Cloud Seeding and Weather Modification Questions and Answers

Answer: C

Both are true and the reason gives the distinction, and this makes it effective at night as well as by day. Solar reflection schemes by contrast do nothing during the night. The distinction matters at high latitudes particularly.

Answer: D

Correct answer: reforestation to absorb carbon dioxide

Reforestation removes a greenhouse gas and is a carbon measure, not a cloud one. The other three act on clouds and their radiative effect: brightening marine stratocumulus with sea salt, thinning cirrus so more heat escapes, and increasing low cloud cover over subtropical oceans.

Answer: A

Seeding aims at a local effect over hours, whereas climate intervention aims at a global effect over decades. The underlying microphysics can nonetheless be very similar. Scale and intent rather than physics separate them.

Answer: B

Deposition studies inform assessments of environmental effect on soils and water. Concentrations measured downwind of long running programmes have generally been very low. Monitoring continues at long established operational sites.

Answer: C

The first two are correct and reflect the monitoring evidence. The third is not supported by measurement, although long term accumulation remains a reasonable subject for continued study. Absence of evidence is not the same as evidence of absence.

Answer: D

The intention is to exhaust the cloud's water before it arrives rather than to stop rain forming. Whether such operations achieve anything measurable is no better established than rain enhancement. The same evaluation problem applies in reverse.

Answer: A

Correct answer: steering the track of a tropical cyclone

Modifying a hurricane’s intensity was attempted and abandoned; steering one has never been a serious proposal, since the energy involved is many orders of magnitude beyond anything seeding could supply. Snowpack enhancement, hail suppression and airfield fog clearance are all genuine applications.

Answer: B

The idea was to broaden the eyewall by seeding and so reduce the peak wind. It was abandoned after it became clear that the storms contained too little supercooled water for the hypothesis to hold. The physical premise itself proved to be wrong.

Answer: C

Both are true and the reason gives the finding, and natural eyewall replacement also mimicked the expected effect. The programme is a useful case study in how a hypothesis can be tested. Abandonment on physical grounds is unusual and instructive.

Answer: D

The natural cycle produces changes resembling those the seeding was expected to cause. This made apparent successes impossible to attribute to the intervention itself. Nature mimicked exactly the change that was sought.