Daily Spectral Solar Radiation

[fjordana]

In Simon Lighting, we are working on a project where we would need the average solar spectral ( only visual range ) on the earth for a giving date/time and ___location.

With this information, we will calculate the CCT during the day in this ___location, and will use it for controlling circadian luminaries. Based on this information, we will set luminaries to follow the solar spectrum during the day.

We have been looking for this information with no success, there are much information about the Total Irradiation on the earth, but there isn't information about its spectral composition.

[GES DISCx - jimacker]

Hello,

Can you use Photosynthetically Available (or Active) Radiation (PAR)? The PAR spectral range is 400-700 nanometers.

You can examine the PAR data products available in Giovanni at the link below. Some PAR products are only available for ocean regions, others are available over both land and ocean.

https://giovanni.gsfc.nasa.gov/giovanni ... eyword=PAR

Note that the PAR diffuse flux and beam flux from MERRA-2 are also available at hourly and 3-hourly temporal resolution from the GES DISC, but these data products are not in Giovanni. Please reply for further information on how to obtain these data products if they would be of use to you.

[fjordana]

I've been analyzing the data available in Giovanni platform about the Photosynthetically Available Radiation (PAR), and the problem is that the values I can obtain are the "integrated" ones in W/m2, but I cannot get their spectral power distribution (SPD) through the visible range for analyzing the spectral variation during the day and estimate sun chromatic coordinates.

[GES DISCx - jimacker]

OK, then we do not have a data product at the GES DISC that will work for you, and you can continue to examine the POWER data products.

[ASDC - bmacpher]

In the new version of POWER, that is currently in beta, Total PAR will be included.

[ASDC - pstackhouse]

Although PAR is included from the CERES project in the upcoming POWER web suite release, it is also integrated and NOT spectral. POWER also includes UV-A and UV-B, from CERES but these are also integrated over those wavelengths. How high of spectral resolution are you seeking?

[fjordana]

As we only needed to estimate the average daily CCT during the year, with a resolution in the visible range on 5 or 10nm would be more than enough

[ASDC - pstackhouse]

Unfortunately, we do not have 5-10 nm spectrally resolved fluxes. Our current radiative transfer model has broader bands than that. This will require a moderate resolution radiative transfer model. Such models have been developed for the CLARREO mission but have not been applied to time histories of cloud and atmospheric properties we've collected and provide through POWER. Perhaps, review NREL's SMARTS model (https://www.nrel.gov/grid/solar-resource/smarts.html) to see if this capability could help you with your data needs.

[dave2468]

Do PAR figures and calculations allow for the variation in the photomorphogenesis with wavelength? In other words, are plant growth lumens figured into the calculations?
I specifically mention plant growth as I am familiar with this, but presume that varying wavelength produces variation in other biological processes with plants.

[fjordana]

In my case, I am not working with plants, my analyses focus on the effect of natural light and its spectral modulation during the day on people.
So I'm looking for an average reliable spectral ( visible range ) values to the daylight to evaluate it modulation during the day and months.