In a normal winter, we see increased clouds in April and May, with the clearest months being June and July. The last few years, the lidar team has been able to collect the most data in July. Unfortunately, we’ve been experiencing surprisingly poor weather for July. We’ve had multiple condition 1 (shelter in place) storms and consistent overcast conditions over the past few weeks. We’ve had a few small opportunities for runs, but we’re hoping for more.
Surprisingly, April was one of our clearest months this winter. We were able to collect to collect nearly 200 hours of data on the STAR lidar system, and significant amounts of Fe Boltzmann lidar data as well. In other years, that number can be as low as 80 hours of data.
We’re not sure why we are experiencing these strange deviations from the standard weather conditions. There are likely many factors, including year to year variability. My theory is that these deviations are in part due to the fact that this is an El Niño year, with ocean temperatures in the south Pacific elevated. Increased evaporation could lead to higher levels of moisture being circulated south to Antarctica, giving us more clouds than we would expect, especially as El Niño continues to increase in strength throughout the year. The effects of the El Niño can always be seen spread around the world, including many areas of the United States, so it wouldn’t be surprising if El Niño had effects on the weather even all the way down here in Antarctica.
Non-standard weather conditions could also be due to the increasing severity of climate change. For every 1º C of global warming, the atmosphere can hold ~7% more moisture. This can lead to increased evaporation in dry areas and increased moisture being circulated to wet areas. This is a part of the reason the US is experiencing worsening wildfires and floods. Antarctica is a desert biome, so we would expect increased evaporation. This may have played a part in the frequent fog we experienced during the summer season, and could play a part in the strange weather conditions we have been experiencing. Since climate change is such a long term process, it is difficult to attribute short term events such as strangely cloudy/clear months to its effects.
As with many atmospheric events, the strange deviation in weather conditions can likely be attributed to a few different factors, but it’s interesting to consider what the different causes could be. Perhaps the effects of El Niño or global warming will someday become a research interest within the Chu research group. We’ll be doing our best to get every hour of data we can so that the Chu research group can continue to investigate the intricacies of the atmosphere.
