The increasing urbanization of the greater Salt Lake City area (GSLA) has contributed to the development of an urban canopy over this area. This canopy refers to the effects of building profiles, varying land surface properties and anthropogenic heating on local meteorological conditions including temperature, humidity, and wind velocity. Urban Canopy Models (UCMs) can be used to represent these characteristics on a mesoscale without needing to develop models accounting for effects of individual buildings. One method used to classify urban areas are Local Climate Zones (LCZs), which assign different properties to different types of urban areas. A baseline model that represents current GSLA conditions was developed using a series of sensitivity studies, which focused on the effects of mesh resolution, land surface models, UCMs, anthropogenic heating rates and LCZ urban classifications. The baseline model was validated using measured meteorological data. Four urban growth scenarios were compared to this baseline model to evaluate the effects of future growth on local 2-meter air temperatures, 2-meter relative humidity, and 10-meter wind speed. Results showed increased urban density did not affect daytime temperatures within the GSLA, but did significantly increase local nighttime temperatures. The effects of anthropogenic heating rates were most noticeable during early nighttime hours. Also, increased urbanization affected local temperatures, but did not appear to have "downwind" effects on other areas. A User Guide documenting the modeling approach was developed to support additional studies.

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Cette thèse est dédiée à la caractérisation des vents descendants de vallée en terrain complexe d'orographie modérée à moyenne latitude, dans le contexte de la réglementation des rejets atmosphériques de Cadarache. Cadarache est un des centres de recherche du "Commissariat à l'énergie atomique et aux énergies alternatives" (CEA), installé dans une petite vallée (CV) confluente à la vallée de la Durance (DV). Ces deux vallées se distinguent par leur taille, et sont le siège d'écoulements aux caractéristiques différentes en stratification stable. Un forçage synoptique faible associé à un ciel dégagé sont dans la région des conditions fréquentes qui favorisent la stabilité atmosphérique et consécutivement la mauvaise dispersion des polluants, faisant de cette situation un sujet d'intérêt majeur. La campagne de mesure KASCADE (KAtabatic winds and Stability over CAdarache for Dispersion of Effluents) constitue le volet expérimental de l'étude. Réalisée pendant l'hiver 2013 elle a couvert 3 mois d'observation continue et complétée de 23 périodes d'observation intensive (POI). L'analyse montre que les écoulements descendant les vallées de Cadarache (CDV) et de la Durance (DDV) dominent pendant toute la période d'étude. La stabilité s'installant dès le coucher du soleil, le courant CDV s'épaissit progressivement. Le profil de vent en forme de jet présente son maximum à environ 30 m où il atteint 2 à 3 m s-1. Il se maintient toute la nuit et disparaît avec l'inversion de stabilité. Comme la station météorologique du centre manque de capteur de vent dans la CV même, une méthode a été développée pour diagnostiquer le CDV en exploitant l'instrumentation actuelle. Ainsi, si la prévision de ce vent n'est pas à la portée du modèle méso-échelle WRF avec une résolution kilométrique, cette méthode le permet en combinant une descente d'échelle dynamique et statistique. Le vent DDV est identifié comme un vent qui suit l'axe de la vallée, fortement corrélé à la stabilité à l'échelle régionale car il n'apparaît que la nuit lorsque le forçage synoptique est faible. Ce vent n'arrive à Cadarache que 6 à 9 heures après le coucher du soleil avec une grande variabilité. D'un autre côté, il est à son maximum au lever du soleil avant que les processus convectifs ne démarrent, et présente un jet autour de 200 m avec des vitesses de 4 à 8 m s-1 et dont la hauteur est corrélée à la profondeur de la vallée. Dans les simulations avec WRF, malgré des défauts, la DV étant bien résolue avec une maille de 1 km, l'occurrence de ce vent est assez bien simulée. Par ailleurs l'examen de ses caractéristiques spatiales montre qu'il s'agit soit d'un écoulement de drainage, soit d'un écoulement canalisé forcé. Bien qu'on ne dispose pas de données suffisantes pour élucider le mécanisme dominant de déclenchement du vent DDV, les deux précédemment identifiés sont de bons candidats. / Stable stratification can be one of the most penalizing condition concerning pollutants in the atmospheric boundary layer. Over complex terrain under these conditions, the relief may modify the flow. Therefore the knowledge of down-valley wind characteristics influencing the wind field at Cadarache and its close surroundings is crucial for safety regulation in the context of sanitary impact of the site. Cadarache is a CEA research centre and located in the Prealps of southeast France. It is embedded in a small valley, the Cadarache Valley (CV), which is one of the tributaries of the larger Durance Valley (DV). The two valleys are distinct in size and therefore react differently to stable conditions, and are investigated by means of observations (field experiment KASCADE : KAtabatic winds and Stability over CADarache for Dispersion of Effluents) and simulations (the Weather Research and Forecasting (WRF) model). To investigate the valley wind behaviour, the KASCADE campaign has been designed and conducted in the winter of 2013, covering a 3-month period and 23 intensive observation periods (IOP). It resulted in a well-documented campaign, from which the analysis shows that the Cadarache and Durance down-valley (CDV and DDV respectively) winds are both dominant flows during the period of investigation. The CDV wind is a thermally driven flow, with regular wind speeds up to 2 - 3 m s-1 up to 50 m agl. It persists throughout the night and disappears in the early morning with the stability. The current observational network of Cadarache lacks means of measurement for inside CDV wind. This work shows that it can be nowcasted from available meteorological tower observations. Due to the CV small scale, currently a wind forecast on kilometer resolution is out of reach, but the methodology developed here can be used to forecast the wind through a combination of dynamical and statistical downscaling. The DDV wind has been recognized as down-valley oriented, and strongly related to stability at a regional scale, as it exists only after sunset when synoptic forcing is very weak. DDV wind arrival at Cadarache is mostly observed 6 to 9 hours after sunset, but however dominantly present around sunrise, when convectively driven processes are not yet established. Jets are observed mostly at around 200 m agl with wind speeds between 4 and 8 m s-1. Despite some (general) deficiencies of the WRF model, the DDV wind is simulated close to reality thanks to the 1-km resolution allowing a correct representation of the Durance valley orography. The ensemble of 23 simulated IOPs allowed further to characterize the flow in a spatial sense and to recognize drainage and flow channelling as most important candidates for the flow mechanism.

Durant l’épisode de canicule-sécheresse de 2003, les peuplements de douglas et de hêtres en Bourgogne ont été lourdement affectés, présentant des symptômes de dépérissement et de surmortalité. Cet épisode semble être la première occurrence d’aléas climatiques attendus dans un futur proche et remet en question leur pérennité en Bourgogne puisque leur vulnérabilité au climat est attribuable à l'amplitude et au cumul des contraintes hydriques exercées durant leur cycle de végétation. Dans le contexte du changement climatique et en réponses aux demandes des gestionnaires forestiers qui s’appuient partiellement sur une cartographie de l’évolution des contraintes climatiques jusqu’à la fin de ce siècle, ce travail explore la capacité d’une chaîne de modélisation hydroclimatique haute résolution couplant le modèle de climat régional WRF alimenté par les réanalyses ERA-Interim au modèle de bilan hydrique Biljou© ˆ simuler des indices de déficit hydrique pour ces deux essences. La première partie de ce travail propose une analyse de la capacité du modèle WRF à simuler chacune des variables atmosphériques de surface qui sont utilisées en entrée du modèle du bilan hydrique. L’analyse de la capacité du modèle à simuler ces variables repose (i) sur une approche comparative directe entre les données simulées par WRF et les observations enregistrées par le réseau de stations Météo-France et les réanalyses SAFRAN à l’échelle de la région, de la station, et du peuplement forestier, (ii) sur une approche indirecte utilisant l’évapotranspiration potentielle (ETP) et la relation entre les indices de croissance radiale et les indices de déficit hydrique calculés par le modèle d’impact pour les deux essences. Les résultats montrent une amélioration significative des données ERA-Interim par le modèle WRF pour chacune des variables ainsi qu’une capacité certaine à les spatialiser à haute résolution. Toutefois, la bonne reproduction de l’ETP par WRF, combinée à la faible corrélation entre la moyenne annuelle des indices de déficit hydrique estimés avec les données WRF et la moyenne annuelle des indices de croissance radiale montrent que les difficultés de WRF à simuler le déficit hydrique sont principalement imputables à ses biais de précipitations. La seconde partie propose l’application d’une post-correction statistique aux données de précipitations WRF. Bien que cette méthode améliore significativement la distribution spatiale des précipitations, leurs variabilités saisonnière et interannuelle et surtout les cumuls précipités, les données post-corrigées ne permettent pas de reproduire un indice de déficit hydrique suffisamment proche de celui estimé à partir des observations ou des analyses SAFRAN. Deux nouvelles simulations résolvant explicitement les processus convectifs et utilisant un guidage spectral ont permis de montrer à partir de deux années types que cette déficience est imputable à l’incapacité de la méthode de correction à résoudre les différences de timing de la variabilité climatique transitoire simulée par WRF. Deux types d’erreurs de modélisation climatique, survenant indépendamment, sont donc d'une importance primordiale pour les études d'impact: (i) la chronologie des événements pluvieux ; (ii) la distribution statistique des précipitations quotidiennes. La combinaison de ces deux éléments contrôle le nombre de jours franchissant le seuil de 40% de réserve relative en eau du sol et indirectement l’intensité des indices de déficit hydrique. / During the 2003 drought and heat wave event, douglas-fir and common beech stands in Burgundy have been heavily affected, and presented symptoms of dieback and mortality. This event seems to be the first occurrence of expected climatic changes in the near future and questions their sustainability in Burgundy since their climate vulnerability is mainly due to the amplitude and accumulated water constraints exercised during their growing cycle. In the context of climate change and in order to provide information to forest managers who partly rely on a mapping of the climatic constraints until the end of this century, this work explores the ability of a high resolution hydroclimatic modelling chain, coupling the regional climate model WRF to the daily lumped water balance model Biljou© in order to simulate soil water deficit indices for these two species. The first part of this paper analyzes the capacity of WRF model to simulate each surface atmospheric variable used as input for the water balance computation. The analysis of model's ability to simulate these variables is based on (i) a direct and comparative approach between WRF simulated data and observations recorded by the Météo-France stations network and SAFRAN reanalyses across the whole region, over stations and forest stands, (ii) on an indirect approach using the potential evapotranspiration and soil water deficit index calculated by Biljou©. Results show a significant improvement upon the ERA-Interim data for each variable and a strong ability to produce reliable data at high resolution. However, the WRF capability to estimate a realist potential evapotranspiration, combined to the the low correlation between the average annual soil water deficit and radial growth indexes, show that the WRF deficiencies in simulating water deficit are mainly attributable to its precipitation biases. The second part proposes to apply a statistical post-correction to the WRF precipitation data. Although this method significantly improves the spatial distribution of precipitation, their seasonal and interannual variability and precipitation amounts, post-corrected data do not produce a water deficit index sufficiently close to those ones estimated from observations or SAFRAN reanalysis. Two new simulations explicitly solving convective processes and using a spectral nudging have shown that this deficiency is mainly attributable to the inability of the correction method to solve timing differences of the transient climate variability simulated by WRF. This work showed that two types of climate modeling errors occurring independently, are major issues for impact studies: (i) the timing of precipitations events ; (ii) the statistical distribution of daily precipitation. Combined together, they control the number of days crossing the 40% threshold of relative extractable water and indirectly the soil water deficit index intensity.

The conventional approach to the frequency analysis of extreme rainfall is complicated by non-stationarity resulting from climate change. In this study significant trends in extreme rainfall are detected using statistical trend tests (Mann-Kendall test and t-test) for all over the Korean Peninsula. The violation of the stationarity for 1 hour annual maximum series is detected for large part of the area especially for southwestern and northeastern regions. For stations showing non-stationarity, the non-stationary generalized extreme value (GEV) distribution model with a location parameter in the form of linear function of time makes significant improvement in modeling rainfall extremes when compared to the stationary GEV model. The Bartlett-Lewis rainfall model is used to generate annual maximum series for the purpose of generating the Intensity-Duration-Frequency (IDF) curve. Using 100 sets of 50 year synthetic annual maxima, it is found that the observed annual rainfall maximum series are reasonably represented by the model. The observed data is perturbed by change factors to incorporate the climate change scenario from the WRF (Weather Research and Forecasting) regional climate model into IDF estimates. The IDF curves for the future period 2040-2079 show highest estimates for all return periods and rainfall durations. The future IDF estimates show significant difference from the IDF estimates of the historical period (1968-2000). Overall, IDF curves show an increasing tendency over time. A historical and future climate simulation is evaluated over the Colorado River Basin using a 111-year simulation (1969-2079) of the WRF climate change scenario. We find the future projections show statistically significant increases in temperature with larger increases in the northern part of the basin. There are statistically insignificant increases in precipitation, while snowfall shows a statistically significant decrease throughout the period in all but the highest elevations and latitudes. The strongest decrease in snowfall is seen at high elevations in the southern part of the basin and low elevations in the northern part of the basin.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-31T20:42:20Z No. of bitstreams: 1 AlexandreTorresSilvaDosSantos_TESE.pdf: 4479347 bytes, checksum: 3c5c147ce62a6256530f17e60cf8fb0f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-03T00:41:26Z (GMT) No. of bitstreams: 1 AlexandreTorresSilvaDosSantos_TESE.pdf: 4479347 bytes, checksum: 3c5c147ce62a6256530f17e60cf8fb0f (MD5) / Made available in DSpace on 2016-06-03T00:41:26Z (GMT). No. of bitstreams: 1 AlexandreTorresSilvaDosSantos_TESE.pdf: 4479347 bytes, checksum: 3c5c147ce62a6256530f17e60cf8fb0f (MD5) Previous issue date: 2014-12-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O objetivo deste trabalho foi determinar a variabilidade sazonal-interanual e tend?ncia da velocidade do vento e validar o modelo num?rico de mesoescala para depois acoplar com o modelo num?rico de microescala no intuito de obter recursos e?licos em algumas localidades no Nordeste do Brasil (NEB). Para isso usamos dois conjuntos de dados de velocidade do vento (esta??es meteorol?gicas e torres anemom?tricas) e dois modelos din?micos; um de mesoescala e outro de microescala. Usamos ferramentas estat?sticas para avaliar e validar os dados medidos e simulados. As simula??es do modelo din?mico de mesoescala foram realizadas atrav?s de m?todos de assimila??o de dados (relaxamento newtoniano e filtro de Kalman). Os principais resultados apontam: (i) Cinco grupos homog?neos de velocidade do vento no NEB com valores maiores no inverno e primavera e menores para ver?o e outono; (ii) A variabilidade interanual da velocidade do vento em alguns grupos se destacaram com valores maiores; (iii) A circula??o de grande escala modificada por fen?menos El Ni?o e La Ni?a alterou a intensidade da velocidade do vento para os grupos com maiores valores; (iv) A an?lise de tend?ncia mostrou valores negativos mais significativos para os grupos G3, G4 e G5 em todas as esta??es do ano e na m?dia anual; (v) O desempenho do modelo din?mico de mesoescala apresentou menores erros nas localidades Paracuru e S?o Jo?o do Cariri e maiores erros foram observados em Triunfo; (vi) Aplica??o do filtro de Kalman diminuir significativamente os erros sistem?ticos apresentados nas simula??es do modelo din?mico de mesoescala; (vii) Os recursos e?licos apontam que as ?reas Paracuru e Triunfo s?o favor?veis para gera??o de energia, sendo que a t?cnica de acoplamento ap?s valida??o apresentou melhor resultado para Paracuru. Conclu?mos que o objetivo do estudo foi alcan?ado, sendo poss?vel agora identificar tend?ncias em grupos homog?neos do comportamento do vento, al?m de avaliar ? qualidade das simula??es tanto com o modelo din?mico de mesoescala como de microescala para responder quest?es necess?rias antes de planejar projetos de pesquisas na ?rea e?lica. / The objective of this study was to determine the seasonal and interannual variability and calculate the trends of wind speed in NEB and then validate the mesoscale numerical model for after engage with the microscale numerical model in order to get the wind resource at some locations in the NEB. For this we use two data sets of wind speed (weather stations and anemometric towers) and two dynamic models; one of mesoscale and another of microscale. We use statistical tools to evaluate and validate the data obtained. The simulations of the dynamic mesoscale model were made using data assimilation methods (Newtonian Relaxation and Kalman filter). The main results show: (i) Five homogeneous groups of wind speed in the NEB with higher values in winter and spring and with lower in summer and fall; (ii) The interannual variability of the wind speed in some groups stood out with higher values; (iii) The large-scale circulation modified by the El Ni?o and La Ni?a intensified wind speed for the groups with higher values; (iv) The trend analysis showed more significant negative values for G3, G4 and G5 in all seasons and in the annual average; (v) The performance of dynamic mesoscale model showed smaller errors in the locations Paracuru and S?o Jo?o and major errors were observed in Triunfo; (vi) Application of the Kalman filter significantly reduce the systematic errors shown in the simulations of the dynamic mesoscale model; (vii) The wind resource indicate that Paracuru and Triunfo are favorable areas for the generation of energy, and the coupling technique after validation showed better results for Paracuru. We conclude that the objective was achieved, making it possible to identify trends in homogeneous groups of wind behavior, and to evaluate the quality of both simulations with the dynamic model of mesoscale and microscale to answer questions as necessary before planning research projects in Wind-Energy area in the NEB

Cette étude s'inscrit dans le cadre de la documentation de la variabilité intrasaisonnière atmosphérique et l'analyse de la prévisibilité sur les régions Afrique Centrale et Golfe de Guinée. Elle porte sur les saisons de l'année pour lesquelles la ZCIT est au dessus de l'équateur. Des travaux menés distinctement sur les mois de Mars à Juin et de Septembre à Novembre, il ressort que les activités convective et pluvieuse au cours de ces saisons sont régies par trois modes principaux de variabilité assez proches. Au cours de ces deux saisons, les systèmes individuels générateurs de pluie se déplacent d'est en ouest, et leur activité est régulée par des enveloppes convectives se déplaçant vers l'est. Des analyses spécifiques ont mis en lumière la forte empreinte de signaux équatoriaux de type onde de Kelvin se propageant vers l'est et dont les phases régulent l'organisation des systèmes convectifs. L'impact relatif d'ondes équatoriales se propageant vers l'ouest (Rossby en particulier) et celui d'advections de masses d'air méditerranéennes n'est pas à négliger, d'autant plus qu'elles sont susceptibles d'interagir avec les ondes de Kelvin, et donc de moduler les phases de l'activité convective. Les forçages externes ainsi identités constituent des sources potentielles de prévisibilité pour les modes intrasaisonniers mis en évidence. Utilisant les données de la base multi-modèle TIGGE, l'analyse de la prévisibilité de chacun des modes principaux de variabilité est réalisée. Se focalisant sur les phases spécifiques de ces modes, les scores obtenus augurent une prévisibilité au delà de 10 jours surtout pour des prévisions initialisées lorsque les principales sources sont actives. / In this study we document the intraseasonal variability of the tropical convection and its predictability during the rainy season over the Central Africa and the Gulf of Guinea. Here, our study mainly focuses on seasons of the year for which the ITCZ is north of the equator. Based separate studies carried out on March to June and September to November seasons, we are able to identify three main modes of variability that modulate tropical convection and rainfall in West and Central Africa. During these two seasons, while individual rain-producing systems move westward, their activity is highly modulated by eastward propagating subregional and regional scale systems. Results of detailed analysis indicate the coupling between tropical convection and equatorial Kelvin wave in the region. The phases of these eastward propagating signals play an important role by regulating the organization of convective systems. Moreover, the role played by westward propagating signals (Rossby wave in particular) and Mediterranean air intrusion needs to be taken into account. These systems by interacting with Kelvin wave, may modulate the phases of convective activity in the region. Therefore, external forcing associated with these systems can be useful to the predictability of the intraseasonal modes the region. A multi model diagnostic study is performed using data available from the TIGGE project in order to evaluate the predictability of each of the main modes of variability. For a typical phase of these modes, there seems to be a statistically significant skill associated with predictability of beyond 10 days, especially for predictions initiated from active main sources.

Many recent studies have highlighted the substantial health-related impacts of particle number (PMno) rather than particle mass. The aim of this study is to determine the correlation of trace gases with PMno, to identify the chemical composition of particle different sizes and to predict the NOx and PMno over Yanbu Industrial City (YIC). Trace gases (NOx, SO2, H2S, O3, CO), PMno with diameter (7nm-10μm), traffic and meteorological parameters were measured at three sampling sites in YIC. The maximum PMno (333,971 cm-3) at downwind site#1 was about 2.5 times higher than that (123,842 cm-3) at upwind site#2 and about 1.2 times higher than that (263,572 cm-3) at downwind site#3. The average PMno distribution at downwind sites consisted of one distinguishable mode (nucleation mode<20nm) whereas the upwind site had two modes (the nucleation and the accumulation modes). The correlation of PMno with NO/NOx (r>0.7) are generally stronger than with NO2 at sites#1 and 2, whereas for site #3 the correlation between PMno with NO2/NOx are better than with NO. PMno has generally either weak or poor correlation with SO2 and CO, respectively. Particle samples of different sizes (7nm-10?m) were chemically analysed using an ion chromatograph (IC) for inorganic ions and inductively coupled plasma mass spectrometry (ICP-MS) for trace metals at site#3. The ionic analysis revealed that sulfate and ammonium was mainly present in particle of size < 0.38μm while nitrate and chloride was mainly present in particles of size > 0.38μm. Non-sea salt sulfate was dominant in all particle sizes compared to the marine sulfate which is minor. The total sulfate and nitrate contributed 50.3% and 24.4% of the total ionic mass respectively followed by chloride (13.3%) and ammonium (10.6%). The trace-metals analysis results indicated that Na represented more than 94% of the total mass and the contributions of the remaining metals (Al, Sr, Zn, V, Cr, Fe, etc) were about 6%. A further part of this study consisted of the coupling of the WRF/CALMET system with the CALPUFF model, which was applied to predict NOx and PMno concentrations. The WRF model was employed to generate the meteorological input data for CALMET. WRF predictions were evaluated with surface data and upper air profiles using RASS/SODAR and radiosondes. WRF tends to underestimate the surface temperature on average with biases of up to -3.4°C and also underestimates temperature profiles with average biases ranging between -2.7 and -5.2oC when compared to the RASS profiler, but with a lower bias (< -2.4°C) when compared to radiosonde profiles. The mean wind speed bias for the majority of the cases was close to the benchmark of ±0.5m/s, but the mean wind direction bias for half of the cases exceeded the benchmark of 10o. It was concluded that WRF predictions can be used for air dispersion modeling to produce reasonable outputs. NOx predictions by CALPUFF showed that the contribution of the traffic to the highest concentrations during the nighttime was up to 80%, but after sunrise the contribution from industries became higher (up to 70%). The highest predicted NOx concentration (~313μg/m3) was much lower than the national ambient standard (660μg/m3) and the community area is affected much by industries during mid-morning hours when the wind shifting from land breeze to sea breeze. The fractional bias (FB) ranged between -0.1 and 1.06 indicating that the model tends to under-predict the NOx observations. PMno predictions of two sizes (7-40nm and 7nm-10μm) were derived based on the NOx predictions. All FB values were ranged between -0.1 and 0.5. It was concluded that PMno predictions were generally better than those of the NOx due mainly to adding the background term (intercept) for the PMno predictions.

abstract: The National Oceanic and Atmospheric Administration (NOAA)’s National Water Model (NWM) will provide the next generation of operational streamflow forecasts at different lead times across United States using the Weather Research and Forecasting (WRF)-Hydro hydrologic system. These forecasts are crucial for flood protection agencies and water utilities, including the Salt River Project (SRP). The main goal of this study is to calibrate WRF-Hydro in the Oak Creek Basin (OCB; ~820 km2), an unregulated mountain sub-watershed of the Salt and Verde River basins in Central Arizona, whose water resources are managed by SRP and crucial for the Phoenix Metropolitan area. As in the NWM, WRF-Hydro was set up at 1-km (250-m) resolution for the computation of the rainfall-runoff (routing) processes. Model forcings were obtained by bias correcting meteorological data from the North American Land Data Assimilation System-2 (NLDAS-2). A manual calibration approach was designed that targets, in sequence, the sets of model parameters controlling four main processes responsible for streamflow and flood generation in the OCB. After a first calibration effort, it was found that WRF-Hydro is able to simulate runoff generated after snowmelt and baseflow, as well as magnitude and timing of flood peaks due to winter storms. However, the model underestimates the magnitude of flood peaks caused by summer thunderstorms, likely because these storms are not captured by NLDAS-2. To circumvent this, a seasonal modification of soil parameters was adopted. When doing so, acceptable model performances were obtained during calibration (2008-2011) and validation (2012-2017) periods (NSE > 0.62 and RMSE = ~2.5 m3/s at the daily time scale). The process-based calibration strategy utilized in this work provides a new approach to identify areas of structural improvement for WRF-Hydro and the NWM. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2020