FA2521-18-Q-B091_Amendment,Questions_Answers.pdf

Amendment to Solicitation FA2521-18-Q-B-091, Nocturnal Lightning

The purpose of this amendment is to incorporate revised Performance Work Statement (PWS), dated 31

Aug 18, Item 5 - This is not a Research Grant or Student Stipend.

Contractors are to acknowledge this change.

Solicitation will close 6 Sep 18, 2:00PM, EST.

Question:

1a. Why doesn’t CCAFS/KSC utilize MERLIN (the TLS200 network at KSC-ER) as the total lightning data source, rather than ENTLN?

Answer:

This is not a matter of CCAFS/KSC using the MERLIN data. Rather it is a matter of the vendor choosing what data source to use in the analysis. As suggested in the work statement, the nocturnally forming thunderstorms tend to be weaker than most of our thunderstorms and so may not always produce cloud-to-ground lightning. Thus total lightning is needed to ensure detection of these thunderstorms.

Unfortunately, the location accuracy of MERLIN becomes very poor very rapidly outside the MERLIN network and would not provide good data source for this analysis. In addition, the MERLIN data have not been available long enough to do this analysis. But the vendor may propose whatever data sources they think is best.

Question:

1b. Is the concern over the length of MERLIN data set available to perform a climatology? It is very unclear from the 1999 Florida State student (Cantrell) masters' thesis what portion was really considered to be "climatology", given that a 3-year data set from CGLSS was used in part of it and a 10-year NLDN data set in another part.

Repeating the answer to 1a, MERLIN is unacceptable for this analysis because its period of available observations is inadequate and because its location accuracies degrades too quickly with distance to be used in the area to be covered in this analysis. There is a statement above about the Cantrell thesis but no question, so no response is provided except to note that the Cantrell thesis was cited only as background information.

2. If you receive NLDN data separately from the 10 sensors (raw data) that feed into MERLIN, is it really a CG-only data set? NLDN has been detecting large quantities of cloud lighting since 2013.

MERLIN only uses the cloud-to-ground portion of the in-range NLDN sensors. We had wanted to also integrate the lightning aloft portion of NLDN into MERLIN but had been told by Vaisala that the lightning aloft data of Vaisala’s NLDN is incompatible with the lightning aloft data of the Vaisala’s TLS-

200 sensors used by MERLIN and so it cannot be integrated. Thus for integration into MERLIN, NLDN is only cloud-to-ground lightning.

3. What forecast time horizon(s) is/are of interest in the prediction of nocturnal thunderstorms?

Nocturnal is nighttime: sunset to sunrise. The key is to design the analysis to ensure the lightning * formed * at night, i.e. had not formed late in the afternoon and merely persisted past sunset as the thunderstorm is presumably dissipating. One way to enforce this is to select the cases such that there was no lightning associated with the forming thunderstorm for a period after sunset to the first lightning, e.g.

1-hour, so the start-time of the data might be sunset + 1-hour. But the design of the analysis is up to the vendor, though hopefully developed in-conjunction with 45 WS to ensure the requirements are met.

4. Specifically, what are the "data available in real time to 45 WS before sunset" that should be considered in this work?

Weather radar, weather satellite imagery, surface weather observations in east central Florida, and

CCAFS weather balloon observations. If the vendor suggests other data as useful precursors to nocturnally forming lightning, they should check with 45 WS if it qualifies as being available in real-time to 45 WS.

5. Related to the issue of forecast horizon, how much time prior to sunset should be considered in the study?

6 hours prior to sunset.

6. Is it correct to assume that "unexplained" nocturnal thunderstorms are the same as the non-synoptically forced cases described in Cantrell's thesis, or should a different definition be considered in this study?

Any non-synoptically forced lightning, or lightning associated with tropical cyclones, that forms at night in east central Florida during the summer lightning season should be considered. The emphasis is on the word 'formed'. As noted above, lightning that had formed before sunset, such as routine afternoon/evening thunderstorms, that happen to persist past sunset do not count as "unexplained".

Another type of 'explained' nocturnally forming lightning are thunderstorms that form over the

Gulfstream at night under deep easterly flow or other very weakly driven weather situations. These thunderstorms tend to stay on the Gulfstream and so are not a concern to 45 WS and should not be included in this analysis. These thunderstorms can easily be excluded by defining the analysis area to exclude the Gulf Stream. An important part of this analysis will be filtering out this 'explained' nocturnal lightning.

7. Could a PDF of the 2010 AMU project report (cited in the RFP) please be made available?

The report is located at https://science.ksc.nasa.gov/amu/final-reports/convergence-bands.pdf

8. Why does government require that the results of this project be federal government property? Is this negotiable?

https://science.ksc.nasa.gov/amu/final-reports/convergence-bands.pdf

The results of this project shall be property of the Federal Government. No, this is not negotiable.

Question:

1) We are assuming that they are "deliverables" or "reports" and that we have to put an amount for each of them and that there would be a total of 4 (2 per year : mid-year then annual for year 1 and mid-year and final for year 2)?

2) Is that what you are looking for? Do we have to do it this way?

Yes, pricing shall be in accordance with solicitation format.