Dozens killed in Portugal fire

As an Australian who has seen many such tragic wild fires, I pray that relief comes soon.

My sincerest condolences to the families and friends of those who have perished in the fires, and my greatest admiration for the heroism of those who fight the fires.

By Max from Other on 18 Jun 2017, 09:01

The relative humidity has been low and contributes to fires. To raise relative humidity one could have floating spray pumps in the sea. The pumps could be operated by wave motion. The air will become humidified and when there is a sea breeze the moist air will blow over the land increasing relative humidity. One could plow the sand near the waves so that water remained in shallow furrows to heat and evaporate. One could put black netting on the sand to be made wet by waves and heat up in the sun so that evaporation occurs and so on. Evaporation depends on the water temperature, the wind speed, the temperature of the air and the relative humidity. Most of the sun penetrates the water and enters deep (especially the visible portion-the infrared portion is absorbed more quickly). You can heat the surface of the sea if you make it dirty or dark with plankton, because all the energy goes into the surface layer of the sea. By plowing sand you increase the surface area and you decrease albedo so more energy is absorbed from the sun (not reflected as much). By making a spray over the sea you increase surface area for evaporation. When there is more evaporation the air cools and becomes more dense and is more likely to blow onto land, especially with a sea breeze. See also http://airartist.blogspot.co.za Using an evaporation equation from engineering toolbox gives me that one could increase evaporation from the sea by more than 10% by raising the temperature of the sea surface by two degrees C. Perhaps iron ore dust could be put in the sea to make it dark and perhaps feed algae. But I am not much good at biology.According to Weather Spark about 7.5 kWh per square metre per day falls on the sea near Lisbon. 1kWh can evaporate 1.6 litres (kg) of water. 7.5*1.6=12 kg of water,which is enough to increase a kilometre high column of air above the 1 square metre of sea significantly. At a temperature of 30 deg C and a relative humidity of 45% a column of air 1000 m high with base of 1 square metre has 13.7 kg of water vapour in. At the same temperature and a relative humidity of 85% the same column has 25.7 kg of water in - 12 kg more (that could be supplied by evaporation in a day). Calculated using 100 kPa pressure for the whole column - not very accurate, but close enough.

By Eddie Miller from Other on 18 Jun 2017, 14:29