Was the 'Rainmaker' responsible for San Diego's worst floods in history?

[zoobyshoe]

In 1915, after four years of drought, the San Diego City Council decided to hire local "rainmaker" Charles M. Hatfield who promised to fill the Morena reservoir for a fee of $10,000.00. After he got to work in Jan. 1916, San Diego suffered the worst floods in its recorded history.

Address:http://www.hatfieldrain.com/name.html

The musical and the film with Burt Lancaster are based on these true events.

Lucky coicidence? Or did he make it rain?

 

[Ivan Seeking]

Very interesting Zooby. I have never heard about this story...other than the movie which I had no idea was based on real events. As a guess I would say that it was luck.

Some links:

---Cloud Seeding Frequently Asked Questions---

Cloud seeding (also known as weather modification) is the deliberate treatment of certain clouds or cloud systems with the intent of affecting the precipitation process(es) within those clouds. Application of this technology is increasing world-wide. This page addresses some key questions relating to cloud seeding and its practical uses. References are provided at the end of this document keyed to numbers at the end of the highlighted topics.


When did application of modern cloud seeding technology begin?


Attempts to modify the weather have been conducted for centuries. However, modern cloud seeding dates from the late 1940's, springing from a discovery at the General Electric labs in Schenectady, New York in 1946. The ability of dry ice shavings to convert supercooled water droplets (those existing as water at temperatures colder than freezing) to ice crystals was observed during the conduct of an unrelated experiment. Later consideration of those observations led to a series of laboratory trials which demonstrated the nucleating properties of various materials in certain cold cloud conditions. Trials in the atmosphere soon followed, and operational cloud seeding programs began in about 1950.

Reference: 1, 2.



What are the most common applications of cloud seeding technology?


The most common intended effects of cloud seeding include precipitation increase (rain and/or snow), fog dispersal (visibility improvement) and hail suppression. Of these, the majority of operational projects focus on precipitation increase.

Reference: 1, 2.




Is cloud seeding effective?


Trials conducted by various researchers under laboratory conditions have documented the effects of cloud seeding materials. Numerous scientific experiments have been conducted to investigate/demonstrate the effects produced by cloud seeding in the atmosphere on various cloud types in a variety of climatic regions. Evaluations (usually statistical) have been made of many operational programs. The results of many of these efforts have been published in the scientific literature and in industry journals.

Summarizing the collective evidence from the various studies and operational projects, Capability Statements have been published by the Weather Modification Association, the American Meteorological Society and the World Meteorological Organization. For precipitation augmentation, the accepted magnitude of increase to be expected from well-designed and properly conducted projects ranges from 5% to 20% for winter precipitation in continental regions and from 5% to 30% for coastal areas. For warm season precipitation increase, single-cloud experiments have indicated increases as large as 100%. Area wide increases over a project area vary with the frequency of occurrence and spatial coverage of suitable cloud systems, plus the ability to treat all favorable clouds. Hail suppression effectiveness, based upon surface hail data, is estimated to be in the range of a 20-50% reduction.

Reference: 3.



Who conducts cloud seeding activities?


The large majority of cloud seeding projects are conducted by a handful of highly specialized commercial firms, working under contract to a variety of sponsors. Some water agencies and hydroelectric power generation companies conduct their own programs. Researchers continue to conduct occasional trials within carefully designed and controlled experimental projects, striving to better understand the various in-cloud effects of cloud seeding, and to refine quantitative estimates of cloud seeding effectiveness.

Reference: 4.

[continued]

http://www.nawcinc.com/wmfaq.html

Seeding of tropical cumulus clouds, and indeed any clouds, requires that they contain supercooled water--that is, liquid water colder than zero Celsius. Introduction of a substance, such as silver iodide, that has a crystalline structure similar to that of ice will induce freezing. In mid-latitude clouds, the usual seeding strategy has been based upon the vapor pressure being lower over water than over ice. When ice particles form in supercooled clouds, they grow at the expense of liquid droplets and become heavy enough to fall as rain from clouds that otherwise would produce none.

Seeding of tropical cumuli sought to exploit the latent heat released by freezing as well. This strategy of "dynamic seeding" assumed that the additional latent heat would add buoyancy, strengthen the updrafts, ensure more low-level convergence, and ultimately cause explosive growth of properly selected cumuli.

The above sketch illustrates an aircraft dispensing pyrotechnics doped with silver iodide into a supercooled cloud that is invigorated by the latent heat released as the boundary between liquid and frozen hydrometeors (blue horizontal line in the cloud on the left) moves down to the zero Celsius isotherm (green horizontal line). It was this transformation that the experimenters hoped to use for construction of an artificial outer eyewall during Project STORMFURY.

http://www.aoml.noaa.gov/hrd/nhurr97/CSEED.HTM

Introduction
The purpose of this paper is to update the findings and concepts summarized in Human Impacts on Weather and Climate by Cotton and Pielke (1995). In that book we describe the concepts related to purposeful weather modification by cloud seeding, inadvertent modification of weather and climate on regional scales, and human impacts on global climate change...

... In this paper I will focus only on three methods of seeding clouds. The first two are related to supercooled clouds and are called the ``static mode'' of cloud seeding and the ``dynamic mode'' of cloud seeding. The third method is the modification of warm clouds by hygroscopic seeding.

http://rams.atmos.colostate.edu/gkss.html

 

[zoobyshoe]

So when you say you suspect he was lucky, do you mean you suspect he accidently seeded the clouds?

 

[jimmy p]

If only Iron Maiden had released the song sooner...

 

[Ivan Seeking]

Originally posted by zoobyshoe
So when you say you suspect he was lucky, do you mean you suspect he accidently seeded the clouds?

No, my first impression is that it must be a complete coincidence. I don't see how he could have done much of significance...just not enough mass released to be of use. Of course, if the atmosphere was supersaturated, if such a thing happens, I guess that in some way he might be the straw that broke the camel's back. Again though, from what little I know about this, the mass concentrations required to seed clouds seems to rule out all claims like this.

 

[zoobyshoe]

January and February are San Diego's typical rainy season. After four years of drought, I would suspect he was simply banking on a natural and inevitable return to normal weather for this time of year when he agreed to take this job. His talent most likely consisted of a good sense of when a drought was going to break naturally, and in only taking jobs where he assessed the chances to be in his favor.

The Mandan Indian rain ritual, it was noted by white visitors to that tribe, had a 100% success rate. The reason was: once started it would never be stopped, going on day after day, even into weeks, until it rained. It would be interesting to find out the length of time Hatfield had to spend on his previous "successes" before it rained. Did it always start as soon as it did in San Diego, or were there times he was at it for weeks before it started?