Some Comparisons in the Thermal Structure of Lakes Wood, Kalamalka, Okanagan, Skaha, and Osoyoos, British Columbia

1973 ◽  
Vol 30 (7) ◽  
pp. 917-925 ◽  
Author(s):  
J. O. Blanton
Keyword(s):  
Thermal Structure ◽  
Heat Content ◽  
Late Summer ◽  
Static Stability ◽  
Rate Of Change ◽  
Direct Relation ◽  
Maximum Heat ◽  
The North ◽  
Relative Ability ◽  
External Cooling

The rate of change of heat contents in the lakes and the relative ability of each lake to transfer heat vertically to warm its hypolimnion was investigated. Rates of warming of hypolimnion water ranged from 0.06 C/month in Okanagan to 0.54 C/month in the north basin of Osoyoos. All lakes reached maximum static stability through the thermocline in late August except for Osoyoos (N), which reached its maximum somewhat earlier. Maximum heat content ranged from 18,100 cal/cm2 in Wood Lake to 33,300 cal/cm2 in Lake Okanagan. Maximum values of heat content were observed in late August in all lakes.There is a direct relation between the hypolimnetic warming rates and the maximum observed stability in the thermocline regions of all the lakes. However, the relatively low rate of Lake Wood indicates that there is an external cooling source such as groundwater influx. The late summer increase in volume of the epilimnion in Wood and the corresponding entrainment of nutrients from the hypolimnion to the epilimnion appear to control the amount of production observed at that time.

scholarly journals Satellite-Derived Ocean Thermal Structure for the North Atlantic Hurricane Season

2016 ◽  
Vol 144 (3) ◽  
pp. 877-896 ◽  
Author(s):  
Iam-Fei Pun ◽  
James F. Price ◽  
Steven R. Jayne
Keyword(s):  
Mixed Layer ◽  
North Atlantic ◽  
Thermal Structure ◽  
Estimation Error ◽  
Mixed Layer Depth ◽  
Heat Content ◽  
Height Anomaly ◽  
The North ◽  
Hurricane Season ◽  
The North Atlantic

Abstract This paper describes a new model (method) called Satellite-derived North Atlantic Profiles (SNAP) that seeks to provide a high-resolution, near-real-time ocean thermal field to aid tropical cyclone (TC) forecasting. Using about 139 000 observed temperature profiles, a spatially dependent regression model is developed for the North Atlantic Ocean during hurricane season. A new step introduced in this work is that the daily mixed layer depth is derived from the output of a one-dimensional Price–Weller–Pinkel ocean mixed layer model with time-dependent surface forcing. The accuracy of SNAP is assessed by comparison to 19 076 independent Argo profiles from the hurricane seasons of 2011 and 2013. The rms differences of the SNAP-estimated isotherm depths are found to be 10–25 m for upper thermocline isotherms (29°–19°C), 35–55 m for middle isotherms (18°–7°C), and 60–100 m for lower isotherms (6°–4°C). The primary error sources include uncertainty of sea surface height anomaly (SSHA), high-frequency fluctuations of isotherm depths, salinity effects, and the barotropic component of SSHA. These account for roughly 29%, 25%, 19%, and 10% of the estimation error, respectively. The rms differences of TC-related ocean parameters, upper-ocean heat content, and averaged temperature of the upper 100 m, are ~10 kJ cm−2 and ~0.8°C, respectively, over the North Atlantic basin. These errors are typical also of the open ocean underlying the majority of TC tracks. Errors are somewhat larger over regions of greatest mesoscale variability (i.e., the Gulf Stream and the Loop Current within the Gulf of Mexico).

scholarly journals A Combined Control Systems and Machine Learning Approach to Forecasting Iceberg Flux off Newfoundland

2021 ◽  
Vol 13 (14) ◽  
pp. 7705
Author(s):  
Jennifer B. Ross ◽  
Grant R. Bigg ◽  
Yifan Zhao ◽  
Edward Hanna
Keyword(s):  
Machine Learning ◽  
Control Systems ◽  
Late Summer ◽  
Forecast Model ◽  
Seasonal Forecast ◽  
Rate Of Change ◽  
Learning Tools ◽  
Systems Model ◽  
The North ◽  
The Impact

Icebergs have long been a threat to shipping in the NW Atlantic and the iceberg season of February to late summer is monitored closely by the International Ice Patrol. However, reliable predictions of the severity of a season several months in advance would be useful for planning monitoring strategies and also for shipping companies in designing optimal routes across the North Atlantic for specific years. A seasonal forecast model of the build-up of seasonal iceberg numbers has recently become available, beginning to enable this longer-term planning of marine operations. Here we discuss extension of this control systems model to include more recent years within the trial ensemble sample set and also increasing the number of measures of the iceberg season that are considered within the forecast. These new measures include the seasonal iceberg total, the rate of change of the seasonal increase, the number of peaks in iceberg numbers experienced within a given season, and the timing of the peak(s). They are predicted by a range of machine learning tools. The skill levels of the new measures are tested, as is the impact of the extensions to the existing seasonal forecast model. We present a forecast for the 2021 iceberg season, predicting a medium iceberg year.

scholarly journals Development and Analysis of the Systematically Merged Atlantic Regional Temperature and Salinity Climatology for Oceanic Heat Content Estimates

2014 ◽  
Vol 31 (1) ◽  
pp. 131-149 ◽  
Author(s):  
P. C. Meyers ◽  
L. K. Shay ◽  
J. K. Brewster
Keyword(s):  
Mixed Layer ◽  
North Atlantic Ocean ◽  
Thermal Structure ◽  
Mixed Layer Depth ◽  
World Ocean ◽  
Heat Content ◽  
Ocean Basin ◽  
Loop Current ◽  
The North ◽  
Regional Temperature

Abstract An oceanic climatology to calculate upper-ocean thermal structure was developed for application year-round in the North Atlantic Ocean basin. The Systematically Merged Atlantic Regional Temperature and Salinity (SMARTS) Climatology is used in a two-layer model to project sea surface height anomalies (SSHA) into the water column at ¼° resolution. SMARTS blended monthly temperature and salinity fields from the World Ocean Atlas 2001 (WOA01) and Generalized Digital Environmental Model (GDEM) version 3.0 based on their performance compared to in situ measurements. Daily mean isotherm depths of 20°C (D20) and 26°C (D26) (and their mean ratio), reduced gravity, and mixed layer depth (MLD) were estimated from the climatology. This higher-resolution climatology resolves features in the Gulf of Mexico (GOM), including the Loop Current (LC) and eddy shedding region. Using SMARTS with satellite-derived SSHA and SST fields, daily values of isotherm depths, mixed layer depths, and ocean heat content (OHC) were calculated from 1998 to 2012. OHC is an important scalar when determining the ocean’s impact on tropical cyclone intensification, because it is a better predictor of SST cooling during hurricane passage. Airborne- and ship-deployed expendable bathythermographs (XBT), long-term moorings, and Argo profiling floats provided over 50 000 thermal profiles to assess satellite retrievals of isotherm depths and OHC using the SMARTS Climatology. The OHC calculation presented in this document reduces errors basinwide by 20%, with a 35% error reduction in the GOM.

Mixed Layer Models and Their Application to Water Quality Problems

1994 ◽  
Vol 29 (2-3) ◽  
pp. 221-232
Author(s):  
M.J. McCormick
Keyword(s):  
Water Quality ◽  
Mixed Layer ◽  
Thermal Structure ◽  
Mass Conservation ◽  
Eddy Diffusion ◽  
Rate Of Change ◽  
Surface Mixed Layer ◽  
Storm Events ◽  
Quality Model ◽  
Mixing Processes

Abstract Four one-dimensional models which have been used to characterize surface mixed layer (ML) processes and the thermal structure are described. Although most any model can be calibrated to mimic surface water temperatures, it does not imply that the corresponding mixing processes are well described. Eddy diffusion or "K" models can exhibit this problem. If a ML model is to be useful for water quality applications, then it must be able to resolve storm events and, therefore, be able to simulate the ML depth, h, and its time rate of change, dh/dt. A general water quality model is derived from mass conservation principles to demonstrate how ML models can be used in a physically meaningful way to address water quality issues.

Rhineland on the Way to its Thousandth Anniversary or Water-Administration in the Next 100–200 Years

1991 ◽  
Vol 23 (1-3) ◽  
pp. 49-55
Author(s):  
E. H. baron van Tuyll van Serooskerken
Keyword(s):  
The Netherlands ◽  
Late Summer ◽  
Water Shortage ◽  
Land Utilization ◽  
Water Control ◽  
Coastal Defence ◽  
The North ◽  
Policies And Measures ◽  
Water Provision ◽  
Water Administration

An inventory is made of the effects of sea level rise and expected climatic change on the level of the district water authorities in the Netherlands and especially the “hoogheemraadschap” of Rhineland in the next 100-200 years. Special attention is paid to the effects on land utilization, coastal defence and water control. The first is hard to describe by lack of research, the second can already be determined in terms of cost; the third can be described in its effects on brackishness and water provision with indication of policies and measures to be taken. Preliminary conclusions are that larger efforts on coastal defence - even with present techniques - will be a realistic answer in terms of cost. The foreseen increase of brackishness in area and salt concentration, will give a significant extra need for fresh water. High cost and even higher risks have to be expected with regard to measures to neutralize the effects of a water surplus in winter and a growing water shortage in (late) summer, while the cost will further grow. Because of the effect a larger area must be drained off and water has to be raised higher as the Netherlands will sink in relation to the North Sea.

scholarly journals The North Sulawesi Seas Water Masses Heat Content in 1995 – 2015

2020 ◽  
Vol 618 ◽  
pp. 012015
Author(s):  
Fauzan L Ramadhan ◽  
Luqman N Chairuasni ◽  
Lamona I Bernawis ◽  
Rima Rachmayani ◽  
Mutiara R Putri
Keyword(s):  
Heat Content ◽  
Water Masses ◽  
The North ◽  
North Sulawesi

scholarly journals Hydrology and circulation in the North Aegean (eastern Mediterranean) throughout 1997 and 1998

2002 ◽  
Vol 3 (1) ◽  
pp. 5 ◽  
Author(s):  
V. ZERVAKIS ◽  
D. GEORGOPOULOS
Keyword(s):  
Surface Layer ◽  
Black Sea ◽  
Sea Water ◽  
Saline Water ◽  
Eastern Mediterranean ◽  
Late Summer ◽  
Cyclonic Circulation ◽  
The Black Sea ◽  
The North ◽  
North Aegean

The combination of two research projects offered us the opportunity to perform a comprehensive study of the seasonal evolution of the hydrological structure and the circulation of the North Aegean Sea, at the northern extremes of the eastern Mediterranean. The combination of brackish water inflow from the Dardanelles and the sea-bottom relief dictate the significant differences between the North and South Aegean water columns. The relatively warm and highly saline South Aegean waters enter the North Aegean through the dominant cyclonic circulation of the basin. In the North Aegean, three layers of distinct water masses of very different properties are observed: The 20-50 m thick surface layer is occupied mainly by Black Sea Water, modified on its way through the Bosphorus, the Sea of Marmara and the Dardanelles. Below the surface layer there is warm and highly saline water originating in the South Aegean and the Levantine, extending down to 350-400 m depth. Below this layer, the deeper-than-400 m basins of the North Aegean contain locally formed, very dense water with different θ /S characteristics at each subbasin. The circulation is characterised by a series of permanent, semi-permanent and transient mesoscale features, overlaid on the general slow cyclonic circulation of the Aegean. The mesoscale activity, while not necessarily important in enhancing isopycnal mixing in the region, in combination with the very high stratification of the upper layers, however, increases the residence time of the water of the upper layers in the general area of the North Aegean. As a result, water having out-flowed from the Black Sea in the winter, forms a separate distinct layer in the region in spring (lying between “younger” BSW and the Levantine origin water), and is still traceable in the water column in late summer.

scholarly journals Spatial Analysis of Coastline Change by Remote Sensing in the North Coast of Karawang Regency

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Roberto Pasaribu ◽  
Firman Agus H. ◽  
Liliek Soeprijadi
Keyword(s):  
Shoreline Change ◽  
Rate Of Change ◽  
North Coast ◽  
Landsat 8 ◽  
Northern Coast ◽  
Shoreline Changes ◽  
The Road ◽  
Coastline Change ◽  
The North ◽  
Landsat 7

<p><em>The existence of the coast in the northern part of Karawang Regency is very worrying. Seawater<strong> </strong>that was far up to tens of meters from the side of the road, is now on the lip of the road, even some parts of the road are cut off due to abrasion of seawater. Some villages were affected by abrasion erosion. One of the effects of damage due to abrasion and sedimentation is the occurrence of shoreline changes. This change in coastline will affect people's lives and spatial planning for the development of the area. For this reason, this study aims to determine the extent and rate of shoreline changes that occurred on the coast of Karawang Regency in the periods of 1989, 1995, 2001, 2005, 2009, 2016, and 2018. The shoreline data was obtained from the extraction of Landsat 3 MSS, Landsat 5 TM, Landsat 7 ETM +, and Landsat 8 </em><em>OLI</em>-<em>TIRS after the NDWI process was previously carried out. While the rate of change is calculated at 6 sample point locations scattered along the northern coast of Karawang Regency. The results showed that the largest area damaged by abrasion occurred in Sedari Village covering an area of 166.802 hectares, and the area formed by the largest sedimentation occurred in Muara Cilamaya Village at 276,318 hectares. Meanwhile, the fastest rate of shoreline change due to abrasion occurred in Sukajaya Village at 10 meters </em>/<em>year, while the slowest in Sedari Village at 3.77 meters / year. The fastest sedimentation process in Muara Cimalaya Village is 4.5 meters / year, while the late one in Tanjung Pakis Village is 3.09 meters / year.</em><em></em></p><p><strong><em>Keywords: </em></strong><em>Abra</em><em>sion, Accretion, Coastline Changes, Karawang</em><em></em></p>

scholarly journals Modeling the climatic implications of the Guliya δ<sup>18</sup>O record during the past 130 ka

2012 ◽  
Vol 8 (3) ◽  
pp. 1885-1914
Author(s):  
D. Xiao ◽  
P. Zhao ◽  
Y. Wang ◽  
X. Zhou
Keyword(s):  
North Atlantic ◽  
Climate Model ◽  
Surface Air Temperature ◽  
Late Summer ◽  
The Arctic ◽  
The Past ◽  
The North ◽  
Precession Cycle ◽  
The North Atlantic ◽  
Anomalous Pattern

Abstract. Using an intermediate-complexity UVic Earth System Climate Model (UVic Model), the geographical and seasonal implications and an indicative sense of the historical climate found in the δ18O record of the Guliya ice core (hereinafter, the Guliya δ18O) are investigated under time-dependent orbital forcing with an acceleration factor of 100 over the past 130 ka. The results reveal that the simulated late-summer (August–September) Guliya surface air temperature (SAT) reproduces the 23-ka precession and 43-ka obliquity cycles in the Guliya δ18O. Furthermore, the Guliya δ18O is significantly correlated with the SAT over the Northern Hemisphere (NH), which suggests the Guliya δ18O is an indicator of the late-summer SAT in the NH. Corresponding to the warm and cold phases of the precession cycle in the Guliya temperature, there are two anomalous patterns in the SAT and sea surface temperature (SST) fields. The first anomalous pattern shows an increase in the SAT (SST) toward the Arctic, possibly associated with the joint effect of the precession and obliquity cycles, and the second anomalous pattern shows an increase in the SAT (SST) toward the equator, possibly due to the influence of the precession cycle. Additionally, the summer (winter) Guliya and NH temperatures are higher (lower) in the warm phases of Guliya late-summer SAT than in the cold phases. Furthermore, the Guliya SAT is closely related to the North Atlantic SST, in which the Guliya precipitation may act as a "bridge" linking the Guliya SAT and the North Atlantic SST.

Storm surges in the North Sea during the winter 1953-4

1956 ◽  
Vol 235 (1201) ◽  
pp. 260-274 ◽  
Keyword(s):  
Sea Level ◽  
North Sea ◽  
Storm Surges ◽  
Rate Of Change ◽  
The North ◽  
Order Of Magnitude ◽  
The North Sea ◽  
Sea Ports ◽  
Phase Angles

Records of sea level for several North Sea ports for the winter of 1953-4 have been in vestigated. They were split into 14-day intervals, and each 14-day record was Fourieranalyzed to determine if any non-astronomical periods were present. There was evidence of some activity between 40 and 50 h period, and a determination of the phase angles at different ports showed that the activity could be due to a disturbance travelling southwards from the north of the North Sea. The disturbance was partly reflected somewhere near the line from Lowestoft to Flushing, so that one part returned past Flushing and Esbjerg towards Bergen while the other part travelled towards Dover, and there was evidence of its existence on the sea-current records taken near St Margaret's Bay. These results were confirmed by subtracting the predicted astronomical tidal levels from the observed values of sea level and cross-correlating the residuals so obtained for each port with those found at Lowestoft. The residuals at Lowestoft and Aberdeen were compared with the meteorological conditions, and it was found that, although they could be attributed to a large extent to conditions within the North Sea, there was an additional effect due to a travelling surge which was of the same order of magnitude at both Lowestoft and Aberdeen and which was closely related to the rate of change with time of the atmospheric pressure difference between Wick and Bergen.

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