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CGU HS Committee on River Ice Processes and the Environment 16th Workshop on River Ice Winnipeg, Manitoba, September 18 – 22, 2011

Comparison of CRISSP modeled and SWIPS measured ice concentrations on the Peace River

Martin Jasek, M.Sc., P. Eng. BC Hydro, Burnaby, BC, Canada, [email protected]

Tadros Ghobrial, M. Sc., Mark Loewen, Ph.D., P. Eng., Faye Hicks Ph.D., P. Eng.,

University of Alberta, Edmonton, AB, Canada, [email protected] , [email protected], [email protected]

The Peace River in Northern Alberta and British Columbia is regulated by BC Hydro’s hydroelectric facilities located at the Bennett and Peace Canyon Dams near Hudson’s Hope, BC. During the winter, higher river levels associated with freeze-up on the Peace River at the Town of Peace River, AB about 400 km downstream are managed by changing flows (or hydroelectric generation). These management decisions are executed in consultation with Alberta Environment. To support these decisions, the river ice model CRISSP is used. However, it is a challenge to quantify calibration parameters that affect ice production in the model. Thus far, these parameters are calibrated indirectly to match the progression rate of the leading edge of the ice cover, stage and ice thickness. However, a more direct measurement of ice production should provide better calibration coefficients. Direct measurements of ice production have been made on the Peace River with the Shallow Water Ice Profiling Sonar (SWIPS) although until recently these measurements were not easily quantifiable. Recently the SWIPS has been tested in a frazil generation tank at the University of Alberta and correlated with volumetric suspended ice concentrations. These correlations can be applied to SWIPS data that have been collected in the field to obtain estimates of volumetric concentrations that can be directly compared to CRISSP model output. This paper discusses such a comparison and the remaining difficulties and uncertainness still outstanding.

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1. Introduction and Background

Since 2003, SWIPS instruments have been deployed in the Peace River. The data collected has given insight into frazil ice formation processes: Jasek et al. (2005), Jasek and Marko (2007 and 2008). Theoretical formulations on suspended ice concentration derived from SWIPS data on the Peace River were also conducted by Marko et al. (2010a,b). In 2008 a 3-year laboratory study in a frazil generation tank and field investigation on the North Saskatchewan River was conducted by the University of Alberta. This paper uses the relationships developed between the processed SWIPS signal and measured frazil ice concentrations in the University of Alberta laboratory and applies them to the Peace River SWIPS data and compares these estimates to CRISSP model predictions.

2. SWIPS Data Processing

2.1 Surface Frazil Pans

The algorithm described in Ghobrial et al. (2011) was used to calculate pan drafts and surface ice concentrations from the raw SWIPS data (sampled at 1Hz, or one profile per second). The algorithm is based on calibrated (site specific) threshold and persistence levels. The threshold is simply a count value above which the signal can reliably be considered to be a return from a pan. The number of bins in which this threshold must be exceeded before a pan bottom can dependably be detected, is the persistence level. It was found that a threshold value of 65,535 counts (i.e. the saturation value of the digitized acoustic return) and a persistence level of 10 bins produced the least number of false targets for the Peace River data. A persistence level of 10 bins means that the smallest pan draft that could be measured was 11 cm (i.e. 10 bins time the 1.1 cm bin size). Water depths were measured using a pressure sensor data logger mounted to the SWIPS platform. The pans’ drafts, tp (m), were then calculated as the difference between the measured water depth and the pan bottoms detected using this algorithm. Surface pan concentrations Csurf (%) were calculated over a 30 minute moving window, by summing the number of profiles with pans and dividing by the total number of profiles measured in that 30 minute window.

2.2 Suspended Frazil Concentration

A 546 KHz frequency SWIPS unit was calibrated for measuring suspended frazil concentration in a frazil generation tank located in the University of Alberta Cold room facility. Ghobrial et al. (2009) described the experimental setup and methods for these tests, and showed that a correlation does exist between the suspended frazil concentration and the raw SWIPS signal. In order to compare between the SWIPS signal from different acoustic frequencies, the raw SWIPS counts were processed and converted to volume backscatter strength Sv (dB) using the equations provided in Ghobrial et al. (2011). A logarithmic regression equation was used to fit measured frazil concentration, C (%) and the corresponding Sv (dB) with a coefficient of determination, R2, of 0.94. The resulting equation was:

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( 7.15 0.042* )1 0 RBC [1] where, C is the frazil concentration (%), and RB is the relative backscatter (dB). RB is calculated as follow,

[2]

where, SL is the SWIPS source level (dB) and Vgeo is the acoustic beam geometric volume (m3) at range R (m). The SWIPS returns from the Peace River field deployment were processed to calculate Sv (dB). The signal was depth averaged from a minimum range of 55 cm up to the bottom of the detected pan in each profile. The depth averaged volume backscatter strength, Svd (dB), was then converted into frazil concentration using equations (1 and 2). A limitation for the estimation of frazil concentration using equation (1) is that the volume backscatter strength, Sv (dB) is a function of the particle size and concentration (Urick 1983). Accordingly, single frequency sonars cannot differentiate between changes in ice concentration and particle size distribution (Gartner 2004). A change in the size distribution could be misinterpreted as a change in concentration unless the instrument was recalibrated using independent particle size distribution measurements. Therefore, estimates of frazil concentration using equation (1) may be less accurate if the particle sizes and shapes differ significantly from those for which the SWIPS was calibrated. The frazil ice particles used for the SWIPS calibration were generated rapidly (e.g. 15 minute duration) in a continuously stirred tank and ranged in diameter between 0.25 to 4.25 mm (Ghobrial et al. 2011). Therefore, estimates of concentrations in rivers at different stages of frazil formation would also be expected to be less accurate. This effect is the topic of future research. Furthermore, the SWIPS unit used on the Peace River is a different 546 KHz unit than the one used for calibrations tests in the University of Alberta lab. It is possible that there could be substantial differences between the “tuning” of the two instruments. Notably the field unit has a substantially longer analog cable than the one used in the lab. This issue will be investigated in the future.

3. Comparison of CRISSP and SWIPS ice concentrations and frazil ice pan thicknesses

3.1 CRISSP Model

CRISSP1D is a comprehensive state-of-the-art ice simulation model for use by hydroelectric utilities and others concerned with river ice issues. The technology addresses both the design and operational issues including the development of procedures for establishing favorable ice formation conditions in the early ice formation period as well as the establishment of operating policies compatible with ice conditions and which will contribute to the maximization of the productivity of generation stations. The model is applicable to a wide range of hydraulic engineering needs, including ice jam related flood analysis studies, applications to wintertime navigation and transportation, climate change studies, and ice related environmental and

101 0 log ( )geo vRB SL V S

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ecological studies. The model is able to simulate river ice processes and associated flow conditions. The ice processes include water temperature and ice concentration distributions of suspended and surface ice, ice cover formation, progression, and consolidation, undercover transport and accumulation, ice jam evolution, thermal growth and decay of ice cover including the effect of a snow cover, cover stability, initiation of break-up, breakup ice run and jam. Specific features of the models include the ability of treating river networks, transitional flows, and internal hydraulic structures. In CRISSP1D the four-point implicit model for river networks developed by Potok and Quinn (1979) is used for solving the St.Venant equations for flow hydraulics. Calculation of ice properties are calculated separately using an Eulerian-Lagrangian technique at a smaller time step than the hydraulics calculation. The two calculations were coupled at every hydraulics time step. In this study we are concerned with looking at the suspended (Cv) and surface ice (Ca) concentrations in CRISSP and comparing them the SWIPS derived values C and Csurf respectively. Shen et al. (1995) described the volumetric rate of loss of ice E from the suspended layer to the surface and anchor ice layers as:

vavbw

ChCCVd

E (1

) [3]

where dw = flow depth; Vb = average rising velocity of the suspended ice, and , , and are mass exchange coefficients at the interfaces between the suspended layer and surface layer and anchor ice. The exchange between the suspended and surface/anchor ice layers depends on frazil particle size, shape, flocculation and turbulence and is poorly understood and therefore has to be determined empirically. In more detail, = probability of deposition of frazil particles reaching the surface layer; = coefficient quantifying the rate of re-entrainment of surface ice per unit area (m/s), and = coefficient quantifying the rate of accretion to the bed per unit area (m/s). The coefficients , , and can be reach specific in CRISSP and Vb is specified globally in the model. Another parameter in CRISSP is the minimum initial thickness of the frazil portion of the ice floe (hf0). This parameter can vary from river to river and is dependent on the ability of the frazil flocs to overcome turbulence to reach and stay at the water surface. For the Peace River, Chen et al. (2005) found a value of 0.3 m to be suitable. However, this was based on some limited and difficult to obtain field measurements so this study also examined the sensitivity of this parameter on the suspended and surface ice concentrations. Additional field measurements by BC Hydro showed that a value of 0.23 m was more suitable. A frazil slush porosity of ice pans of 0.67 and a porosity of a newly formed ice cover of 0.60 were used. A series of CRISSP runs varying Vb, , , and hf0 were performed and compared to SWIPS data for suspended ice, surface ice concentration and ice pan thickness or draft. The progression of the leading edge of the ice cover (ice front) was also compared as that is the most important verification output of the model and the most significant from a hydroelectric operation/ice jam mitigation perspective. Run 1 is from a calibration of CRISSP currently used operationally by

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BC Hydro to forecast ice front progression. This calibration has been used successfully over the last 5 years but there is room for improvement. Runs 2-18 look at different values Vb, , , and hf0 and are summarized in Table 1. Plots of ice quantities and ice front progression rates are found in Figures 3.3.1 through to 3.8.2. Since the arrival of the ice front changes with different variables chosen, and ice quantities change abruptly with the arrival of the ice front, the ice quantities decrease sharply in value on different dates and times in the figures. Therefore, only comparisons between CRISSP and SWIPS derived values prior to these discontinuities were made.

3.2 Adjustment of SWIPS derived surface ice concentration

The surface ice concentration in any river is very dependent on variations in the surface width. Natural rivers can vary widely in width in short distances, distances short enough where little additional ice production or melt can occur. This is true of the Peace River. At the SWIPS location, the Peace River is about 350 m wide. However, less than 1 km upstream the river is only 250 m wide due to the geomorphological influence of the Smoky River Delta. Ice pans are concentrated at this section as the river narrows from a 700 m wide section upstream of the Smoky River. Downstream of the constriction the ice pans do not spread out significantly but stay in a 250 m wide swath closer to the left bank where the SWIPS instrument is located. The average width of the Peace River for tens of km upstream and downstream of the SWIPS location is about 400 m. This width is used for the cross sections in CRISSP model. This is because an average or smoothed width appears to provide numerically smoother solutions that match observed ice front progression rates. To adjust the SWIPS derived surface ice concentrations to the average width of the Peace River, they were multiplied by a factor of 400/250. This resulted in some values being greater than 1, in which case the values were truncated at unity.

3.3 Comparison of SWIPS frazil quantities with the current operationally calibrated CRISSP model

For the operational calibration of CRISSP Vb, , , and hf0 are 0.0004 m/s, 1.0, 0 m/s, 0 m/s, 0.23 m respectively. Figure 3.3.1a shows that the CRISSP suspended ice concentrations are about an order of magnitude higher than the SWIPS derived values. This could be the result of the difficulties in obtaining accurate suspended ice concentrations from a single frequency instrument (Marko et al. 2010a,b), differences in the lab and field instruments described in Section 2, or differences in frazil size distributions or particle shape between the lab and the Peace River. Figure 3.3.1b shows that the CRISSP surface ice concentrations are close but slightly lower than the SWIPS derived values. Since there is much more confidence in the ability of the SWIPS to detect the bottom of ice pans than quantities of surface ice, the small discrepancy could possibly be due to the result of local cross section and transverse surface ice concentration variation not accounted for by the simplified surface width-based adjustment in the model, as discussed above (Sec 3.2).

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Figure 3.3.1c shows that the CRISSP pan drafts are very close to the SWIPS derived values. Figure 3.3.2 shows the observed and CRISSP simulated ice fronts based on the operational calibration of CRISSP. The figure shows that the current calibration of CRISSP produces reasonable predictions of ice front behavior especially during the ice front upstream advance period in the winter, which is the emphasis of this study.

3.4 Effect of frazil rise velocity and the probability of a frazil particle reaching a surface layer

Figure 3.4.1a,b,c and Figure 3.4.3a, b, and c show the CRISSP suspended and surface ice quantities for various values of Vb, . However, based on Equation 3, . and Vb can be considered as one parameter Vb. It was found that increasing Vb brought the CRISSP values of suspended ice closer to the SWIPS derived values. However, this caused surface ice concentrations and pan drafts to significantly exceed the SWIPS derived values. It also caused the ice front to advance more quickly than observed (Figures 3.4.2 and 3.4.4). This suggests that the issue may be with the SWIPS derived suspended ice concentrations rather than the CRISSP calibrated ones. However, the possibility that the model provides accurate estimates of surface ice concentration while overestimating suspended frazil concentrations should also considered.

3.5 Effect of the coefficient of re-entrainment of the surface ice

In the current operational version of CRISSP and also in Chen et al. 2005, was found to be best set to zero. However, in this study its effect on the ice quantities was investigated. Non-zero values of this input variable made all ice quantities deviate further from the SWIPS derived values and dramatically reduced the ice front progression rates (Figure 3.5.2). The factor increased CRISSP concentrations further away, decreased surface ice concentrations below, and increased pan drafts much higher than SWIPS derived values (Figure 3.5.1). This supports the choice for keeping as zero for the Peace River.

3.6 CRISSP runs with combined changes in frazil rise velocity and coefficient re-entrainment of surface ice

An attempt was made to vary Vb, , and in various combinations to see if ice quantities would better match SWIPS derived values and observed ice fronts. Figures 3.6.1 and 3.6.2 show that this was not successful. Comparing Run 1 with Run 13 (Table 1 and Figure 3.6.1) confirmed that Vb does behave as one parameter in CRISSP as Equations 3 suggests.

3.7 Effect of the coefficient of the rate of accretion to the bed (anchor ice)

Although previous calibrations of CRISSP did not show that this parameter needed to be non-zero for successful calibration to the observed ice front progression rates, the parameter was investigated in this study. Figure 3.7.2 shows that this parameter affects the ice progression rate very little. Figure 3.7.1a shows that it did slightly improve (or decrease) the suspended ice concentrations towards the SWIPS derived values. However, it also caused the surface ice

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concentrations to vary widely below and above the SWIPS derived values in Figure 3.7.1b. Pan drafts in Figure 3.7.1c tended to be lower than SWIPS derived values with increasing . The wide variation in CRISSP surface ice concentrations when is non-zero can be explained by sudden releases of anchor ice when the anchor ice thickness buoyancy exceeds the specified bed material size of 0.05m specified in the model. In reality, bed material size has a distribution so the timing of buoyancy induced anchor ice releases would be more uniform through time. Fortunately this parameter does not change the time-averaged volumes of ice going down the river as demonstrated by it negligible effect on the ice front progression rates. However, it may be responsible for reducing the suspended ice concentrations to some degree.

3.8 Effect of the minimum initial thickness of the frazil ice floe

The calibrated hf0 for the operational calibration of CRISSP is 0.23 m. A smaller value of 0.01 m was tested to see its effect on the ice quantities. It had a very small effect on suspended ice concentrations (Figure 3.8.1a) but it increased surface ice concentrations above SWIPS derived values and pan drafts below SWIPS derived values. It also decreased the rate of ice front advance as shown in figure 3.8.2. Overall it shows that the present value of 0.23 m is reasonable. An initial ice pan thickness of 0.30 m was also tested in order to ascertain differences from the Chen et al. (2005) calibration. Neither the ice front advance rates nor the ice quantities were significantly different from the present operational calibration.

4. Comparison with suspended ice concentrations in other studies

SWIPS derived values of suspended ice concentrations in this study ranged between 0.005 % to 0.033 % and had typical values of approximately 0.015 % (Figure 4.1a). The lower limit never did reach zero, even during periods when the water temperature was above freezing. It is thought this may be due to the presence of suspended sediments in the water column. Marko and Jasek (2010b) obtained values of 0.002 % and 0.008 % on the Peace River for a different open water suspended frazil period (January 2006) using a theoretical formulation based on the Rayleigh backscatter law and some assumptions of frazil particle size and shape. These are about half of the values of the present study but of the same order of magnitude. CRISSP suspended frazil concentrations in this study generally ranged between 0 % to 0.3 % with very brief peaks up to 0.65 % at the onset of supercooling (Figure 4.1b). These latter peaks may just be brief numerical aberrations and not representative of the field. Typical values for CRISSP suspended ice concentration were around 0.15 %, about an order of magnitude larger than the SWIPS derived values. For comparison, here are some concentrations measured or estimated in other studies: In the lab: 0.06 to 0.6 % (Ettema et al. 2003); 0.10 to 0.17 % (Ye et al. 2004), 0.012 to 0.135 % (Ghobrial. et al. 2011). In the field: 0.25 % (Tsang 1984); 0.004 to 0.04 % (Daly 1994); 0.0006 % (Richard et al. 2010). Unfortunately, comparison with these results does not indicate if either the SWIPS or CRISSP suspended ice concentrations are more accurate since both the field and laboratory studies included concentrations in the range of values predicted from the SWIPS correlation and CRISSP.

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5. Conclusions

A comparison between CRISSP modeled ice quantities (suspended frazil concentration, surface ice concentration, and average frazil pan draft) and estimates computed using a SWIPS derived correlation was conducted. The BC Hydro operational calibration of CRISSP produced ice pan drafts that were close to SWIPS derived values and the CRISSP surface ice concentrations were also close but slightly lower than the SWIPS derived values. The small discrepancy in the latter could possibly be due to the result of local cross section and transverse surface ice concentration variation not accounted for by the simplified model vs. field river width-based adjustment. An important verification of CRISSP predictions in this investigation was the accuracy of simulating the observed ice front progression rates. The rate of the ice front advance is a function of the surface ice discharge upstream of the ice front. Also, the computed ice fronts by the CRISSP model agreed very well with observed values. CRISSP and SWIPS derived estimates of pan drafts and surface ice concentrations also agreed well, (which is essentially the surface ice discharge if the velocity and surface width is known) and this provides further evidence that the SWIPS derived surface ice concentrations and pan drafts are reasonably accurate. Further work is planned to compute SWIPS derived surface ice discharge in order to compare with CRISSP values. Unlike the surface ice concentrations and the pan drafts, the CRISSP suspended ice concentrations differed substantially from the SWIPS derived values. The CRISSP values were about an order of magnitude greater than the SWIPS derived ones. This left two possibilities, either the calibration of the CRISSP model was incorrect despite giving accurate surface ice concentrations, ice pan drafts and ice front progression rates, or the SWIPS detection of suspended ice concentrations was too low. The former was investigated in this study. A series of CRISSP runs were performed changing various input variables that affected or potentially affected surface ice concentrations. These were Vb, , , and hf0. No combination of these variables could produce suspended ice concentrations close to SWIPS derived values without degrading the agreement between CRISSP and SWIPS values for ice pan drafts and surface ice concentrations or the agreement between simulated and observed ice front progression rates. This suggests that the SWIPS derived suspended ice concentrations are too low. The most plausible explanations for this are that the properties of the frazil ice in the Peace River are significantly different from the properties of the frazil ice produced in the tank during the SWIPS calibration experiments, or there is a difference in the detection sensitivity or gain curve calibrations between the University of Alberta and BC Hydro Instruments. Comparing SWIPS derived and CRISSP suspended ice concentrations to previous studies did not help determine which was more accurate as both were in the range of previously measured field and laboratory values. The effect of the CRISSP input variable of (the rate of accretion of suspended ice to the bed) to form anchor ice showed that this factor decreased the predicted suspended ice concentration bringing it into closer agreement with the SWIPS derived values. This suggests that this process

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may be an explanation for some, but not all, of the discrepancy since an exceedingly large value of was needed to induce a match between CRISSP and SWIPS derived values of suspended ice. Evidently, further work needs to be carried out to determine how the SWIPS instrument could be better used to determine suspended ice quantities in rivers. One possibility is to perform the frazil ice tank measurements with the exact unit used on the Peace River. A second would be to have the BC Hydro SWIPS unit calibrated to determine more accurate gain curves for the instrument or if the instrument needs a correction for non-linear detector behavior. This was done with the University of Alberta 546 kHz unit but not for the BC Hydro one. Another avenue is the future use of multi-frequency units that may allow for the detection of frazil particle size distributions that may occur between the laboratory and the field environments. BC Hydro plans to deploy a 4-frequency unit next winter in the Peace River. Accurate gain curves for all 4 transducers are required for this method to be successful. The performance of the 4-frequency unit could be evaluated by conducting tests in the frazil ice tank. Acknowledgments Alberta Environment and Timberoot Environmental Inc. assisted deployment of the SWIPS into the Peace River in the Fall of 2010. The former performed data downloads throughout the winter. References Chen, F., Shen, H.T., Andres, D., and Jasek, M. (2005) Numerical simulation of surface and

suspended freeze-up ice discharges, Proceedings, ASCE World Water & Environmental Resources Congress, Anchorage, AK. May 15-19, 2005.

Daly, S.F., 1994. International Association for Hydraulic Research Working Group on Thermal

Regimes: Report on Frazil Ice. U.S. Army Corps of Engineers Special Report 94-23. 43p. Ettema, R., Chen, Z., Doering, J,. 2003. Making Frazil Ice in a Large Ice Tank. Proceedings of

the 12th Workshop on the Hydraulics of Ice Covered Rivers, Committee on River Ice Processes and the Environment, Edmonton, Canada, 13 pp.

Potok, A.J., and Quinn, F.H. (1979). A hydraulic transient model of the upper St. Lawrence

River for water resources research, Water Resources Bulletin, 15(6). Shen, H, T., Wang, D. S., and Lal, A.M.W. (1995). Numerical simulation of river ice processes.

Journal of Cold Regions Engineering, 107-118. Gartner, J.W., 2004. Estimating suspended solids concentrations from backscatter intensity

measured by acoustic doppler current profiler in San Francisco Bay, California. Marine Geology 211, no. 3-4: 169-187.

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Ghobrial, T.R., Loewen, M.R., Hicks, F., (2009). Frazil ice measurements using the shallow water ice profiling sonar. Proceedings of 15th Workshop on River Ice, St. John’s, Newfoundland and Labrador, June 15 - 17, 2009, pp. 14-26.

Ghobrial, T.R., Loewen, M.R., Hicks, F. (2011). Evaluation of the shallow water ice profiling

sonar for measuring frazil ice. Final Report NSERC CRD Grant. 6-May-2011. Jasek,M., Marko, J.R., Fissel, D., Clarke, M., Buermans, J., Paslawski, K., 2005. Instrument for

detecting freeze-up, mid-winter and break-up processes in rivers. Proceedings of 13thWorkshop on the Hydraulics of Ice Covered Rivers, Hanover, NH.

Jasek M., Marko, J.R., 2007. Instrument for detecting suspended and surface ice runs in rivers.

Proceedings of 15thWorkshop on the Hydraulics of Ice Covered Rivers, Quebec City, QC. Jasek, M., Marko, J.R., 2008. Acoustic detection and study of frazil ice in a freezing river during

the 2007–2008 winter. Proceedings of 19th International Association for Hydraulic research Symposium on Ice, Vancouver, B.C., Canada. 10p.

Marko, J. R., Jasek, M., 2010a. Sonar detection and measurements of ice in a freezing river I: methods and data characteristics. Cold Regions Science and Technology. Vol 63, Issue 3 p. 121 – 134.

Marko, J. R., Jasek, M., 2010b. Sonar detection and measurements of ice in a freezing river II:

observations and results on frazil ice. Cold Regions Science and Technology. Vol 63, Issue 3 p. 135 – 153.

Richard, M., Morse, B., Daly, S.F. and J. Emond, 2010. Quantifying suspended frazil ice using

multi-frequency underwater acoustic devices. River Research and Applications. DOI: 10.1002/rra.1446.

Tsang, G. (1984). Concentration of frazil in flowing water as measured in laboratory and in the field. Proceedings of the 7th IAHR Ice Symposium, 1984, Hamburg, Germany.

Urick, R.J., 1983. Principles of Underwater Sound. 3rd Edition. McGraw-Hill, Inc., 423 pp. Ye, S.Q., Doering, J.C., Shen, H.T., 2004. A Laboratory Study of Frazil Evolution in a Counter

Rotating Flume. Canadian Journal of Civil Engineering, 31(6), 899-914.

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Table 1. Comparison of CRISSP runs with SWIPS data and progression of the leading edge (Ice front).

Input Variables Simulated Relative to SWIPS

Derived

Vb

(m/s) (m/s) (m/s)

Initial Ice Pan

Thickness (m) Suspended Ice Surface Ice

Pan Thickness

Ice Front Progression Relative to Observed

Run 2 0.004 1 0 0 0.23 close high high much faster Run 3 0.001 1 0 0 0.23 high close close slightly faster Run 1 0.0004 1 0 0 0.23 higher close close close Run 4 0.00004 1 0 0 0.23 highest low low slower Run 1 0.0004 1 0 0 0.23 higher close close close Run 5 0.0004 1 0.00001 0 0.23 high low high slow Run 6 0.0004 1 0.0001 0 0.23 higher lower higher slower Run 7 0.0004 1 0.001 0 0.23 highest lowest highest much slower Run 1 0.0004 1 0 0 0.23 higher close close close Run 8 0.0004 0.9 0 0 0.23 higher close close very slightly slower Run 9 0.0004 0.5 0 0 0.23 highest close close very slightly slower Run 10 0.0004 0.1 0 0 0.23 high low low slower Run 1 0.0004 1 0 0 0.23 higher close close close Run 11* 0.004 0.1 0 0 0.23 higher close close close Run 12 0.004 1 0.00001 0 0.23 high but closer low high too slow then too fast Run 13** 0.004 1 **0.00001 0 0.23 high but closer low high close and then too fast Run 1 0.0004 1 0 0 0.23 higher close close close Run 14 0.0004 1 0 0.0001 0.23 high but closer higher & lower lower close Run 15 0.0004 1 0 0.0004 0.23 high, even closer higher & lower lower close Run 1 0.0004 1 0 0 0.23 higher close close close Run 16 0.0004 1 0 0 0.01 high but closer closer low slower Run 17 0.0004 1 0 0 0.30 higher close slightly higher close Run 18 0.0002 1 0 0 0.30 much higher close slightly higher close

* Same result as Run 1, ** = 0 for milder downstream reaches of Peace River

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0.0%

0.1%

0.2%

0.3%

0.4%

0.5%

0.6%

0.7%

01-Nov 11-Nov 21-Nov 01-Dec 11-Dec 21-Dec 31-Dec 10-Jan

Sus

pend

ed F

razi

l Ice

C

once

ntra

tion

SWIPS

CRISSP

a)

0%10%20%30%40%50%60%70%80%90%

100%


Sur

face

ice

Con

cent

ratio

n SWIPS

CRISSP

b)

00.10.20.30.40.50.60.70.80.9

1


Ice

Pan

Dra

ft (m

)

SWIPS

CRISSP

c)

Figure 3.3.1 a) Suspended ice concentrations b) surface ice concentrations and c) ice pan drafts

comparison between SWIPS derived values and those obtained from the operationally calibrated CRISSP model (Vb, = 0.0004 m/s,1.0, = 0 m/s, = 0 m/sand hf0 = 0.23 m).

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0

100

200

300

400

500

600

700

800

900

1-Nov 1-Dec 31-Dec 31-Jan 2-Mar 2-Apr 2-May 1-Jun

Dis

tan

ce f

rom

Ben

net

t D

am (

km)

Observed

Operationally Calibrated CRISSP Model

Figure 3.3.2. Comparison of ice fronts between operationally calibrated CRISSP model (Vb, =

0.0004 m/s,1.0, = 0 m/s, = 0 m/sand hf0 = 0.23 m) and observed values.

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0.0%0.1%0.2%0.3%0.4%0.5%0.6%0.7%


Sus

pend

ed ic

e C

once

ntra

tion

SWIPS

CRISSP, Vb = 0.00004 m/s

CRISSP, Vb = 0.0004 m/s*



a)

0%10%20%30%40%50%60%70%80%90%

100%

01-Nov 11-Nov 21-Nov 01-Dec 11-Dec 21-Dec 31-Dec 10-JanSur

face

Ice

Con

cent

ratio

n SWIPS





b)

00.10.20.30.40.50.60.70.80.9

1


Ice

Pan

Dra

ft (m

) SWIPS





c)

* indicates operational calibration of CRISSP Figure 3.4.1 a) Suspended ice concentrations b) surface ice concentrations and c) ice pan drafts comparison between SWIPS derived values and from CRISSP runs with various frazil particle

rise velocities. (Vb varies as indicated,1.0, = 0 m/s, = 0 m/sand hf0 = 0.23 m).

263

0

100

200

300

400

500

600

700

800

900


Dis

tan

ce f

rom

Ben

net

t D

am (

km)

ObservedVb = 0.00004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 mVb = 0.0004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m*Vb = 0.001 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 mVb = 0.004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m

* opertional calibration of CRISSP Figure 3.4.2. Comparison of CRISSP ice fronts with observed for various values of frazil rise

velocity (Vb varies as indicated,1.0, = 0 m/s, = 0 m/sand hf0 = 0.23 m).

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0.0%0.1%0.2%0.3%0.4%0.5%0.6%0.7%


Sus

pend

ed ic

e C

once

ntra

tion

SWIPS

Alpha = 1.0*

Alpha = 0.9

Alpha = 0.5

Alpha = 0.1

a)a)a)a)

0%10%20%30%40%50%60%70%80%90%

100%


face

Ice

Con

cent

ratio

n SWIPS

Alpha = 1.0*

Alpha = 0.9

Alpha = 0.5

Alpha = 0.1

b)

00.10.20.30.40.50.60.70.80.9

1


Ice

Pan

Dra

ft (m

) SWIPS

Alpha = 1.0*

Alpha = 0.9

Alpha = 0.5

Alpha = 0.1

c)

* indicates operational calibration of CRISSP Figure 3.4.3 a) Suspended ice concentrations b) surface ice concentrations and c) ice pan drafts comparison between SWIPS derived values and from CRISSP runs with various probability

of deposition of frazil particles reaching the surface layer). (Vb = 0.0004 m/s,varies as indicated, = 0 m/s, = 0 m/sand hf0 = 0.23 m).

265

0

100

200

300

400

500

600

700

800

900


Dis

tan

ce f

rom

Ben

net

t D

am (

km)

ObservedVb = 0.0004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m*Vb = 0.0004 m/s, Alpha = 0.9, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 mVb = 0.0004 m/s, Alpha = 0.5, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 mVb = 0.0004 m/s, Alpha = 0.1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m

* opertional calibration of CRISSP Figure 3.4.4. Comparison of CRISSP ice fronts with observed for various probability of

deposition of frazil particles reaching the surface layer). (Vb = 0.0004 m/s,varies as indicated, = 0 m/s, = 0 m/sand hf0 = 0.23 m)

266

0.0%0.1%0.2%0.3%0.4%0.5%0.6%0.7%


Sus

pend

ed ic

e C

once

ntra

tion

SWIPS

Beta = 0 m/s*

Beta = 0.00001 m/s

Beta = 0.0001 m/s

Beta = 0.001 m/s

a)a)a)a)

0%10%20%30%40%50%60%70%80%90%

100%


face

Ice

Con

cent

ratio

n SWIPS

Beta = 0.0 m/s*

Beta = 0.00001 m/s

Beta = 0.0001 m/s

Beta = 0.001 m/s

b)

00.5

11.5

22.5

33.5

4


Ice

Pan

Dra

ft (m

)

SWIPS

Beta = 0.0 m/s*

Beta = 0.00001 m/s

Beta = 0.0001 m/s

Beta = 0.001 m/s

c)

* indicates operational calibration of CRISSP Figure 3.5.1 a) Suspended ice concentrations b) surface ice concentrations and c) ice pan drafts comparison between SWIPS derived values and from CRISSP runs with various values of

coefficient of re-entrainment of the surface ice). Vb = 0.0004 m/s, = 1.0, varies as indicated, = 0 m/sand hf0 = 0.23 m.

267

0

100

200

300

400

500

600

700

800

900


Dis

tan

ce f

rom

Ben

net

t D

am (

km)

ObservedVb = 0.0004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m*Vb = 0.0004 m/s, Alpha = 1, Beta = 0.00001 m/s, Gamma = 0 m/s, hfo = 0.23 mVb = 0.0004 m/s, Alpha = 1, Beta = 0.0001 m/s, Gamma = 0 m/s, hfo = 0.23 mVb = 0.0004 m/s, Alpha = 1, Beta = 0.001 m/s, Gamma = 0 m/s, hfo = 0.23 m

* opertional calibration of CRISSP Figure 3.5.2. Comparison of CRISSP ice fronts with observed for various values of

coefficient of re-entrainment of the surface ice). Vb = 0.0004 m/s, = 1.0, varies as indicated, = 0 m/sand hf0 = 0.23 m.

268

0.0%0.1%0.2%0.3%0.4%0.5%0.6%0.7%


Sus

pend

ed ic

e C

once

ntra

tion SWIPS

Vb = 0.0004 m/s, Alpha = 1.0,Beta = 0 m/s*

Vb = 0.004 m/s, Alpha = 0.1,Beta = 0 m/s

Vb = 0.004 m/s, Alpha = 1.0,Beta = 0.00001 m/s

a)a)a)a)

0%10%20%30%40%50%60%70%80%90%

100%


face

Ice

Con

cent

ratio

n SWIPS

Vb = 0.0004 m/s, Alpha = 1.0,Beta = 0 m/s*

Vb = 0.004 m/s, Alpha = 0.1,Beta = 0 m/s

Vb = 0.004 m/s, Alpha = 1.0,Beta = 0.00001 m/s

b)

00.5

11.5

22.5

33.5

4


Ice

Pan

Dra

ft (m

)

SWIPS

Vb = 0.0004 m/s, Alpha =1.0, Beta = 0 m/s*

Vb = 0.004 m/s, Alpha =0.1, Beta = 0 m/s

Vb = 0.004 m/s, Alpha =1.0, Beta = 0.00001 m/s

c)

* indicates operational calibration of CRISSP Figure 3.6.1 a) Suspended ice concentrations b) surface ice concentrations and c) ice pan drafts

comparison between SWIPS derived values and from CRISSP runs with various values of Vb,, Vb,, vary as indicated, = 0 m/sand hf0 = 0.23 m.

269

0

100

200

300

400

500

600

700

800

900


Dis

tan

ce f

rom

Ben

ne

tt D

am

(km

)Observed

Vb = 0.0004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m*

Vb = 0.004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m

Vb = 0.0004 m/s, Alpha = 0.1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m

Vb = 0.004 m/s, Alpha = 0.1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m

Vb = 0.004 m/s, Alpha = 1, Beta = 0.00001 m/s, Gamma = 0 m/s, hfo =0.23 mVb = 0.004 m/s, Alpha = 1, Beta = 0.00001 m/s upstream of 550 km ,Gamma = 0 m/s, hfo = 0.23 m

* opertional calibration of CRISSP Figure 3.6.2. Comparison of CRISSP ice fronts with observed for various values of Vb,,

Vb,, vary as indicated, = 0 m/sand hf0 = 0.23 m.

270

0.0%0.1%0.2%0.3%0.4%0.5%0.6%0.7%


Sus

pend

ed ic

e C

once

ntra

tion SWIPS

Gamma = 0 m/s*

Gamma = 0.0001 m/s

Gamma = 0.0004 m/s

a)a)a)a)

0%10%20%30%40%50%60%70%80%90%

100%


face

Ice

Con

cent

ratio

n SWIPS

Gamma = 0 m/s*

Gamma = 0.0001 m/s

Gamma = 0.0004 m/s

b)

00.10.20.30.40.50.60.70.80.9

1


Ice

Pan

Dra

ft (m

)

SWIPS

Gamma = 0 m/s*

Gamma = 0.0001 m/s

Gamma = 0.0004 m/s

c)

* indicates operational calibration of CRISSP Figure 3.7.1 a) Suspended ice concentrations b) surface ice concentrations and c) ice pan drafts comparison between SWIPS derived values and from CRISSP runs with various values of coefficient of the rate of accretion to the bed or anchor ice). Vb = 0.0004 m/s, = 1.0, = 0,

varies as indicated,and hf0 = 0.23 m.

271

0

100

200

300

400

500

600

700

800

900


Dis

tan

ce f

rom

Ben

net

t D

am (

km)

ObservedVb = 0.0004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m*Vb = 0.0004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0.0001 m/s, hfo = 0.23 mVb = 0.0004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0.0004 m/s, hfo = 0.23 m

* opertional calibration of CRISSP Figure 3.7.2. Comparison of CRISSP ice fronts with observed for various values of

coefficient of the rate of accretion to the bed or anchor ice). Vb = 0.0004 m/s, = 1.0, = 0, varies as indicated,and hf0 = 0.23 m.

272

0.0%0.1%0.2%0.3%0.4%0.5%0.6%0.7%


Sus

pend

ed ic

e C

once

ntra

tion

SWIPS

hf0 = 0.01 m

hf0 = 0.23 m*

hf0 = 0.30 m

a)a)a)a)

0%10%20%30%40%50%60%70%80%90%

100%


face

Ice

Con

cent

ratio

n SWIPS

hf0 = 0.01 m

hf0 = 0.23 m*

hf0 = 0.30 m

b)

00.10.20.30.40.50.60.70.80.9

1


Ice

Pan

Dra

ft (m

) SWIPS

hf0 = 0.01 m

hf0 = 0.23 m*

hf0 = 0.30 m

c)

* indicates operational calibration of CRISSP Figure 3.8.1 a) Suspended ice concentrations b) surface ice concentrations and c) ice pan drafts

comparison between SWIPS derived values and from CRISSP runs with various values of initial ice pan thickness ( hf0. Vb = 0.0004 m/s, = 1.0, = 0, = 0,and hf0 varies as shown.

273

0

100

200

300

400

500

600

700

800

900


Dis

tan

ce f

rom

Ben

net

t D

am (

km)

Observed


Vb = 0.0004 m/s, Alpha = 1, Beta = 0 m/s, Gamma = 0 m/s, hfo = 0.23 m*


* opertional calibration of CRISSP Figure 3.8.2. Comparison of CRISSP ice fronts with observed for various values of initial ice pan

thickness (hf0. Vb = 0.0004 m/s, = 1.0, = 0, = 0,and hf0 varies as shown.

0

1

2

3

4

5

6

7

0.000%

0.005%

0.010%

0.015%

0.020%

0.025%

0.030%

0.035%


Wat

er T

empe

ratu

re (o

C)

Sus

pend

ed F

razi

l ice

C

once

ntra

tion

Suspended Ice (SWIPS)

Measured Water Temperature

a)

01234567

0.0%0.1%0.2%0.3%0.4%0.5%0.6%0.7%


Wat

er T

empe

ratu

re (o

C)

Sus

pend

ed F

razi

l ice

C

once

ntra

tion

Suspended ice (CRISSP)

Water Temperature (CRISSP)

b)

Figure 4.1 Suspended ice concentrations and water temperatures for a)SWIPS and b)CRISSP.

comparison of crissp modeled and swips measured ice ... · comparison of crissp modeled and swips...

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