1W0X1 Air Force

Radiation, Conduction, and Convection

A perfect absorber and Emitter of radiation. This is a theory and there are NO perfect black bodies.

The ratio of emitted radiation from an object to the emitted radiation from a black body at the SAME FREQUENCY (Wavelength) and Temp.

Ratio of absorbed radiation by an object to the absorbed radiation by a black body at the same wavelength and temp.

Ratio of the total amount of radiation from the object to the total amount of incident radiation. The Albedo of an object is a measurement of its reflectivity

Occurs when energy at a specific wavelength contacts an object about the same size as the wavelength of the incident radiation.

Ratio of energy that passes through an object to the total amount of energy received.

Planck's Law, Kirchoff's Law, Wien's Law

Amount of radiation emitted by a black body at a given wavelength is proportional to its Temperature.

This law is a derivation of Planck's Law, SAYS the wavelength of the MAX irradiance of a black body depends on its Temp.

Says for objects in thermodynamic equilibrium (steady Temp), absorption of radiant energy must be equal to the emission of radiant energy. (IF an object receives more energy than it emits, the object warms, if it emits more than it absorbs the object cools.

It is an observation that is more frequent than synoptic reports. Animated looping, so you can see the system in motion.

Travel from pole to pole (N to S) Angle is 98.7 and the Altitude is 472NM, global coverage every 12 hrs. Best for global military mission.

19312NM/35800KM over the equator. Stays there due to the balance between centrifugal force and gravity. Same angular velocity of the rotating earth. best for fronts/lows/ severe weather/ clouds/ non-cloud features.

Geosynchronous and Polar Orbiting

You see the reflectivity of features that are converted to brightness values. Wavelength = 0.4-0.74 microns

You see the Temperature of features that are converted to brightness values. Measures the reflected sunlight and emitted energy. Wavelength = 0.75-2.0 micrometers

You see the amount of moisture sensed in a vertical layer that is converted to a brightness value. GOES = 6.7 microns METEOSAT = 7.1 microns AKA Moisture Channel

Influences the interpretation of clouds, cloud patterns, terrain features, and other atmospheric phenomena. (Time of year/latitude/cloud height)

Between 610-240MB. Mid and high level moisture affects the sensor much more than lower level moisture for WV.

Determining Jets/circulation centers/troughs/ridges/wind maximums/vorticity maximums/ and TS areas.

Surges that are associated with large-scale circulations.

Measure the long-wave radiation of objects (clouds and ground) using a wavelength of 10.2-12.8 microns. DOES NOT depend on reflected sunlight for an image.

Assigning a gray shade to a temperature range.

Assigning a range of temperature to a range of gray shades.

It is a GOES enhancement. Curve closest to a straight linear curve. WV uses this.

It is a GOES enhancement. A cool season general purpose curve. From -13 to -50 is associated with precip during a cool season.

It is a GOES enhancement. All purpose curve, most commonly used for convective activity.

It is a GOES enhancement. This is a wintertime curve, used to define water currents, low status, and coastal fog, helps determine freezing line.

It is a GOES enhancement. Designed for cloud interpretation in colder Northern Latitudes in the winter. Its easier to determine low-mid clouds.

It is a GOES enhancement. Designed for W coast forecasters to enhance systems over the Pacific.

Any loss of energy due to absorption and scattering of IR radiation by atmospheric elements. Greatest in the tropics due to moisture content.

The more water vapor there is, the greater the attenuation?

Energy sensed by the satellite from 2 or more sources along the same line of sight. Inaccurate cloud-tops, and the amount of contamination depends on the viewing angle.

Loss of resolution caused by the Oblique (shallow) viewing angle that results in a distortion near the edge of the picture on any type of METSAT image. Overestimates the loud coverage. Most noticeable in Geosynchronous.

Time it takes for the sensor to heat up/cool off when it reacts to large temp changes.

This measures the critical atmospheric, oceanographic, and land parameters. Shows the eye of the vortex and deeply convective regions.

It is the Temp of an object/SFC appears to have when we measure the intensity of its emitted radiation at a particular frequency/wavelength. (Low emissivity-water- looks colder than they really are)

Passively detects emitted and reflected microwave radiation at 4 frequencies (19.3-22.2-37.0-85.5 gigahertz GHz) the 22.2, has 1 channel and measures WV unpolarized signal. The others have 2 channels (One horizontal/vertical). Orbits at 833KM, 98.8 inclination. Takes 102 minutes and gives 14.1 revolutions per day. Speed = 6.58km/sec. Scans 1400KM. Gaps = occur between 30N and 30S. 99% probability of viewing a storm in the tropics at least once a day. Resolution is 25KM, the rain rate resolution is the highest at 15KM and lowest at 50KM.

Little-no attenuation. Ice clouds are transparent to microwave.

2 forms: SDR (Sensor data records) and EDR (environmental data records)

environmental data records: derived from the SDR and contain environmental parameters directly usable by meteorologists and oceanographers. AKA Oceanic total precipitable water.

It depends on the SFC type. Land-sea-ice parameter.

SDR, accurate within 1 Kelvin. EDR, within 12KM resolution.

22.2 = viewing WV 85 = viewing rain/clouds 19 & 37 =Viewing surface phenomena.

0.9-.95 at microwave frequencies.

They are interested in soil moisture. Helps determine the trafficability

The precision of tracking, means they can locate the eye at the sfc. 85 channel reveal eye and wind streaming into PBL.

Translation, Rotation, Divergence, and Deformation

Movement in a straight line.

Turning about a point

Spreading or contracting of the wind field.

The stretching or shearing of the wind field.

Rotation and deformation are the 2 main types of motion. They are responsible for the shape of the cloud mass on satellite.

Best spatial resolution. Only available during the daylight. Entire synoptic-scale features do not fit on the screen. Best to find surface cyclones.

24 hours a day, easier to determine cloud tops , low level items are hard to detect. Best to find upper-level cyclones

Analyze the jet stream and synoptic systems, shows the interaction between the middle lats and the tropical systems. Interpretation is not straightforward. Used to detect upper deformation zones.

Most loopers enhance the pixel brightness rather than the Temp. You cannot split repeat colors, no more than 2 colors is best.

Planetary scale: 3-6 hr intervals are best Synoptic scale: 2 HR is satisfactory, 1 HR is ideal. Generally the smaller the size and time scales of the phenomena, the shorter the intervals needed between the pictures is the loop.

From synoptic scale systems, along the southern edge of the coldest cloud tops. Rapidly cooling cloud tops are the indication that precip will increase.

The cloud pattern is the first indicator. A slight S shape develops on the cold-air side of the cloud pattern.

Cumulus or altocumulus.

Low-level cloud that develop because of LL convergence.

A nearly continuous cloud formation, where elements are connected and the line is les that 1 inch in width. Formed by LL instability by a large air/sea temp difference. Strong vertical speed shear or strong LL winds >15kts and an inversion that caps the vertical development of a cloud.

Very similar to cloud lines, although the elements are NOT connected, they are parallel. Formed due to strong vertical wind shear and surface heating. Not more than 60NM.

Variety of grey shades on IR, during the different seasons. Easiest to see on VIS, because of the contrast between the cloud and the terrain. In a MT or hilly areas have a vein-like appearance. They are their brightest over deep terrain. May look like snow on mountain ridges. On FIR looks dark grey, due to the small thermal contrast. Sometimes black stratus)

These are low clouds caused by the advection of warm moist air over a cooler area.

It is a stratiform cloud with its base on the ground. Composed of water droplets. Radiation and sea fog are the best seen on imagery. Dissipates from the outer edges into the middle due to differential heating.

Formed by the spreading out of CU or the lifting of status. Needs a stable layer aloft, and limited vertical mixing in the lower levels, usually a subsidence or radiation inversion. Forms due to weak CAA over a warm surface. VIS= light grey to white shaded, continuous sheet of parallel rolls or cellular elements textured appearance.

Small vertically developed clouds formed due to surface heating, LL convergence, or both. VIS= unorganized Popcorn shapes. Uniform lighter gray shade.

Needs a more unstable atmosphere, more vertically developed the CU, easier to see on imagery. They are circular clouds.

CU cloud with strong vertical development, with or without a anvil cirrus plume. Can develop singularly, in clusters, or in lines. We can find the overshooting tops when the sun angle is low. Smaller CB clouds are hard to find when they are embedded in a cirrostratus shield.

Closed packed, form over oceans. Found in large sheets, generally winds <20KTS and direction is perpendicular to the strands. Formed due to LL instability, or to convective mixing with a strong subsidence inversion. On FIR similar to stratus, thermally warm.

usually form over water, behind the mid-lat cyclones caused by strong CAA over warmed water. Associated with cyclonic or straight-line flow. Weak inversion caps vertical development. Usually higher than the closed cell. Looks like chicken wire. Has larger cloud elements.

Speeds are usually greater than 80KTs

VIS works best, because of the brightness contrast. Sun angle is an important factor. Best to see at a low cloud angle.

Filmy, diffuse appearance med-light grey scale on VIS and FIR it is dark-medium

VIS= appears to be dull, filmy, and diffuse light-med scale depending on density. FIR=appear I=only if it is at high alts, or large concentrations. Contamination is a large factor.

Caused by the reflection of the suns rays off the water surface directly into the METSAT data, seen only on VIS. Occurs only in stable conditions, with light or calm winds. Geostationary=circular shape. Polar=the higher the wind speed the larger and more diffuse the glint zone

To estimate the surface wind speeds, direction, in an anticyclonic flow and sea state.

Seen only on VIS. Transition from day to night.

Neutral point. Center of the deformation zone where winds are calm

Horizontal axis where the wind is moving away form the col

Horizontal axis of winds moving towards the col

Baroclinic zone, Vorticity comma-cloud system, deformation zone

Associated with the thickness ribbon

Associated with a vorticity max

Dry slot.

AKA cirrostratus. Forms on the equatorward side of the jet. AKA Cirrus shields. The jet axis position is 1 lat on the poleward side of the cloud edge.

Forms parallel to, and on the equatorward side of the jet stream.

If the jet stream axis is located with this cloud feature, its about 1 degrees of lat on the poleward side of the cirrus cloud.

When you see a 500MB trough intersect a frontal cloud band, the trough is in a N-S orientation. You may see a Slight S develop, or you may see a separate cluster or small comma cloud develop in the cold air behind the band.

When the CU begins to take on the comma cloud shape the minor is developing into a major short wave trough.

Usually found in the upper deformation zone. The Low is positioned slightly West of the center of the swirl of the cloudiness within the deformation cirrus.

Usually NE-SW direction

Caused by mid-level deformation ahead of the Jet Max, upstream from the leaf

Organized, persistent, deep convection. During the warm season. Forms in the moist unstable zone in the afternoon. Cells grow and merge, begins to look like one cell. Trigger=Convergence of the outflow boundary associated with the individual cells

For tropical cyclones. Day by day changes in the cloud pattern of the storm and its environment

The pattern the clouds forms, is the intensity of the cyclone. We use the T number to describe the rate of development or dissipation of the tropical cyclone, defined by the cloud features related to its intensity.

A indicator of the tropical cyclone development. Operational practice.