FEMA's Outdated Flood Zone Maps 21

[Oops409]

Only 3% of residents in Asheville, NC, for example, had flood insurance, according to an article I read. Looking at FEMA's Flood Maps, it is understandable why residents would not have flood insurance.

FEMA flood maps will need to be updated to reflect modern risks, and risks due to more and more urbanization and growth since maps were developed, along with whatever weather cycles we are now experiencing.

Marion, NC below

https://hazards-fema.maps.arcgis.co...655413029,-82.5308610411255,35.60463469500095

 

[FacEngrPE]

If cloud seeding a hurricane is successful, the rainfall rate would increase.
Condensing water vapor to rain liberates heat. Hurricanes are heat engines. So does seeding a hurricane make it stronger or weaker?

 

[IRstuff]

Condensing water vapor to rain liberates heat.

It's unclear how much of a hurricane is still water vapor; the fact that you can see clouds in a hurricane suggests that there are already plenty of water droplets in the storm. Moreover, given sustained winds in excess of 90 mph, it's unclear whether seeding would do much of anything, since there should already be tons of water droplets in the storm that can help with nucleation, assuming you could even dump enough of anything that would make a noticeable dent in the storm system.



TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[3DDave]

Interesting video tying weather control to hurricanes.

Never knew the link between Kurt Vonnegut and rain cloud seeding.

Can the Government Control Hurricanes?

 

[TugboatEng]

As engineers, does anyone find it disappointing that NASA's scientists think kJ/cm² is a measurement of heat content?

https://science.nasa.gov/earth/clim...nature-hurricanes-in-a-changing-climate/?s=09

Anywhoo, we know the heat brings the moisture the atmosphere but it's the cold air that intensifies the storm into a hurricane.

https://nhmu.utah.edu/sites/default/files/attachments/All About Hurricanes.pdf

A general warming of the earth should reduce the intensity of hurricanes.

 

[3DDave]

Generally warming the Earth increases the vertical temperature gradient, which is what drives hurricanes.

A parallel is adding heat to a pot of water - does the water become more turbulent or less turbulent? Does the water vapor become stable as the room temperature rises?

As engineers, does anyone find it disappointing that NASA's scientists think kJ/cm² is a measurement of heat content?

Is there context for that?

 

[dik]

The warming of the water (Oceans) increases that and adds more water vapour, rapidly increasing the intensity of the hurricanes.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

in the UK?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[TugboatEng]

Sorry, it was NPR that doesn't know the difference between rate and total. The NASA article provided no data whatsoever.

This one is claiming kJ/cm² is measurement of heat.

https://www.npr.org/2024/10/08/nx-s1-5143320/hurricanes-climate-change

 

[TugboatEng]

Dik, what causes wind to blow? I assume you know so what creates the density difference? How does insulation lead to higher temperature differentials?

 

[3DDave]

That is a sensible measure to use because the transfer is across the 2 dimensional surface between the water and the air above it. It represents the energy available per square centimeter at that interface.

https://en.wikipedia.org/wiki/Ocean_heat_content#Definition

 

[TugboatEng]

The depth of every measurement is infinitely higher than depth of the surface area so the errors will be extremely infinite. If you can't see this you're blinded by politics.

 

[3DDave]

It's basic oceanographic methodology and heat transfer. It's a measure of the ocean thermal storage as viewed at the heat transfer surface. They aren't taking a core sample that is 1 cm^2 and a mile deep. It condenses a complicated thermal profile into how much energy is stored under some averaged 1 cm^2.

Drop a recording thermometer with a depth sensor into the ocean and integrate the area under the graph. As that profile applies to a huge area it can be normalized to 1 cm^2. Where does the infinite error come from?

As far as I know integration and normalization are mathematics and not politics.

 

[1503-44]

Infinite depth? No. It's surface area. Heat content contained in a unit volume below the surface is the only heat available that can transfer across the air/surface interface. J/m3 becomes J/m2 when it is transferred at the interface. Once some heat is removed from a unit volume of surface water, it sinks and warmer water in the adjacent parcel moves over to replace it.

"A general warming of the earth should reduce the intensity of hurricanes." Why?

More heat increases available power. Even though the temperature gradient above may not be as steep, cold air at some altitude is there, as is the reduced pressure that will also cause the parcel of air to cool, even if you do not allow heat exchange with the next parcel. As humid air is less dense to begin with and the rate of cooling of humid air is less than dry air, a parcel of warm air will remain unstable moving upwards and, once displaced upward, will displace denser cool air above. The warmer the warm air is will only increase circulation velocity. It may only have to overcome reaching a greater altitude to cool to condensation temperature. If the warm air is 5°C hotter than previous years, it only needs 500 to 1000m more altitude to reach condensation temperature. Latent heat released from condensation then kicks it higher. Off to the races.
LAPSE RATE

https://en.m.wikipedia.org/wiki/Lapse_rate

The higher circulation additionally increases heat transfer rate and evaporation.
I do not see any decreasing cause-effect that a higher general earth/sea temperature would produce.

The Utah hurricane pdf got me thinking about the Coriolis effect (it is not a force). They say that within 5° of the equator it is too weak to cause rotation and kick off a hurricane. I do not believe it is weakness of the Coriolis effect that is to blame. Actually that is maximum at the equator. What causes a net weakness if you want to use those terms is that, if any rotation does try to develop, it is in one direction on the north latitude side and the opposing direction on the south side. Net effect is that no rotation develops at all, even though the effect is at maximums.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[dik]

only used car salesmen, mathematicians, astronomers, and politicians use 'infinitely'.
-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[1503-44]

It's in both the mathematician's and astronomer's dictionary too, although astronomers used to think it was a whole lot shorter.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[TugboatEng]

It's basic oceanographic methodology and heat transfer. It's a measure of the ocean thermal storage as viewed at the heat transfer surface.

We can call it what it is, flux. No need to be so wordy. Flux is not a measurement of heat content. Why does NASA, a supposedly respected organization, not know this?


And no, integrating surface flux over depth does not provide any useful information.

 

[3DDave]

It's not flux. Flux is the rate of heat transfer. This is the amount of heat that is stored under that 1 cm^2.

I can edit too -

The integration is of each cc under that 1 cm^2 to get the heat contained in the column.

 

[TugboatEng]

How do you know how much heat is stored in the column without a column height?

 

[1503-44]

Flux would be the heat transferred through the interface. They were only talking about the heat available at the interface. To get the flux, the heat available must be multiplied by the heat transfer coefficient of the water-to-air interface.

Air-Sea Flux

https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2019.00430/full

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[3DDave]

They lower a thermometer to measure and record the temp and the depth as far down as needed. That provides a temperature profile. Integrating that temperature profile vs depth is an indication of the heat stored in that column of water.