ALBERT

Description: The successful planning and execution of a major field campaign relies on the availability and reliability of weather forecasts on a range of timescales. Here, we describe the wide range of forecast products generated in support of a field campaign that took place in India in 2016 as part of the Interaction of Convective Organization with Monsoon Precipitation, Atmosphere, Surface and Sea (INCOMPASS) project. We show examples of the suite of plots generated every day from the forecasts and supplied to the mission scientists, and describe how these were used to plan the flights. We highlight the benefits of having access to forecasts from a range of model resolutions and configurations; these allowed judgements to be made about uncertainty particularly in the amount and location of deep convective rainfall, which is an important consideration for flight planning. Finally, we discuss the legacy of the forecasting activity, which has not only advanced our understanding of monsoon forecasting but has also created a large database of targeted model forecast products for the whole of the 2016 monsoon season. These can be used by researchers for comparisons with in situ observations as well as future modelling studies. This article is protected by copyright. All rights reserved.

Description: The present study explores the mechanisms responsible for the strong intraseasonal cooling events in the Thermocline Ridge region of the southwestern Indian Ocean. Air sea interface and oceanic processes associated with Madden Julian Oscillation are studied using an Ocean General Circulation Model and satellite observations. Sensitivity experiments are designed to understand the ocean response to intraseasonal forcing with a special emphasis on 2002 cooling events, which recorded the strongest intraseasonal perturbations during the last well-observed decade. This event is characterized by anomalous Walker circulation over the tropical Indian Ocean and persistent intraseasonal heat flux anomaly for a longer duration than is typical for similar events (but without any favorable preconditioning of ocean basic state at the interannual timescale). The model heat budget analysis during 1996 to 2007 revealed an in-phase relationship between atmospheric fluxes associated with Madden Julian Oscillation and the subsurface oceanic processes during the intense cooling events of 2002. The strong convection, reduced shortwave radiation and increased evaporation have contributed to the upper ocean heat loss in addition to the slower propagation of active phase of convection, which supported the integration of longer duration of forcing. The sensitivity experiments revealed that dynamic response of ocean through entrainment at the intraseasonal timescale primarily controls the biological response during the event, with oceanic interannual variability playing a secondary role. This study further speculates the role of oceanic intraseasonal variability in the 2002 droughts over Indian subcontinent.

Description: Sea surface temperature (SST) in the region off southern tip of India (STI, 75–83°E, 5–8°N) exhibited a prominent variability in the intraseasonal time scale (both 30–90 d and 10–30 d band) during boreal summer. Mechanisms associated with this intraseasonal variability are studied using three-dimensional ocean general circulation model (OGCM) sensitivity experiments, satellite observed outgoing longwave radiation, SST and winds for the period 1998–2007. The background oceanic structure of the STI characterized by a shallow thermocline and moderate mixed layer provided ideal conditions for strong oceanic sub-surface processes. The model mixed layer heat budget reveals that the oceanic processes such as horizontal advection and vertical processes are the dominant mechanisms in the STI region as compared with air-sea flux. Sensitivity experiments with the OGCM reveals that the ocean dynamical processes contribute to most of the intraseasonal SST variability and the wind stress contributes to 85% of the variability whereas surface flux contributes to only 15% for the 30–90 d SST variability. Higher amplitude of surface flux perturbation and its contribution to SST in the 10–30 d as compared with the 30–90 d band are evident in the model experiment and are consistent with the observational analysis. There is year-to-year variability in the relative role of horizontal and vertical processes for different intraseasonal SST events over STI. Copyright © 2012 Royal Meteorological Society

Description: Long time series of in situ observations from the north Indian Ocean are used to compute the momentum transfer coefficients over the north Indian Ocean. The transfer coefficients behave nonlinearly for low winds (

Description: The first in situ observations of planetary boundary layer responses to antecedent rain and irrigation in India (aircraft). A comparison of three models (ERA‐Interim, ERA5 and NCUM) reveals the influence of surface‐induced temperature gradients on the location and strength of large‐scale shear and confluence associated with the monsoon trough. Our results provide observation and model‐based evidence that soil moisture–atmosphere interactions play an important role in the early phase of the Indian summer monsoon. Abstract This article presents a land–atmosphere case‐study for a single day during monsoon onset, incorporating data from a research aircraft, satellite products and model outputs. The unique aircraft observations reveal temperature and humidity contrasts of up to 5 K and 4 g/kg in the planetary boundary layer induced by spatial variations in soil moisture. Both antecedent rain and irrigation were found to be drivers of this atmospheric variability. There is also evidence of soil moisture‐induced mesoscale circulations above some surfaces. This is the first time such responses have been observed in situ over India. Soil moisture‐driven temperature anomalies are larger than those found in previous observational studies in the African Sahel. Moreover, irrigation in the region is extensive, unlike in the Sahel, and has a similar atmospheric effect to antecedent rainfall. This implies that historical changes in irrigation practices are likely to have had an important influence on mesoscale processes within the Indian monsoon. We also examine evidence linking soil moisture and cloud formation. Above wetter soils we observed a suppression of shallow cloud, whilst the initiation of deep convection occurred mostly in areas affected by wet–dry soil moisture boundaries. To investigate the impact of soil moisture heterogeneity on large‐scale wind flow, three model depictions of the day are assessed: the European Centre for Medium‐Range Weather Forecasts ERA‐Interim and ERA5 reanalyses, and a high‐resolution (1.5 km) simulation generated using the Indian National Centre for Medium Range Weather Forecasting regional convection‐permitting Unified Model. We find evidence indicating surface flux uncertainties in the models lead to ∼3.5 hPa anomalies in the monsoon trough. This does affect the simulation of monsoon circulation and rainfall. Better representation of mesoscale land–atmosphere coupling is likely to improve the depiction of convection within weather and climate models over India.

Description: Primary production in over half of the world's oceans is limited by fixed nitrogen availability. The main loss term from the fixed nitrogen inventory is the production of dinitrogen gas (N(2)) by heterotrophic denitrification or the more recently discovered autotrophic process, anaerobic ammonia oxidation (anammox). Oceanic oxygen minimum zones (OMZ) are responsible for about 35% of oceanic N(2) production and up to half of that occurs in the Arabian Sea. Although denitrification was long thought to be the only loss term, it has recently been argued that anammox alone is responsible for fixed nitrogen loss in the OMZs. Here we measure denitrification and anammox rates and quantify the abundance of denitrifying and anammox bacteria in the OMZ regions of the Eastern Tropical South Pacific and the Arabian Sea. We find that denitrification rather than anammox dominates the N(2) loss term in the Arabian Sea, the largest and most intense OMZ in the world ocean. In seven of eight experiments in the Arabian Sea denitrification is responsible for 87-99% of the total N(2) production. The dominance of denitrification is reproducible using two independent isotope incubation methods. In contrast, anammox is dominant in the Eastern Tropical South Pacific OMZ, as detected using one of the isotope incubation methods, as previously reported. The abundance of denitrifying bacteria always exceeded that of anammox bacteria by up to 7- and 19-fold in the Eastern Tropical South Pacific and Arabian Sea, respectively. Geographic and temporal variability in carbon supply may be responsible for the different contributions of denitrification and anammox in these two OMZs. The large contribution of denitrification to N(2) loss in the Arabian Sea indicates the global significance of denitrification to the oceanic nitrogen budget.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ward, B B -- Devol, A H -- Rich, J J -- Chang, B X -- Bulow, S E -- Naik, Hema -- Pratihary, Anil -- Jayakumar, A -- England -- Nature. 2009 Sep 3;461(7260):78-81. doi: 10.1038/nature08276.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geosciences, Princeton University, Princeton, New Jersey 08544, USA. bbw@princeton.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19727197" target="_blank"〉PubMed〈/a〉

Description: Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3182531/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3182531/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉International Multiple Sclerosis Genetics Consortium -- Wellcome Trust Case Control Consortium 2 -- Sawcer, Stephen -- Hellenthal, Garrett -- Pirinen, Matti -- Spencer, Chris C A -- Patsopoulos, Nikolaos A -- Moutsianas, Loukas -- Dilthey, Alexander -- Su, Zhan -- Freeman, Colin -- Hunt, Sarah E -- Edkins, Sarah -- Gray, Emma -- Booth, David R -- Potter, Simon C -- Goris, An -- Band, Gavin -- Oturai, Annette Bang -- Strange, Amy -- Saarela, Janna -- Bellenguez, Celine -- Fontaine, Bertrand -- Gillman, Matthew -- Hemmer, Bernhard -- Gwilliam, Rhian -- Zipp, Frauke -- Jayakumar, Alagurevathi -- Martin, Roland -- Leslie, Stephen -- Hawkins, Stanley -- Giannoulatou, Eleni -- D'alfonso, Sandra -- Blackburn, Hannah -- Martinelli Boneschi, Filippo -- Liddle, Jennifer -- Harbo, Hanne F -- Perez, Marc L -- Spurkland, Anne -- Waller, Matthew J -- Mycko, Marcin P -- Ricketts, Michelle -- Comabella, Manuel -- Hammond, Naomi -- Kockum, Ingrid -- McCann, Owen T -- Ban, Maria -- Whittaker, Pamela -- Kemppinen, Anu -- Weston, Paul -- Hawkins, Clive -- Widaa, Sara -- Zajicek, John -- Dronov, Serge -- Robertson, Neil -- Bumpstead, Suzannah J -- Barcellos, Lisa F -- Ravindrarajah, Rathi -- Abraham, Roby -- Alfredsson, Lars -- Ardlie, Kristin -- Aubin, Cristin -- Baker, Amie -- Baker, Katharine -- Baranzini, Sergio E -- Bergamaschi, Laura -- Bergamaschi, Roberto -- Bernstein, Allan -- Berthele, Achim -- Boggild, Mike -- Bradfield, Jonathan P -- Brassat, David -- Broadley, Simon A -- Buck, Dorothea -- Butzkueven, Helmut -- Capra, Ruggero -- Carroll, William M -- Cavalla, Paola -- Celius, Elisabeth G -- Cepok, Sabine -- Chiavacci, Rosetta -- Clerget-Darpoux, Francoise -- Clysters, Katleen -- Comi, Giancarlo -- Cossburn, Mark -- Cournu-Rebeix, Isabelle -- Cox, Mathew B -- Cozen, Wendy -- Cree, Bruce A C -- Cross, Anne H -- Cusi, Daniele -- Daly, Mark J -- Davis, Emma -- de Bakker, Paul I W -- Debouverie, Marc -- D'hooghe, Marie Beatrice -- Dixon, Katherine -- Dobosi, Rita -- Dubois, Benedicte -- Ellinghaus, David -- Elovaara, Irina -- Esposito, Federica -- Fontenille, Claire -- Foote, Simon -- Franke, Andre -- Galimberti, Daniela -- Ghezzi, Angelo -- Glessner, Joseph -- Gomez, Refujia -- Gout, Olivier -- Graham, Colin -- Grant, Struan F A -- Guerini, Franca Rosa -- Hakonarson, Hakon -- Hall, Per -- Hamsten, Anders -- Hartung, Hans-Peter -- Heard, Rob N -- Heath, Simon -- Hobart, Jeremy -- Hoshi, Muna -- Infante-Duarte, Carmen -- Ingram, Gillian -- Ingram, Wendy -- Islam, Talat -- Jagodic, Maja -- Kabesch, Michael -- Kermode, Allan G -- Kilpatrick, Trevor J -- Kim, Cecilia -- Klopp, Norman -- Koivisto, Keijo -- Larsson, Malin -- Lathrop, Mark -- Lechner-Scott, Jeannette S -- Leone, Maurizio A -- Leppa, Virpi -- Liljedahl, Ulrika -- Bomfim, Izaura Lima -- Lincoln, Robin R -- Link, Jenny -- Liu, Jianjun -- Lorentzen, Aslaug R -- Lupoli, Sara -- Macciardi, Fabio -- Mack, Thomas -- Marriott, Mark -- Martinelli, Vittorio -- Mason, Deborah -- McCauley, Jacob L -- Mentch, Frank -- Mero, Inger-Lise -- Mihalova, Tania -- Montalban, Xavier -- Mottershead, John -- Myhr, Kjell-Morten -- Naldi, Paola -- Ollier, William -- Page, Alison -- Palotie, Aarno -- Pelletier, Jean -- Piccio, Laura -- Pickersgill, Trevor -- Piehl, Fredrik -- Pobywajlo, Susan -- Quach, Hong L -- Ramsay, Patricia P -- Reunanen, Mauri -- Reynolds, Richard -- Rioux, John D -- Rodegher, Mariaemma -- Roesner, Sabine -- Rubio, Justin P -- Ruckert, Ina-Maria -- Salvetti, Marco -- Salvi, Erika -- Santaniello, Adam -- Schaefer, Catherine A -- Schreiber, Stefan -- Schulze, Christian -- Scott, Rodney J -- Sellebjerg, Finn -- Selmaj, Krzysztof W -- Sexton, David -- Shen, Ling -- Simms-Acuna, Brigid -- Skidmore, Sheila -- Sleiman, Patrick M A -- Smestad, Cathrine -- Sorensen, Per Soelberg -- Sondergaard, Helle Bach -- Stankovich, Jim -- Strange, Richard C -- Sulonen, Anna-Maija -- Sundqvist, Emilie -- Syvanen, Ann-Christine -- Taddeo, Francesca -- Taylor, Bruce -- Blackwell, Jenefer M -- Tienari, Pentti -- Bramon, Elvira -- Tourbah, Ayman -- Brown, Matthew A -- Tronczynska, Ewa -- Casas, Juan P -- Tubridy, Niall -- Corvin, Aiden -- Vickery, Jane -- Jankowski, Janusz -- Villoslada, Pablo -- Markus, Hugh S -- Wang, Kai -- Mathew, Christopher G -- Wason, James -- Palmer, Colin N A -- Wichmann, H-Erich -- Plomin, Robert -- Willoughby, Ernest -- Rautanen, Anna -- Winkelmann, Juliane -- Wittig, Michael -- Trembath, Richard C -- Yaouanq, Jacqueline -- Viswanathan, Ananth C -- Zhang, Haitao -- Wood, Nicholas W -- Zuvich, Rebecca -- Deloukas, Panos -- Langford, Cordelia -- Duncanson, Audrey -- Oksenberg, Jorge R -- Pericak-Vance, Margaret A -- Haines, Jonathan L -- Olsson, Tomas -- Hillert, Jan -- Ivinson, Adrian J -- De Jager, Philip L -- Peltonen, Leena -- Stewart, Graeme J -- Hafler, David A -- Hauser, Stephen L -- McVean, Gil -- Donnelly, Peter -- Compston, Alastair -- 068545/Z/02/Wellcome Trust/United Kingdom -- 075491/Z/04/Z/Wellcome Trust/United Kingdom -- 084702/Wellcome Trust/United Kingdom -- 085475/Wellcome Trust/United Kingdom -- 085475/B/08/Z/Wellcome Trust/United Kingdom -- 085475/Z/08/Z/Wellcome Trust/United Kingdom -- 090532/Wellcome Trust/United Kingdom -- 898/Multiple Sclerosis Society/United Kingdom -- AI076544/AI/NIAID NIH HHS/ -- CA104021/CA/NCI NIH HHS/ -- G0100594/Medical Research Council/United Kingdom -- G0400017/Medical Research Council/United Kingdom -- G0700061/Medical Research Council/United Kingdom -- G0901310/Medical Research Council/United Kingdom -- G0901461/Medical Research Council/United Kingdom -- G19/2/Medical Research Council/United Kingdom -- K23N/S048869/PHS HHS/ -- NS032830/NS/NINDS NIH HHS/ -- NS049477/NS/NINDS NIH HHS/ -- NS049510/NS/NINDS NIH HHS/ -- NS067305/NS/NINDS NIH HHS/ -- NS19142/NS/NINDS NIH HHS/ -- NS26799/NS/NINDS NIH HHS/ -- NS43559/NS/NINDS NIH HHS/ -- PDA/02/06/016/Department of Health/United Kingdom -- R01 NS026799/NS/NINDS NIH HHS/ -- R01 NS049477/NS/NINDS NIH HHS/ -- R01 NS049477-06A1/NS/NINDS NIH HHS/ -- RR020092/RR/NCRR NIH HHS/ -- RR024992/RR/NCRR NIH HHS/ -- UL1 TR000448/TR/NCATS NIH HHS/ -- Medical Research Council/United Kingdom -- England -- Nature. 2011 Aug 10;476(7359):214-9. doi: 10.1038/nature10251.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21833088" target="_blank"〉PubMed〈/a〉

Description: All cancers carry somatic mutations in their genomes. A subset, known as driver mutations, confer clonal selective advantage on cancer cells and are causally implicated in oncogenesis, and the remainder are passenger mutations. The driver mutations and mutational processes operative in breast cancer have not yet been comprehensively explored. Here we examine the genomes of 100 tumours for somatic copy number changes and mutations in the coding exons of protein-coding genes. The number of somatic mutations varied markedly between individual tumours. We found strong correlations between mutation number, age at which cancer was diagnosed and cancer histological grade, and observed multiple mutational signatures, including one present in about ten per cent of tumours characterized by numerous mutations of cytosine at TpC dinucleotides. Driver mutations were identified in several new cancer genes including AKT2, ARID1B, CASP8, CDKN1B, MAP3K1, MAP3K13, NCOR1, SMARCD1 and TBX3. Among the 100 tumours, we found driver mutations in at least 40 cancer genes and 73 different combinations of mutated cancer genes. The results highlight the substantial genetic diversity underlying this common disease.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3428862/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3428862/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stephens, Philip J -- Tarpey, Patrick S -- Davies, Helen -- Van Loo, Peter -- Greenman, Chris -- Wedge, David C -- Nik-Zainal, Serena -- Martin, Sancha -- Varela, Ignacio -- Bignell, Graham R -- Yates, Lucy R -- Papaemmanuil, Elli -- Beare, David -- Butler, Adam -- Cheverton, Angela -- Gamble, John -- Hinton, Jonathan -- Jia, Mingming -- Jayakumar, Alagu -- Jones, David -- Latimer, Calli -- Lau, King Wai -- McLaren, Stuart -- McBride, David J -- Menzies, Andrew -- Mudie, Laura -- Raine, Keiran -- Rad, Roland -- Chapman, Michael Spencer -- Teague, Jon -- Easton, Douglas -- Langerod, Anita -- Oslo Breast Cancer Consortium (OSBREAC) -- Lee, Ming Ta Michael -- Shen, Chen-Yang -- Tee, Benita Tan Kiat -- Huimin, Bernice Wong -- Broeks, Annegien -- Vargas, Ana Cristina -- Turashvili, Gulisa -- Martens, John -- Fatima, Aquila -- Miron, Penelope -- Chin, Suet-Feung -- Thomas, Gilles -- Boyault, Sandrine -- Mariani, Odette -- Lakhani, Sunil R -- van de Vijver, Marc -- van 't Veer, Laura -- Foekens, John -- Desmedt, Christine -- Sotiriou, Christos -- Tutt, Andrew -- Caldas, Carlos -- Reis-Filho, Jorge S -- Aparicio, Samuel A J R -- Salomon, Anne Vincent -- Borresen-Dale, Anne-Lise -- Richardson, Andrea L -- Campbell, Peter J -- Futreal, P Andrew -- Stratton, Michael R -- 077012/Z/05/Z/Wellcome Trust/United Kingdom -- 088340/Wellcome Trust/United Kingdom -- 093867/Wellcome Trust/United Kingdom -- 10118/Cancer Research UK/United Kingdom -- CA089393/CA/NCI NIH HHS/ -- P30 CA016672/CA/NCI NIH HHS/ -- WT088340MA/Wellcome Trust/United Kingdom -- Cancer Research UK/United Kingdom -- Chief Scientist Office/United Kingdom -- Department of Health/United Kingdom -- England -- Nature. 2012 May 16;486(7403):400-4. doi: 10.1038/nature11017.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton CB10 1SA, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22722201" target="_blank"〉PubMed〈/a〉

Description: Nitrous oxide (N2O) is a powerful greenhouse gas and a major cause of stratospheric ozone depletion, yet its sources and sinks remain poorly quantified in the oceans. We used isotope tracers to directly measure N2O reduction rates in the eastern tropical North Pacific. Because of incomplete denitrification, N2O cycling rates are an order of magnitude higher than predicted by current models in suboxic regions, and the spatial distribution suggests strong dependence on both organic carbon and dissolved oxygen concentrations. Furthermore, N2O turnover is 20 times higher than the net atmospheric efflux. The rapid rate of this cycling coupled to an expected expansion of suboxic ocean waters implies future increases in N2O emissions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Babbin, Andrew R -- Bianchi, Daniele -- Jayakumar, Amal -- Ward, Bess B -- New York, N.Y. -- Science. 2015 Jun 5;348(6239):1127-9. doi: 10.1126/science.aaa8380.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geosciences, Princeton University, Princeton, NJ 08544, USA. Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. babbin@mit.edu. ; School of Oceanography, University of Washington, Seattle, WA 98105, USA. ; Department of Geosciences, Princeton University, Princeton, NJ 08544, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26045434" target="_blank"〉PubMed〈/a〉

Description: We introduce the National Centre for Medium Range Weather Forecasting's (NCMRWF) high-resolution (330 m) Unified Model implementation targeted at fog and visibility prediction over Delhi, the ‘Delhi Model’ (DM). The requirement for running the DM in real time is that Delhi is highly vulnerable to fog-related issues and that low visibility conditions affect both airborne and ground transport during winter months. Enhanced orographic features at 330 m resolution, in conjunction with other surface boundary conditions used by the DM, have led to improvements in the simulation of spatio-temporal variability of visibility. During the winter season, the increased levels of pollution can have a significant impact on fog, or smog formation. Sensitivity experiments carried out using specified aerosol mass concentrations show that the visibility predicted by the DM is highly sensitive to the presence of aerosol. The impact of the urban heat island on visibility prediction is also investigated using recent high-resolution land use data from the Indian Space Research Organisation (ISRO) in the model. We introduce a high-resolution (330 m) operational model targeted at fog and visibility prediction over Delhi, the “Delhi Model”. Delhi is highly vulnerable to fog-related issues, and low visibility conditions affect both airborne and ground transport during winter months. Enhanced orographic features and land use information at high resolution lead to improvements in the spatio-temporal variability of fog, when compared to lower resolution models.