The penguins at Dumont d'Urville Station experience the rain. There are some strange phenomena occurring at our planet's poles. While they may be expanses of frigid cold and intense snowfall, recent advances in geophysics are insinuating that these seemingly dead wastelands may be coming to life, and not in a nice way.
Evidence shows that the climate continues to warm and that there is an increase in precipitation in Antarctica. There are two new papers published in Geophysical Research Letters that are at the forefront of understanding new weather patterns. The rain data from ten stations across Antarctica was studied by Etienne Vignon and colleagues.
The stations were chosen due to their consistent archives of meteorological data as well as their geographic distribution: nine of them were located along the coastlines of Antarctica, while one was located directly at the South Pole. The data was used to show the behavior of the rain. The occurrence and character of precipitation events can be tracked by the stations, even though they are unable to describe the amount of rain that has fallen.
The researchers searched each station's record for "rainy days", defined in their manuscript as "any day during which there is at least one report of rain or shower in the past or present synoptic weather reports." The key was used to find days of drizzle. A map of the ten stations used for the study shows that most of the precipitation is along the coast.
During the summer months, stations along the East Antarctic coast report anywhere from zero to 22 days of liquid precipitation. There are upwards of 50 to 93 rainy days a year on the north-western edge of the Antarctic Peninsula. From 2000 to 2015, the number of rainy days decreased.
The work is one of the first attempts to understand the behavior of precipitation, but the researchers were curious about the future. They relied on the power of seven simulations within the CMIP6 project, which is a common climate model used within the field of geophysics, in addition to the present and historical data they collected across the ten weather stations. A high carbon emission scenario and an intermediate carbon emission scenario were used for the simulations.
The results of the team's simulations show that there will be an increase in the amount of precipitation across the continent. In the high emissions scenario, there will be an increase in total precipitation. This scenario showed two periods of increased precipitation, between 2015 to 2034 and again from 2081 to 2100.
A positive trend in annual average precipitation is observed, but to a lesser degree, in the intermediate emissions scenario. "All and all, that rain will increase in a warming climate should be of no surprise to anyone, but the magnitude at which this occurs on such a cold continent is of interest." said Richard Bintanja, a climate scientist and professor in the Netherlands who wasn't involved with this study A Seattle and New Zealand based research team has obtained data from the World Wide Lightning Location Network. There is a small burst of energy in the radio wave spectrum from lightning strikes.
As the waves bounce between the ground and the ionosphere, they can be detected as a lightning strike using incredibly sensitive receivers all over the globe. The research team used data from the WWLLN to study lightning strikes. The analysis was done by latitude, where lightning strikes above 65 North occurred.
The team constrained the data for each year since they found few lightning strikes in the northern part of the country. The team only analyzed data points that were detected by six or more WWLLN stations in order to ensure authenticity of a lightning strike. The researchers found that there was an upward trend in the amount of lightning strikes in the summer.
The team compared their lightning strike data to the global temperature change data from the National Oceanographic and Atmospheric Administration. The correlation between the lightning strike and global temperature change data is significant, as both show upward trends. What does changing weather mean for the poles?
It is possible that rain can cause a snowball of consequences. Vignon says that rain can help the melting of the snowpack. The melt can cause instability and melting in ice sheets.
The birds' feathers are not yet waterproof and can freeze as they encounter wind and rain, which may make them more hostile. The northern part of the world is a huge gateway for shipping vessels. Shipping vessels face an increased risk of getting struck by lightning as lightning strikes increase across the North Pole.
When there are a lot of people and they don't know about the lightning threat, it becomes a problem. The studies attempt to understand the behavior of weather phenomena at the poles. Understanding and monitoring these meteorological changes is crucial for determining how similar behavior in different parts of the world may evolve.
There is a reference to present and future of rain in Antarctica. The quotes from the press release have been adapted for use in the book. There are quotes from a press release.