A Seasonal Rogue Wave





“Just weeks after Christine’s last art expo in 1994, she was invited to stay in a famous home twenty miles south of Carmel at Rocky Point. As reported in the Carmel Pinecone, Rosamond had had nightmares about a giant wave causing her demise. On March 26, 1994, Rosamond was exploring tidal pools in a cove along with her sister and eight-year-old daughter, Drew. A rogue wave, unusual for that time of year, rushed into the cove. The sister was able to save the child, but Rosamond was swept out to sea. She was 46.[6] 

What you see in the Pinecone report, is everything is Christine’s fault. She did not want to go have lunch. She did not want to rent fishing poles. She thought the tide was low. She wanted to sit on that “final rock” with her back to the sea. This suggests Christine was suicidal, and thus – she deserved to die. She felt it was safe to bring Drew down into that Death Trap. Christine should have considered  – the freak out of season – Rogue Wave!

Huh? What do you called this………..A Suspended Narrative. A hanging – whatever! It must be the talk of the office! I think Wikipedia has given up in Rosamond’s bio. Rogue waves are not seasonal. However there is a in depth study. (see below) Forgive the pun. True Weather – matters! As you can see there are no tide-pools in that cove. This arguing over weather has been going on for………………..too long! Trump claims it did not rain on the day of his inauguration.


Once again, why put the life of a eight year old – in harms way! Who invited Christine and Drew to Rocky Point? Vicki’s name is not given. Was it known?

“Who wants to go down into the Black Yaw of Death and play with the Powerful Waves?”

Years ago I suggested a board game, a Dungeons and Dragons, where the object is – to get Rosamond NEAR the water then – IN THE WATER! Vicki gets the game going with her Pinecone interview.

Here is Trump saying folks are soaking wet, when they are not! He just fired Bolton. If I edit Wikipedia, I ill try and leave this image. How about a video game – with stick figures?

Sixteen days ago I asked Shamus Dundon if he picked up Vic’s fishing poles before he went to Rocky Point.


“What did you get?”

“I don’t remember.”

But, it wasn’t fishing poles – for sure? That much you do remember? I really do love Dael Kingshill, because she loves these scenarios.  She is into D&D.  How to get a fishing pole in Shamus’ hands. Drew and Vicki were addicted to Everquest. What will become of Vicki’s character that she empowered? My sister got in early in the game. Of course it is a great tragedy when ANYONE doesn’t get to play anymore. But – you got to play fair!  I find myself crying – all of a sudden!

After being down in The Yaw of Death, with a child, Vicki suggests they go to town to rent fishing poles. Where did Vicki think the best fishing spot would be? When I read how she has Christine disappear the high tide – I grieved for the loss of both my sisters! Vicki disappeared a mother and aunt’s concern for the safety of a child. It wasn’t Drew’s time.

“It must have been Christine’s time, and perhaps she knew so. I was
there as an afterthought. She and Drew were going to spend the whole
weekend at a guest house. Christine went back and sat down on the
final rock after saying we should go get lunch and rent fishing
poles. She always had nightmares about water, tidal waves, the
ocean’s power, the water taking control. She was facing her
nightmare; she sat back down as if she had conquered those fears. I
didn’t understand why we weren’t leaving. It must have been a
WE WERE IN DANGER. We weren’t just frolicking on the rocks.” Vicki
said. “We were responsible people, and aware of the water at all
times. It was a full moon weekend with lots of tidal action. A friend
told me that five other people were swept out to sea ( from
California’s north coast) over the same period. We went to look for
shells and tide pool creatures. Christine was sure the tide was going
out. Did she know what lay a head?”

Here is the Pinecone newspaper’s article. Wikipedia insists on references.

This blog is under attack by women. Vicki Presco severely abused me. She GASLIGHTED me and The Art World. The credulity of Wikipedia – was already under attack! My child got sucked into this destructive evil. My biography will tell it like it is.

Trump has declared The Press – THE ENEMY! Telling The Enemy BIG LIES, is the norm. Art and the Free Press are in deep trouble. If this blog gets taken down, I will see an attorney. My struggle for The Truth – IS EPIC! I lost everyone – over fishing poles.

I believe Shamus Dundon took Drew Benton down to that cove – TO FISH! Vicki was there. Christine Rosamond Benton – was not there. She was up in the house getting ready for her sober birthday party. Shamus ran into the house to call 911 because Drew was in the water. Christine ran out of the house – and down to that cove. If she had a jacket on, she took it off before she dove into the water to save her with eight year old daughter! But, why bother putting on a coat? Vicki and Shamus planted that suede coat at the cove. This is the only scenario that involves KNOWN FACTS. One fishes at HIGH TIDE. Did Shamus check when that would be? Shoot, I gave the End Game away – and profits!

I labeled the Pinecone account “Doc.3”. I sent a copy of my report to the Sherriff’s Office, the Coroner, and John Detro – who turned out to be friends with Stacey Pierrot and Jacci Belford. John showed them my report. Shamus gave me a call.

The World of Literature comes under attack. Two books tried to give the Real World a Real Death Scene – AND FAILED! I am still being used as a smokescreen! I am a BIG PART of the coverup. I am made out to be INSANE – BY A DOZEN WOMEN! This will be the crux of – MY STORY! I am sure Christine hates what is happening to me – from above!

Dael Kingsmill is a professional actress, and thus she is in the public domain. I get to write about her, even employ her Thespian Art to explain how tales and legends are made. For this is what we got in regards to Wikipedia’s treatment of “Christine Rosamond”. Because she is a woman – Dael is able to get away with murder! The Giant Hog Woman downstairs sticks pins in me – all day!

When I get the funds I want to hire Ms. Kingsmill to tell……The Tale of Rosamond. This would make a great Gothic play, that has Rosamond clinging to the rocks, tearing her nails off, as what she fears the most, pulls her to her…………..Final End! Dael Kingsmill would make a great Rosamond! Christine was………….overly dramatic!

Why didn’t the Sharpie Artists put a Pinocchio Nose on Trump? In my play ‘A Seasonal Rogue’ the noses of women on stage will grow long with each fib, with every Weather Lie!

They say your life passes before you WHEN YOU DIE! But, because we don’t have a real Death Scene, we don’t get the true story of a world famous WOMAN ARTIST.  The remedy for this, is to have The Old School Teacher that Julie Lynch INVENTED, come talk to Rosamond – on the rocks. She is……..The Old Crone! Dael Kingsmill would make a great Old Crone. I wonder if my enemies are trying to hire her?

“Well, my pretty. I see you’ve gotten yourself – in another fine mess! I don’t think you’re going to get out of this one. However! You might as well confess. Speak to me about your brother. He found out about your secret, didn’t he. This is why you tried to destroy him, employing every member of you family. When they agreed to help you, their fate was sealed.”

What the world will see is The Greatest Art Lesson – off all time – aimed at women! Ten thousand women will leave the theatre in tears, and take up art. ‘The Testing and Tormenting of John’ scene, will inspire ten thousand men to become writers, and avoid ugly and obese women who hold a grudge.

What I am going to do right now, is send out some of my posts to HBO, Netlix, Showtime, and others, to see if I can get a Cable Televisions Series.

I think Kim Haffner should get off THC and got to an acting school. I want her to play Rosemary. When she comes on stage, you will hear a pin drop. She waddles to the closet door. Behind it is four year old Rosamond drawing by flashlight. She knows she has to stop Christine from becoming a famous artist, because she only wants her older brother to be known all over the world. Alas we find out why. This is the best kept secret in the history of art. I want Kingsmill to write this scene…………’Caught In The Closet’.

I have had not time to author a review of Dael’s amazing work. She is the epitome of what everyone with a Big Brain – should be.

“Flaunt it, baby! Flaunt it!

Dael has a wealth of characters lurking inside, and thus a shit-load of expressions. Her hands are claws that tear into your chest – and yank your heart out!

I suspect the original Gleemen, were, Gleewomen. Men stole this art – to make money! I would watch Big Brother if Dael was on it. How about a show called ‘Cool Scars’ that will be the antithesis of the Doctor Phil show. Dael will give lessons to women, who claim they are victims, on how to be Great Victims – and how to own great emotional scars – that will never heal! Males will be demonized – and publicly castrated – like I was!

The Alley Gang were setting me up for Blackmail. I was not invited to the party at Rocky Point, or the Movie Idea Scrum. This is what I deserve! I deserve to whipped with an inch of my life – and locked in a dark closet – in Rosamond’s place. In the end, Rosamond is as good an artist, as I am a bad artist. This is a devastating approach that we see the President of the United States, who is claiming everyone – is making him look bad! He needs to hire Ms. Kingsmill to be his……….Svengali? How about Rasputin? I would love to see Dael do ‘The Wife of Rasputin’ and talk about the rumors about the size of his his penis She would have them rolling in the isles! She needs to meet her Sid. How about a Talk show?

There is no blame cast on Shamus Dundon, because, he left his family – and went hunting for lizards. When alas we arrived at the final excuse twenty four years ago, I wanted to ask him and Vicki, this…….

“Why didn’t Drew ask Christine if she can go hunt lizards with Shamus?”


Shamus had just got out of Aire force boot camp, and was stationed in Oklahoma City. He wanted to see his family who were going to be in one place. Like his father and uncle, Jim and Michael, he wanted to look like a hero. How could he do that?

If you went fishing with Captain Vic – you always caught fish! Shannon caught with Vic. I see Shamus and Drew marching up the hill, into the house, and throwing two King Salmon in the counter! Fishing on the coast is a more popular activity, then tide-pooling!

The fact Drew ended up in the water, is really played down. This is a dead giveaway!

John Presco

Copyright 2019

John Presco

Copyright 2019




Play both videos at same time with SillyDillyKitty music turned down to get to the real truth of how these poor cats feel! TERRIFIED! How deep does that water look to you? Tide-pools…………MY ASS!




Why Did Kim Hafner Target Me?


Captured on video is Kim Hafner telling me she is communicating with my daughter, and she is behind her in the Character Assassination Ms. Hafner has instigated, and is leading. My attorney can take my daughter’s deposition to see if her treachery is true. This goes for Ms. Hafner’s claim Alley Valkyrie and her friends warned her about me. This is also a lie! This creature employs the terrorism of witches who attacked my newspaper, Hafner also attacks my newspaper – along with my sister’s biography. She denies kicking Clark! How doe she live with herself!!!!

I suspect Kim thinks I was putting the make on her, trying to seduce her with books and my family tree. Why would it take these things? Who in the fuck does she think she is?


Seasonal intensification and trends of rogue wave events on the US western seaboard


Studies of changes in wave climate typically consider trends in sea state statistics, such as the significant wave height. However, the temporal variability of individual rogue waves, which pose a hazard to users of the sea and coastal environment has not been investigated. We use time series of continuous surface elevation over 124–270 months (spanning 1994–2016), from 15 wave buoys along the US western seaboard, to investigate regional trends in significant wave height and individual rogue waves. We find high spatial variability in trends in significant wave height and rogue waves across the region. Rogue wave occurrence displays a mostly decreasing trend, but the relative height – or severity – of the waves is increasing. We also identify seasonal intensification in rogue waves with increased rogue wave occurrence, of higher severity, in the winter than in the summer. Therefore, the common practice of stating a single occurrence likelihood for an ocean basin is not valid. In addition, the buoy data show that the magnitude and significance of trends in significant wave height increases towards higher percentiles, supporting previous findings.


Global mean significant wave height has increased over the past 30 years1,2,3. Young et al.3, analysed satellite altimetry from 1985–2008 that indicated weak trends in monthly global mean significant wave height (HS) and indicated that the largest waves (90th and 99th percentile Hs) have increased in amplitude over this period. This is also true for waves along the highly populous western seaboard of the United States of America. These were shown to be increasing, with 90th and 99th percentile of mean monthly Hs increasing by over 1% per year, over a 23 year period3. In-situ measurements yielded negative trends offshore of Washington and Oregon, and positive offshore of California, all of which were of small magnitude4. Similarly, neutral or weakly decreasing trends in Hs have also been seen in other observation-based studies5,6. In addition, decreasing trends in mean peak wave period (Tp) were seen from 1992 to 2012 for most of the mid-latitude North Pacific6.

Rogue waves are transient individual waves larger than expected for the surrounding sea state, and are known to occur on the US western seaboard7,8. The region has a population of over 50 million people with significant coastal infrastructure. Ports in the region handle 49% of the total U.S. containerised trade and Port of Los Angeles and Port of Long Beach together make Southern California the largest gateway for U.S. containerised imports9. In addition, there is a high volume of tanker, bulk carrier, Roll On–Roll Off, passenger, and fishing activity focused around the ports in the region (Fig. 1). Vessels also service the offshore structures deployed to support the Californian oil and gas industry10, as well as test beds for renewable energy devices (Fig. 1). Rogue waves at the shoreline have fatally swept people out to sea at Point Reyes, Maverick’s beach, and Arcata, in California and Depoe Bay, Oregon11. Rogue wave-ship collisions have resulted in fatalities, cargo loss, and ships foundering12. In the region, the NOAA research vessel R/V Ballena capsised off Point Conception, California13. In 2006, M/V Westwood Pomona encountered a rogue wave off Port of Coos Bay, injuring one and damaging the vessel. In Brookings Harbor, Oregon, four waves caused ship damage11.

Figure 1

Overview map of the United States western seaboard. The locations of the 15 Datawell Waverider buoys are shown (yellow points), along with ports (triangle markers) and offshore structures (pink hexagons). ESRI Basemap Sources: Esri, GEBCO, NOAA, National Geographic, DeLorme, HERE, Geonames.org, and other contributors.

Rogue waves are differentiated from normal waves as waves of height (h) greater than 2Hs (hHs>2)(hHs>2) , or with a crest height (Cr) greater than 1.25Hs (CrHs>1.25)(CrHs>1.25) 14. Previous research on rogue waves evaluates their occurrence likelihood from compiled datasets across multiple locations7, and typically give one statistic for their occurrence15. Recent work has expanded this to consider their spatial variability along the US western seaboard8, and seasonality16, but the interannual temporal variability of the phenomenon is unknown. Here we provide a detailed temporal analysis of the wave record from 15 Datawell Waverider buoys along the US western seaboard (Fig. 1), managed by the Coastal Data Information Program (CDIP). They were selected as they store the raw surface displacement data and provide a uniform sampling platform with a duration of over 10 years. First, we analyse whether there is a statistically significant monotonic trend in the monthly binned sea state characteristics over sampling periods of 124–270 months and compare to the findings of previous studies. Temporal variability of individual rogue wave events, and their height and relative abnormality are assessed on both a decadal and seasonal scale for the first time.


Are Wave Heights Increasing?

The mean Hs over the sampling period of the buoys show small decreasing trends of less than 0.5% yr−1 for most buoys; although these are not statistically significant (Red bars – Fig. 2) they are similar to what is seen in satellite data3. The trends from buoys in the Southern Californian Bight are slightly more complex, with four buoys displaying an increasing trend. These four buoys include the only statistically significant buoy and displays an increase in the 90th percentile of Hs (Blue bars – Fig. 2). Elsewhere buoys show a reduction in the 90th percentile of Hs. Trends in 99th percentile of Hs (Green bars – Fig. 2) have the largest magnitudes. Trends are mostly positive, with magnitudes around 0.02 m yr−1, and three buoys have statistically significant trends. In Oregon, Umpqua Offshore shows a reduction of 0.004 m yr−1 (0.96% y−1). In California, Anacapa Passage, Santa Monica Bay, San Pedro, and Dana Point show increases of 0.009 to 0.021 m yr−1 (0.5–1.1%y−1). The magnitude of significant wave height trend increases at extreme values (90th and 99th percentiles) supporting previous findings3; however, the sign of the trends are more spatially variable than seen in 2° × 2° satellite data3.

Figure 2

Trend in the mean (red), 90th percentile (blue), and 99th percentile (green) of significant wave height as a percentage of the location’s time series mean. Empty and half-filled circles indicate the 90th and 95th levels of statistical significance, respectively, deemed by the seasonal Mann-Kendall test.

Trends in the mean wave crest heights are weak and none are statistically significant. Trends in the 99th percentile of crest height are stronger, with the three buoys that showed statistically significant results for the 99th percentile of Hs also having significantly increasing mean crest heights (TABLE S1). The trend in mean peak wave period (Tp) and mean zero-crossing wave period (Tz) are reducing as projected by Hemer et al.17; however, in locations sheltered from the dominant wave direction – inshore buoys between point conception and San Diego – the mean Tz is increasing. Here the buoys are more wind-sea dominated and respond to changing wind forcing3, whereas more exposed buoys are swell dominated, and changes in wind-sea are less discernible. The magnitudes of the trends are less than 0.3% y−1. Furthermore, the distribution of energy over frequency components, as described by the spectral bandwidth parameter, ν (see Methods), is also reducing at most locations (TABLE S1).

Are Rogue Wave occurrences increasing?

Rogue wave occurrence is variable on an interannual timescale, and there is considerable spatial variability within the region (Green bars – Fig. 3). Rogue wave occurrence is reducing within the Southern Californian Bight, but elsewhere trend and magnitude vary. As a percentage of the average occurrence at each location, rogue wave occurrences are increasing at 1.5% y−1 at the most southerly buoy, Mission Bay, CA. Although larger increasing trends of 0.6, 0.81, and 0.84 % y−1 are seen in the north at Grays Harbor, Point Reynes, and Harvest, respectively, these are not statistically significant. Buoys that do have significant trends are ones with a reduction in rogue wave occurrence: −1.3% y−1 at Cape Mendocino, CA.; −1.6% y−1 at Santa Monica Bay, CA.; and −1% y−1 at Dana Point CA. (Fig. 3).

Figure 3

Trends in rogue wave occurrence (green), Excess Abnormality Index (Excess AI; blue), and rogue wave height (yellow), as a percentage of the mean value of the time series. Empty and half-filled circles indicate the 90th and 95th significance levels, respectively, as determined by a seasonal Mann-Kendall test.

We have discussed the trends in occurrence of rogue waves, but the temporal variability of the size of the rogue waves is unknown and is important in determining their impact on the coastal marine industry. The Abnormality Index (AI) gives a useful metric for how large a rogue is with respect to the background sea (see Methods). Here we investigate the excess AI, defined as {(HrogueHs)2}{(HrogueHs)−2} for a wave height rogue, or {(CrrogueHs)1.25}{(CrrogueHs)−1.25} for a crest height rogue. Most buoys show minimal change in excess AI, but Grays Harbor, WA. and Diablo Canyon, CA. show statistically significant increases over time of greater than 1% y−1 (Blue bars – Fig. 3). At these locations rogue waves are getting monotonically larger with time, relative to the background sea (Hs), and therefore more hazardous to maritime industry at Grays harbor, and coastal infrastructure such as the nuclear power plant at Diablo Canyon. There is however, minimal temporal variability in the absolute height of rogue waves (Yellow bars – Fig. 3). As a percentage of the mean rogue wave height, trends are all less than 0.02% y−1.

The frequency and intensity of the weather systems in the region are connected to the Aleutian Low5,18, and indirectly to the El Niño Southern Oscillation (ENSO)19 and the Arctic Oscillation20. Signals of increased Hs and Tp during the 1997–1998 and 2015–2016 El Niño years are seen in the dataset, and previous analyses21. However, we find no discernible link between the interannual variations in rogue wave occurrence and climate variability indices.

The analysis is aimed at assessing the interannual variability of rogue waves and determining monotonic linear trends over the wave buoy observational period. It does not necessarily indicate that the trends are a result of global climate change as interannual climate variations have long-term oscillations that will influence the wave climate on a longer time scale than the data record presented here. Furthermore, the length of this dataset is too short to differentiate a steady trend from an accelerating trend.

Seasonal Intensification of Rogue Waves

The only previous research on seasonality showed an increase in rogue wave occurrence in the both summer and winter16. In contrast., we find that rogue waves are more prevalent in the winter months (December-January-February, blue – Fig. 4A) than summer (June-July-August, red). Grays Harbor, WA. and Goleta Point, CA. have almost double the probability of rogue wave occurrence in winter compared to summer. The exceptions are the buoys with the lowest wave energy, Dana Point, CA., and Oceanside CA. The contrast to previous findings is possibly due to a different choice of rogue wave definition and analysis approach, differing record lengths and the inclusion of buoys from different regions, as compared to Imai (2010)16. Our analysis shows the need to determine seasonal occurrence statistics for individual rogue waves rather than just annual averages.

Figure 4

Mean Winter (blue) and Summer (red) values for each buoy, from north to south, for (A) the rogue wave occurrence, (B) rogue wave height, (C) Abnormality Index (AI), and (D) spectral bandwidth parameter Nu. Error bars denote two standard error about the mean.

Winter also yields larger rogue waves than summer (Fig. 4B), with exposed northern locations displaying the largest seasonal variation, with almost a 2 m variation in average seasonal height at Cape Mendocino. In contrast, rogue waves in the sheltered locations of the Southern Californian Bight have a seasonal variation in height of less than 0.5 m. Seasonality in the absolute height of rogue waves is expected because rogue wave height is a function of Hs, which is well known to vary seasonally. During boreal spring and summer, high atmospheric pressure dominates and the waves are forced by north-westerly winds and storms in the southern hemisphere, resulting in lower wave energy conditions17,18,22. Outside of this, the wave climatology is dominated by mid-latitude North Pacific extra-tropical cyclones, Eastern Pacific tropical storms, and local winds22,23,24,25,26, resulting in large seas, dominated by swell22,27. Thus, greater seasonality can be seen at exposed and swell dominated locations, and the distribution of rogue wave height across the region mirrors that of Hs (Supplementary Table S1).

Excess AI gives an indicator of the size of the rogues compared to Hs and hence unaffected by seasonality in Hs. Half the buoys locations show statistically significant seasonality in Excess AI (Fig. 4C), revealing rogue waves to be ‘more rogue’ during the winter months than during the summer. There are therefore a greater number of rogue waves in winter, and those waves are more severe. The cause of this seasonality may be related to the variation of spectral bandwidth (Fig. 4D), which displays clear seasonality across the region, with bandwidth increasing in the winter months. This mirrors the seasonal distribution in seasonal rogue wave occurrence (Fig. 4A), and seasonal excess AI (Fig. 4C). Previous work has shown a rogue waves occur in seas with a large spectral bandwidth8,28. A regression of spectral bandwidth trend and rogue wave occurrence trend for each of the buoy locations displays a linear relationship between decreasing rogue wave occurrence and decreasing bandwidth.


The interannual variability of monthly binned significant wave heights in the US western seaboard shows weak decreasing trends in the mean. In line with previous studies, the magnitude and significance of the trend increased at higher percentiles of Hs, but the present analysis indicates high spatial variability in the trend’s magnitude and sign throughout the region. For the first time, we show that rogue waves have interannual temporal variability, and the magnitude and sign of the trend varies over the region, with only the Southern Californian Bight showing a consistent negative trend, and is likely a reflection of the physical complexity of the region. Some locations show that the rogues are getting larger relative to the background sea; however, there is no trend in absolute rogue wave height. However, on a seasonal scale, rogue waves show intensification, with rogues being more prevalent and more severe in the winter than the summer. This is likely due to the increase in spectral bandwidth in the winter. The analysis demonstrates that if statistics of rogue waves are to prove useful for shipping and offshore operations, they must account for spatial and temporal variability on seasonal and interannual timescales, rather than simply relying on a single value for an entire region for all times.

Material and Methods

Observational data

To perform rogue wave analysis, the individual wave height (h) of each wave needs to be known, as well as the significant wave height (Hs) of the sea over the standard analysis period of 20-minutes. Individual wave height can be calculated both from fixed platforms and surface following wave buoys. Fixed platforms use visual or acoustic methods of estimating the distance from a fixed point to the free surface, and are subject to inaccuracies due to spray and wave interactions with the structure. Wave buoys are neutrally buoyant and track the free surface and measure wave height using accelerometers. They are subject to inaccuracies due to the restoring force of the mooring so potentially avoiding the true peak of the wave. Here we chose to use wave buoys due to their broad distribution across the region, public data accessibility, and unparalleled continuity of measurement. The majority of wave buoys deployed globally calculate sea state statistics onboard, and do not store the raw surface elevation. As a result, time-series of rogue waves are limited in duration and count to those buoys that do store the raw surface elevation (η). The Coastal Data Information Program (CDIP), operated by Scripps Institution of Oceanography, manages a portfolio of wave buoys around the coastlines of the United States and its overseas dependencies. Of these, 15 have a raw surface elevation data duration of at least 10 years and are located in the US western seaboard (Supplementary Table S1). The buoys use accelerometers to measure waves with periods of 1.6–30 s and wave heights up to 40 m with a vertical resolution of 0.01 m.

Calculating sea state parameters

The data obtained from the buoys is a time series of vertical displacement sampled at a rate of 3.84 Hz but logged at a sampling frequency of 1.28 Hz.

This is split into non-overlapping 20-minute seas, and the sea state parameters are calculated, as outlined in Cattrell et al.8. In situ measurements require substantial quality control (QC), we perform a strict QC procedure, as outlined in Cattrell et al.8, to obtain a reliable dataset.

Seas are flagged as rogue if they contain a wave or crest height that exceeds a threshold in relation to the significant wave height (Hs)14:




where Hmax is the maximum zero-crossing wave height, Crmax is the maximum crest height, and Hs is the significant wave height, estimated as four times the standard deviation of the sea surface elevation from a 20-minute observation period.

The Abnormality Index (AI) gives a metric to the severity of the rogue waves:


For ease of interpretation we normalise the AI and examine the excess AI:


Spectral bandwidth can be an indicator of the strength of nonlinear focusing29 and the spectral bandwidth parameter ν is calculated from the moments of the spectrum:


where S(f) is the non-directional energy density spectrum, with Hs=4m0−−−√Hs=4m0 .


where m0, m1, and m2 are the zeroth-, first-, and second-order spectral moments, respectively, calculated from Eq. 5.

For narrow bandwidths ν tends to zero, and the wave energy is concentrated near the spectral peak frequency, as individual waves have similar frequency with differing amplitudes modulated by the wave envelope. Values of ν approaching 1 are due to a broad spectrum, with wave energy distributed over a wide spread of frequencies.

Correcting for changes in buoy type

Over time, the buoys deployed at each of the 15 locations were upgraded; however, the hull-form and mass of the buoys remains constant, and hence their response to the wave field. The accelerometry also remain constant, and the recorded response is the same across the entire time series. As the buoys were upgraded from the MK1 to the MK2, and then to the MK3 over the course of the time series, there is a change in sample completeness. This results from the MK1 using a shore-based data receiver, whereas the MK2 onwards had on-board data loggers. As with all rare event sampling, rogue wave detection is a function of sampling time; therefore, the rogue wave occurrence count needs to be normalised as a function of sampling.


Estimation of the trend

The aim is to determine the magnitude of a monotonic trend and whether it is statistically significant. A Theil-Sen estimator, an unbiased estimator of the slope in a linear regression, is displayed on the time series of monthly mean resampled data to indicate the trend. The Mann-Kendall (MK) test is a non-parametric test of randomness against trend30,31. The presence of a monotonic trend and significance level was assessed using a seasonal MK test, which has been extensively utilised in hydrology research, and was deemed to be the most accurate for assessing trends in the wave data3.

The seasonal MK test runs a MK test on each season individually (Boreal Winter: November-January; Spring: February–April; Summer: May–July; Autumn: August–October). The overall statistic is calculated from summing each of the season’s MK statistic. Statistical significance at the 90th, 95th, and 99th percent level was determined with a two-sided p-value of the overall statistic, less than 0.1, 0.05, and 0.01, respectively. Further sensitivity analysis using bootstrapping is detailed and presented in Supplementary Tables S2 and S3.

Links with teleconnections

Taking the mean percentage rogue wave occurrence for each season for each year, and plotting against the Multivariate ENSO Index (MEI21); yields no relationship32.


  1. 1.

    Gulev, S. K. & Grigorieva, V. Last century changes in ocean wind wave height from global visual wave data. Geophys. Res. Lett. 31, 1–4 (2004).

  2. 2.

    Tokinaga, H. & Xie, S. P. Wave- and Anemometer-based sea surface wind (WASWind) for climate change analysis. J. Clim. 24, 267–285 (2011).

  3. 3.

    Young, I. R., Zieger, S. & Babanin, A. V. Global trends in wind speed and wave height. Science (80-.). 332, 451–5 (2011).

  4. 4.

    Gemmrich, J., Thomas, B. & Bouchard, R. Observational changes and trends in northeast Pacific wave records. Geophys. Res. Lett. 38 (2011).

  5. 5.

    Wang, X. L. & Swail, V. R. Changes of extreme Wave Heights in northern Hemisphere Oceans and related atmospheric circulation regimes. J. Clim. 14, 2204–2221 (2001).

  6. 6.

    Sasaki, Y. N., Minobe, S. & Miura, Y. Decadal sea-level variability along the coast of Japan in response to ocean circulation changes. J. Geophys. Res. Ocean. 119, 266–275 (2014).

  7. 7.

    Baschek, B. & Imai, J. Rogue Wave Observations Off the US West Coast. Oceangraphy 24, 158–165 (2011).

  8. 8.

    Cattrell, A., Srokosz, M., Moat, B. & Marsh, R. Can rogue waves be predicted using characteristic wave parameters? J. Geophys. Res. Ocean. (2018).

  9. 9.

    U.S. Department of Transportation: Maritime Administration. U.S. Waterborne Foreign Trade by U.S. Customs Ports 2000–2015. Online (2015). Available at: https://www.marad.dot.gov/wp-content/uploads/xlsx/DS_ContainerPorts_00to15.xlsx. (Accessed: 7th May 2018).

  10. 10.

    OSPR. Oil Platforms. Available at: https://map.dfg.ca.gov/metadata/ds0357.html. (Accessed: 8th May 2018) (2007).

  11. 11.

    Nikolkina, I. & Didenkulova, I. Rogue waves in 2006–2010. Nat. Hazards Earth Syst. Sci. 11, 2913–2924 (2011).

  12. 12.

    Fedele, F., Lugni, C. & Chawla, A. The sinking of the El Faro: Predicting real world rogue waves during Hurricane Joaquin. Sci. Rep. 7 (2017).

  13. 13.

    Kharif, C., Pelinovsky, E. & Slunyaev, A. Rogue Waves in the Ocean. Advances in Geophysical and Environmental Mechanics and Mathematics, https://doi.org/10.1017/CBO9781107415324.004 (Springer-Verlag, 2009).

  14. 14.

    Haver, S. Evidences of the Existence of Freak Waves. In Rogues Waves 2000 (2000).

  15. 15.

    Benetazzo, A. et al. On the shape and likelihood of oceanic rogue waves. Sci. Rep. 7 (2017).

  16. 16.

    Imai, J. Rogue Ocean Wave Observations. Thesis, (California State University, 2010).

  17. 17.

    Hemer, M. A., Fan, Y., Mori, N., Semedo, A. & Wang, X. L. Projected changes in wave climate from a multi-model ensemble. Nat. Clim. Chang. 3, 471–476 (2013).

  18. 18.

    Graham, N. E. & Diaz, H. F. Evidence for intensification of North Pacific winter cyclones since 1948. Bull. Am. Meteorol. Soc. 82, 1869–1893 (2001).

  19. 19.

    Allan, J. C. & Komar, P. D. Climate Controls on US West Coast Erosion Processes. J. Coast. Res. 223, 511–529 (2006).

  20. 20.

    Thompson, D. W. J. & Wallace, J. M. The Arctic oscillation signature in the wintertime geopotential height and temperature fields. Geophys. Res. Lett. 25, 1297–1300 (1998).

  21. 21.

    Barnard, P. L. et al. Extreme oceanographic forcing and coastal response due to the 2015-2016 El Niño. Nat. Commun. 8 (2017).

  22. 22.

    Bromirski, P. D., Cayan, D. R. & Flick, R. E. Wave spectral energy variability in the northeast Pacific. J. Geophys. Res. C Ocean. 110, 1–15 (2005).

  23. 23.

    Adams, P. N., Inman, D. L. & Graham, N. E. Southern California Deep-Water Wave Climate: Characterization and Application to Coastal Processes. J. Coast. Res. 244, 1022–1035 (2008).

  24. 24.

    Alves, J. H. G. M. Numerical modeling of ocean swell contributions to the global wind-wave climate. Ocean Model. 11, 98–122 (2006).

  25. 25.

    Fan, Y., Lin, S.-J., Held, I. M., Yu, Z. & Tolman, H. L. Global Ocean Surface Wave Simulation Using a Coupled Atmosphere–Wave Model. J. Clim. 25, 6233–6252 (2012).

  26. 26.

    Shimura, T., Mori, N. & Mase, H. Ocean waves and teleconnection patterns in the northern hemisphere. J. Clim. 26, 8654–8670 (2013).

  27. 27.

    Bromirski, P. D., Cayan, D. R., Helly, J. & Wittmann, P. Wave power variability and trends across the North Pacific. J. Geophys. Res. Ocean. 118, 6329–6348 (2013).

  28. 28.

    Fedele, F., Brennan, J., Ponce De León, S., Dudley, J. & Dias, F. Real world ocean rogue waves explained without the modulational instability. Sci. Rep. 6 (2016).

  29. 29.

    Janssen, P. Nonlinear Four-Wave Interactions and Freak Waves. J. Phys. Oceanogr. 33, 863–884 (2003).

  30. 30.

    Kendall, M. G. Rank Correlation Methods (1948).

  31. 31.

    Sen, P. K. Estimates of the Regression Coefficient Based on Kendall’s Tau. J. Am. Stat. Assoc. 63, 1379–1389 (1968).

  32. 32.

    NOAA. NOAA MEI. Online (2018). Available at: https://www.esrl.noaa.gov/psd/enso/mei/. (Accessed: 14th March 2018).

Download references


We thank James Behrens and Datawell for discussions regarding the temporal analysis of Waverider buoy data. This project is partially supported by the Lloyd’s Register Foundation; further funding was supplied through the Southampton Marine and Maritime Institute at the University of Southampton, and the Engineering and Physical Sciences Research Council (EPSRC). B.M. was supported by the NERC funded Project ACSIS. The wave data were provided by, and freely available from, the Coastal Data Information Program (CDIP), Integrative Oceanography Division, operated by the Scripps Institution of Oceanography, under the sponsorship of the US Army Corps of Engineers and the California Department of Boating and Waterways. Data accessible at: http://thredds.cdip.ucsd.edu/thredds/catalog/cdip/archive/catalog.html.

Author information

A.C. conducted the formal analysis and writing of the original draft, M.S. and B.I.M. provided critical feedback and helped shape the research, analysis and manuscript, R.M. supervised the project provided critical feedback on the manuscript

About Royal Rosamond Press

I am an artist, a writer, and a theologian.
This entry was posted in Uncategorized. Bookmark the permalink.

1 Response to A Seasonal Rogue Wave

  1. Reblogged this on Rosamond Press and commented:

    This is the crux of my book, along with the lies pubished on the emowerment group. Those lies are proof there is a cover-up, because I suspect Hather and Stage Mommy have kept in touch with MY family.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.