#Monsoon2021: So Far, It’s Been Wet, Wild And A Valuable Part Of Arizona’s Moisture Mix — #Arizona Department of Water Resources #ColoradoRiver #COriver #aridification

Photo credit: Arizona Department of Natural Resources

From the Arizona Department of Natural Resources

Even before the substantial torrents of summer rains over the past week or so finally paused, water and weather experts were acting to contain the public’s excitement about the impact of the monsoon on the Southwest’s long-running drought.

The rainfall is great, they noted. Rainfall in an arid place is almost always a welcome event. But truth be told, summer storms just aren’t drought-killers. Fending off drought – especially the kind of long-running drought the Southwest has experienced — takes deep winter snowpack in the region’s mountainous watersheds. After more than two decades of dry conditions, it would take several consecutive years of deep snowpack to release from drought’s grip.

“It’s helpful, but it also doesn’t solve the problem,” observed ADWR’s Chief Hydrologist Jeff Inwood earlier this week.

So, are we to conclude that summer rainstorms have no meaningful effect on drought conditions? Absolutely not!

Graphic credit: Arizona Department of Natural Resources

The near historic lack of monsoon moisture in 2020 contributed substantially to the extraordinarily low rate of runoff into the Colorado River system this spring. A lack of spring rain helped dry out soils to such an extent that those thirsty soils soaked up far more watershed runoff than normal this spring.

As a result, Rocky Mountain region snowpack from the 2020-2021 snow-season peaked at 89 percent of seasonal median. Contrary to the expectation that relatively higher precipitation would result in a larger runoff volume, unregulated inflow into Lake Powell gauged at an utterly abysmal 54 percent of average. The 30-year (1981-2010) average for unregulated inflow into Lake Powell is 10.83 million acre-feet. The forecasted unregulated inflow for Water Year 2021 (Oct. 1, 2020 – Sept. 30, 2021), as of July, according to data from the Bureau of Reclamation, stands at just 3.248 million acre-feet, which is 30 percent of the normal.

A healthy summer rainy season helps mitigate that soil absorption.

Monsoon rain can help rehydrate our soils, which helps get snowmelt runoff into the reservoirs. Also, some portion infiltrates into the ground and replenishes the aquifers. Not a lot, to be sure, but some.

“By soaking the soils with these monsoon rains, it will help additional moisture and rains runoff into streams and ultimately into reservoirs,” added Inwood.

In the meanwhile, it doesn’t hurt to revel in the healthy moisture delivery dropped off in recent days by Mother Nature.

Monsoon 2021 rainfall measured at Tucson International Airport set one of several records set this season with 5.88 inches of rain through July 25.

At Phoenix Sky Harbor International Airport, meanwhile, National Weather Service officials reported 1.67 inches for the month as of July 25, making 2021 the wettest July since 2013 and the 17th wettest on record. Overall the Phoenix Rainfall Index for July 2021 (that is, the average of all the official rain gauges throughout the Valley), stood at 2.66 inches, making July 2021 the wettest month overall in the Valley since October 2018.

Want more Happy Weather Talk? Through July 26, total monsoon rainfall at Sky Harbor was 1.84 inches, which exceeds the combined total rainfall for the 2019 and 2020 monsoon seasons (1.66 inches).

Cumululative time spent in severe #drought conditions in US (January 2010 through July 2021) — @Bewickwren #aridification

Cumululative time spent in severe #drought conditions in US. ⁦Data via The National Drought Mitigation Center at the University of Nebraska-Lincoln.

Critical measures of global heating reaching tipping point, study finds — The Guardian #ActOnClimate

Photo credit: NRCS

From The Guardian (Katharine Gammon):

Carbon emissions, ocean acidification, Amazon clearing all hurtling toward new records

A new study tracking the planet’s vital signs has found that many of the key indicators of the global climate crisis are getting worse and either approaching, or exceeding, key tipping points as the earth heats up.

Overall, the study found some 16 out of 31 tracked planetary vital signs, including greenhouse gas concentrations, ocean heat content and ice mass, set worrying new records.

“There is growing evidence we are getting close to or have already gone beyond tipping points associated with important parts of the Earth system,” said William Ripple, an ecologist at Oregon State University who co-authored the new research, in a statement.

“The updated planetary vital signs we present largely reflect the consequences of unrelenting business as usual,” said Ripple, adding that “a major lesson from Covid-19 is that even colossally decreased transportation and consumption are not nearly enough and that, instead, transformational system changes are required.”

While the pandemic shut down economies and shifted the way people think about work, school and travel, it did little to reduce the overall global carbon emissions. Fossil fuel use dipped slightly in 2020, but the authors of a report published in the journal BioScience say that carbon dioxide, methane and nitrous oxide “have all set new year-to-date records for atmospheric concentrations in both 2020 and 2021”.

In April 2021, carbon dioxide concentration reached 416 parts per million, the highest monthly global average concentration ever recorded. The five hottest years on record have all occurred since 2015, and 2020 was the second hottest year in history.

The carbon dioxide data on Mauna Loa constitute the longest record of direct measurements of carbon dioxide in the atmosphere. C. David Keeling of the Scripps Institution of Oceanography began measurements in 1958 at the NOAA weather station. NOAA started its own CO2 measurements in May of 1974, and they have run in parallel with those made by Scripps since then. Credit: NOAA and Scripps Institution of Oceanography.

The study also found that ruminant livestock, a significant source of planet-warming gases, now number more than 4 billion, and their total mass is more than that of all humans and wild animals combined. The rate of forest loss in the Brazilian Amazon increased in both 2019 and 2020, reaching a 12-year high of 1.11 million hectares deforested in 2020.

Ocean acidification is near an all-time record, and when combined with warmer ocean temperatures, it threatens the coral reefs that more than half a billion people depend on for food, tourism dollars and storm surge protection.

However, there were a few bright spots in the study, including fossil fuel subsidies reaching a record low and fossil fuel divestment reaching a record high.

In order to change the course of the climate emergency, the authors write that profound alterations need to happen. They say the world needs to develop a global price for carbon that is linked to a socially just fund to finance climate mitigation and adaptation policies in the developing world.

The authors also highlight the need for a phase-out and eventual ban of fossil fuels, and the development of global strategic climate reserves to protect and restore natural carbon sinks and biodiversity. Climate education should also be part of school curricula around the globe, they say.

Green Mountain Reservoir about 17 billion gallons below normal — The Summit Daily #BlueRiver #ColoradoRiver #COriver #aridification

Green Mountain Reservoir. Photo credit: Colorado Parks & Wildlife

From The Summit Daily (Taylor Sienkiewicz):

Downstream call placed on the reservoir for irrigation water rights

Green Mountain Reservoir, one of the biggest reservoirs in Summit County, located in Summit County, is low this summer, but it’s not as low as in previous drought years.

The reservoir is currently storing about 101,000 acre-feet of water — 32.9 billion gallons — James Heath, division engineer for the Colorado Division of Water Resources, said in an email. He noted that the reservoir is typically nearly full around this time of year. A full Green Mountain Reservoir is about 154,000 acre-feet of water, or approximately 50 billion gallons.

However, Heath said in previous drought years like 2002 and 2012, there was less water stored in the reservoir than there is this year.

Heath explained that the runoff from the Blue River this year was not enough to fill both Dillon Reservoir, which is upstream, and Green Mountain Reservoir, which is downstream…

Releases from Green Mountain Reservoir make their way to the Colorado River to appease those downstream with senior water rights. Heath said these releases replace upstream depletions from West Slope diversions and the Colorado Big Thompson project, which delivers the approximate volume of Dillon Reservoir to the South Platte Basin.

Heath noted that there has been a call for irrigation water rights downstream in the Grand Valley, which means senior water users have requested to restrict the use of water among junior water users because there is not enough water in the system to allow all water diversions. This requires Green Mountain Reservoir to stop storing, pass inflows and make releases.

While calls on Green Mountain Reservoir can restrict use for junior water users, there is a group of western Colorado water users that have historically benefited from releases out of Green Mountain Reservoir, called historic user pool beneficiaries, that are allowed to continue to divert after a call is placed on the river.

Since July 10, the reservoir water level has dropped about 7,000 acre-feet, or 2.2 billion gallons, according to the Colorado Division of Water Resources website. For most of July, Green Mountain Reservoir’s discharge to the Blue River was below the historic average.