu Himal, Nepal (2019) (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/e39647f5-fb72-4d16-acbd-9784ed2167b8
Potter, E., Fyffe, C., Orr, A., Quincey, D., Ross, A., Rangecroft, S., Medina, K., Burns, H., Llacza, A., Jacome, G., Hellstrom, R., Castro, J., Cochachin, A., Montoya, N., Loarte, E., & Pellicciotti, F. (2023). WRF regional climate model output over Peru, and Cordillera Blanca and Vilcanota-Urubamba regions, Peru, from 1980 to 2018 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/7f3e4cfc-b75b-4758-85fc-58634bd7b1d1
Potter, E., Fyffe, C., Orr, A., Quincey, D., Ross, A., Rangecroft, S., Medina, K., Burns, H., Llacza, A., Jacome, G., Hellstrom, R., Castro, J., Cochachin, A., Montoya, N., Loarte, E., & Pellicciotti, F. (2023). Precipitation and temperature data from statistically downscaled CMIP5 models, Cordillera Blanca and Vilcanota-Urubamba regions, Peru, from 2019 to 2100 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/67ceb7c8-218c-46e1-9927-cfef2dd95526
Potter, E., Fyffe, C., Orr, A., Quincey, D., Ross, A., Rangecroft, S., Medina, K., Burns, H., Llacza, A., Jacome, G., Hellstrom, R., Castro, J., Cochachin, A., Montoya, N., Loarte, E., & Pellicciotti, F. (2023). Precipitation and temperature climate change indices calculated from WRF data and statistically downscaled CMIP5 models, Cordillera Blanca and Vilcanota-Urubamba regions, Peru, from 1980 to 2100 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/b56d30e8-edaa-4225-96d7-fcc689e930c7
Orr, A., & Phillips, T. (2023). MetUM high-resolution simulations of extreme warm temperature events over South Orkney Islands from 1 to 17 January 1991 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/0b011472-c766-4190-8718-8cf4be95daa6
Potter, E., Fyffe, C., Orr, A., Quincey, D., Ross, A., Rangecroft, S., Medina, K., Burns, H., Llacza, A., Jacome, G., Hellstrom, R., Castro, J., Cochachin, A., Montoya, N., Loarte, E., & Pellicciotti, F. (2023). Bias-corrected temperature and precipitation data from the WRF regional climate model output, Cordillera Blanca and Vilcanota-Urubamba regions, Peru, from 1980 to 2018 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/2cf25580-9b79-440f-8505-6230dd377877
Orr, A., Boberg, F., & Phillips, T. (2022). MetUM and HIRHAM5 simulations of summer near-surface temperatures over Antarctica from 1979 to 2019 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/05f8bd4b-97b1-43d0-a1c6-66aea7021aaf
Orr, A., & Phillips, T. (2021). Kilometre and sub-kilometre scale atmosphere-only model simulations using the Met Office Unified Model of a foehn wind event over the Larsen C Ice Shelf, Antarctic Peninsula on 27 January 2011 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/c5cc491e-7119-4500-b05a-e5e34274438f
Orr, A., & Phillips, T. (2021). Fine-scale atmosphere-only model simulation of near-surface temperature and wind from a reanalysis-driven Met Office Unified Model simulation of the Brunt Ice Shelf for the year 2015 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/20f3bf27-bf33-4c21-8164-005667b2ddb8
Bannister, D., Orr, A., & Phillips, T. (2019). Model-simulated and bias-corrected daily total precipitation from a reanalysis-driven Weather Research and Forecasting simulation of the Beas and Sutlej river basins in the Himalaya, 1980 to 2012 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/74fab393-2718-4bdb-b229-190ae72a9fe1
Deb, P., Orr, A., & Turner, J. (2018). Polar Weather Research and Forecasting (WRF) simulation of West Antarctic climate, summer 1980-2015 (Version 1.0) [Data set]. Polar Data Centre, Natural Environment Research Council, UK. https://doi.org/10.5285/9536f22e-37dd-4f37-948b-e19c70e15292
Anderson, P., King, J., Lachlan-Cope, T., Orr, A., Marshall, G., Kirchgaessner, A., & Smith, V. (2012). Weather Research and Forecasting (WRF) model output for Larsen Ice Shelf at 4km resolution (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/00591
Anderson, P., King, J., Lachlan-Cope, T., Marshall, G., Orr, A., & Kirchgaessner, A. (2012). Weather Research and Forecasting (WRF) model output for Larsen Ice Shelf at 1km resolution (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/00592
Anderson, P., King, J., Lachlan-Cope, T., Marshall, G., Orr, A., & Kirchgaessner, A. (2012). Surface Energy Budget (SEB) measurements of the snowpack taken at Larsen camp, Larsen C Ice Shelf, Jan 2011 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/00590
King, J., Anderson, P., Orr, A., Marshall, G., Lachlan-Cope, T., & Kirchgaessner, A. (2012). Larsen Ice Shelf Unified Model (UM) output run at 4km resolution (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/00593
King, J., Anderson, P., Lachlan-Cope, T., Orr, A., Marshall, G., & Kirchgaessner, A. (2012). Larsen Ice Shelf Unified Model (UM) output run at 1.5km resolution (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/00594
PRESCIENT supports long-term, strategically important measurements and capabilities for the wider science community.
PolarRES investigates polar climate processes in the Arctic and Antarctic, improving global climate projections and reducing uncertainties to better assess environmental and social impacts.
The Big Thaw studies snow and glacier changes in the Alps and Himalayas to improve forecasts of mountain water resources for global communities.
SURFEIT unites UK and international scientists to study Antarctic ice and atmosphere interactions, improve sea-level projections, and support climate action.
This project investigated how much water is stored in the glaciers and snow of the Upper Indus Basin, and how climate variability influences water availability.
OFCAP was an integrated programme of field observations, analysis and modelling aimed at understanding how the westerly winds in the Antarctic Peninsula influence the climate.
Polar Expertise – Supporting Development
A new study featuring contributions from British Antarctic Survey (BAS) scientists has identified 100 pressing research questions on climate change and water resources in the Upper Indus Basin (UIB) that must be answered to protect the communities that live there.
A new study by scientists from British Antarctic Survey (BAS) has used computer modelling to rank the factors responsible for the Larsen C ice shelf melt according to their severity.
The Polar Regions play a crucial role in balancing global climate – with the poles heating up much faster than the rest of the world. Yet, climate projections for these […]
A new study involving scientists from British Antarctic Survey (BAS) suggests for the first time that warm winds are creating large surface melting of ice shelves in Antarctica during the […]