According to data from the U.S.-based National Centers for Environmental Information (NOAA), 2022 was the sixth warmest year since 1800 – that is, since we have had data on global temperatures. But, most significantly, the past nine years have been the warmest on record overall. Why then do we continue to observe extreme cold events such as frost waves? We ask this question especially during the winter. Let's clarify.
Global warming explained with physTo explain the meaning of global warming, let’s start with a simpleclassical physics problem. If you drive your car on the highway for a distance of 100 km at a constant speed of 100 km/h, it will take you60 minutes. If, on the other hand, you drive the same route for 60 km at 120 km/h and for the last 40 km at 90 km/h, you will takeless than 57 minutes. It is true that for a certain stretch your speed was very low, but onaverage your speed was above 100 km/h and therefore yourtravel time was reduced.
The same reasoning applies to the temperature of the Earth's atmosphere. Global warming is that climate phenomenon which, since the end of the 19th century, records a global increase in the average temperature on Earth.
The word "average" is very important because it means that global warming does not affect all areas of the Planet equally. Some areas are warming a lot, some less, and some may even experience a decrease in temperatures. But what does matter, and this is the point that scientists all agree on, is that globally the average temperature recorded each year is increasing, to the tune of almost one degree centigrade over the last century.
That global warming is taking place is confirmed by the United Nations Intergovernmental Panel on Climate Change (IPCC) in its latest report, which states, "It is virtually certain that there has been [...] a reduction in the number of cold days and nights globally since 1950. Both cold and warm extremes show a rise in temperatures."
But then, what are the frost waves due to?
The polar vortex hypothesiThere is no doubt about it:extreme cold weather events continue to occur. The latest example is thewinter storm that swept across much of the United States during Christmas 2022, with temperatures reaching minus 50 degrees Celsius, high winds, and heavy snowfall.
The scientific community attributes these sudden and intense waves of cold to ripples in the polar vortex, a current of cold air that generally rotates stably over the Earth's poles. It may happen that these eddies begin to undulate, bringing cold air even to mid-latitudes and thus causing the frost waves.
Again, however, the IPCC tells us that there is no scientific evidence linking climate change to an increase in polar vortex ripples. On the contrary, all the evidence indicates that the decrease in global cold extremes is also affecting the mid-latitudes.
So, in conclusion, while it is scientifically proven that episodes such as the Christmas 2022 winter storm are related to polar vortex ripples, we must consider that such events are to be regarded as exceptional episodes occurring within a rapidly warming global climate context.
Coldest March in Antartica 20th March 2020
the world’s southernmost continent is currently the coldest its ever been for the
time of year.
Last Friday, Antarctica set a record for its coldest March temp ever recorded,
not just for the day, but for the entire month.
The Vostok Station clocked a bone-chilling -75.3C (-103.54F) on the morning of
Friday, March 20, as spotted by @TempGlobal on Twitter:
world so far.
every single day has been above the average. Thailand is warmin faster than any country, not sure why.
some might be related to the shallow waters of the gulf of thailand which don't mix much and get warmer and
Snowpack on Eagle Island melted 4 inches in about a week.
Such rapid melting is caused by sustained high temperatures significantly above freezing.
Such persistent warmth was not typical in Antarctica until this century.
A heat wave this month in Antarctica sent temperatures soaring into the mid- to high-60s across northern portions of the normally frigid continent.
Surprisingly, the warmth melted about 20% of an Antarctic island's snow in only nine days, according to newly released images from NASA, leaving behind ponds of melted water where the snow had been.
"I haven’t seen melt ponds develop this quickly in Antarctica," said Mauri Pelto, a glaciologist at Nichols College in Massachusetts, in a statement. “You see these kinds of melt events in Alaska and Greenland, but not usually in Antarctica.”
Pelto said that during the heat wave, which peaked from Feb. 6 to 11, snowpack on Eagle Island melted 4 inches. This means that about 20% of seasonal snow in the region melted in this one event on Eagle Island, Pelto said.
The temperature peaked at 64.9 degrees Fahrenheit at Argentina’s Esperanza Base on Feb. 6, which was Antarctica's warmest temperature on record. A reading of 69.3 degrees was measured a few days later at a research station on Seymour Island, on Feb. 9, but that reading has not yet been officially verified.
Janruary 2020
Drought Hits Thailand
Thailand is experiencing its worst drought in possibly four decades. About half of the major reservoirs in the country stand below 50 percent of capacity. River levels are so low that saltwater from the ocean is creeping upstream and affecting drinking water supplies. And in a country where 11 million people work in farming, crop production and the economy are expected to suffer.
The drought conditions in Thailand were caused by a shorter-than-normal monsoon season and below-average annual rainfall in 2019. According to the Mekong River Commission (MRC), the monsoon rains arrived almost two weeks later and departed three weeks earlier in the Lower Mekong Basin, which includes Lao PDR (Laos), Thailand, Cambodia, and Vietnam. The MRC also stated an El Niño event created abnormally high temperatures and high evapotranspiration. Thailand was predicted to be affected particularly hard; the country is only two months into the dry season and reservoirs for irrigation and drinking are already low.
The map above shows soil moisture anomalies, or how much the water content near the land surface was above or below the norm for southeast Asia from January 1 to February 7, 2020. The measurements were derived from data collected by the Soil Moisture Active Passive (SMAP) mission, the first NASA satellite dedicated to measuring the water content of soils. SMAP’s radiometer can detect water in the top 5 centimeters (2 inches) of the ground. Scientists use that surface layer data in a hydrologic model to estimate how much water is present even deeper in the root zone, which is important for agriculture.
NASA Earth Observatory image by Lauren Dauphin using soil moisture data from NASA-USDA and the SMAP Science Team. Story by Kasha Patel.
Posted 17th February 2020:
Antarctica hits 69F, 20.7c, degrees days after record-breaking heat earlier.
If certified, the reading would be the
hottest temperature recorded on the frigid continent
A view of Orne Harbour in South Shetland Islands, Antarctica. (Johan Ordonez/AFP/Getty Images)
A weather research station on Seymour Island in the Antarctic Peninsula registered a temperature of 69.3 degrees (20.75 Celsius) on Feb. 9, according to Márcio Rocha Francelino, a professor at the Federal University of Vicosa in Brazil.
The nearly 70-degree temperature is significantly higher than the
65-degree reading taken Feb. 6 at the Esperanza Base along Antarctica’s Trinity Peninsula. The World Meteorological Organization (WMO) is reviewing that reading to see whether it qualifies as the continent’s
hottest temperature on record.
The new data, which was reviewed by The Washington Post, came from a research station that has been in place for 12 years, used mainly for monitoring the layer of permanently frozen soil known as permafrost. Francelino said the temperature sensor is located in a flat and open area, without obstacles.
Randall Cerveny, a meteorologist at Arizona State University who verifies
extremes for the WMO, previously called the Esperanza reading a
“likely record.” On Thursday, he said the organization is looking into the new
report, too, but urged caution about the higher reading.
He said many questions will have to be answered before the nearly 70-degree
reading is considered the hottest temperature yet recorded on the planet’s coldest continent.
“We will want to look very critically at the station’s metadata (how long was
it in place, how good has its observations been, what type of instruments
were used, when were they last calibrated, etc.),” he said in an email.
“All of those things are critical to determining the validity of the observation.”
No comments:
Post a Comment