We are balloon mapping the receding shoreline of the Salton Sea in Southern California. This is California's largest inland lake and now has a shoreline projected to recede by several hundred feet over the next 10 years. We are mapping the shore over time to show the increase of playa and potential increase in airborne dust. I am a professor working from Loma Linda University, but partnering with local organizations, notably the Alianza of Coachella Valley.
We have had successful mapping missions before: https://mapknitter.org/maps/yachtclubtest
We were mapping yesterday with 3 mylar balloons filled with commercial grade helium. The mylar ballons were made from emergency sleeping bags taped with foil tape and held the helium well. They are very light and have lifted the camera rig in the past. The camera is a Canon SX260 on a picavet suspended underneath the cluster of three mylar balloons.
There were 15 of us at the Salton Sea yesterday and it was 110 degrees at 5pm at the seashore yesterday and the balloon would only rise about 20feet at the most. It was the same rig that lifted the balloon successfully in February and earlier days of the year when it was much cooler. The helium was much cooler when it came from the tank and I think the temperature of the helium gas may have kept the balloon from rising. From researching solar balloons, I know that the gas in the balloon needs to be hotter than the ambient air temperature.
Is the helium lift a function of temperature? Has anyone else dared to balloon map in such heat?