monsoons

Phoenix Is Frying | Earth Wise

August 15, 2023 By EarthWise Leave a Comment

The mythical Phoenix is a bird that repeatedly dies in a fire of its own making. During July, the five million inhabitants of greater Phoenix Arizona may have felt like they were reliving that myth as multiple temperature records were shattered in a massive heatwave.

On June 30, the high temperature in Phoenix was 110 degrees. From then on, the daily highs were relentlessly at or above 110 degrees, topping out at 119 on July 20. The previous record for consecutive days at or above 110 was 18 set in June 1974. The streak continued all the way until July 31, when incoming desert monsoons resulted in the high temperature dropping to 107 degrees – ending the streak at 31 days. Along the way, there were 16 days with temperatures at or above 115 degrees.

During the month, there were 17 consecutive days when the lowest temperature in Phoenix was at least 90 degrees. The previous record for that was 7 days, set in 2020. Because of these lofty low temperatures, July was also the hottest month in terms of average temperature with a reading well above 102 degrees. It was the first time that the average temperature has ever been in three digits. The previous record was 99.1 degrees in 2020.

Phoenix is an extreme case, but it was not alone in having a hot July. Globally, it was the hottest July on record that included major heat waves in the U.S., Mexico, China, southern Europe, and elsewhere. The daily record for the hottest average temperature on Earth ever measured was also broken several times during the month.

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Phoenix heat wave is shattering temperature records

Photo, posted September 22, 2022, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

2022 Temperature Report | Earth Wise

February 8, 2023 By EarthWise Leave a Comment

The average surface temperature for the Earth in 2022 tied with 2015 as the fifth warmest on record. The warming trend for the planet continued with global temperatures 1.6 degrees Fahrenheit above the average baseline for 1951-1980 that NASA uses for its studies. Compared with the late 19th century average used in setting climate goals, global temperatures are up about 1.1 degrees Celsius, or 2 degrees Fahrenheit.

Overall, the past nine years have been the warmest since modern recordkeeping began in 1880. The rising temperatures have moved in concert with rising levels of greenhouse gases entering the atmosphere from human activity. Many factors can affect the average temperature in any given year including El Nino and La Nina conditions in the Pacific. But the longer-term trend is quite clear. Global temperatures continue to rise.

Greenhouse gas emissions have reached all-time high levels despite increasing efforts to reduce them. There was a real drop in levels in 2020 due to reduced activity during COVID-19 lockdowns, but they rebounded soon thereafter.

The Arctic region continues to experience the strongest warming trends, as much as four times the global average. Arctic warming has a major impact on weather at lower latitudes as it changes the behavior of the jet stream as well as affecting ocean currents and water temperatures.

As global temperatures continue to rise, rainfall and tropical storms have become more intense, droughts have become more severe, and ocean storm surges have had increasing impact. From torrential monsoons in Asia to megadroughts in the U.S. Southwest, extreme weather has become the new normal.

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NASA Says 2022 Fifth Warmest Year on Record, Warming Trend Continues

Photo, posted June 20, 2020, courtesy of Daxis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tracking Global Forest Changes | Earth Wise

January 30, 2023 By EarthWise Leave a Comment

India is one of the most biodiverse countries in the world. An estimated 47,000 plant species and 89,000 animal species can be found in India, with more than 10% of each thought to be on the list of threatened species.

India is also one of the 10 most forest-rich countries in the world. Trees cover approximately 25% of the nation. But this is still a significant decline from years past. In fact, between the 1890s and 1990s, a combination of rapid development and resource overexploitation caused India to lose nearly 80% of its native forest area. Today, as India’s forests continue to disappear, researchers are trying to help preserve what forest remains.

Using satellite-monitoring data, researchers from The Ohio State University have developed a deep learning algorithm that could provide real-time land use and land cover maps for parts of India.

The land use monitoring system was trained using satellite data from Norway’s International Climate and Forests Initiative. By combining this data with a global land cover map produced by Tsinghua University in China, the researcher team’s deep learning model was able to acquire a more detailed type of base map of the area. Using their model, the researchers were able to process 10 monthly maps. Their research was recently presented at the annual meeting of the American Geophysical Union.

Using these maps, the researchers were able to detect seasonal shifts across india. These include changes to barren land, how crop land was affected by monsoons, and the distribution of forests in mountainous regions.

Understanding the impact of these seasonal changes will help scientists better predict the effects of climate change on forests.

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Using deep learning to monitor India’s disappearing forest cover

Photo, posted January 20, 2013, courtesy of Frontier Official via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Bengal Water Machine | Earth Wise

October 31, 2022 By EarthWise Leave a Comment

Over the past three decades, the owners of 16 million small farms in the Bengal Basin of Bangladesh have been pumping shallow groundwater during dry seasons to irrigate rice paddies. By lowering groundwater levels in this way during the dry season, the ability of leakage from rivers, lakes, and ponds to replenish the groundwater was greatly enhanced. Capturing surface water not only improved the recovery of groundwater levels but only helped to reduce flooding during monsoons.

The net result of this enormous collective groundwater pumping by millions of farmers has been the creation of vast natural reservoirs underground that are comparable to what is contained by many of the world’s largest dams. This system of sustaining irrigation has transformed what was previously a famine-prone country into a food-secure nation.

The details of this remarkable transformation have been laid out in a study by University College London recently published in the journal Science. According to the study, over the course of 30 years, more than 75 cubic kilometers of fresh water was captured by this process, which is equivalent to the combined reservoirs of China’s Three Gorges Dam and the Hoover Dam in the U.S.

The authors of the study described the water cycling process as “The Bengal Water Machine” and argue that it can be a sustainable alternative to conventional approaches to seasonal river flow storage for irrigation, which typically involve dams and reservoirs. Such approaches are difficult to implement in densely populated alluvial plains where sand, silt, and clay are laid down by annual floodwaters.

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Millions of farmers “replumb” world’s largest delta

Photo, posted February 2, 2010, courtesy of Melanie Ko via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sahara Greening And Tropical Cyclones

July 25, 2017 By EarthWise

Global weather patterns are influenced by environmental conditions in places around the world. One of the world’s major weather creators is the Sahara Desert. The Sahara is the largest hot desert in the world. The only larger deserts of any sort are in the polar extremes of the planet and are thus not hot deserts at all.