Climate Change

[Skybird]

Originally Posted by Rockstar

According to NASA and NOAA ‘climate change’ does not cause drought in the Untied States. The Pacific Decadel Oscillation (PDO) does and though the current drought in western U.S is bad it’s not the worst that’s ever happened.

Aree there two different NASAs, and two different NOAAs?

Autumn 2021

https://climate.nasa.gov/news/3117/d...-on-the-range/

https://cpo.noaa.gov/News/ArtMID/787...Can-Still-Help

And what you probabaly had on mind:
https://www.drought.gov/research-spo...en-megadrought

But you cannot conclude from that that droughts in California are not linked to climate warming. The authors clearly say the current years of mega draught would not have been as bad without the impact of climate warming as they now are . You make the classical mistake: you conclude from shorter termed phenomenons, in this case the PDA, on long term climate changes. But that is not what the authors are arguing.

This study builds on previous research on the southwestern megadrought. A study published in 2020 in the journal Science says a megadrought as bad or worse than anything even from known prehistory is very likely in progress, and warming climate is playing a key role. The 2020 research, which was also led by Williams, considered data only up to 2018, missing the exceptional dry years of 2020 and 2021. The 2020 study found that the 19-year period from 2000 to 2018 was probably the second driest in at least 1,200 years, but was still a few years shorter than the "megadroughts" of the past.

[Rockstar]

PDO is the climate phenomena which is producing the drought in the western U.S. that and the consumption of 332 billion gallons of water a day in California alone

[Skybird]

Originally Posted by Rockstar

PDO is the climate phenomena which is producing the drought in the western U.S. that and the consumption of 332 billion gallons of water a day in California alone

Both that, and factor X, where X is climate warming.

And the authors say that quite clearly.

Don't claim that NASA said something which it certainly has not said at all.

[Rockstar]

From NASA’s Jet Propulsion Laboratory California Institute of Technology.

https://sealevel.jpl.nasa.gov/data/v...l-oscillation/


What is the Pacific Decadal Oscillation?

The PDO is a long-term (10-20 year) oscillation of the Pacific Ocean in response to the changes in the atmosphere. During a warm (positive) phase, the response of the ocean to low atmospheric pressure over the Aleutian Islands causes ocean currents to bring warm waters in the Eastern Pacific Ocean and along the coast of North America and cool nutrient-rich waters in the western Pacific Ocean. This leads to higher sea levels along the coastlines of the Northeast Pacific. During a cool (negative) phase the Eastern Pacific Ocean becomes cooler and the Western Pacific Ocean becomes warmer. This leads to lower sea levels along the coastlines of the Northeast Pacific.

Why do we care?

The PDO has impacts on fisheries, especially on salmon production in Alaska which is enhanced during a warm phase. Also, the PDO has impacts on weather: a warm (cold) phase tends to cause heavy rains (droughts) in Eastern Pacific Ocean and droughts (floods) in Asia and Australia. In terms of sea-level change, the PDO is associated with sustained increases and decreases in sea level over the course of a decade or more, causing changes in coastal impacts.

————————

Pacific Decadal Oscillation Influences Drought

Recent sea level height data from the U.S./France Jason altimetric satellite during a 10-day cycle ending June 15, 2004, shows that Pacific equatorial surface ocean heights and temperatures are near neutral, but perhaps tending towards a mild La Niña for this summer and into the fall. “In the U.S. we are still under the influence of the larger than El Niño and La Niña Pacific Decadal Oscillation shift in Pacific Ocean heat content and temperature patterns. Much of the nation’s western farmland and forests are really dry as we continue to struggle with a severe 6-year drought. The reality is that the atmosphere is acting as though La Niña is present. This continuing oceanic pattern in the Pacific and atmospheric pattern over the western U.S. is also a precursor for an active hurricane season for the East and Gulf coasts for our coming summer and fall,” said JPL oceanographer Dr. Bill Patzert.

These images show sea surface height anomalies with the seasonal cycle (the effects of summer, fall, winter, and spring) removed. The differences between what we see and what is normal for different times and regions are called anomalies, or residuals. When oceanographers and climatologists view these “anomalies” they can identify unusual patterns and can tell us how heat is being stored in the ocean to influence future planetary climate events. Each image is a 10-day average of data, ending on the date indicated.

https://earthobservatory.nasa.gov/im...uences-drought

[Skybird]

So what? I do not deny pdo, but that it explains droughts' net amplitude all alone, as you implied.

[mapuc]

After having read Skybirds comment in his thread about this bicycle and how the water in the river is historical low I came to think of all the news I have seen from around the world.

We have since some year back a world drought.

If it's due to climate change I can't say. Have it happened before ?

No continent, except Antarctica, has been spared, according to the SPEI Global Drought Monitor.

https://www.latimes.com/world-nation...use-strategies

SPEI https://spei.csic.es/index.html

Markus

[em2nought]

Change is the only constant.