Global Temperature November 2016 Preliminary

Climate Forecast System Reanalysis  (CFSR) monthly global surface temperature anomaly estimates for 2014 through November 2016 from the University of Maine Climate Change Institute (UM CCI) and from WeatherBELL (WxBELL) are graphed below along with monthly global temperature anomaly estimates for the lower troposphere derived from satellite measurements provided by the University of Alabama at Huntsville (UAH).  All three of these estimates showed a slight increase from October to November.  The November UM CCI and WxBELL estimates are preliminary and may change slightly when final estimates are released.  Click on the graph below to see a larger copy.

figure-1-global-temp-anom-2014-2016-nov-prel

Also shown for comparison are monthly global temperature anomaly estimates from five other major sources, including lower tropospheric estimates from Remote Sensing Systems (RSS), and surface estimates from the US National Center for Environmental Information (NCEI), US National Aeronautics and Space Administration (NASA) Goddard Institute of Space Studies (GISS), the UK Hadley Climate Research Unit Temperature version 4 (CRUT4), and the Berkeley Earth Surface Temperature (BEST), all  final through October 2016, except CRUT4 which is final through September 2016.  All estimates have been synced to the latest climatological reference period 1981-2010.

See the Monthly Trends page and the Daily Update page for the latest graphs of monthly and daily trends for the UM CCI CFSR estimates (access from the menu at the top of this page).

Global Temperature October 2016 Preliminary

Climate Forecast System Reanalysis  (CFSR) monthly global surface temperature anomaly estimates for 2014 through October 2016 from the University of Maine Climate Change Institute (UM CCI) and from WeatherBELL (WxBELL) are graphed below along with monthly global temperature anomaly estimates for the lower troposphere derived from satellite measurements provided by the University of Alabama at Huntsville (UAH).  All three of these estimates showed a slight decrease from September to October.  The October UM CCI and WxBELL estimates are preliminary and may change slightly when final estimates are released.  Click on the graph to see a larger copy.

figure-1-global-temp-anom-2014-2016-oct-prel

Also shown for comparison are monthly global temperature anomaly estimates from five other major sources, including lower tropospheric estimates from Remote Sensing Systems (RSS), and surface estimates from the US National Center for Environmental Information (NCEI), US National Aeronautics and Space Administration (NASA) Goddard Institute of Space Studies (GISS), the UK Hadley Climate Research Unit Temperature version 4 (CRUT4), and the Berkeley Earth Surface Temperature (BEST), all  final through September 2016.  All estimates have been synced to the latest climatological reference period 1981-2010.

Global Temperature September 2016 Preliminary

The September preliminary Climate Forecast System Reanalysis (CFSR) monthly global surface temperature anomaly estimates from the University of Maine Climate Change Institute (UM CCI) and from WeatherBELL (WxBELL) show a slight drop from August with levels similar to July as can be seen in the graph below.  The graph includes monthly estimates beginning January 2014.  The preliminary UM CCI global average temperature estimate of 15.92C ties the previous highest September 2003 CFSR estimate, for records beginning 1979.

figure-1-global-temp-anom-2014-2016-sep-prel

Also shown for comparison are monthly global temperature anomaly estimates from six other major sources, including lower tropospheric estimates from the University of Alabama at Huntsville (UAH) and Remote Sensing Systems (RSS), and global surface temperature anomaly estimates from the US National Center for Environmental Information (NCEI), US National Aeronautics and Space Administration (NASA) Goddard Institute of Space Studies (GISS), the UK Hadley Climate Research Unit Temperature version 4 (CRUT4), and the Berkeley Earth Surface Temperature (BEST), all  final through August 2016.  All estimates have been synced to the latest climatological reference period 1981-2010.

For longer trend graphs of the latest monthly UM CCI CFSR estimates, see the “Monthly Trends” page from the menu at the top of this post and for more detailed daily estimates, see the “Daily Updates” page.

Global Temperature August 2016 Preliminary

Climate Forecast System Reanalysis  (CFSR) monthly global surface temperature anomaly estimates for 2014 through August 2016 from the University of Maine Climate Change Institute (UM CCI) and from WeatherBELL (WxBELL) are graphed below along with monthly global temperature anomaly estimates for the lower troposphere derived from satellite measurements provided by the University of Alabama at Huntsville (UAH).  All three of these estimates showed a slight increase from July to August.  The August UM CCI and WxBELL estimates are preliminary and may change slightly when final estimates are released.

Figure 1 Global Temp Anom 2014-2016 Aug prelimnary

Also shown for comparison are monthly global temperature anomaly estimates from five other major sources, including lower tropospheric estimates from Remote Sensing Systems (RSS), and surface estimates from the US National Center for Environmental Information (NCEI), US National Aeronautics and Space Administration (NASA) Goddard Institute of Space Studies (GISS), the UK Hadley Climate Research Unit Temperature version 4 (CRUT4), and the Berkeley Earth Surface Temperature (BEST), all  final through July 2016.  All estimates have been synced to the latest climatological reference period 1981-2010.

For longer trend graphs of the latest monthly UM CCI CFSR estimates, see the “Monthly Trends” page from the menu at the top of this post.

Global Temperature July 2016 Preliminary

The graph below includes the latest monthly Climate Forecast System Reanalysis  (CFSR) global surface temperature anomaly estimates for 2014 through July 2016 from the University of Maine Climate Change Institute (UM CCI) and WeatherBELL (WxBELL) as well as the latest monthly global temperature anomaly estimates for the lower troposphere derived from satellite measurements provided by the University of Alabama at Huntsville (UAH).  All three of these estimates showed a slight increase from June to July.

Figure 1 Global Temp Anom 2014-2016 July

Also shown for comparison are monthly global temperature anomaly estimates from five other major sources, including lower tropospheric estimates from Remote Sensing Systems (RSS), and surface estimates from the US National Center for Environmental Information (NCEI), US National Aeronautics and Space Administration (NASA) Goddard Institute of Space Studies (GISS), the UK Hadley Climate Research Unit Temperature version 4 (CRUT4), and the Berkeley Earth Surface Temperature (BEST), all  final through June 2016.  The UM CCI and WxBELL July 2016 estimates are preliminary and may change slightly when final estimates are released.  All estimates have been synced to the latest climatological reference period 1981-2010.

For longer trend graphs of the latest monthly UM CCI CFSR estimates, see the “Monthly Trends” page from the menu at the top of this post.

Global Temperature June 2016 Preliminary

As of this writing on 2016 July 1, estimates of global temperature anomalies are available from three sources through June 2016.  The monthly global temperature anomaly estimates from these three sources since 2014 are presented in the graph below.

Figure 1 Global Temp Anom 2014 thru 2016 July

The graph includes monthly Climate Forecast System Reanalysis  (CFSR) global surface temperature anomaly estimates for 2014 through June 2016 from the University of Maine Climate Change Institute (UM CCI) and WeatherBELL (WxBELL) and monthly global temperature anomaly estimates for the lower troposphere derived from satellite measurements provided by the University of Alabama at Huntsville (UAH).  Also shown for comparison are monthly global surface temperature anomaly estimates from the US National Center for Environmental Information (NCEI) through May 2016.  The UM CCI and WxBELL June 2016 estimates are preliminary.

For longer trend graphs of the latest monthly UM CCI CFSR estimates, see the “Monthly Trends” page from the menu at the top of this post.

Mauna Loa Temperature Trend

Mauna Loa on the big island of Hawaii is probably more famous for being a large active shield volcano and for carbon dioxide and solar measurements than for temperature measurements.  However, the Mauna Loa Observatory (MLO) has been making continuous temperature measurements since 1977 and the data return is overall very good.  The observatory is run by the Earth System Research Laboratory (ESRL) which is part of the US National Oceanic and Atmospheric Administration (NOAA).  For more information, see this link: Mauna Loa Observatory.

The observatory is at an elevation of 3,397 meters (11,141 feet) above mean sea level about 5 kilometers (3 miles) north of the Mauna Loa summit that reaches to 4,169 meters (13,679 feet) above sea level.  See the map below for the position of the observatory relative to the summit.

Contour map of the summit of Mauna Loa

Contour map of the summit of Mauna Loa.
The observatory is at the location labeled “Weather Station”.

Below is a photograph of the MLO looking north toward Mauna Kea.  The tall tower has temperature sensors at 2 meters, 10 meters, and 35 meters above ground level.

I downloaded hourly meteorological data that is available by FTP from the ESRL web site here: FTP Data Finder.  I loaded the data into an Excel workbook by year and compiled daily, monthly, and annual statistics for temperature at 2 meters above ground level.  The average annual data return for temperature at 2 meters over the period from 1977 through 2015 was 97%, but there were a few fairly large gaps in the data.  The largest gap was from March 29 to April 29 of 1984. Since most of April was missing, I removed it from the data set.  I also compiled annual weighted means using the monthly averages in an attempt to make sure every month was weighted the same from year to year even if there was substantial missing data.  This is not a perfect approach and is subject to increased uncertainty if there is a large data gap near the beginning or end of a month where temperatures are normally rising or falling on average over the course of the month.  So, the incompleteness does add a small amount of uncertainty to the results, especially for the years with the lowest data returns – 1984, 1993, and 2001 with data completeness of 87, 88, and 88 percent respectively.

The annual average temperatures and associated trend are displayed in Figure 1.  The data show a fairly significant upward trend of +0.0264 degrees Celsius (C) per year (Coefficient of Determination R2=0.2537).  This temperature trend corresponds to +1.03C over the 39 year period of record and to +2.64C if it continued for 100 years.

Mauna Loa annual weighted mean temperature for 1977-2015.

Figure 1. Mauna Loa annual weighted monthly mean temperature for 1977 through 2015 (click to enlarge).

I noticed that since the high peak in 1995, the rise looks much weaker than before the peak.  So I made separate graphs for 1977-1994 shown in Figure 2 and for 1995-2015 shown in Figure 3.  The temperature trends in these graphs confirm that the rise was indeed steeper before 1995 than since 1995.

Mauna Loa annual weighted mean temperature 1977-1994

Figure 2. Mauna Loa annual weighted monthly mean temperature 1977 through 1994 (click to enlarge).

The temperature trend for 1977 through 1994 was +0.0345C per year, corresponding to -0.62C over the 18 year period or to +3.45C if that trend continued for 100 years.  The temperature trend for 1995 through 2015 was +0.194C per year, which is +0.41C over the 21 year period and would be only +1.94C if it continued for 100 years.  The statistical confidence in both of these trends is weak with R2=0.1038 for 1977-1994 and R2=0.0539 for 1995 to 2015.

Mauna Loa annual weighted mean temperature 1995-2015

Figure 3. Mauna Loa annual weighted monthly mean temperature 1995 through 2015 (click to enlarge).

Even though MLO is in the tropics at a latitude of 19.5 degrees north of the equator, the temperature shows a pronounce seasonal pattern as can be seen in Figure 4.  On average the highest monthly average temperature is for June and the lowest for February.

Mauna Loa monthly average temperature 2015

Figure 4. Mauna Loa monthly average temperature for 2015 as compared to the most recent climatological reference period of 1981 through 2010 (click to enlarge).

The most recent 1981-2010 standard climatological reference period averages are 5.2C for February and 9.1C for June.  Figures 5 and 6 show the temperature trend graphs for these two months respectively.

Mauna Loa February average temperatures 1977-2015

Figure 5. Mauna Loa February average temperatures 1977 through 2015
(click to enlarge).

The trend for February is only +0.0106C per year, corresponding to +0.41C over the 39 year period and to +1.06C if it continued 100 years.  The trend for June is much higher at +0.0279C per year, or +1.09C over the 39 year period and would be +2.79C if it continued 100 years.  The February graph also shows a larger variability in monthly average temperature from year to year compared to the June graph.

Mauna Loa June average temperatures 1977-2015

Figure 6. Mauna Loa June average temperatures 1977 through 2015
(click to enlarge).

Regardless how the data are sliced, the temperature trend at the MLO is significantly upward, although with a hint of a slower increase since 1995.  There is a slight chance that expansion of the observatory over time could have an effect similar to a miniature urban heat island that increases over time with the expansion.  How much influence the expansion might have on the temperature trend is difficult to determine without additional information about potential heat sources at the observatory and how they may have changed over time.  Even if we assume that such influences are insignificant, the upward temperature trend could be from natural causes and not necessarily from CO2.  From what I recall reading, hypothetical warming induced by CO2 should occur primarily at higher latitudes and not in the tropics.  Consequently, the observed upward trend is likely to be from unknown natural causes or possibly from increasing localized heat influence over time or both.