Study shows China's severe weather patterns changing drastically since 1960

February 17, 2017 by A'ndrea Elyse Messer
"A monsoon is one of the major drivers of severe weather because it affects the three necessary 'ingredients' for severe weather, which are wind shear, instability and triggering," said Fuqing Zhang, professor of meteorology and atmospheric science, Penn State. Credit: Douglas M. Paine

In one of the most comprehensive studies on trends in local severe weather patterns to date, an international team of researchers found that the frequency of hail storms, thunderstorms and high wind events has decreased by nearly 50 percent on average throughout China since 1960.

The team analyzed data from the most robust meteorological database known, the Chinese National Meteorology Information Center, a network of 983 weather observatories stationed throughout China's 3.7 million square miles. Meteorologists have been collecting surface weather data through the network since 1951 or earlier, which provided the researchers an unprecedented look at local occurrences.

"Most of the data published on trends in severe weather has been incomplete or collected for a limited short period," said Fuqing Zhang, professor of meteorology and atmospheric science and director, Center for Advanced Data Assimilation and Predictability Techniques, Penn State. "The record we used is, to the best of our knowledge, the largest, both in time scale and area of land covered."

The team, who report their findings today (Feb. 17) in Scientific Reports, found that the strength of the East Asian Summer Monsoon decreased at a rate strongly correlated to that of severe weather throughout the same time period. The monsoon is an annually recurring, long-term weather phenomenon that brings warm, moist air from the south to China in the summer, and cooler air from the north to China in the winter. A monsoon's strength is measured by calculating the average meridian wind speed in this area.

"We believe that changes in monsoon intensity are affecting severe weather in the area because of the strong correlation we found, but we cannot say the monsoon is the exclusive cause," said Zhang. "A monsoon is one of the major drivers of severe weather because it affects the three necessary 'ingredients' for severe weather, which are , instability and triggering."

Wind shear is the difference between the wind speed and direction at different altitudes. Because a monsoon brings southerly winds into China, a weaker summer monsoon would decrease the overall low tropospheric wind shear. The weaker monsoons would also bring less warm, moist air from the south—one of the most common sources of instability in the atmosphere. A common triggering mechanism for severe convective weather is lifting by the front, a high temperature gradient across the monsoon, and this would also be reduced in a weaker summer monsoon.

Some studies suggest that climate change may be one of the reasons that the Asian Summer Monsoon weakened. One factor in monsoon formation is the difference between the temperature above land and the temperature above adjacent ocean or sea. A warming climate would affect the difference between these two and, as a result, simulations show that this could continue decreasing the 's strength. However, the team noted that other major changes in the area—such as an increase in industrialization and air pollution in China in the 1980s—might have played a significant role in the region's atmospheric changes and could affect the severe weather.

While a decrease in severe weather might sound beneficial, it may not always be a good thing.

"There are many natural cycles that rely on severe weather and the precipitation it brings," said Qinghong Zhang, professor of atmospheric and oceanic sciences, Peking University, lead author of the study, who conducted this research while on sabbatical at Penn State. "A decrease in storms could potentially lead to an increase in droughts. Also, some theorize that while the frequency of severe weather decreases, their intensity could potentially increase. We cannot say if this is true yet, but it is something we will analyze in the future."

This was the first study in its level of detail because of the amount of data collected by the Chinese National Meteorology Information Center. The study also showed that occurrences of hail remained relatively steady from 1961 through the 1980s before plummeting.

"The frequency of thunderstorms and high winds decreased gradually over the time period we studied, but not hail," said Qinghong Zhang. "This is something we don't fully understand at this point but plan to investigate more."

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15 comments

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Chris_Reeve
1 / 5 (4) Feb 17, 2017
Given their emerging concern about severe pollution problems, China is well positioned to receive the climate change media virus. Perhaps it can become the go-to destination for U.S. climate scientists seeking a new safe space.
RealityCheck
4.3 / 5 (6) Feb 17, 2017
Hi Chris_Reeve. :)

Mate, you've seen ample evidence of my impartiality/objectivity when it comes to observations/commentary, regardless of the discipline/science involved. Yes? So, re your post:
Given their emerging concern about severe pollution problems, China is well positioned to receive the climate change media virus. Perhaps it can become the go-to destination for U.S. climate scientists seeking a new safe space.
I trust you will therefore understand why I cannot allow your above ill-informed and/or obviously politically/personally biased/motivated comment to stand unchallenged by the Reality evolving around us globally.

Egs:-

1) In Moree (Northern NSW, OZ) they have had 51 consecutive days of above-35 C temps; the previous record was a measly 17-19 consecutive day of such temps!

2) At least one of our beaches reached SAND TEMPS of 75 C; yes, that is C, not F, mate! Conservationists had to intervene to move/shade Turtle nests/eggs!

Reality NOW, mate. :)
RealityCheck
3.8 / 5 (6) Feb 17, 2017
Re the China weather topic/article, it should also include the effects of China's frequent/widespread use of "Cloud Seeding" to 1) make systems drop rain in preferred areas/times and 2) reduce the moisture load of dangerous systems before they 'break' later over sensitive/vulnerable agricultural/infrastructure locations etc.

Cloud seeding and moisture load reduction etc must affect the otherwise natural evolution of storm systems to their previous less frequent but more extreme dynamics/events.

Anyhow, all such studies should be careful to include ALL factors and not just the factors most easily quantified/available due to weather data which may not take into account the effects of seeding and other changing dynamics data not easily gathered' for the study.

Good luck to us all. :)
ddaye
5 / 5 (3) Feb 17, 2017
China is well positioned to receive the climate change media virus.
The President of the global superpower insists China started this.
rrrander
1 / 5 (2) Feb 18, 2017
Sorry socialist greenloons. China won't be doling out billions for your worldwide wealth re-distribution scheme.
unrealone1
1 / 5 (1) Feb 18, 2017
What about for the last 10,000 years, 60 years of data, there is not enough data points to make any predictions?
Anonym
1 / 5 (3) Feb 18, 2017
@RealityCheck: You call 35C hot??? (Just kidding, but you must be quite young.) Heat waves happen, man. That's the reality. In my neck of the woods, we had a record-breaking summer with 43 straight days over 100F (38C) and for the whole summer, 69 days over 100F. I'll never forget that summer because I worked in an un-airconditioned commercial kitchen. :-(

That was the summer of 1980, the place was north Texas, and the CO2 concentration was 280ppm. A few years before, the professional catastrophist James Hansen had warned that global cooling was going to end civilization by the year 2000. LOL.

By the way, that record still stands.

Plus ca change, baby!
Shootist
1 / 5 (2) Feb 18, 2017
The weather changes over time.

So does climate.

Human caused climate change is a singular fraud upon mankind.

"The polar bears will be fine" - Freeman Dyson
Anonym
1 / 5 (3) Feb 18, 2017
Oh, and I LOVE the robot who wrote the headline for this article, which if you haven't read the story, implies the weather has worsened in China rather than the opposite. Here is an object lesson in propaganda. Let's look at the difference a simple phrase can make:

"Study shows China's severe weather patterns changing drastically since 1960"

Let's get rid of "changing drastically" (as in "climate change," the writer's not-so-subtle allusion) and make it "decreasing," because that is what the severe weather actually did. Note the huge change in affect:

"Study shows China's severe weather has decreased significantly since 1960"

The headline sorta suggests a contretemps between climate as experienced and the hypothesized "climate change." Can't have that!

As Twain said, the difference between the right word and the almost-right word is the difference between lightning and the lightning bug. Or news and fake news, in this case.
Chris_Reeve
1 / 5 (2) Feb 18, 2017
Re: "What about for the last 10,000 years, 60 years of data, there is not enough data points to make any predictions?"

What about the Venus Pioneer mission?

_Pioneering Venus: A Planet Unveiled_ at http://www.amazon...9RXS7S8/

"One main objective of the Multiprobe mission was to test the belief that the 'runaway greenhouse effect' caused the high surface temperature."

(H. E. Revercomb, L. A. Sromovsky, and V. E. Suomi, "Net Thermal Radiation in the Atmosphere of Venus," _Icarus_ 61, p521-538 (1985))

"The magnitudes of the *corrections* for both instruments are determined by *forcing agreement* with a range of *calculated net fluxes* at one altitude deep in the atmosphere, where the net flux *must be* small because of the large density of co2."
RealityCheck
3 / 5 (2) Feb 18, 2017
Hi Anonym. :)
@RealityCheck: You call 35C hot??? (Just kidding, but you must be quite young.) Heat waves happen, man. That's the reality. In my neck of the woods, we had a record-breaking summer with 43 straight days over 100F (38C) and for the whole summer, 69 days over 100F. I'll never forget that summer because I worked in an un-airconditioned commercial kitchen. :-(

That was the summer of 1980, the place was north Texas, and the CO2 concentration was 280ppm. A few years before, the professional catastrophist James Hansen had warned that global cooling was going to end civilization by the year 2000. LOL.

By the way, that record still stands.

Plus ca change, baby!
But it's the SUDDEN/EXTREME CHANGEs in 'norms' in ANY place; in my example a place where most consecutive days over 35C WAS 17-19, but NOW 51 consecutive days!

Such TRENDING extreme CHANGES create havoc/costs to health, infrastructure, agriculture etc.

PS: I am 67; not young as you imagined. :)
RealityCheck
3 / 5 (2) Feb 18, 2017
Hi Chris_Reeve. :)

Didn't you understand my earlier explanation elsewhere regarding Venus situation and atmosphere preventing escape of internal heat coming up to surface/atmos? Even if solar radiation is totally blocked at high altitudes, the build-up over billions of years of heat from internal source would produce what we observe now. Again, it's the atmospheric thickness/constituents etc properties which ultimately determines a NET resultant temp/effect regardless where the heat came from. In the case of Venus, the heat cannot escape to space as readily as on our planet, so the the part of the 'greenhouse effect' that most applies is the trapping/internal reflection of heat/radiation from 'below'; which creates the observed situation despite little sunlight reaching down into lower atmospheric layers.

Please try to discern the relevant factors/effects and try to avoid simplistic overviews which miss the crucial aspects which explain the actual situation. Thanks. :)
RealityCheck
3 / 5 (2) Feb 18, 2017
Hi Shootist.:)
The weather changes over time.

So does climate.

Human caused climate change is a singular fraud upon mankind.
It's RATE OF CHANGE that is so damaging/costly for existing humanity and current infrastructure/agriculture/economies/health etc. How long before you 'get' that very important subtlety, mate? Your simplistic sloganeering ignores all of the actual reality involved, and just panders to the naive and simple 'minds' which politicians and religionist 'exploit' to their own self-interested advantage, at great costs to humanity as a whole, well into future generations.

"The polar bears will be fine" - Freeman Dyson
Dyson admitted otherwise since his early ignorant remarks. We now know that as sea-ice sheets/packs melt, the most crucial 'hunting' areas/prey (seals/dolphins at 'breathing holes') are no longer available/easy. They will therefore be constrained to poorer/less-dependable prey/areas on land, competing with grizzlies etc.

Get now? :)
BubbaNicholson
not rated yet Feb 19, 2017
Petroleum sheens diminish evaporation and decrease winds and cyclones as evidenced by diminished hurricanes after ocean oil spills.
antialias_physorg
5 / 5 (1) Feb 20, 2017
The weather changes over time.

So does climate.

Not at the speed it has been changing since the industrial revolution. Change is not the issue. It's the SPEED at which it's happening. To a slow crawl over many thousands of years we (and other life) could adapt. Change at the rate that is occuring now is a threat to our ability to sustain ourselves at the level we're at.

Sorry socialist greenloons. China won't be doling out billions for your worldwide wealth re-distribution scheme.

China installed more solar than any other country last year. They have massive smog problems in their cities and are starting to see that if they have to continue shutting down factiries that means their economy will suffer.

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