Sudden Oak Life by Lee Klinger

Quadruple rainbow over Black Rock desert in Nevada, 2010. Photo by Valerie Velardi.

Update: After a bit of searching I have found that the photo above actually depicts a supernumerary rainbow, not a true quadruple rainbow.

March was a particularly wet month in Big Sur with 8.81” of rain measured at my home, compared to the March average of 5.60” over the past 10 years measured at Big Sur station, just a mile or so away. The wet March triggered landslips and mudslides that closed Highway 1 and prevented me from getting home to record the pH during the height of the rains. (As of this writing, Highway 1 is still closed between Big Sur and Carmel with a projected opening date of early May.) However, I was able to record the pH of four rainfall events and the data are shown below. Read the rest of this entry »

Big Sur coast, December 2010 (photo by Lee Klinger)

The December 2010 rain pH data for Big Sur are in and the results are posted in the table below. Note that I was away on travels during November 2010 , so I do not have pH data to report for that month. Rainfall amount, however, was recorded and totaled 1.89″ (h/t Lauren Gamblin). Read the rest of this entry »

The first rains of the season have fallen here in Big Sur and the data are rather surprising . . .

Another double acid rainbow in Big Sur (photo by Lee Klinger)

Read the rest of this entry »

Acid rainbow over Big Sur (photo by Lee Klinger)

April numbers are in for the rain pH in Big Sur. Precipitation total was 6.12″ for April and pH readings were made for seven rainfall events. The April values shown below are tending slightly higher (less acidic) than previous readings (see here, here, here, here, and here).

Rainfall amounts and pH in Big Sur - April 2010

Another acid rainbow in Big Sur (photo by Lee Klinger)

Below are the rainfall amounts and pH results from Big Sur for March 2010. With the notable exception of one rainfall event on the 9th, the pH values in March were a bit lower (more acidic) than average over the past four years (see here, here, here, and here).

Rainfall amounts and pH in Big Sur - March 2010

Acid rain falling on Big Sur (photo by Lee Klinger)

Below are the rainfall amounts and pH results from Big Sur for February 2010. In general the pH values are a bit higher (less acidic) than average over the past four years (see here, here, and here).

Rainfall amounts and pH in Big Sur - February 2010

What these and other rainfall pH data show is that the average pH of rainfall events in Big Sur over the past four years fluctuates significantly, with values spanning an entire unit of pH. This means that some events are 10 times more acidic than other events. Who knew that the rainfall pH of individual weather systems varies to such a degree?

Could these fluctuations be due to sampling error? Almost certainly not. After each set of measurements I check the accuracy of the pH meter and sensor using the 4.00 and 7.00 standards used in the calibration. For the 29 sets of samples measured so far this rainy season, the 4.00 and 7.00 standards were measured at 3.99 ± 0.02 and 6.99 ± 0.01, respectively. That darn good accuracy in my opinion.