Edward "Ned" K Vizy

Research Scientist Associate V/ Lecturer, Department of Earth and Planetary Sciences, Jackson School of Geosciences

Email: ned@jsg.utexas.edu
Work: +1 512 585 1937
Office: JGB 5.220G
Mailcode: C9000

Dr. Edward (Ned) Vizy is a Research Scientist Associate in the Department of Geological Sciences at the University of Texas at Austin. He is an atmospheric scientist, and his work is focused primarily on understanding regional climate variability/climate change over the tropics/sub-tropics including Africa and the Americas. Dr. Vizy has over fifteen years experience developing and adapting high resolution regional climate system models for use in addressing climate related issues.

Dr. Vizy's current interests include understanding the relationship between the development of precipitation systems and the diurnal cycle of rainfall and how they relate to extreme weather, understanding the role of eastern South Atlantic ocean/atmosphere feedback processes and their influence on regional climate variability, and how extreme weather events (i.e., droughts, heat waves, floods, hurricanes) are projected to change in the future and assessing what impact these changes will have on society. Dr. Vizy earned his PhD in Atmospheric Science from Cornell University in 2003.

Areas of Expertise

climate dynamics, atmospheric dynamics, climate change, extreme weather events, climate system modeling, hurricanes, paleoclimate, mesoscale modeling

Current Research Programs & Projects

Northern African monsoon systems: Basic dynamics, interannual and decadal variations ( view )

Influence of the Equatorial Atlantic Cold Tongue and Angola Current on Atlantic Basin Climate Variability

Regional Climate Resilience and Sensitivity in the Tropics and Subtropics ( view )

Role of Mesoscale Convective Systems in Determining the Diurnal Cycle of Precipitation over Sub-Saharan Northern Africa

Select Past Research

Collaborative research: Climate forecasting, adaptation backcasting: Coupling human response to climate change in Malawi

Climate Change and African Political Stability: Collaborative research with the Robert S. Strauss Center for International Security and Law

Member – Task Team 4: Climate Sensitivity to AMOC: Climate/Ecosystem Impacts, AMOC Science Team, US CLIVAR (2014 - Present)

Vizy, E.K.. & Cook, K.H.. (2023). Is the climate of the Congo Basin becoming less able to support a tropical forest ecosystem?. Jorunal of Climate, 36(23), 8171-8193. doi:https://doi.org/10.1175/JCLI-D-23-0275.1.

Vizy, E. K.. & Cook, K.H.. (2023). West African Sahel extreme rainfall events: Understanding storm development over the Damergou Gap using WRF convection-permitting simulations. Quarterly Journal of the Royal Meteorological Society, 149(752), 959-983. doi:https://doi.org/10.1002/qj.4443.

Cook, K.H.. & Vizy, E.K.. (2023). Understanding the regionality of diurnal cycles of precipitation in the Lake Victoria Basin during boreal fall. Climate Dynamics. doi:https://doi.org/10.1007/s00382-023-06950-0.

Andrews, P.C.., Cook, K.H.. & Vizy, E.K.. (2023). Mesoscale convective systems in the Congo Basin: Seasonality, regionality, and diurnal cycles. Climate Dynamics. doi:https://doi.org/10.1007/s00382-023-06903-7.

Zhao, S., Cook, K.H.. & Vizy, E.K.. (2023). How shrinkage of Lake Chad affects the local climate. Climate Dynamics, 61, 595-619. doi:https://doi.org/10.1007/s00382-022-06597-3.

Cook, K.H.. & Vizy, E.K.. (2022). Hydrodynamics of regional and seasonal variations in Congo Basin precipitation. Climate Dynamics, 59, 1775-1797. doi:https://doi.org/10.1007/s00382-021-06066-3.

Vizy, E.K.. & Cook, K.H.. (2022). Distribution of extreme rainfall events and their environmental controls in the West African Sahel and Soudan. Climate Dynamics, 59, 997-1026. doi:https://doi.org/10.1007/s00382-022-06171-x.

Cook, K.H.., Vizy, E.K.., Liu, Y.. & Liu, W. (2021). Greenhouse-gas induced warming amplification over the Arabian Peninsula with implications for Ethiopian rainfall. Climate Dynamics, 57, 3113-3133. doi:https://doi.org/10.1007/s00382-021-05858-x.

Cook, K.H.., Fitzpatrick, R.G.J.., Liu, W.. & Vizy, E.K.. (2020). Seasonal asymmetry of equatorial East African rainfall projections: Understanding differences between the response of the Long Rains and Short Rains to increased greenhouse gases. Climate Dynamics, 55, 1759-1777. doi:https://doi.org/10.1007/s00382-020-05350-y.

Cook, K.H.., Liu, Y.. & Vizy, E.K.. (2020). Congo Basin drying associated with poleward shifts of African thermal lows. Climate Dynamics, 54, 863-883. doi:https://doi.org/10.1007/s00382-019-05033-3.

Fitzpatrick, R.G.J.., Parker, D.J.., Marsham, J.H., Rowell, D.P.., Guichard, C.M.., Taylor, K.H.., Cook, K.H.., Vizy, E.K.., Jackson, L.S.., Finney, D.., Crook, J.., Stratton, R.. & Tucker, S,. (2020). What drives the intensification of mesoscale convective systems over the West African Sahel under climate change?. Journal of Climate, 33(8), 3151-3172. doi:https://doi.org/10.1175/JCLI-D-19-0380.1.

Khanna, J.., Cook, K.H.. & Vizy, E.K.. (2020). Opposite sensitivity to climate change-induced surface warming trends in dry and wet regions in the tropics and subtropics. International Journal of Climatology, 40(14), 5887-5905. doi:https://doi.org/10.1002/joc.6554.

Liu, W.., Cook, K.H.. & Vizy, E.K.. (2020). Influence of Indian Ocean SSTs on East African short rains. Climate Dynamics, 54, 4991-5011. doi:https://doi.org/10.1007/s00382-020-05265-8.

Liu, W.., Cook, K.H.. & Vizy, E.K.. (2020). Role of the West African westerly jet in the seasonal and diurnal cycles of precipitation over West Africa. Climate Dynamics, 54, 843-861. doi:https://doi.org/10.1007/s00382-019-05035-1.

Liu, Y.., Cook, K.H.. & Vizy, E.K.. (2020). Delayed retreat of the summer monsoon over the Indochina peninsula linked to surface warming trends. International Journal of Climatology, 41(3), 1927-1938. doi:https://doi.org/10.1002/joc.6938.

Vizy, E.K.. & Cook, K.H.. (2020). Interannual variability of East African rainfall: Role of seasonal transitions of the low-level cross-equatorial flow. Climate Dynamics, 54, 4563-4587. doi:https://doi.org/10.1007/s00382-020-05244-z.

Cook, K.H.. & Vizy, E.K.. (2019). Examining the adjustment of the surface heat balance to SST trends of the tropical and subtropical oceans in atmospheric reanalyses. International Journal of Climatology, 40(4), 2253-2269. doi:https://doi.org/10.1002/joc.6330.

Cook, K.H.. & Vizy, E.K.. (2019). Contemporary climate change of the African monsoon systems. Current Climate Change Reports, 5, 145-159. doi:https://doi.org/10.1007/s40641-019-00130-1.

Han, F.., Cook, K.H.. & Vizy, E.K.. (2019). Changes in intense rainfall events and drought across Africa in the 21st century. Climate Dynamics, 53, 2757-2777. doi:https://doi.org/10.1007/s00382-019-04653-z.

Liu, W.., Cook, K.H.. & Vizy, E.K.. (2019). The role of mesoscale convective systems in the diurnal cycle of rainfall and its seasonality over sub-Saharan Northern Africa. Climate Dynamics, 52, 729-745. doi:https://doi.org/10.1007/s00382-018-4162-y.

Sun, Y.., Vizy, E.K.. & Cook, K.H.. (2019). Land-atmosphere interactions in the southeastern Atlantic: Interannual variability. Climate Dynamics, 52, 539-561. doi:https://doi.org/10.1007/s00382-018-4155-x.

Vizy, E.K.. & Cook, K.H.. (2019). Understanding the summertime diurnal cycle of precipitation over sub-Saharan West Africa: Regions with daytime rainfall peaks in the absence of significant topographic features. Climate Dynamics, 52, 2903-2922. doi:https://doi.org/10.1007/s00382-018-4315-z.

Vizy, E.K.. & Cook, K.H.. (2019). Observed relationship between the Turkana low-level jet and boreal summer convection. Climate Dynamics, 53, 4037-4058. doi:https://doi.org/10.1007/s00382-019-04769-2.

Cook, K.H.., Vizy, E.K.. & Sun, X.. (2018). Multidecadal-scale adjustment of the ocean mixed layer heat budget in the tropics: Examining ocean reanalyses. Climate Dynamics, 50, 1513-1532. doi:https://doi.org/10.1007/s00382-017-3703-0.

Vizy, E.K.. & Cook, K.H.. (2018). Mesoscale convective systems and nocturnal rainfall over the West African Sahel: Role of the Inter-tropical front. Climate Dynamics, 50, 587-614. doi:https://doi.org/10.1007/s00382-017-3628-7.

Vizy, E.K.., Cook, K.H.. & Sun, X.. (2018). Decadal changes of the South Atlantic ocean Angola-Benguela frontal zone since 1980. Climate Dynamics, 51, 3251-3273. doi:https://doi.org/10.1007/s00382-018-4077-7.

Sun, X.., Cook, K.H.. & Vizy, E.K.. (2017). The South Atlantic subtropical high: Climatology and interannual variability. Journal of Climate, 30, 3279-3296. doi:https://doi.org/10.1175/JCLI-D-16-0705.1.

Thiaw, W.M.., Janicot, S.., Bekele, E.., Cook, K.H.., Fontaine, B.., Mekonnen, A.., Ndiaye, O.., Tamo, P.-H. K.., Vizy, E.K.. & Kiladis, G.. (2017). Chapter 7: Subseasonal forecasting. Meteorology of Tropical West Africa: The Forecasters Handbook (, pp. 255-288): John Wiley & Sons Ltd. doi:https://doi.org/10.1002/9781118391297.ch7.

Vizy, E.K.. & Cook, K.H.. (2017). Seasonality of the observed amplified Sahara warming trend and implications for Sahel rainfall. Journal of Climate, 30, 3073-3094. doi:https://doi.org/10.1175/JCLI-D-16-0687.1.

Cook, K.H.. & Vizy, E.K.. (2016). The Congo basin Walker circulation: Dynamics and connections to precipitation. Climate Dynamics, 47, 697-717. doi:https://doi.org/10.1007/s00382-015-2864-y.

Justino, F.., Stordal, F.., Vizy, E.K,.., Cook, K.H.. & Pereira, M.P.S.. (2016). Greenhouse gas induced changes in the seasonal cycle of the Amazon basin in coupled climate-vegetation regional model. Climate, 4(1), 1-12. doi:https://doi.org/10.3390/cli4010003.

Vizy, E.K.. & Cook, K.H.. (2016). Understanding long-term (1982-2013) multi-decadal change in the equatorial and subtropical South Atlantic climate. Climate Dynamics, 46, 2087-2113. doi:https://doi.org/10.1007/s00382-015-2691-1.

Zhang, G.., Cook, K.H.. & Vizy, E.K.. (2016). The diurnal cycle of warm season rainfall over West Africa. Part I: Observational analysis. Journal of Climate, 29, 8423-8437. doi:https://doi.org/10.1175/JCLI-d-15-0874.1.

Zhang, G.., Cook, K.H.. & Vizy, E.K.. (2016). The diurnal cycle of warm season rainfall over West Africa. Part II: Convection-permitting simulations. Journal of Climate, 29, 8439-8454. doi:https://doi.org/10.1175/JCLI-d-15-0875.1.

Cook, K.H.. & Vizy, E.K.. (2015). Detection and analysis of an amplified warming of the Sahara Desert. Journal of Climate, 28, 6560-6580. doi:https://doi.org/10.1175/JCLI-D-14-00230.1.

Cretat, J.., Vizy, E.K.. & Cook, K.H.. (2015). The relationship between African easterly waves and daily rainfall over West Africa. Observations and regional climate simulations. Climate Dynamics, 44, 385-404. doi:https://doi.org/10.1007/s00382-014-2120-x.

Rodrigues-Fonseca, B.., Mohino, E.., Mechoso, C.R.., Caminade, C.., Biasutti, M.., Gaetani, M.., Garcia-Serrano, J.., Vizy, E.K.., Cook, K.., Xue, Y.., Polo, I.., Losada, T.., Druyan, L.., Fontaine, B.., Bader, J.., Doblas-Reyes, F.J.., Goddard, L.., Janicot, S.., Arribas, A.., Lau, W.., Colman, A.., Vellinga, M.., Rowell, D.P.., Kucharski, F.. & Voldoire, A.. (2015). Variability and Predictability of West African Droughts. A review in the role of Sea Surface Temperature Anomalies. Journal of Climate, 28, 4034-4060. doi:https://doi.org/10.1175/JCLI-D-14-00130.1.

Vizy, E.K.., Cook, K.H.., Chimphamba, J.. & McCusker, B.. (2015). Projected changes in Malawis growing season. Climate Dynamics, 45, 1673-1698. doi:https://doi.org/10.1007/s00382-014-2424-x.

Busby, J.W.., Cook, K.H.., Vizy, E.K.., Smith, T.G.. & Bekalo, M.. (2014). Identifying hot spots of security vulnerability associated with climate change in Africa. Climatic Change, 124, 717-731. doi:https://doi.org/10.1007/s10584-014-1142-z.

Cretat, J.., Vizy, E.K.. & Cook, K.H.. (2014). How well are daily intense rainfall events captured by current climate models over Africa?. Climate Dynamics, 42, 2691-2711. doi:https://doi.org/10.1007/s/00382-013-1796-7.

Vizy, E.K.. & Cook, K.H.. (2014). Impact of cold air surges on rainfall variability in the Sahel and wet African tropics: A multi-scale analysis. Climate Dynamics, 43, 1057-1081. doi:https://doi.org/10.1007/s00382-013-1953-z.

Vizy, E.K.. & Cook, K.H.. (2014). Capturing the Atlantic cold tongue and coastal upwelling in an intermediate-level ocean model coupled to a regional climate model. Climate Dynamics, 42, 345-366. doi:https://doi.org/10.1007/s00382-013-1807-8.

Cook, K.H.. & Vizy, E.K.. (2013). Projected changes in East African rainy seasons. Journal of Climate, 26, 4664-4687. doi:https://doi.org/10.1175/JCLI-D-12-00455.1.

Vizy, E.K.., Cook, K.H.., Cretat, J.. & Neupane, N.. (2013). Projections of a wetter Sahel in the 21st century from global and regional models. Journal of Climate, 26, 4664-4687. doi:https://doi.org/10.1175/JCLI-D-12-00533.1.

Cook, K.H.. & Vizy, E.K.. (2012). Impact of climate change on mid-21st century growing seasons in Africa. Climate Dynamics, 39, 2937-2955. doi:https://doi.org/10.1175/2009JCLI3210.1.

Pu, B.., Vizy, E.K.. & Cook, K.H.. (2012). Warm season response over North America to a shutdown of the Atlantic meridional overturning circulation and CO2 increases. Journal of Climate, 25, 6701-6720. doi:https://doi.org/10.1175/JCLI-D-11-00611.1.

Vizy, E.K.. & Cook, K.H.. (2012). Mid-21st century changes in extreme events over northern and tropical Africa. Journal of Climate, 25, 5748-5767. doi:https://doi.org/10.1175/JCLI-D-11-00693.1.

Cook, K.H.. & Vizy, E.K.. (2010). Hydrodynamics of the Caribbean low-level jet and its relationship to precipitation. Journal of Climate, 23, 1477-1494. doi:https://doi.org/10.1175/2009JCLI3210.1.

Druyan, L.., Feng, J.., Cook, K.H.., Xue, Y.., Fulakeza, M.., Hagos, S.., Konare, A.., Moufouma-Okia, W.., Rowell, D.P.. & Vizy, E.K.. (2010). The WAMME regional model intercomparison study. Climate Dynamics, 35, 175-192. doi:https://doi.org/10.1007/s00382-009-0676-7.

Vizy, E.K.. & Cook, K.H.. (2010). Influence of Amazon/Orinoco plume on the summertime Atlantic climate. Journal of Geophysical Research - Atmospheres, 115, D21112. doi:https://doi.org/10.1029 /2010JD014049.

Vizy, E.K.. & Cook, K.H.. (2009). Tropical storm development from African easterly waves in the eastern Atlantic: A comparison of two successive waves using a regional model as part of NASA AMMA 2006. Journal of Atmospheric Science, 66, 3313-3334. doi:https://doi.org/10.1175/2009JAS3064.1.

Vizy, E.K.. & Cook, K.H.. (2009). A mechanism for African monsoon breaks: Mediterranean cold air surges. Journal of Geophysical Research - Atmospheres, 114, D01104. doi:https://doi.org/10.1029/2008JD010654.

Cook, K.H.., Vizy, E.K.., Launer, Z.S.. & Patricola, C.M.. (2008). Springtime intensification of the Great Plains low-level jet in coupled GCM simulations of the 21st century. Journal of Climate, 21, 6321-6340. doi:https://doi.org/10.1175/2008JCLI2355.1.

Cook, K.H.. & Vizy, E.K.. (2008). Effects of 21st century climate change on the Amazon rainforest. Journal of Climate, 21, 542-560. doi:https://doi.org/10.1175/2007JCLI1838.1.

Vizy, E.K.. & Cook, K.H.. (2007). Relationship between Amazon and High Andes Rainfall. Journal of Geophysical Research - Atmospheres, 112, D7107. doi:https://doi.org/10.1029/2006JD0079980.

Cook, K.H.. & Vizy, E.K.. (2006). South American climate during the Last Glacial Maximum: Delayed onset of the South American monsoon. Journal of Geophysical Research - Atmospheres, 111(D2), 2110. doi:https://doi.org/10.1029/2005JD005980.

Cook, K.H.. & Vizy, E.K.. (2006). Coupled model simulations of the West African monsoon system: 20th century simulations and 21st century predictions. Journal of Climate, 19, 3681-3703. doi:https://doi.org/10.1175/JCLI3814.1.

Vizy, E.K.. & Cook, K.H.. (2005). Evaluation of Last Glacial Maximum sea surface temperature reconstructions through their influence on South American climate. Journal of Geophysical Research - Atmospheres, 110, D11105. doi:https://doi.org/10.1029/2004JD005415.

Vizy, E.K.. & Cook, K.H.. (2003). Connections between the summer East African and Indian rainfall regimes. Journal of Geophysical Research - Atmospheres, 108(D16), 4510. doi:https://doi.org/10.1029/2003JD003452.

Vizy, E.K.. & Cook, K.H.. (2002). Development and application of a mesoscale climate model for the tropics: Influence of sea surface temperature anomalies on the West African monsoon. Journal of Geophysical Research - Atmospheres, 107(D3), 4023. doi:https://doi.org/10.1029/2001JD000686.

Vizy, E.K.. & Cook, K.H.. (2001). Mechanisms by which Gulf of Guinea and Eastern North Atlantic sea surface temperatures can influence African rainfall. Journal of Climate, 14, 795-821. doi:https://doi.org/10.1175/1520-0442(2001)014<0795:MBWGOG>2.0.CO;2.

2020Fall GEO 347G Climate System Modeling-Wb
2020Fall GEO 387G Climate System Modeling-Wb
2018Fall GEO 347G Climate System Modeling
2018Fall GEO 387G Climate System Modeling
2015Fall GEO 347G Climate System Modeling
2015Fall GEO 387G Climate System Modeling