It never fails. Hurricanes and tropical cyclones always bring out the manmade global warming alarmists, with their claims of unusually warm sea surface temperatures along the storm tracks. Of course those fictionally warmed sea surface temperatures were caused by rising CO2 emissions. We expected and saw that nonsense when Sandy struck the east coast of the U.S. mainland back in 2012. Not unexpectedly, data contradicted the claims. See the posts here and here.
The same unwarranted alarmist claims magically appeared when the two tropical cyclones (Iselle and Julio) threatened Hawaii last week. Iselle’s storm track is shown on the map to the right. (Please click on it to enlarge.) I’ve highlighted the coordinates I’ve used for Iselle’s storm track…before it reached Hawaii. Julio’s track was similar but ran a little north of Iselle’s. So, were the sea surface temperatures along Iselle and Julio’s storm tracks unusually warm, and have the sea surface temperatures there warmed during the satellite era?
The weekly Reynolds OI.v2 sea surface temperature anomalies for the coordinates of 15N-20N, 155W-120W, for the week centered on August 6, 2014, were above the 1971-2000 average. (Those are the base years used by NOAA for the Reynolds OI.v2 data.) But they were not unusually warm as shown by the horizontal red line. They have been warmer quite regularly since the start of the weekly data in January 1990. And it’s blatantly obvious that the sea surface temperatures have cooled there. The cooling rate is -0.3 deg C/decade since 1990, based on the linear trend shown in blue.
Weekly Iselle and Julio Storm Track SST Anomalies
The monthly satellite-enhanced Reynolds OI.v2 data stretches back as far as November 1981. The July 2014 sea surface temperature anomalies for Iselle and Julio’s storm tracks (shown in red) were not unusually warm, and the sea surface temperatures there have cooled since November 1981 based on the linear trend (shown in blue).
Monthly Iselle and Julio Storm Track SST Anomalies
HOW FAR BACK CAN WE GO AND STILL SHOW NO WARMING IN THAT PART OF THE EASTERN TROPICAL NORTH PACIFIC?
The next graph shows the NOAA ERSST.v3b-based sea surface temperature anomalies for the coordinates of 15N-20N, 155W-120W, from January 1880 to July 2014. I’ve highlighted the period of January 1930 through July 2014 in brown. Since January 1930, the warming rate of the sea surface temperatures for Iselle and Julio’s storm track is only +0.004 deg C/decade. That’s 4 one-thousandths of a degree C per decade. And as shown by the red horizontal line, the sea surface temperature anomalies back as far as the 1880s were comparable the July 2014 value…if you believe sea surface temperature data back that far.
Long-Term Monthly Iselle and Julio Storm Track SST Anomalies
YEAH BUT, YEAH BUT, YEAH BUT
History has shown, if I were to end the post there, then someone would say something to the effect of, Greenhouse gases have increased the amount of moisture in the air, making tropical storms worse than before.
To counter that nonsense, we turn to the NCEP/DOE Reanalysis-2 outputs of Specific Humidity, which represents the amount of moisture in the column of atmosphere. The units are kilogram of water vapor/kilogram of dry air. For Iselle and Julio’s storm tracks, there is nothing unusual high in the specific humidity for July 2014, and the trend since 1979 shows a decrease, not increase, in specific humidity southeast of Hawaii.
Monthly Iselle and Julio Storm Track Specific Humidity Anomalies
The weekly and monthly Reynolds OI.v2 sea surface temperature data are available through the NOAA NOMADS website here. The long-term monthly NOAA ERSST.v3b sea surface temperature data are available through the KNMI Climate Explorer. And the monthly specific humidity output of the NCEP-DOE Reanalysis-2 is available from the NOAA NOMADS website here.