Monday, May 18, 2015

New Study Finds a Hot Spot in the Atmosphere

NASA high altitude research balloon. (Credit: NASA) Click to Enlarge.
A new study, just published in Environmental Research Letters by Steven Sherwood and Nidhi Nashant, has answered a number of questions about the rate at which the Earth is warming.  Once again, the mainstream science regarding warming of the atmosphere is shown to be correct.  This new study also helps to answer a debate amongst a number of scientists about temperature variations throughout different parts of the atmosphere.
One important area to consider is the troposphere.  It is the bottom portion of the atmosphere where most weather occurs.  Tropospheric temperatures can be taken by satellites, by weather balloons, or other instruments.  In the past, both satellites and weather balloons reported no warming or even a cooling.

However, that original work was shown to be faulty and now even the most strident sceptics admit that the troposphere is warming.  But obtaining an accurate estimate of the rate of warming is difficult.  Changes to instruments, errors in measurements, short term fluctuations all can conspire to hide the “real” temperature.

This is where the new study comes in.  The authors develop a new method to account for natural variability, long-term trends, and instruments in the temperature measurement.  They make three conclusions.

First, warming of the atmosphere in the tropical regions of the globe hasn’t changed much since the late 1950s.  Temperatures have increased smoothly and follow what is called the moist-adiabatic rate (temperature decrease of humid air with elevation).  This result is in very close agreement with climate computer models and it contradicts the view that there is a slowdown in climate change.

Second, the vertical height of the tropics that has warmed is a bit smaller than the models predict.  Finally, there is a change in observed cooling in the stratosphere – the layer of the atmosphere above the troposphere.

Taken together, these results show that the tropospheric warming has continued as predicted by scientists years ago.
But this new study finds a clear signal of the [so-called “tropospheric] hotspot.  In fact, the temperature in the troposphere is rising roughly 80% faster than the temperature at the Earth’s surface (within the tropics region).  This finding agrees very well with climate models which predicted a 64% difference.

Read more at New Study Finds a Hot Spot in the Atmosphere

No comments:

Post a Comment