Four weeks of climate data: Southern Tropics Temperature Recap

As a general rule, it would be fair to say that the most extreme warming is happening in the Arctic Circle and Western Antarctica. The Western Antarctic warm zone doesn't seem to be radiating out much heat to nearby areas, which is not surprising when you see how far away anything "nearby the Antarctic really is and when you consider the harsh seas and skies that surround the South Pole.

The Southern Tropics have no slice that gets near our somewhat arbitrary level of 1° C rise in temperature over the 56 year period we have chosen to look at, based on Strong La Niña currents.

Tomorrow, our last region, the southern temperate zone, with even more water and less land mass than the southern tropics.

Four weeks of climate data: Northern Tropics Temperature Recap

Because there is less land mass and more ocean, I split the regions other than the Northern Temperate Zone into six sections instead of twelve. As you can see, only the section including Africa and Arabia are showing significant warming. I think it makes sense for me to do some more region testing based on specific areas that are defined by climate and ecosystem, and the Sahara is certainly one of those regions.

The last two slices of the planet, the Southern tropic and Temperate Zones, will be recapped tonight and tomorrow.

Four weeks of climate data: Northern Temperate Western Hemisphere Temperature Recap

The Western Hemisphere of the Northern Temperate Zone doesn't have as much land or as many people as the Eastern Hemisphere of the same zone, and the temperatures aren't as quite as warm. Still, the region is warming noticeably over the 56 year period, in this case only using grid points that have reports from 90% of the seasons between Winter 1955 and Fall 2010.

Tomorrow, I will continue the trip south through both tropical zones. On Friday, I will finish with the Southern Temperate Zone.

I'm working on a new idea of how to look at the data which I call De-Niñoization. The idea is to subtract the El Niño-La Niña effects from each season to see if the data fits a linear regression better. My guess is that we could see improvement in regions close to the temperature anomaly which spreads across the Indian and Pacific Oceans, radiating in strength from close to the equator, but likely less helpful when we look at regions far from the warming water. My test case will be tropical India vs. Greenland, where we would expect the Indian data to become very nearly linear while the Greenland data might become even more erratic.

Four weeks of climate data:Northern Temperate Eastern Hemisphere Temperature Recap

I changed the method of accepting data for this recap. Previously, if a grid point on my map reported 75% of the time, I considered it reliable and added it to total from which the averages were taken.  I saw this was a problem in some of the very sparsely covered regions, like the Indian Ocean region that only had two islands reporting, one much warmer than the other. Today, I re-sampled the data for the Northern Temperate Zone and increased the reporting threshold to 90% of the time. This increased the temperature readings in some regions, decreased it in others, and evened the data out considerably. The number represents the difference in the median of the era 1999-2010 and the era 1955-1975. The years are chosen because all of them were strong La Niña years.


With these readings, the consensus is clear. This region, easily the most populous in the world, went up about a degree Celsius over a 56 year time span, 1955-2010. I am not certain why the second section shows so much more warming than the rest. I'll split it up into smaller parts to see if the north or the south is making the difference.

According to climatologists, the unexploded time bomb in this region is a permafrost located in Siberia, some of it in the Arctic and some in the temperate. "Perma" is relative, but this particular chunk has been ice for about 10,000 years and covers an area equal to France and Germany combined. If this melts, and it has started, the effect is not just albedo (frost reflects heat, land absorbs more) but the amount of carbon dioxide that will be released as the ice becomes water and the bubbles trapped in the ice are released into the atmosphere.

To be clear, this region is not warming at the pace of the Arctic Circle, but it is warming consistently if we look at the data from the most consistently reporting weather stations.  Later today, we will look at the numbers from the Western Hemisphere, again relying on the grid points that report at least 90% of the time.

Four weeks of climate data: Antarctica Temperature Recap

What do the numbers mean? These are the increases in the median temperatures Celsius from the 1955-1975 era to the 1999-2010 era in these six slices of the Antarctica out to 60° South Latitude. That gives as all the Antarctic Peninsula and adds no part of any other continent.



Why the question marks? Using the methodology below of only using grid points with at least 90% of the seasons between 1955 and 2010 reporting, the slice south of Africa and the slice directly opposite had no readings at all.

Why those years? All four of those years are strong La Niña years.

What's the methodology? Splitting each slice into a 10 × 10 grid and looking for grid points that reported temperatures in at least 90% of the seasons between 1955 and 2010.

Are these numbers big or small? They are all over the place. The rise of 1.92° C and 2.77° C in the two regions surrounding the Antarctic Peninsula are very large indeed, as is the -1.17° C drop in the region south of the Indian Ocean.  There isn't another region in the ones we chose that had a drop that steep.

 What's the cause?  In the two slices with big increase, the change is albedo, areas where ice on the sea surface melts and exposes more water. Losing oceanic ice does NOT increase sea level, but it does mean more heat is absorbed. This is a feedback loop.


As for the region getting cooler, this may be due to more sea ice than before.

What's the main problem? Melting ice caps in the land mass around the Antarctic Peninsula.

What do humans have to do with this? Once again, greenhouse gases.

For answers to more questions, check out the Arctic recap.


Tomorrow, the temperate zone of the Northern Hemisphere, by far the most populous zone and the most land mass, so it is split into twelve slices instead of just six.

Four weeks of climate data: Arctic Circle Temperature Recap

It's time for a visit from my blog partner, Hypothetical Question Asker.

What do the numbers mean? These are the increases in the median temperatures Celsius from the 1955-1975 era to the 1999-2010 era in these six slices of the Arctic Circle.

Why those years? All four of those years are strong La Niña years.

What's the methodology? Splitting each slice into a 10 × 10 grid and looking for grid points that reported temperatures in at least 90% of the seasons between 1955 and 2010.

Are these numbers big or small? These numbers are hella big, as we say in Oakland. One degree in 56 years is a Big Damn Deal and the smallest number here is 1.38° C.

What's the cause?  In most of the slices, the big change is albedo, areas where ice on the sea surface melts and exposes more water. Losing oceanic ice does NOT increase sea level, but it does mean more heat is absorbed. This is a feedback loop.

What's the main problem? Melting ice caps in the land mass close to the pole, most notably Greenland but also the northernmost islands of Canada.

What do humans have to do with this? Greenhouse gases are our main contribution to the mix as far as the Arctic is concerned. Carbon dioxide (CO2), which is measured in parts per billion in the atmosphere, is at an unprecedented level. The thing is, the earth's climate is a very big thing that doesn't evenly distribute anything.

 If CO2 levels are higher than ever, why aren't temperatures higher than ever? That is a fair question. Not every system increases linearly. For example, gravity increases linearly when mass is increased, but decreases by the reciprocal of the square when distance increases. Other systems only increase by the square root or fourth root of some important variable. The greenhouse gas model hasn't been pushed to this level before, so maybe we will find out a linear increase isn't in the cards. In this case, slower would be better.

Is global warming to blame for Katrina or Sandy or the droughts in the Midwest?  Here, the predictive model doesn't state that exactly. The most that climate scientists can say is the odds of certain things happening seem to be on the rise and that rise is definitely noticeable.  For example, there are events called "100 year storms", based on the idea they can be expected to happen every 100 years. In some parts of the globe, the odds of the "100 year storm" have increased so much that they might now be fairly called "10 year storms" or even "5 year storms".

Later today, a similar recap for Antarctica.

Four weeks of climate data:Southern Temperate Region #6

The last region is the temperate section of the South Atlantic.

Just so we are clear, temperate islands are NOT tropical islands, and ten degrees of latitude can make a huge difference. It's cool in Tristan de Cunha and COLD in the South Georgia Islands.

A few years were taken out because only one island or the other was reporting. Taken together the Summer temperature jumped over a degree, which is definitely to be noticed.

On the other hand, the Fall median barely moved, though the record highs and lows did show a big jump.

In the Winter data, both the record high and median more of less flatline.

Spring shows increase in the high and median.

Confidence of the region warming:90.8%
Confidence of increasing rate: 79.2%
Change in median temperature from the 1955-1975 interval to the 1999-2010 interval: 0.46° C

We are not 95% confident the trend is warming here and the median composite rose less than a half degree Celsius in 56 years, which is not a serious cause for alarm.

This is the last region to look at in our Four Weeks of Climate Data, so now we will go into recap mode, looking at what regions are showing serious increases of more than a degree C from 1955-2010 and which ones are not warming as fast, starting with our six slices of the Arctic.

Four weeks of climate data: Southern Temperate Region #5

The fifth region of the Southern Temperate Zone is the last major land mass to be covered, as the last region which will be discussed later today is just two small islands in the south Atlantic.

As we can see, the actual land mass of Chile, Uruguay and Argentina is very well represented, as are a few islands both east and west.

The high temperature records haven't moved much in the Summer months, but the coldest Summers are getting warmer noticeably and the median has risen slightly.

Again, the record warmest in Fall is bouncing around, but the coldest Fall since the early 1970s has jumped up about a degree while the median is almost unchanged.

Winter gives us an idea of what data should look like if there was no overall trend.

Spring on the other hand shows upward movement in the low temperature measurement and two upward steps and one downward in the median and high measurement systems.

Confidence of the region warming: 97.7%
Confidence of decreasing rate: 88.5%
Change in median temperature from the 1955-1975 interval to the 1999-2010 interval: 0.15° C



There are important people in the history of statistics who were not in love with confidence tests, W. Edwards Deming being the best known. This data goes a long way towards proving Dr. Deming's point. We are confident of a warming trend because of 24 upward steps and 12 downward, and not quite confident of a slowing rate of warming because of 9 increasing steps and 15 decreasing steps.  More to the point, 0.15° C is really small for 56 years.

Later today, two little islands in the middle of the South Atlantic get their say, our last data points covering the globe.

Four weeks of climate data:Southern Temperate Region #4

Now we look at the temperate part of the South Pacific Ocean between New Zealand and South America.

Most of the famous South Pacific Islands are in the tropics. The best known of these islands are Easter Island, rightmost at (-105° long, -30° lat) and Pitcairn, where the Bounty mutineers settled, the second rightmost.

The low temperatures for Summer bounce around a lot, but the median shows steady increase.

Fall numbers show an increase at nearly every step.

Again, the low temperatures are bouncing around but the median grows steadily.

The cold Spring late last decade keeps this graph from showing steady increase everywhere.

Confidence of the region warming: 99.%
Confidence of decreasing rate: 65.8%
Change in median temperature from the 1955-1975 interval to the 1999-2010 interval: 0.45° C

We get a similar story to many of our regions. Yes, it's warming. No, we can't say if the rate is increasing or decreasing with any confidence and the amount of warming is in the range of a half degree Celsius in 56 years.


Tomorrow, our last two regions, Temperate South America and the temperate south Atlantic.

Four weeks of climate data: Southern Temperate Region #3

 And now we hit a big clump of land the the Southern Temperate Zone, Australia and New Zealand.

Unlike that one island in the south Indian Ocean, most of the land here is between the 25th and 45th parallels, which makes for more moderate weather in general.

All three of our measurement systems have two upward steps and one downward step. The increase in the median from the first era to the last is less than half a degree.

In the Fall, the general trend of increase is more noticeable, but the difference in medians from first to last is slightly less that the Summer change.

The increasing trend is more noticeable in the Winters and the median jump is over a half degree.

Spring is bouncing up and down more randomly than the other seasons, but the median shows a steady increase of about a half a degree.

Confidence of the region warming: 99.9%
Confidence of decreasing rate: 65.8%
Change in median temperature from the 1955-1975 interval to the 1999-2010 interval: 0.44° C

We get a similar story to many of our regions. Yes, it's warming. No, we can't say if the rate is increasing or decreasing with any confidence and the amount of warming is in the range of a half degree Celsius in 56 years.

Later today, the fourth region, the Pacific islands between New Zealand and South America.

Four weeks of climate data:Southern Temperate Region #2

 The second region of the Southern Temperate Zone is the Indian Ocean with a few scattered islands.

There were only readings from a few islands, and the only weather station that kept consistent readings from 1955 to 2010 was on the French controlled island Kerguelen.

As I said earlier, this "temperate zone" is cold. This is down in The Fifties and Summer average temperatures wander between 3° C to 7° C. For Americans, that's between 37.4° F and 44.6° F.

Cold. The coldest metric shows an increase, but the median and high show that the 90s were a little warmer than the first decade of this century.

 

The Fall numbers look similar to Summer, only more so, the 90s warmer that The Oughts.

Winter's pattern is different. Generally we see an increase across all metrics, but very little overall.

Spring is like Winter, but all the metrics show the big jump between the 1955-1975 era and the 1975-1988 period.

Confidence of the region warming: 99%
Confidence of decreasing rate: 97.9%
Change in median temperature from the 1955-1975 interval to the 1999-2010 interval: 0.55° C

One island in an expanse of ocean, but it counts as a region.  It's warming but the rate is slowing down and the level of warming over 56 years is not particularly alarming.

Tomorrow, Australia and New Zealand lumped together in the third region then the gap between New Zealand and South America as Region #4.

Four weeks of climate data:Southern Temperate Region #1

Instead of starting the Southern Temperate Region with a series of maps, let me just say how the split works in words.
Region #1. Southern Africa and Madagascar
Region #2: Southern Temperate Indian Ocean*
Region #3: Temperate Australia and New Zealand
Region #4: Southern Temperate Pacific Ocean*
Region #5: Temperate South America
Region #6: Southern Temperate Atlantic Ocean*

The asterisks on the oceanic section are because I didn't just use the polar region to look at Antarctic, but the 60th latitude instead so that no part of Antarctica would be ignored.  In my defense, the region south of the 60th latitude and north of the Antarctic Circle is famously cold, choppy and nasty with almost no land mass except the Antarctic Peninsula.
 

Southern Africa and Madagascar are pretty well covered. The grid point out in the middle of nowhere is probably Iles Crozet, a group of islands still administered by France.

Summers are getting warmer and the median and lowest temperature trends are getting increasingly warm each era.

Both the warmest and coldest records took a dip this century, but the median is getting warmer, more quickly at the turn of the century than previously. More than that, the median increase is more than a degree Celsius, a cause for alarm.

The Winter is steady but slow. Every step would be upward except that the record high is from the mid 1990s.

Almost perfect increasing trends everywhere except that the record in the 1980s was warmer that the record in the 1990s. Again, close to a degree increase in the medians.

Confidence of the region warming: 99.999%
Confidence of decreasing rate: 79.2%
Change in median temperature from the 1955-1975 interval to the 1999-2010 interval: 0.79° C

It's warming for sure, and at 0.79° C, it's warming faster that the region just to the north, which is Southern Tropical Africa. I don't consider 0.79° C a cause for alarm, but neither is it a cause for complacency.

Later this evening, the section of the Indian Ocean south of the Tropic of Capricorn and north of the 60th parallel.

Four weeks of climate data: Southern Tropics Region #6

 The last slice of the Southern tropics is all in the Atlantic Ocean between South America and Africa.

One station reported enough to be noticed from 1955 to 2010. This is the island of Ascension.

Notice there are gaps in the record in the first era from 1955 to 1975. Even so, there is enough data to be used under my system.

This is a region much like the rest of the Southern tropics.

If there is one difference, it's Winter. The median from 1999 to 2010 is slightly lower than the median from 1955 to 1975. It's anyone's guess if this would still be true if the missing years in the 1950s and 1960s existed.
 

Here's the overall story.

Confidence of the region warming: 99.5%
Confidence of increasing rate: 89%
Change in median temperature from the 1955-1975 interval to the 1999-2010 interval: 0.37° C


The Southern Tropics have some variation, but the basic story is we are confident of the warming, not confident of an increasing rate and the difference in the median values from the first era to the last are all well below a degree C.


Tomorrow, we start out look at the last section of the globe, the Southern Temperate Zone, which has even less land mass than the Southern Tropics.

Four weeks of climate data: Southern Tropics Region #5

 One of the main reasons I made the slices of the Southern Tropics different widths was to make sure one slice covered all of the land mass of South America that lies inside this region.

As you can see, there are some grid points in the Amazon basin that aren't covered in the era of 1955 to 2010, but overall the coverage is strong.

The low temperature graph of the Summer data shows steady warming, but barely a half degree. The other measurement bounce around a little, but they also show mild warming.

Again, generally warming but only slightly.

In all four of the graphs, the warmest reading of these 56 years happened some time in the 1990s.

And the Spring most resemble the Winter data.

Confidence of the region warming: 97.7%
Confidence of increasing rate: 50%, could go either way which means no confidence at all
Change in median temperature from the 1955-1975 interval to the 1999-2010 interval: 0.33° C


Yet again, we have a warming region, but it is not warming by very much or is it showing signs of speeding up. Later today, the last slice of the Southern Tropics, a few islands in the tropical southern Atlantic.