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FEMA's Outdated Flood Zone Maps 21

Oops409

Mechanical
Apr 25, 2024
193
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.

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Marion, NC below

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NASA hangs a thermometer from a satellite all of the way to the ocean?
 
NOAA does.

I feel like I'm missing the context of the complaint and the thread of research that got there.
 
A user claims warming oceans causing intensification of hurricanes.

I do some browsing of articles claiming warming of the oceans is causing intensification of hurricanes.

I discover that the units being used to measure heat content are not units of heat.

I chose to share this absurd oversight in hopes of encouraging users to be more skeptical of what they read.



The hear content is the ocean has not been broadly measured, only surface temperatures have.
 
Did that link not work?
Ocean heat content is a term used in physical oceanography to describe a type of energy that is stored in the ocean. It is defined in coordination with a particular formulation of the thermodynamic equation of state of seawater. TEOS-10 is an international standard approved in 2010 by the Intergovernmental Oceanographic Commission.

Calculation of ocean heat content is closely aligned with that of enthalpy at an ocean surface, also called potential enthalpy. OHC changes are thus made more readily comparable to seawater heat exchanges with ice, freshwater, and humid air. OHC is always reported as a change or as an "anomaly" relative to a baseline. Positive values then also quantify ocean heat uptake (OHU) and are useful to diagnose where most of planetary energy gains from global heating are going.

To calculate the ocean heat content, measurements of ocean temperature from sample parcels of seawater gathered at many different locations and depths are required. Integrating the areal density of ocean heat over an ocean basin, or entire ocean, gives the total ocean heat content. Thus, total ocean heat content is a volume integral of the product of temperature, density, and heat capacity over the three-dimensional region of the ocean for which data is available. The bulk of measurements have been performed at depths shallower than about 2000 m (1.25 miles).

The areal density of ocean heat content between two depths is computed as a definite integral:
heat_zor1ks.png


where
c[sub]p[/sub] is the specific heat capacity of sea water, h2 is the lower depth, h1 is the upper depth,

rho (z) is the in-situ seawater density profile, and

Theta (z) is the conservative temperature profile.

c[sub]p[/sub] is defined at a single depth h0 usually chosen as the ocean surface. In SI units,

H has units of Joules per square metre (J·m−2).
 
I only see measurements of surface temps too, and nothing on heat content of oceans or heat content of atmosphere. Only surface temp measurement changes. So not looking at total system parameters.
 
Surface temperature is the most important variable.
It is the ONLY means that heat content is transferred to air.
The temperature at the bottom of the ocean means nothing.

"Thermal imaging has been done for decades by scientific missions like NASA's Landsat and the European Sentinel satellites," Reinicke said. "But these satellites are only collecting thermal data at a very coarse resolution — 100 meters, 500 meters or 1,000 meters [330 feet, 1,650 feet or 3,300 feet]. There's not been a commercial mission that is capturing data under 10 meters (resolution) [33 feet] in the thermal spectrum."
SatVu



--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."
 
So why don't they use temperature instead of a meaningless unit like kJ/cm²?
 
It seems though the claimed "Global Warming" should be based upon total NET thermal gain of all systems in our atmosphere to be accurate.

Some areas gain while others loose heat.

Surface temp does not reflect total change of system, IMO.


 
A deeper warm layer can drive a hurricane more than a shallow warm layer. A hot shallow layer many not have nearly as much heat as a deeper warm layer. Surface temp is important, but the ability to deliver heat to an area on the surface is more important, so one needs to know the water column heat content deliverable to an area on the surface.

Why else would oceanographers use it?
 
Is the temperature of the air above a boiling pot of water = 212°F ?
Not all the heat of the water is transferred to the air above it.

The air above is warmed by the amount of heat that is transferred from the water to the Air across the interface.

Air Temperature depends on the amount of heat transferred at the interface and the heat capacity of the air. Its viscosity is 100 times air. Mass even more. That's the slow motion part of the system. Air is rising well before water begins to cool off and sink. When it does, more warm surface water flows in from the side. Water is not very dependent on vertical circulation. It does not usually do that anyway as it is colder and denser below. It does not want to rise on its own. It wants to stay in whatever level it happens to be in. A heated surface layer STAYS AT THE TOP. It does not sink until cooled, then it probably does not sink far down.

Air Temperature can then be calculated, its pressure-density, buoyancy, and the resulting upward force.
Then you can calculate the acceleration, velocity of the rising air as it tracks upward and compare that to the existing atmospheric temperature, pressure, density profile to see if it will be stable, or unstable. If it is unstable, it continues upward, circulation may develop. If stable, it stays where it is, moving only horizontally, if at all.

Heat capacity of air is 1/4 the water. Not much water is needed for kicking off the buoyancy potential of air.

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

I am guessing you don't care about the way this is derived, but I don't know why, so I'll just let you stew about it.

Start with "H has units of Joules per square metre (J·m−2)" and work backwards.
 
Opps. Integrate the worldwide measurements, or let NWS supercomputer do it for you.

Oceanographers are probably more interested in heat transfer between undersea layers, the mixing potential, especially between surface and deeper density driven currents. Those are more dependent on temperatre-density and salinity. Near glacial melts, there are fresh water currents that remain above cooler, salty water for long stretches, until they either cool, or mixing increases salinity. Upper layer currents do not sink. The Gulf Stream runs thousands of miles on the surface with little mixing of layers below. What little heat is lost to the atmosphere is insignificant to the bulk of ocean currents. Gulf Stream cools near Europe and then branches out, one flowing south along the west coast past me, still on the surface. That starts getting warmer again as it approaches Cape Verde, then loops back west. All the colder currents run underneath. Water does not rapidly change levels, unless crossing thermal vents or welling up at islands, undersea mounts.

One thing very different with these latest storms I noticed is that they are forming in the western Caribe, not off Cape Verde, which is where most Atlantic hurricanes begin. The water in Canarias has not gotten excessively warm this year, although minimum air temperatures have generally been 5°C warmer for an entire year now, the max temps have not risen this year like the last. Last year we had 5°C hotter max air temps than previous times. Is the hotter water shifting west? $64 question.

Last time I'm saying this...
Nobody cares about depth. Heat transfer is ONLY ACROSS the surface J/m[sup]2[/sup] Water layers do not mix unless forced to. No need to consider lower layers. They do not rise. Water layers are inherently stable. Heating at the top layers keeps the hot water there at the top. Hot water does not sink. Cooler water sinks and does not return.

Water is completely opposite to the atmosphere, where heating is from the bottom and hotter air balloons upward.


--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."
 
Wooden bucket used to measure sea surface temperatures during World War II.
The Mariners’ Museum

Wooden_bucket_used_to_measure_sea_surface_temperatures_during_World_War_II_tvgxeq.jpg


Changes to Sea Surface Temperature Measurements
Much like the trends on land, sea surface temperature measurement practices have also changed significantly.

Before about 1940, the most common method for measuring sea surface temperature was to throw a bucket attached to a rope overboard from a ship, haul it back up, and read the water temperature. The method was far from perfect. Depending on the air temperature, the water temperature could change as the bucket was pulled from the water.

So how do we 'Scientifically' calibrate all the methods that were utilized over the years?

Easy, they just "Massage the Data"...

EDIT: I wonder if NIST has standardized the bucket diameter, 'depth' , material, time of day, core material temperature and process, etc. for Mariner's use?

 
It's a BIT BUCKET now.

26 Sept
Caribe is HOT
Canarias cooler than normal.

Screenshot_20241011-222832_Brave_de60f0.jpg


--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."
 
Opps said:
Heat transfers from hot surfaces to cold surfaces. In my youth when water skiing on a lake, the depth of the warm water gradient was always deeper in the late summer than early spring. Thus it would appear the warmer surface temps were transferring heat to the layers below?

No. Probably the exact opposite.
Earth temperatures warm the water below the ice.
Warming from the bottom creates instability.
Circulation is thereby established,
It's the air temps that freeze the ice.
The earth warms the water from below.
Ice is good insulation.
And it floats, keeping the insulation at the surface.
Stays warmer below the ice.
U water 0.606 Btu/h-ft-F°
U Ice 2.18 Btu/h-ft-F°
The temperature of the water below might get higher in winter than in summer in some windy cool Northern climates.

GOOD thing ice floats, or evolution would have been radically different.
If water froze from the bottom, Life might have died off rather quickly.

Conduction in a liquid or gas only happens when two adjacent parcels remain in contact. That requires stability. Any heat transfer cools one and heats the other. The resulting difference in density sinks one in relation to the other, so it moves up or down causing convection. Which is why convection is almost always responsible for the bulk of heat redistribution in a liquid or gas. It literally moves the parcel with all its heat from one place to another. Conduction only transfers a relatively small portion of heat from one parcel to the next parcel and so on, in a fixed grid. Its more efficient to carry the whole parcel from one place to wherever its going to wind up.

Water is especially unique, because even when decreasing its temperature the last few degrees to freezing, it suddenly causes a reversal of density-temp curve, getting lighter and moving upward. Very cold water is forced to the surface to freeze. Its like the only substance that does that.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."
 
Henry's what do they have to do with any of this? Or maybe you mean little h, enthalpy?
 
TugboatEng,

heat_znjvzc.png


Since you overlooked it the first time.
 
1503-44's red highlights is lacking a time dimension to be meaningful. Can you please say what your H is? It's not a standard symbol used in thermodynamics.
 
I posted the explanation. Go back and read that. Or not.
 

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