Contrails to Steer or De-energize Hurricanes

[Harry Anastopoulos]

I have had this theory bouncing around in my head since 9/11 and I would like someone's feedback.

It was a published fact that grounding air traffic in the United States in the days following the 9/11 attacks made a significant measurable impact on North American continental temperatures.  I believe average temperatures rose by over 1 degree Celsius due to the lack of the the artificial "clouds".

What would happen if a country sent a small fleet of aircraft to deliberately create contrails to shield the oceanic waters from sun light leading up to the approach of a hurricane?  I have read that every degree of ocean temperature can make a 10-20 mph difference in hurricane airspeed.  It is also published that cloud cover during the day blocks solar radiation, but cloud cover at night creates a blanketing effect to retain solar heat.  Such a plan would have to retain the contrails during daylight hours and allow them to dissipate during the evening to allow heat to otherwise escape back into the atmosphere.

Couldn't this be a low-cost approach to de-energize a hurricane or also even potentially create a steering effect away from more populated areas?

These comments are not related to the terraforming plans that others have come up with more recently to combat climate change by blocking the sun.  I think about this every time I hear news reports that a storm is expected to strengthen as it hits the warm open waters of the Gulf Of Mexico.

 

 

[swansont]

Aren’t hurricanes driven by the ocean temperature, which is not going to be affected much in the short term by more clouds?

[TheVat]

4 hours ago, Harry Anastopoulos said:

It was a published fact that grounding air traffic in the United States in the days following the 9/11 attacks made a significant measurable impact on North American continental temperatures. 

Fact?  No.  In climatology, short term fluctuations are not much use as data.  The brief temperature rise could have been from other causes.  Contrails do sometimes persist as cirrus clouds, sometimes called cirrus aviaticus, but the research I've seen finds little clearcut effect on overall radiative forcing (climatology lingo for net atmospheric heat gain from trapping outgoing longwave radiation).  

The science is not even there yet on how the radiative forcing might be increased at night by clouds formed by jet condensation nuclei, let alone how nighttime RF balances with daytime cooling.  This paper can give some idea of where the research was going a few years back.

http://ui.adsabs.harvard.edu/abs/2009AtmEn..43.3520L/abstract

A key comment from the abstract:

The lack of physical process models and adequate observational data for aviation-induced cirrus effects limit confidence in quantifying their RF contribution....

 

 

Edited August 7 by TheVat
addend

[DeepBlueSouth]

[apologies {to everyone}, I did not expect this to be my first post... but for once; between education and experience, I do actually feel well in hand to weigh in here....]

having been born and raised in New Orleans, tropical cyclones have always been of particular cultural and personal significance for me. that being said, OP, your hypothesis has been speculated upon in the past, the results of which nearly led to a [quite rare] lawsuit against the US military for the first known attempt at tropical system modification in late 1947:

Quote

from Project Stormfury - Wiki:  Project Cirrus was the first attempt to modify a hurricane. It was a collaboration of the General Electric Corporation, the US Army Signal Corps, the Office of Naval Research, and the US Air Force.^[1] After several preparations and initial skepticism by government scientists,^[6] the first attempt to modify a hurricane began on October 13, 1947 on Hurricane Cape Sable that was heading west to east and out to sea.^[5]

The project's two B-17s and a B-29 of the 53rd Weather Reconnaissance group were dispatched from MacDill Field, Florida, to intercept the hurricane.^[7] The seeding B-17 flew along the rainbands of the hurricane, and dropped nearly 180 pounds (82 kilograms) of crushed dry ice into the clouds.^[1] The crew reported "Pronounced modification of the cloud deck seeded".^[5] It is not known if that was due to the seeding. Next, the hurricane changed direction and made landfall near Savannah, Georgia. The public blamed the seeding, and Irving Langmuir claimed that the reversal had been caused by human intervention.^[6] Cirrus was canceled,^[5] and lawsuits were threatened. Only the fact that a system in 1906 had taken a similar path, as well as evidence showing that the storm had already begun to turn when seeding began, ended the litigation.^[5] This disaster set back the cause of seeding hurricanes for eleven years.

At first the seeding was officially denied and it took years before the government admitted it. According to the September 12, 1965 edition of the Fort Lauderdale News and Sun-Sentinel, in 1947 a hurricane "went whacky" and "Twelve years later it was admitted the storm had in fact been seeded."^[8]

now I am not familiar with any specific concrete measure of how each degree of sea level surface temperature may impact a storm's wind speed in tens of miles per hour [presumably you mean measured as Celsius, this being a science forum...? those suggested numbers mentioned seem pretty bold otherwise.] however you are correct in the statement about the sunlight reflectivity of high cloud as well as its surface heat retention in the evening hours impacting the temperature in a specific region, on land leastways. I am unsure how this phenomena repeats over large bodies of water, much less "the Gulf" or the Atlantic. it is not uncommon for both of these regions to be populated by a great deal of high barometric pressure in summer and early meteorological autumn, which does indeed lead to calm, clear, sunny, and [during these seasons in these regions] HOT weather; veritable proving grounds for tropical cyclones over open water.

a side note about the measure of tropical cyclone strength here: the NOAA; as well as other private and government entities studying and warning folks of major weather events; are working towards moving away from the historic bellwether of the Saffir-Simpson Scale; which heavily relied upon wind speed as measure of a storm's potential. most damage and fatalities of any system are caused primarily by storm surge and rainfall induced flooding. [the more well known Fujita scale for tornadic cyclone strength measurement has also been similarly updated to the Enhanced Fujita scale, hence F3 or F1 in the 20th century being worked into EF3 or EF1 tornadic cyclones, etc.]

many factors beyond just ambient air or sea level surface temperatures impact the formation and cultivation of tropical cyclones; sometimes their paths, storm surge heights, rainfall totals, speed of motions, and of course peak wind speeds [sustained and gusts] can be impacted by variables which are not considered at time of forecasts. in the case of the misbegotten Project Cirrus, an unreported pressure gradient recorded at sea was cited as scientific evidence [in court, no less] of the natural forces which contributed the storm's turn into the Savannah, GA region. also such an event had happened before, and thus likely could in the future, direct human interaction notwithstanding.

Swansont is also correct here, storm strength intensification, including the most feared RAPID intensification, is quite common even at night. high sea level surface temperatures, lack of wind shear, and ambient humidity itself are the three legs of a hypothetical stool upon which a strong tropical cyclone must rest. take away one of these, and the storm will most certainly weaken [or cease to intensify before landfall leastways].

thanks for the citation, TheVat! I look forward to reading that later on tonight. there has been much speculation [keyword... speculation] over the years about what other methods might be employed to control them [or simply weaken or dissipate them], ranging from scientists' proposals to those of military leaders and even that one president; with varying degrees of ridiculousness, so I will not mention them here. HOWEVER, they're a fun read if atmospheric sciences are of interest!

the best thing to do to avoid the impact of hurricanes is to do what I did, hard as it seems, I just moved inland, away from ANY water which could rise to dangerous levels. if my property floods, we're ALL in a lot of trouble, my losses would be pointless to consider. without the formation of glacial lakes upon local plateaus, the nearby creek nor the Tennessee River herself couldn't ever flood their banks this much, even during the worst rain events possible [I have witnessed both of these in under 20 years here, as well as both worst droughts, several tornadoes {including a direct strike from an EF0} and yes, even several tropical cyclones this far inland. something something human induced climate something]

[*oho, my Fortean side makes an appearance, tread carefully] Fidel Castro felt that Project Stormfury was an attempt to steer hurricanes [presumably into Cuba], although he cited no evidence. many fellow Gulf Coast refugees I have known over the years argue tooth and nail that the [US] government has been "creating and controlling hurricanes" for many years now, though their evidence is presumably of the same source as Fidel Castro's. most of them have told me they feel the motive for using them against the mainland US is "for the insurance money". I woefully inform them that I am unsure whether they're less acquainted with how our atmosphere works, or how property insurance works [particularly after a major hurricane].

Michio Kaku, among other accomplished scientifically-literate futurists [e.g real, actual scientists; not autodidactic corporate officers who never show their work], have made it abundantly clear that we are more likely some 1000 years away from generating even a small thunderstorm, much less creating and controlling something as tremendously powerful as a major tropical cyclone.

[LaurieAG]

Probably better off using re entering space junk. Between the mid 1960's and the mid 1970's the central east coast of Australia had things called 'Cyclone banks' which were sand banks in the ocean that were 100 meters or so out from the normal beach break sandbanks which usually only broke (10 foot + waves) during cyclones. If you had started surfing there around 50 years ago you would know them well. After the mid 1970's they disappeared and haven't really come back yet, mainly due to sand dredging/bypass operations at two main river mouths since. Back then it was only the Apollo program that would dump stage 3 rocket boosters in the eastern pacific but now with China, the US and a couple of other countries having active space programs who knows.