A notable feature in the first 20-year satellite altimetry records is an anomalously fast sea level rise (SLR) in the western Pacific impacting island nations in this region. This observed trend is due to a combination of internal variability and external forcing. The dominant mode of dynamic sea level (DSL) variability in the tropical Pacific presents as an east-west see-saw pattern. To assess model skill in simulating this variability mode, we compare 38 Coupled Model Intercomparison Project Phase 5 (CMIP5) models with 23-year satellite data, 55-year reanalysis products, and 60-year sea level reconstruction. We find that models underestimate variance in the Pacific sea level see-saw, especially at decadal, and longer, time scales. The interannual underestimation is likely due to a relatively low variability in the tropical zonal wind stress. Decadal sea level variability may be influenced by additional factors, such as wind stress at higher latitudes, subtropical gyre position and strength, and eddy heat transport. The interannual variability of the Nino 3.4 index is better represented in CMIP5 models despite low tropical Pacific wind stress variability. However, as with sea level, variability in the Nino 3.4 index is underestimated on decadal time scales. Our results show that DSL should be considered, in addition to sea surface temperature (SST), when evaluating model performance in capturing Pacific variability, as it is directly related to heat content in the ocean column.

The climate variability over the North Atlantic region is described in the 10-50 year band, using a 500-year integration of the Hamburg ECHAMl/LSG coupled general circulation model. In order to isolate nearly periodic components of the atmosphere and the ocean, the multichannel version of the singular spectrum analysis (MSSA) is applied to 11 components of the climate system. In doing so the main focus is on the turbulent exchange between the two subsystems. One interdecadal oscillation of the system ocean and atmosphere is detected with a period of about 18 years. The associated anomalies of sea level pressure (SLP) are situated east of Newfoundland while these of the geopotential height at 500 hPa are slightly shifted to the East. Both the fields undergo a primarily standing oscillation. The sea surface temperature (SST) and the sub surface temperature anomalies have a large extension along the 40° N latitude circle with most of their variability south of Newfoundland. lt is found that the SST anomaly is primarily generated by the temperature advection in the upper ocean layer which is coupled to the Subpolar Gyre strength and Ekman pumping vertical velocity. Both the processes are forced by the atmosphere. In a further analysis applied only to the SST and the Geopotential height at 500 hPa over the whole Northern Hemisphere this 18 year mode was also isolated. The modes obtained by the local and hemispheric analyses are well correlated both in time and space, suggesting a more active role of atmosphere than of the ocean, in addition a strong modulation of the amplitude of the oscillation due to local processes over the North Atlantic was detected. / Die Klimavariabilität über dem Nordatlantik wird anhand einer 500 Jahre Integration des Hamburger gekoppelten Klimamodels ECHAMl/LSG untersucht. Um periodische Komponenten in Ozean und Atmosphäre zu isolieren, wird die MSSA ("multichannel singular spectrum analysis") auf 11 Komponenten des Klimasystems angewandt. Bei den Analysen wird besonderes Augenmerk auf den turbulenten Austausch zwischen beiden Subsystemen gelegt. Es kann eine Oszillation des gekoppelten Systems mit einer Periode von etwa 18 Jahren detektiert werden. Die Anomalie des Bodendrucks weist ihre maximale Amplitude östlich von Neufundland auf, während die Anomalie des 500 hPa Geopotentials leicht östlich dazu verschoben ist. Die Anomalie der SST zeigt ihre größte Variabilität südlich von Neufundland. Diese wird im wesentlichen durch die Temperaturadvektion in der oberen Ozeanschicht generiert, welche im wesentlichen an den subpolaren ozeanischen Wirbel sowie an das "Ekman pumping" gekoppelt ist. Beide Prozesse werden durch die Atmosphäre angetrieben. In einer weiteren Analyse, in der die MSSA auf die SST und das 500 hPa Geopotential der gesamten nördlichen Hemisphäre angewandt wird, kann ebenfalls ein Oszillation von 18 Jahren detektiert werden. Diese Mode korreliert räumlich und zeitlich gut mit dem der lokalen Analyse über dem Nordatlantik, welches auf ein aktivere Rolle der Atmosphäre hinweist. Die starken Unterschiede der Amplitudenmodulation könnten durch lokale Prozesse bedingt sein.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-15T15:02:00Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) IMPACTO DAS MUDANÇAS CLIMÁTICAS NA DISPONIBILIDADE HÍDRICA NO BIOMA CAATINGA.pdf: 2818779 bytes, checksum: 28004dc087409be6895f9c9b3478017c (MD5) / Made available in DSpace on 2016-04-15T15:02:00Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) IMPACTO DAS MUDANÇAS CLIMÁTICAS NA DISPONIBILIDADE HÍDRICA NO BIOMA CAATINGA.pdf: 2818779 bytes, checksum: 28004dc087409be6895f9c9b3478017c (MD5) Previous issue date: 2015-03-10 / A modelagem de clima tornou-se uma ferramenta fundamental na elaboração de cenários climáticos futuros em todo o mundo, auxiliando dessa forma no estudo dos impactos das mudanças climáticas sobre populações e biomas mais vulneráveis aos efeitos do clima, assim como permite avaliar como será o clima futuro contribuindo no monitoramento climático. Deste modo, estudar a modelagem climática e, consequentes cenários climáticos em regiões mais vulneráveis como o semiárido nordestino é de grande importância para auxiliar o planejamento e elaboração de políticas públicas para combate e mitigação dos efeitos das mudanças e variabilidade do clima. Com isso, o presente trabalho visa analisar os impactos das mudanças climáticas na disponibilidade hídrica no bioma Caatinga gerando cenários de mudanças climáticas utilizando o modelo regional ETA – CTPTEC, e aliando as tendências climáticas futuras para o município de Petrolina no Estado de Pernambuco, município este que possui clima semiárido e apresenta um grande potencial agrícola no sertão Pernambucano, além de verificar como esses cenários climáticos futuros podem interferir na vida da população local e na conservação e preservação do bioma Caatinga. As análises dos dados foram feitas por meio de correlação dos valores observados e modelados da precipitação, temperatura do ar, e evapotranspiração. Ainda foi realizada a comparação das médias mensais, apreciação dos balanços hídricos, e elaboração de tendências climáticas até 2040. Os resultados apresentaram correlação de R2 0,516 para os dados de temperatura do ar e fraca correlação com dados de precipitação R2 0,097, além de uma tendência de aumento da temperatura para 2040. No que concerne a precipitação não apresentou tendência. A correlação da evapotranspiração potencial foi R2 0,4916, maior que a correlação da evapotranspiração real R2 0,0881, o que pode ser explicado devido aos erros nos dados de entrada do modelo, como também aos anos avaliados (um ano chuvoso seguido por dois anos secos). Dessa forma não seriam diferentes as correlações do Índice de Área Foliar, onde a correlação com dados de precipitação observada foi de R2 0,3021 e com a precipitação modelada foi de R2 0,1187. Nas comparações das médias estiveram mais próximas para temperatura em torno de 0,2°C e altas diferenças na precipitação atingindo 152,11 mm no ano de 2011, e os balanços hídricos modelados e observados, apresentaram ambos, deficiência hídrica durante praticamente todo o ano, com altas taxas de evapotranspiração com totais anuais em torno de 568,5 mm, o que pode vir a interferir na vegetação de Caatinga e na vida da população local, principalmente no que diz respeito ao abastecimento de água. / Climate modeling became a fundamental tool in the designing of future climate scenarios all over the world, thus being helpful in the analysis of the impacts of climate changes on populations and biomes more vulnerable to the effects of climate, besides that, it also permits evaluate how the future climate will be, thus contributing to the climate monitoring. Therefore, to study climate modeling and consequent climate scenarios in more vulnerable regions like the Northeastern semi-arid is very important to assist the planning and elaboration of public policies to combat and mitigate the effects of change and variability of the climate. Thus, the present work analyzes the impacts of climate change on water availability in the Caatinga biome generating climate change scenarios using the ETA model - CTPTEC, and combining future climate trends for the city of Petrolina in Pernambuco State, a municipality that has a semi-arid climate and that presents a great agricultural potential in the Pernambuco backlands, besides verifying how these future climate scenarios can interfere in the lives of the local population and in the conservation and preservation of the Caatinga scrub. The data analyses were made through the correlation of the observed and modeled values of the precipitation and air temperature, in addition to the correlation and evapotranspiration. Also was performed to compare the monthly average assessment of water balances, besides of the elaboration of climate trends until 2040. The results showed a correlation R2 0.516 for air temperature data and weak correlation with R2 0.097 precipitation data, and a trend Increase temperature to 2040. As regards the precipitation showed no tendency. The correlation of potential evapotranspiration was R2 0.4916, higher than the correlation of actual evapotranspiration R2 0.0881, which might be due to errors in model input data, but also the years evaluated (a rainy year followed by two dry years). Thus would not be different correlations of Leaf Area Index could not be different, where the correlation with observed rainfall data was 0.3021 and R2 with patterned precipitation was R2 0.1187. Mean comparisons were closer to average temperature of 0.2 °C and high differences in precipitation reaching 152.11 mm in 2011, and the modeled and observed water balance showed both water deficit during the entire year with high rates of evapotranspiration with annual total around 568.5 mm, which will interfere in the Caatinga vegetation and life of the local population, especially with regard to water supply.

Northern regions of Canada are of special interest for renewable energy investment due to the high cost of traditional energy generation in remote communities (Das & Canizares 2016b). However, climate variability and change have a substantial impact on renewable energy yield and system vulnerability (e.g., Ravestein et al. 2018; van der Wiel et al. 2019), and the North will experience more dramatic impacts due to climate change compared with other parts of Canada (Serreze 2015). Using the Canadian Regional Climate Model Version 4 (CanRCM4) large ensemble driven by Representative Concentration Pathway 8.5, current and future wind and solar energy potential, variability and covariability in northern Canada were assessed. Eight focal communities were additionally selected for in-depth analysis based on the work of Das & Canizares (2016b). Robust increases in annual average wind power potential (WPP) are projected across the northernmost part of the study area by 2070-2099 (up to 30%), with changes most pronounced in cold seasons. Decreases in WPP are projected for southern areas. Solar power potential (SPP) is projected to decrease across the study area, with robust changes emerging by as early as 2010-2039. For the focal communities, WPP stability (as measured through inter- and intra-annual variability) is projected to increase, while SPP stability is projected to decrease. The changes in WPP variability are associated with a dampening of the seasonal cycle of WPP in the north. Monthly mean WPP and SPP are negatively correlated, with approximately oppositely-phased seasonal cycles. Combined wind/solar installations therefore show reduced sub-annual variability, stabilizing power supplies relative to installations of solely wind or solar power. Drivers of change in WPP and SPP are complex, but changes in sea ice across the 21st century will play an important role for both WPP and SPP. Over the northern ocean regions, the influence of sea ice loss on roughness length is found to be more important than impacts on surface layer stability. Changes in storm winds also play a role, but impacts due to synoptic storm activity are difficult to distinguish from shifts in the wind speed distribution. Decreases in SPP can be attributed to projected reductions in downwelling shortwave radiation, which in turn are closely associated with changes in cloud characteristics (e.g., optical depth), as measured through CanRCM4 column liquid/ice water content. Clear-sky changes in shortwave radiation were not directly assessed, but are potentially impacted by robust increases in column water vapour. Overall, northern regions of Canada and the focal communities show high potential for renewable energy generation across the 21st century. Projected increases in wind power resources and wind power stability in the focal communities could enhance the cost-savings and emissions reductions predicted based on current climate assessments (e.g., Das & Canizares 2016b). With ever improving technologies and declining costs, the viability of renewable power in the north is likely to become even more certain in years to come. / Graduate

L’augmentation globale des températures au cours de la période 1850-2012 n’est pas uniforme à l’échelle du globe et l’Arctique se réchauffe deux fois plus que la moyenne. Cependant, la couverture temporelle trop courte des données instrumentales rend difficile la distinction entre la variabilité climatique naturelle et celle liée au forçage anthropique. L’étude de la variabilité climatique « exempte » de l’influence humaine est alors réalisée à partir de données proxies indirectes provenant d’archives paléoclimatiques continentales et marines. Dans la région Arctique-subarctique, les enregistrements disponibles à haute résolution sur les derniers 2000 ans ont été centralisé dans la base de données PAGES Arctic 2k. Les objectifs de ces travaux sont l’amélioration de la caractérisation et de l’interprétation de la variabilité climatique sur les derniers 2000 ans, en allant plus loin que la tendance millénaire et les périodes climatiques majeures mais aussi en s'intéressant au rôle et l’expression spatiale de la variabilité interne du système climatique. Cette thèse s'appuie sur la base de données PAGES Arctic 2k permettant l'étude des variations de températures dans la région Arctique-subarctique mais aussi d'une nouvelle base de données permettant de reconstruire les variations hydroclimatiques (précipitations et humidité) dans la région et créée lors de cette étude. L'utilisation de méthodes d'analyse du signal climatique sur des enregistrements régionaux calculés à partir de ces deux bases de données a permis de mettre en évidence une variabilité climatique dans la région Arctique-subarctique s’exprimant depuis les échelles multi-décennales à millénaire. En particulier, les variabilités multi-décennales sont en lien avec la variabilité interne du système climatique. Les variations hydroclimatiques et de températures s'exprimant aux échelles multi-décennales dans la région sont en effet caractérisées par des fréquences spécifiques aux oscillations climatiques régionales (oscillation Atlantique Nord et oscillation Pacifique décennale), en particulier sur les derniers 200 ans. Les travaux réalisés sur la base de données de températures et la réflexion autour de la création et l’exploitation de la base de données hydroclimatiques ont également conduit à la définition d’une méthodologie de travail avec une base de données paléoclimatiques, depuis sa construction jusque la définition de ses limites, notamment en termes de représentativité spatiale des séries contenues dans la base de données et de l'assimilation de données avec des saisonnalités différentes. / The temperature increase during the 1850-2012 period is not uniform globally and the Arctic is warming twice as much as the average. However, the short time coverage of instrumental data makes it difficult to distinguish natural climate variability and anthropogenic forcing. The study of climatic variability "free" of human influence requires the use of proxies data measured in continental and marine palaeoclimatic archives. In the Arctic-subarctic region, high resolution records have been centralized in the Arctic 2k PAGES database. The objectives of this work are to improve the characterization and interpretation of climatic variability over the last 2000 years, going beyond the millennial trend and the major climatic periods, but also by focusing on the role and spatial expression of the internal variability of the climate system. This thesis is based on the Arctic 2k PAGES database, which allows the study of temperature variations in the Arctic-subarctic region, as well as a new database to reconstruct hydroclimatic variations (precipitation and humidity) in the region and created during this study. The use of climate signal analysis methods on regional records calculated from these two databases has highlighted climate variability in the Arctic-subarctic region from the multi-decadal to millennial scales.In particular, multi-decadal variability is related to the internal variability of the climate system. The hydroclimatic and temperature variations expressed at multi-decadal scales in the region are characterized by frequencies specific to regional climate oscillations (North Atlantic oscillation and decadal Pacific oscillation), particularly over the last 200 years. The work done on the temperature database and the reflection on the creation and exploitation of the hydroclimatic database have also led to the definition of a working methodology with a palaeoclimatic database, from its construction to the definition of its limits, in particular in terms of the spatial representability of the series contained in the database and the assimilation of data with different seasonings.

Changes in climate influence agricultural production. This study looks at the impacts of climate variability in the Utah regions of the Upper Colorado River Basin by combining regression techniques with interview data to explore how climate variability affects agricultural production and how the farmers are adapting their practices to these changes. The results show that climate does not have any significant impact on cattle and hay production in the study area on a decadal scale. However, on an annual basis temperature seems to have more impact than precipitation. Among non-climatic variables, commodity prices and their regulations by the government are the most important factors that influence the year-to-year production. Farmers are well-aware of these impacts and have adapted significantly to the changes that occur on a year-to-year basis.

Land use change and climate variability are the main drivers of watershed hydrological processes. The main objective of this study was to assess the impact of land use change and climate variability on hydrology of the Mara River Basin in East Africa. Land use maps generated from satellite images were analyzed using the intensity analysis approach to determine the patterns, dynamics and intensity of land use change. Changes in measured streamflow caused separately by land use change and climate variability were separated using the catchment water-energy budget based approach of Budyko framework. The information on past impact of climate variability on streamflow was used to develop a runoff sensitivity equation which was then used to predict the future impact of climate change on streamflow. Finally, the impact of agroforestry on watershed water balance was predicted using SWAT (Soil and Water Assessment Tool) model. Deforestation and expansion of agriculture were found to be dominant and intensive land use changes in the watershed. The deforestation was attributed to illegal encroachment and excision of the forest reserve. The deforested land was mainly converted to small scale agriculture particularly in the headwaters of the watershed. There was intensive conversion of rangeland to largescale mechanized agriculture which accelerated with change of land tenure (privatization). The watershed has a very dynamic land use change as depicted by swap change (simultaneous equal loss and gains of a particular land use/cover) which accounted for more than half of the overall change. This implies that reporting only net change in land use (of MRB) underestimates the total land use change. The results show that streamflow of Nyangores River (a headwater tributary of the Mara River) significantly increased over the last 50 years. Land use change (particularly deforestation) contributed 97.5% of change in streamflow while the rest of the change (2.5%) was caused by climate variability. It was predicted that climate change would cause a moderate 15% increase in streamflow in the next 50 years. SWAT model simulations suggested that implementation of agroforestry in the watershed would reduce surface runoff, mainly due expected improvement of soil infiltration. Baseflow and total water yield would also decrease while evapotranspiration would increase. The changes in baseflow (reduction) and evapotranspiration (increase) were attributed to increased water extraction from the soil and groundwater by trees in agroforestry systems. The impact of agroforestry on water balance (surface runoff, baseflow, water yield and evapotranspiration) was proportional to increase in size of the watershed simulated with agroforestry. Modelling results also suggested that climate variability within the watershed has a profound effect on the change of water balance caused by implementation of agroforestry. It is recommended that authorities should pay more attention to land use change as the main driver of change in watershed hydrology of the basin. More effort should be focused on prevention of further deforestation and agroforestry may be considered as a practical management strategy to reverse/reduce degradation on the deforested parts of the watershed currently under intensive cultivation.

Background: Climate change and the consequences of global warming is probably one of the greatest issues of our time. Among other concerns, global warming is thought to have a great impact on hydrology worldwide. When the atmosphere warms up, river runoff patterns are altered. Nevertheless these future changes are assumed to increase the hydropower potential in some countries. In the public debate it is often referred to a nine year old investigation claiming an increase of 15-20 % in Swedish energy production from hydropower due to the river runoff increase. On the other hand recent research is hinting that the effect of global warming might be masked by climate variability in the nearest future. This study seeks to investigate whether or not the hydropower-intensive company Fortum will benefit from increased future hydropower potential due to climate change. Methods: Using historical data, the impacts of global warming on the future potential power production in different types of hydropower plants are estimated by the statistical approach of probability density functions. Moreover spectral analysis is used to investigate the impacts of climate variability in various Swedish watersheds. The study investigates both the nearest future, represented by the years 2021-2050, and the end of the century, represented by the years 2069-2098. Results: The future hydropower production is shown to be strongly dependent on the geographical location of a power plant and of the specific power plant type. Although all Swedish rivers where Fortum operates is given more river runoff in the future, some hydropower plants might  suffer from lower hydropower potential due to increased runoff variability. However all reservoir-type power plants in the study, with ability to store water, are calculated to benefit from increased river runoff. Only the run-of-river type power plants, operating with unregulated river flow, are not yet proven to benefit from a changing climate. When considering both specific river and type of power plant, this study indicates that the hydropower potential in the rivers where Fortum operates is expected to increase with 4-15 % towards the end of the century. The one exception is the unregulated river Västerdalälven where this study indicates a possibility of decreased hydropower potential due to climate change. The results of the spectral analysis indicates that up to 30 % of the coefficient of variation in the  monthly mean runoff data is explained by low-frequent periodic fluctuations due to natural climate variability, linked to somewhat predictable climate indices. Conclusion: Natural climate variability is likely to be the dominating factor in the nearest future, at least in regulated rivers. Although there are uncertainties about the future potential power production in the run-of-river type power plants, one cannot deny that most of the Swedish rivers where the major hydropower companies operate are strongly regulated. Adding the fact that river runoff will increase as a consequence of global warming, Fortum is likely to gain from an increased hydropower potential. However, this present study highlights the inaccuracies in using the out-of-date estimation of 15-20 % hydropower-potential increase as a forecast of future potential power production in all Fortum-operated hydropower plants.

The climate variability over the North Atlantic region is described in the 10-50 year band, using a 500-year integration of the Hamburg ECHAMl/LSG coupled general circulation model. In order to isolate nearly periodic components of the atmosphere and the ocean, the multichannel version of the singular spectrum analysis (MSSA) is applied to 11 components of the climate system. In doing so the main focus is on the turbulent exchange between the two subsystems. One interdecadal oscillation of the system ocean and atmosphere is detected with a period of about 18 years. The associated anomalies of sea level pressure (SLP) are situated east of Newfoundland while these of the geopotential height at 500 hPa are slightly shifted to the East. Both the fields undergo a primarily standing oscillation. The sea surface temperature (SST) and the sub surface temperature anomalies have a large extension along the 40° N latitude circle with most of their variability south of Newfoundland. lt is found that the SST anomaly is primarily generated by the temperature advection in the upper ocean layer which is coupled to the Subpolar Gyre strength and Ekman pumping vertical velocity. Both the processes are forced by the atmosphere. In a further analysis applied only to the SST and the Geopotential height at 500 hPa over the whole Northern Hemisphere this 18 year mode was also isolated. The modes obtained by the local and hemispheric analyses are well correlated both in time and space, suggesting a more active role of atmosphere than of the ocean, in addition a strong modulation of the amplitude of the oscillation due to local processes over the North Atlantic was detected. / Die Klimavariabilität über dem Nordatlantik wird anhand einer 500 Jahre Integration des Hamburger gekoppelten Klimamodels ECHAMl/LSG untersucht. Um periodische Komponenten in Ozean und Atmosphäre zu isolieren, wird die MSSA ('multichannel singular spectrum analysis') auf 11 Komponenten des Klimasystems angewandt. Bei den Analysen wird besonderes Augenmerk auf den turbulenten Austausch zwischen beiden Subsystemen gelegt. Es kann eine Oszillation des gekoppelten Systems mit einer Periode von etwa 18 Jahren detektiert werden. Die Anomalie des Bodendrucks weist ihre maximale Amplitude östlich von Neufundland auf, während die Anomalie des 500 hPa Geopotentials leicht östlich dazu verschoben ist. Die Anomalie der SST zeigt ihre größte Variabilität südlich von Neufundland. Diese wird im wesentlichen durch die Temperaturadvektion in der oberen Ozeanschicht generiert, welche im wesentlichen an den subpolaren ozeanischen Wirbel sowie an das 'Ekman pumping' gekoppelt ist. Beide Prozesse werden durch die Atmosphäre angetrieben. In einer weiteren Analyse, in der die MSSA auf die SST und das 500 hPa Geopotential der gesamten nördlichen Hemisphäre angewandt wird, kann ebenfalls ein Oszillation von 18 Jahren detektiert werden. Diese Mode korreliert räumlich und zeitlich gut mit dem der lokalen Analyse über dem Nordatlantik, welches auf ein aktivere Rolle der Atmosphäre hinweist. Die starken Unterschiede der Amplitudenmodulation könnten durch lokale Prozesse bedingt sein.

Climate variability is important to understand as its effects on groundwater are complex than surface water. Climate association between Groundwater Storage (GWS) and sea level changes have been missing from the Intergovernmental Panel on Climate Change, demanding a requisite study of their linkage and responses. The current dissertation is primarily focused on the ongoing issues that have not been focused on the previous literatures. Firstly, the study evaluated the effects of short-term persistence and abrupt shifts in sea level records along the US coast by utilizing popular robust statistical techniques. Secondly, the study evaluated the variability in groundwater due to variability in hydroclimatic variables like sea surface temperature (SST), precipitation, sea level, and terrestrial water storage. Moreover, a lagged correlation was also analyzed to obtain their teleconnection patterns. Lastly, the relationship between the groundwater rise and one of the most common short-term climate variability, ENSO was obtained. To accomplish the research goals the current dissertation was subdivided into three research tasks.The first task attempted to answer a major question, Is sea level change affected by the presence of autocorrelation and abrupt shift? This question reflects the importance of trend and shift detection analysis in sea level. The primary factor driving the global sea level rise is often related to climate change. The current study investigates the changes in sea level along the US coast. The sea level records of 59 tide gauge data were used to evaluate the trend, shift, and persistence using non-parametric statistical tests. Mann-Kendall and Pettitt’s tests were utilized to estimate gradual trends and abrupt shifts, respectively. The study also assessed the presence of autocorrelation in sea level records and its effect on both trend and shift was examined along the US coast. The presence of short-term persistence was found in 57 stations and the trend significance of most stations was not changed at a 95% confidence level. Total of 25 stations showed increasing shift between 1990–2000 that was evaluated from annual sea level records. Results from the current study may contribute to understanding sea level variability across the contiguous US. The second task dealt with variability in the Hydrologic Unit Code—03 region. It is one of the major U.S. watersheds in the southeast in which most of the variability is caused by Sea Surface Temperature (SST) variability in the Pacific and Atlantic Ocean, was identified. Furthermore, the SST regions were identified to assess its relationship with GWS, sea level, precipitation, and terrestrial water storage. Temporal and spatial variability were obtained utilizing the singular value decomposition statistical method. A gridded GWS anomaly from the Gravity Recovery and Climate Experiment (GRACE) was used to understand the relationship with sea level and SST. The negative pockets of SST were negatively linked with GWS. The identification of teleconnections with groundwater may substantiate temporal patterns of groundwater variability. The results confirmed that the SST regions exhibited El Niño Southern Oscillation patterns, resulting in GWS changes. Moreover, a positive correlation between GWS and sea level was observed on the east coast in contrast to the southwestern United States. The findings highlight the importance of climate-driven changes in groundwater attributing changes in sea level. Therefore, SST could be a good predictor, possibly utilized for prior assessment of variabilities plus groundwater forecasting. The primary goal of the third task is to better understand the effects of ENSO climate patterns on GWS in the South Atlantic-Gulf region. Groundwater issues are complex and different studies focused on groundwater depletion while few emphasized, “groundwater rise”. The current research is designed to develop an outline for assessing how climate patterns can affect groundwater fluctuation, which might lead to groundwater rise. The study assessed the effect of ENSO phases on spatiotemporal variability of groundwater using Spearman Rank Correlation. A significant positive correlation between ENSO and GWS was observed. An increasing trend was detected in GWS where most grids were observed in Florida by utilizing the non-parametric Mann-Kendall. A positive magnitude of the trend was also detected by utilizing Theil-Sen’s Slope method with high magnitude in the mid-Florida region. The highest GWS anomalies were observed in the peak of El Niño events and the lowermost GWS was observed during La Niña events. Furthermore, most of the stations were above normal groundwater conditions. This study provides a better understanding of the research gap between groundwater rise and ENSO.