Temperatures Medieval Climatic Anomaly
Question: How do current global temperatures compare to those associated with the Medieval Climatic Anomaly? Are there any good references to this information?
The average precipitation values for the SW USA are interesting. In our region of Northern California the average annual precipitation has decline 23% since the 1870’s (close to the end of the Little Ice Age). Despite the usual ups and downs the trend line is consistent (box car averaging). According to the Jepson Manual, Second Edition, there is abundant evidence that there were two major periods of drought in California, each lasting ~ 100 years, during the Medieval Climate Anomaly. Temperatures in the Sierra Nevada Mountains were as much as 3 C above present temperatures (the starting point of “present temperatures” is not clear). During July, temperatures in our portion of the Sierra Nevada (6,600 feet elevation) averaged 5.21 F above average. So far, August is running 6.14 F above average, and for 2021 to date 2.28 F (1.2667 C) above average. Over the last 17 years, the rate of temperature increase has been greater at higher elevation than those recorded at lower elevations (my personal temperature data recorded at 1,500 feet elevation ~ 40 years).
I have many questions concerning how the ENSO, MJO, and other climatic trends influence the SW monsoon. I look forward to this posting.