Harnessing Ocean Energy from Coastal and Offshore Pakistan

There is potential for harnessing renewable energy from coastal waves and tides, from the coastal and offshore areas of Pakistan. The Sindh coast is a complex creek network located in the 170 km of the Indus deltaic area. The flood and ebb of tides in and out of these creeks have a high velocity of 0.2–0.5 m/s. NIO Pakistan has conducted preliminary feasibility surveys for energy extraction from the Indus deltaic creek system. The 17 major creeks have the capacity to produce estimated energy of approximately 1100 MW. The seawater ingresses inland at some places up to 80 km due to the tidal fluctuation, which is favorable for energy extraction from tidal currents in coastal Sindh. In total, 71% of our Planet Earth is covered by the oceans. The oceans are massive collectors of solar radiation received from the sun. The oceans store the potential energy that is received in the form of incident radiation from the sun that generates thermal energy. A 10 °C temperature difference can be harnessed between the surface and bottom water, using a working fluid. The thermal difference absorbed by the oceans can be converted into electricity through ocean thermal energy conversion (OTEC). The ocean tidal and wave energy has advantages over energy produced using different fossil fuels; there are also several benefits of using renewable sources of ocean energy. Viability of ocean energy in Pakistan is discussed in this paper.

Coastal Wave Extremes around the Pacific and Their Remote Seasonal Connection to Climate Modes

At first order, wind-generated ocean surface waves represent the dominant forcing of open-coast morpho-dynamics and associated vulnerability over a wide range of time scales. It is therefore paramount to improve our understanding of the regional coastal wave variability, particularly the occurrence of extremes, and to evaluate how they are connected to large-scale atmospheric regimes. Here, we propose a new “2-ways wave tracking algorithm” to evaluate and quantify the open-ocean origins and associated atmospheric forcing patterns of coastal wave extremes all around the Pacific basin for the 1979–2020 period. Interestingly, the results showed that while extreme coastal events tend to originate mostly from their closest wind-forcing regime, the combined influence from all other remote atmospheric drivers is similar (55% local vs. 45% remote) with, in particular, ~22% coming from waves generated remotely in the opposite hemisphere. We found a strong interconnection between the tropical and extratropical regions with around 30% of coastal extremes in the tropics originating at higher latitudes and vice-versa. This occurs mostly in the boreal summer through the increased seasonal activity of the southern jet-stream and the northern tropical cyclone basins. At interannual timescales, we evidenced alternatingly increased coastal wave extremes between the western and eastern Pacific that emerge from the distinct seasonal influence of ENSO in the Northern and SAM in the Southern Hemisphere on their respective paired wind-wave regimes. Together these results pave the way for a better understanding of the climate connection to wave extremes, which represents the preliminary step toward better regional projections and forecasts of coastal waves.

Minute Sea-Level Analysis (MISELA): a high-frequency sea-level analysis global dataset

Sea-level observations provide information on a variety of processes occurring over different temporal and spatial scales that may contribute to coastal flooding and hazards. However, global research on sea-level extremes is restricted to hourly datasets, which prevent the quantification and analyses of processes occurring at timescales between a few minutes and a few hours. These shorter-period processes, like seiches, meteotsunamis, infragravity and coastal waves, may even dominate in low tidal basins. Therefore, a new global 1 min sea-level dataset – MISELA (Minute Sea-Level Analysis) – has been developed, encompassing quality-checked records of nonseismic sea-level oscillations at tsunami timescales (T<2 h) obtained from 331 tide-gauge sites (https://doi.org/10.14284/456, Zemunik et al., 2021b). This paper describes data quality control procedures applied to the MISELA dataset, world and regional coverage of tide-gauge sites, and lengths of time series. The dataset is appropriate for global, regional or local research of atmospherically induced high-frequency sea-level oscillations, which should be included in the overall sea-level extremes assessments.

MISELA: 1-minute sea-level analysis global dataset

Sea-level observations provide information on a variety of processes occurring over different temporal and spatial scales that may contribute to coastal flooding and hazards. However, global research of sea-level extremes is restricted to hourly datasets, which prevent quantification and analyses of processes occurring at timescales between a few minutes and a few hours. These shorter period processes, like seiches, meteotsunamis, infragravity and coastal waves, may even dominate in low-tidal basins. Therefore, a new global 1-minute sea-level dataset – MISELA (Minute Sea-Level Analysis) – has been developed, encompassing quality-checked records of nonseismic sea-level oscillations at tsunami timescales (T < 2 h) obtained from 331 tide-gauge sites (https://doi.org/10.14284/456, Zemunik et al., 2021b). This paper describes data quality-control procedures applied to the MISELA dataset, world and regional coverage of tide-gauge sites and lengths of time-series. The dataset is appropriate for global, regional or local research of atmospherically-induced high-frequency sea-level oscillations, which should be included in the overall sea-level extremes assessments.

From weekly to seasonal variability of the North Brazil - Equatorial Undercurrent retroflection

&lt;p&gt;The northward flow in the western tropical Atlantic Ocean is carried mainly by North Brazil Current (NBC), hence playing a major role in the cross-equatorial exchange of properties. As thermocline waters reach the equator, they largely retroflect to feed the Equatorial Undercurrent (EUC), a quasi-permanent zonal current that brings salty and highly-oxygenated waters to the eastern side of the basin. This retroflection system is governed by the zonal pressure gradient, which is driven by the trade winds. Hence, the wind fluctuations represent the major source of variability at seasonal and interannual scales. However, at shorter time scales, the variability of the retroflection system may be associated with both interior and coastal waves. In the present study we describe the water mass balance at the NBC-EUC retroflection area using a combination of shipboard observations and numerical reanalysis. The observations, from an oceanographic campaign in April 2010, provide a synoptic view of the retroflection region and allow assessing the goodness of the numerical data. We then use the ocean reanalysis GLORYS2v4 to analyse the temporal variability of this region, from intra-seasonal to seasonal scales, and use Lagrangian simulations to identify the principal water mass pathways feeding the retroflection. We find a substantial seasonal cycle in the boundary and interior (southern and northern) origins of those waters that feed the EUC. Our results also show the propagation of high-frequency waves (16-30 days) along the coast from the south, probably as coastal trapped waves, while waves with 30-60 days period come from the northern hemisphere, probably as westward Rossby waves reach the coast of America and follow south as Kelvin waves. These short-term fluctuations have a high impact on the water mass pathways that feed the EUC and the retroflection structure itself.&lt;/p&gt;

Observed Seasonal and Interannual Controls on Coastal Oxygen and Dead Zones in the Indian Ocean

&lt;p&gt;A major concern is that global de-oxygenation will expand Oxygen minimum zones (OMZs) and favor coastal dead zones (DZs) where already low oxygen levels threaten ecosystems and adjacent coastal economies. The northern Indian ocean is home to both intense OMZs and DZs, and is surrounded by many kilometers of biodiverse and commercially valuable coastline. Exchanges between OMZs and shelf waters that contribute to coastal DZs are subject to the strong monsoonal seasonal cycle and the interannual variability of the Indian Ocean Dipole (IOD). &amp;#160;There is, however, no observational constraints on how these exchanges influence coastal DZs at the scale of the entire northern Indian Ocean.&lt;/p&gt;&lt;p&gt;In this work, we examine the timing and processes that favor low-oxygen concentrations along the coasts of the Bay of Bengal (BoB) and Arabian Sea (AS) using multi-decadal time series of oxygen profiles (Bio-Argo, World Ocean Database and repeat hydrography) combined with a suite of satellite data. Seasonally, we show that coastal oxygen is lowest during winter/spring in the BoB and summer/fall in the AS, closely following the seasonal propagation of coastal waves and wind-driven upwelling. Interannually, observations indicate that positive IODs increase coastal O2 in summer/fall in the AS, partly offsetting the seasonal signal; a result in agreement with prior modeling work (Vallivattathillam et al 2017). Observations reveal, however, that positive IODs favor low coastal O2 conditions and increase the risk of coastal DZs year-round in the BoB and in winter/spring in the AS, whereas negative IODs favor low O2 in summer/fall in the AS.&lt;/p&gt;&lt;div&gt; &lt;div&gt; &lt;div&gt;&amp;#160;&lt;/div&gt; &lt;/div&gt; &lt;/div&gt;

Drumming the waves: conveying coastal geoscience with rhythm

&lt;p&gt;It is difficult to educate the public about geoscience and to create a message that will be heard in a noisy world. Coastal geoscience in particular&amp;#8212;despite its growing importance as sea-level rises and storminess increases&amp;#8212;has not penetrated effectively into the public sphere. High-energy coasts attract increasing numbers of visitors, most unaware of hazards related to stochastic wave behaviour. Photo-seekers in the Instagram era are driving up accidents in extreme environments, and it&amp;#8217;s increasingly common for people to be caught off guard and dragged into the ocean by rogue waves. Creative ways are needed to build awareness of the hazards, as well as the beauty, of high-energy coasts.&lt;/p&gt;&lt;p&gt;&quot;Drumming the Waves&quot;, a musical representation of wave interactions with boulder beaches, is an NSF-funded musician-geoscientist collaboration. Informed by the shared physics of sound and water waves, the composition will showcase how mutual interference among wave sets gives rise to chaotic seas, rogue waves, and ocean swell; and how waves can be amplified unpredictably in the coastal zone. Minimalist compositional techniques are employed to overlap and superimpose multiple series of small and seemingly inconsequential rhythmic and melodic musical events, leading to composite results that are unpredictable, sometimes chaotic, and occasionally extreme.&lt;/p&gt;&lt;p&gt;A visceral artistic approach helps capture the &amp;#8216;feeling&amp;#8217; of coastal waves and the impact of their interaction with boulder beaches, conveying sea states from serene calm to extreme chaos. Audio samples recorded at coastal locations in Ireland and the UK, both in air and beneath the ocean surface, are interwoven in the soundscape. We use wave sounds both in their natural audio state and in processed form. Creating new sounds by interacting field recordings of waves with electronic audio processers provides an artistic representation of the ubiquitous power and energy present in coastal environments. The temporal and erratic nature of coastal waves informs the musical structures on a macro level, exploring the contrast between the simple rhythm of tides and swell, and the irregular ephemerality of turbulent sea conditions. On a micro level, parallels between ocean and audio waves shapes are exploited to create novel musical events by shaping LFO (low frequency oscillator) and noise gates to mimic two-dimensional coastal wave models. Periodic emergence of unexpectedly large sound events mimics hazardous rogue wave generation.&lt;/p&gt;&lt;p&gt;We will build educational content around the music, to contextualise and explain it, and to draw attention specifically to boulder beaches, wave hazards, and the science of high-energy coasts. Simple worksheets showing wave spectra will be paired with percussion rhythms and melody that can be layered by students, either drumming and singing together, or mixing audio loops within a DAW (Digital Audio Workstation) such as GarageBand. This will permit students to build complex spectra from simple underlying wave forms. PowerPoint slides and explanatory text, pitched at the appropriate level, will be distributed to teachers for combined music/science learning. Using music to convey the science of wave interactions and wave amplification opens new doors and prospects for engaging and educating the public.&lt;/p&gt;

Estimated View of Renewable Resources as a Sustainable Electrical Energy Source, Case Study

Renewable energy resources for energy generation in the Gaza Strip (GS) emerge as a complementary resource, not only to meet the need of society for energy in various forms, but also to find available, sustainably, and less costly resources for institutions as with individuals. These resources could provide safety in use, increase energy security, and address environmental concerns. This work aimed to assess the renewable energy potential in the GS, which has few natural resources and a real crisis in energy supply. Therefore, an integrated evaluation methodology is assumed for renewable energy potential; the methodology comprises mathematical as well as software programming to assess the renewable energy. The results reveal the assessment of the existing four renewable energy sources: solar, wind, wave, and biomass. The estimations exhibit that the solar and biomass resources are dominant. The methodology consists of mathematical models for calculating the energy outputs from different resources in the study area. ArcGIS 10.1 software used for calculating solar radiation, WindSim 9.0.0 software for estimating wind energy and OpenWEC software tool for evaluating the force stored in coastal waves. The potential of each energy and the integration of all are depicted in individual maps by ArcGIS. It was found that if anaerobic digestion technology is applied, 65.15 MW electric power could be produced from about one-and a third million tons/year of biomass. Depending on the available statistical data due to the specified annual time period and the household electric demand that is about 120 MW at the corresponding time, this means that the energy from biomass can cover more than half of the demand. In addition, solar energy potentials were estimated to reach 1195 GWh/year. Therefore, the existing power may be replaced by biomass and solar energy. It also demonstrates that the energy potential maps can be used as metrics for possible sustainability projects in the GS.