What Cloud-Adjusted Solar Radiation represents
The 0.75 and 3.4 coefficients make small cloud fractions weakly attenuating and heavy cover increasingly influential. It is a compact bulk parameterization.
Cloud-Adjusted Solar Radiation begins with clear-sky irradiance, total cloud cover. Mark each value as observed, remotely sensed, modeled, assumed, or derived, and preserve its valid time and spatial support.
Cloud amount, overlap, and layers
Cloud fraction is an area or sky-dome proportion, while a ceiling is a height classification and optical depth is attenuation. Cloud-Adjusted Solar Radiation should not substitute one quantity for another merely because each relates to cloud.
When layers enter Cloud-Adjusted Solar Radiation, state whether overlap is random, maximum, observed, or ignored. Adding layer percentages directly can exceed 100% and double-count vertically aligned cloud.
Visibility and contrast conventions
Visibility from Cloud-Adjusted Solar Radiation depends on the target contrast threshold and extinction units. Meteorological optical range fixes a two-percent contrast convention; a general contrast range or runway screening estimate may use another threshold.
Do not equate Cloud-Adjusted Solar Radiation optical distance with prevailing visibility, slant range, night visual range, or official RVR without the required observation and processing conventions.
Solar geometry and radiation conventions
Solar elevation is measured above the geometric horizon, while azimuth here is clockwise from true north. Cloud-Adjusted Solar Radiation must retain whether radiation is normal to the rays or incident on a horizontal surface.
Civil time is not solar hour angle. Longitude, time zone, equation of time, atmospheric refraction, shading horizon, and surface tilt belong in Cloud-Adjusted Solar Radiation only when the displayed model explicitly includes them.
Formula and convention
The working relationship is G = G_clear[1 − 0.75(C/100)^3.4]. Cloud-Adjusted Solar Radiation uses only the displayed entries and does not retrieve imagery, station observations, ephemerides, forecasts, or runway systems.
Keep percentages as percentages at entry and convert them to fractions only where the formula shows it. For Cloud-Adjusted Solar Radiation, retain angle direction, optical threshold, height reference, and distance unit with the answer.
Checked numerical example
At 800 W/m² clear-sky irradiance and 60% cover, adjusted irradiance is approximately 694.35 W/m².
Reset restores this Cloud-Adjusted Solar Radiation example. Repeat it independently with the stated constants and rounding before replacing demonstration values with observations or scenarios.
Collecting compatible inputs
Use clear-sky irradiance and total cover for the same surface, time, and averaging interval. Preserve how total cover was obtained and whether layers overlap.
Record site, coordinates, elevation, timestamp, time zone, path direction, wavelength or sensor band, target definition, cloud-layer method, solar-time convention, averaging period, and quality flags when relevant to Cloud-Adjusted Solar Radiation.
Continue the Cloud-Adjusted Solar Radiation workflow with the related Cloud Cover Percentage from Oktas Calculator, keeping the same observation support and conventions.
Spatial and temporal representativeness
Cloud and visibility can change across seconds, kilometres, viewing directions, and vertical layers. One Cloud-Adjusted Solar Radiation input set represents only its declared path, footprint, and interval.
When combining several Cloud-Adjusted Solar Radiation samples, document weights and retain individual values so variability is not hidden by a single mean or total.
Interpreting Cloud-adjusted irradiance
At full cover the equation retains 25% of clear-sky irradiance; at zero cover it retains 100%. Intermediate response is nonlinear.
Compare Cloud-Adjusted Solar Radiation outputs only after aligning reference height, sky footprint, path, illumination, contrast convention, and temporal average. Similar numbers can describe different optical or geometric quantities.
Boundary and monotonic checks
Zero cover preserves clear-sky irradiance. Inputs are constrained to nonnegative irradiance and 0–100% cover.
For Cloud-Adjusted Solar Radiation, change one input at a time and predict whether the answer should rise, fall, or remain fixed. Unexpected behavior can expose percent-fraction, degree-radian, metre-kilometre, or layer-order mistakes.
Where the model stops
Cloud optical depth, type, multilayer structure, sun-cloud geometry, diffuse enhancement, surface albedo, and local calibration are absent. The equation is a scenario, not a forecast.
Cloud-Adjusted Solar Radiation is transparent educational arithmetic, not a cloud observation, weather forecast, solar-resource assessment, flight rule, runway visual range report, instrument calibration, or operational safety authority.
Continue the Cloud-Adjusted Solar Radiation workflow with the related Cloud Solar Attenuation Calculator, keeping the same observation support and conventions.
Uncertainty and sensitivity
Vary the least certain Cloud-Adjusted Solar Radiation input over a credible range and retain the resulting spread in cloud-adjusted irradiance. Display precision cannot overcome observer classification, retrieval uncertainty, spatial variability, or an empirical coefficient.
A Cloud-Adjusted Solar Radiation sensitivity range is not automatically a probability interval. It omits correlations, model-form error, sampling mismatch, sub-grid cloud structure, nonuniform visibility paths, and uncertainty outside the entered variables.
Continue the Cloud-Adjusted Solar Radiation workflow with the related Maximum-Overlap Total Cloud Cover Calculator, keeping the same observation support and conventions.
Frequent clouds and visibility errors
Typical Cloud-Adjusted Solar Radiation errors include mixing oktas and tenths, confusing AGL with MSL, adding overlapping layers, treating degrees as radians, using sea-level-reduced visibility, or applying a two-percent constant to a five-percent threshold.
Reject impossible Cloud-Adjusted Solar Radiation combinations rather than forcing an answer. Keep a clear zero distinct from missing or obscured sky, preserve signs on hour angle, and verify every inverse distance and logarithm denominator before downstream use.
Checking this optical result
How can I verify Cloud-Adjusted Solar Radiation?
Repeat G = G_clear[1 − 0.75(C/100)^3.4] with the recorded conversions, then test the checked example and a physical boundary.
Why could another source disagree?
Another source may use different cloud overlap, optical threshold, solar convention, coefficient, sensor path, height reference, or rounding than Cloud-Adjusted Solar Radiation uses.
Is this an operational visibility or aviation value?
No. Cloud-Adjusted Solar Radiation does not replace official weather observations, RVR systems, flight procedures, warnings, or qualified judgment.
How should the result be rounded?
Keep full precision inside Cloud-Adjusted Solar Radiation, then round no more finely than the least certain measurement or model assumption supports.
When should I recalculate?
Recalculate Cloud-Adjusted Solar Radiation when its site, time, path, layer, sky footprint, illumination, source observation, or model assumption changes.