When the dew point is lower than the temperature, is the air considered to be saturated or unsaturated?
444733
Unsaturated.  The air can still take on more humidity.  When the dew point is at or above the air temperature, you have fog or other percipitation.
62749
If by saturation you mean it is raining then 100% humidity.
719759
Definitely over Panama. The amount of moisture the air can hold has a strong (exponential) dependence on temperature.\nTherefore, on cold weather it holds much less moisture before it condensates.
620707
As air gets warmer it's able to contain more water vapor.  An easy way to illustrate this is in a steamy kitchen or bathroom where you'll see that condensation forms on the coldest surfaces such as windows, mirrors, tiles etc.\n\nWhen the amount of water vapor in the air reaches it's maximum point the air is described as being saturated (saturation vapor pressure or SVP for short).  SVP is therefore reached more quickly when the air is cooler.\n\nWhen air reaches SVP it has to deposit the excess moisture which it does as dew or condensation and the point at which this occurs is called the dew point.  The colder the temperature the lower the dew point which helps explains the cool mornings when there's dew on the grass.\n\nHumidity is a measure of the amount of water vapor that's present in the air and is measured as a percentage of the maximum possible.  So a Relative Humidity (or RH) or say 60%, means that the air contains 60% of the maximum possible water vapor.  As mentioned, the amount of water vapor possible increases with temperature and so RH is affected by temperature.  An RH of 80% in a hot tropical climate is going to feel much damper and humid than an RH of 80% in a cooler climate.
334098
Hot air *can* contain more moisture than cold air, but it depends on how much moisture is available for it to contain.
1034117
no clouds are not solid they are made  up of water  vapor and gas. Clouds are formed when air contains as much water vapor (gas) as it can hold. This is called the saturation point, and it can be reached in two ways. First, moisture accumulates until it reaches the maximum amount the volume of air can hold. The other method reduces the temperature of the moisture filled air, which in turn lowers the amount of moisture it can contain. Saturation, therefore, is reached through evaporation and condensation, respectively. When saturation occurs, moisture becomes visible water droplets in the form of fog and clouds.\n\nIt should be noted that condensation by itself does not cause precipitation (rain, snow, sleet, hail). The moisture in clouds must become heavy enough to succumb to gravity and return to earth's surface. This occurs through two processes. In cold clouds ice crystals and water droplets exist side by side. Due to an imbalance of water vapor pressure, the water droplets transfer to the ice crystals. The crystal seventually grow heavy enough to fall to earth. In the second process, water droplets in warm clouds collide and change their electric charge.Droplets of unlike charge attract one another and merge, thereby growing until they have sufficient weight to fall.\n\nThere is no difference between fog and clouds other than altitude. Fog is defined as a visible moisture that begins at a height lower than 50 feet. If the visible moisture begins at or above 50 feet, it is called a cloud. Two common types of fog are called radiation fog and advection fog. Radiation fog forms during the night as the earth's surface cools and the air immediately above it cools in turn by conduction. If the air is moist enough, the cooling causes it to reach saturation and visible water droplets form. We often call this type of fog ground fog because it lies so close to the surface. Advection fog forms when warm moist air moves over a colder surface (advection means to move horizontally). A perfect example is on the west coast of continents. Prevailing westerly winds move moist air from over a warm ocean area to over the colder waters off the coast. Fog forms and is carried by the westerly over the land.\n\nClouds can form anywhere in the troposphere, and although condensed liquid, they are light enough to float in the air and move from place to place by the wind. Clouds are classified according to appearance and height. Based on appearance, there are two major types: Clouds of vertical development, formed by the condensation of rising air; and clouds that are layered, formed by condensation of air without vertical movement. When clouds are classified by height, there are four classes: high, middle, low, and vertical development.\n\nCloud names, of which there are twelve, combine appearance and height. A brief description of the root name will indicate this combination of features.
824709
even if the air isnt polluted, there is still carbon dioxide and water vapor in the air.  When carbon dioxide(CO2) and water(H2O) react in air, they form Carbonic Acid (H2CO3).  Since it is an acid, it is acidic
22072
Clouds aren't just random droplets of water. What they are is tiny droplets of water that have condensed from water vapor in areas where the conditions (temperature, air pressure and humidity) are exactly right. Anywhere where you have the correct combination of these conditions, you'll get a cloud. Anywhere that you don't, you don't.\n\nAreas with this kind of conditions don't occur in random tiny places. Instead, there will be a large area of one condition that gradually shifts into another. (If this doesn't make sense, think of just temperature. You don't get a different temperature at every spot on the globe. Instead, you get a large area of warm air that gradually shifts into a large area of cooler air. The same is true for air pressure and humidity.) This is why you get a large area of 'cloud' in one place and nothing at all in another. You can think of clouds as being physical maps of the weather conditions in the sky.\n\nThis is also what holds the clouds up. In general, if a cloud is high up in the sky, the conditions just below it aren't right for the cloud to form. As the water droplets fall, they reach areas with the wrong temperature or pressure and evaporate again. Only if the clouds become densely packed enough for the water to form large enough droplets can the droplets fall to the ground. Not all clouds form high up, either... sometimes the right conditions can occur at groundlevel, giving us fog.
238050
All weather is brought about by thermal conditions. Cold as used in the term "cold front" is only a relative term. There is still quite a bit of "heat" in cold air. You must remember all measurements referencing thermal conditions are really a reference to absolute zero where there is no thermal activity.
819238
Yes it does decrease because cold air can hold less water vapour than warm air. So at altitude water vapour gets "squeezed out" and forms droplets which make clouds and fall as rain.
743246
Not sure I understand what you are asking.\nYou can choose to specify either temperature or pressue at the saturation point, but not both.\n\nIf the refrigerant is boiling, that's a 2-phase solution. The mixture will range from all liquid to all gas without a change in pressure or temperature. It will be saturated vapor by definition.\n\nFor common refrigerants it is probably simpler to look up the information - it should be published or at least available from the manufacturer.
922889
Because air at ground level and a significant distanace above is rarely saturated - when it is, fog forms - which is a cloud on the ground. It has to be saturated a significant distance above ground or else you only get shallow areas of ground fog or dew/frost (if it is unsaturated say 50-200 feet above ground).\n\nBases of what we normally consider to be clouds rarely touch the ground because rising air motion is required to saturate the air and form the cloud. If it has to rise to do that, it cannot occur on the ground - though such clouds can be advected to a higher location and perhaps reach ground level there - or as is more common, the rising motion occurs up a slope with a cloud forming at some point along it.
652464
I think you mean water saturation point, right?  If so, that's the dew point.
1146229
Dew point is the temperature at which the moisture in the air would condense. Relative humidity is the relationship between dew point and ambient temperature. If they are the same, relative humidity is 100%.  The answer is b.
922250
Low pressure is related with storms\nHigh pressure is related with good weather\n\nThe way i understood is... that is a measure of air pressure\nif its sunny then all the air above is pushing down\n\nif there are storms there is water and stuff in the air taking up space therefore less air pushing down \n\ndoes that make sense
781580
I live in Virginia too.  The answer can be described in two words.  Low dewpoint.  In the summer, you have temps in the 90s and dewpoints in the 70's, making it muggy overnight.  This time of year, the dewpoint is very low, in the 30's and 40's.  The sun is the only thing that holds the temp up.   The humidity is lower in the daytime and higher at night.  It is all about the dewpoint. The higher the dewpoint, the worse it feels to your skin.  The dewpoint can also be too low too.  Making your skin very dry.  I like that because you have a different variety of temps in the same day.  If you like warm weather, go out in the middle of the day. If you like cold weather, go out near dusk.  You have your choice.
350316
A reading of 100 percent relative humidity means that the air is totally saturated with water vapor and cannot hold any more, creating the possibility of rain. This doesn't mean that the relative humidity must be 100 percent in order for it to rain -- it must be 100 percent where the clouds are forming, but the relative humidity near the ground could be much less.\n\nHumans are very sensitive to humidity, as the skin relies on the air to get rid of moisture. The process of sweating is your body's attempt to keep cool and maintain its current temperature. If the air is at 100-percent relative humidity, sweat will not evaporate into the air. As a result, we feel much hotter than the actual temperature when the relative humidity is high. If the relative humidity is low, we can feel much cooler than the actual temperature because our sweat evaporates easily, cooling us off.