Commens:

• Temperatures at 1500 meters, not influenced by Urban Heat Islands, went up 0.6 degrees Celsius.
• Temperatures at 3500 meters went up 0.38 degrees Celsius.
• Temperatures at 5500 meters went up very slightly 0.18 degrees Celsius.
• The height in meters of air pressure, has also gone up approximately 16.7 meters
• Air pressure from the sea has gone up approximately 1.0 milibar
• One of the reasons for more rainfall could be the growing difference between the lower and upper levels of the atmosphere. The thunderstorm index relates t the difference between 500 and 850 milibar.

The 15 hottest years in Israel – Temperature 850 mb, average altitude 1500 metes:

1979 – Average Temperature 14.32

1998 – Average Temperature 14.24
1962 – Average Temperature 14.16

2001 – Average Temperature 14.12

1961 – Average Temperature 14.11
1999 – Average Temperature 14.06
2004 – Average Temperature 14.01

1955 – Average Temperature 13.98
1985 – Average Temperature 13.94

1978 – Average Temperature 13.90
2002 – Average Temperature 13.85

2005 – Average Temperature 13.84

1980 – Average Temperature 13.81

2003 – Average Temperature 13.79

2006 – Average Temperature 13.73

1998 – 2006 – Within this period the last 8 years all had temperatures hotter than usual, top 15.

1976 – 1997 – In this period 3 years in a row (1978 – 1980) were hotter than usual, 1979 being the hottest year since the establishment of the state of Israel.

1955 – 1975 – This period experienced 3 years of hotter temperatures than usual out of which 2 were following years (1955, 1961 1962)

Temperature at 850 milibar is usually what is used to determine ground temperature. These maps provide temperature values at an altitude f 1500 meters, which are not affected by Urban Heat Islands and therefore changes in these values are noteworthy.

A rise of 0.58 degrees Celsius in the past 30 years represents ground heating of 0.6 – 0.8 degrees. In addition a 0.6 degrees difference represents a rise in temperature every 100 meters. Such an increase in average yearly temperatures can significantly reduce snowfall in Jerusalem and the mountains situated 600 – 800 meter high. 

Temperatures of the Mediterranean sea

Israel is located along the coast of the Mediterranean Sea. As a result temperatures are moderate all year long especially in the coastal areas. Up until two decades ago water temperatures were hottest in September and stayed around 28.0 degrees. In the past 20 years temperatures of sea waters have risen and today they reach 30.0 degrees every year in September. 1998 was the hottest summer since the establishment of state of Israel; water temperatures in the coast of Israel reached 31.6 degrees! The heating of waters during September led to higher temperatures in the whole of the coastal area mainly during the summer.

Changes in Rainfall Distribution

The Greenhouse Effect appears to be a fact. The question is are we looking towards a decrease in rainfall, an increase in rainfall or no change at all. It is difficult to answer this question. Here are a few contrasting events from the past years:

1. Over the past few years there has been a noted change in rainfall distribution. This change is mainly in the past 10 years and it is still difficult to estimate if this is a temporary change or the beginning of a new tendency. There have already been a number of following years where rain has terminated in February which is early. The same phenomenon has occurred with beginning of the season with rainfall starting only in December. This shortening of the winter season has also been experienced in other parts of the world. Blossoms are premature, snow is delayed and even bird migration begins earlier.
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