Wednesday, May 24, 2017

More drought as land gets hotter relative to the oceans

Local governments could check their cities for air temperature rise: says
"Global warming caused by human activities that emit heat-trapping carbon dioxide has raised the average global temperature by about 1°F (0.6°C) over the past century. In the oceans, this change has only been about 0.18°F (0.1°C). This warming has occurred from the surface to a depth of about 2,300 feet (700 meters), where most marine life thrives." that Cape Town was 1 deg C hotter than average. Geography books point out that warm air temperatures over land with cold sea temperatures usually mean low rainfall. It appears the difference between sea and land temperatures for Cape Town is becoming large at an unusually high rate. To repeat my previous ideas I think floating sea spray generators driven by waves to increase humidity over the sea and solar air heaters on roofs or in gardens in Cape Town to make air rise and cause convectional rain would be a cheap solution. The urban heat island effect can cause 10% more rain and I think my idea would have an even greater effect. 
Using :
Los Angeles was 0.9 deg C above normal.
Cape Town was 1 deg C above normal
Another problem: Land is getting less solar radiation and the lower atmosphere is heating because of the greenhouse effect: Personally I think cool roofs and cool pavements, etc, are making the situation worse. They prevent ground from getting hotter which reduces convection and makes pollution worse and rainfall less. If you increase convection with hotter surfaces you can get more clouds and clouds reduce solar energy falling on a city dramatically - you might get less than half the solar energy falling on a city if you have cloud formation. It seems that with global warming the following could be happening: With all the air pollutants put in the air by man, less solar energy is reaching the ground so the ground cannot warm up the air above it so much (this is discussed in physical geography books and so on). This reduces air temperatures near the ground and this increases relative humidity near the ground because relative humidity decreases with increasing temperatures unless moisture is added (and increases with reducing temperatures). Added to this, the lower atmosphere is warming because of the greenhouse effect. When air is heated by the ground it may rise, but it comes into contact with the heated air in the lower atmosphere and cannot rise so easily there because this air parcel heated by the ground needs to be hotter (less dense) than the surrounding air. Because of this less clouds form. To give credence to my theory look at the relative humidity near the ground and higher up in the diagram at The relative humidity at ground level has remained high throughout the years but is decreasing higher up. says, "the improved analysis shows that the atmospheric (lower troposphere) temperatures are warming faster than the Earth’s surface." For convectional rain to occur we need the Earth's surface to heat air above it so it can rise. Now the air is being heated less by the ground and when it tries to rise and cause convectional rain it comes into contact with hotter air, so it tends to sink and so does not tend to rise and cool so much, which could cause condensation and rain. One solutions is to make land darker with biochar, and so on, so it heats up more.

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