The COVID-19 shutdown is making weather prediction more difficult:
The World Meteorological Organization's Global Observing System -- one third of the WMO's overarching World Weather Watch program -- was established in 1963 and provides a variety of atmosphere and ocean surface measurements to the WMO's 193 member states. These measurements are gathered from satellite and ground-based observation platforms, as well as commercial aircraft. They're then disseminated via the WMO's Global Telecommunication System (GTS) before being processed by the Global Data-processing and Forecasting System (GDPFS).
The ground and satellite components of that system are largely automated and generally immune to at least the immediate impacts of the COVID-19 pandemic. Lars Peter Riishojgaard, Director, Earth System Branch in WMO's Infrastructure Department believes that the impact of losing those aerial observations will still be "relatively modest." However, he explained in a recent press release, "as the decrease in availability of aircraft weather observations continues and expands, we may expect a gradual decrease in reliability of the forecasts."
[...] More immediate is the problem with the system's aircraft-based sensors; primarily that they're no longer in the sky, collecting vital ambient temperature, wind speed and direction readings. Aircraft rely on the Aircraft Meteorological Data Relay program (AMDAR) to collect the necessary data using onboard sensors, process and transmit it to relay stations on the ground via radio or satellite link.
[...] "As of March 31, the daily output of meteorological data from U.S. commercial aircraft has decreased to approximately half of normal levels," the NOAA rep continued. They were also quick to point out that "even though a decrease in this critical data will possibly negatively impact forecast model skill, it does not necessarily translate into a reduction in forecast accuracy since National Weather Service meteorologists use an entire suite of observations and guidance to produce an actual forecast."
[...] Thankfully, meteorologists won't be flying completely blind with so many airlines effectively out of commission. The ECMWF began pulling wind data from the Aeolus satellite in January. As for the NOAA, "while the automated weather reports from commercial aircraft provide exceptionally valuable data for forecast models, we also collect billions of Earth observations from other sources that feed into our models, such as weather balloons, surface weather observation network, radar, satellites and buoys," the spokesperson told Engadget. "Additionally, NOAA will soon be using COSMIC-2 GPS radio occultation satellite data to further increase observations throughout the depth of the tropical atmosphere."
(Score: 1, Insightful) by Anonymous Coward on Monday April 27 2020, @09:02PM (3 children)
It's Trump's fault. 100%
(Score: -1, Redundant) by Anonymous Coward on Monday April 27 2020, @09:17PM
People lighting themselves up with ozone emitting UV lights gonna start a trend.
(Score: 0, Funny) by Anonymous Coward on Monday April 27 2020, @11:03PM
Don't worry, once we get some of those injectable disinfectants, things will start to take off.
If that is still not enough, Georgia gov Brian Kemp thinks praying to MrMagicGod will help.
(Score: -1, Offtopic) by Anonymous Coward on Tuesday April 28 2020, @06:31AM
Jesus. That was a joke. It should modded troll or funny, but insightful? Morons.
(Score: 4, Interesting) by Anonymous Coward on Monday April 27 2020, @09:29PM (1 child)
Weather forecasts are heavily influenced by computer models, which are rather sophisticated simulations of the atmosphere. To get a useful simulation of the atmosphere, the state of the model at its start should be a very good approximation of the state of the actual atmosphere. It's not totally accurate because of the limited resolution of the models, observational error, and the limited spatial availability of observations. To get the state of the model close to the atmosphere's actual state, it's nudged with actual observations through a process called data assimilation. The primary value of AMDAR observations is that they're used in data assimilation.
Rawinsondes are generally launched twice a day at 00 and 12 UTC, though sometimes more frequently in times of hazardous weather. Aircraft observations are a very good source of in situ observations in between the rawinsonde launches. There aren't a whole lot of other in situ upper air observations. Perhaps the lack of AMDAR observations could be supplemented by more frequent rawinsonde launches. There's also still a considerable amount of AMDAR observations because instruments are mounted on freight aircraft, which haven't been impacted nearly as much as passenger aircraft. There are also ways to obtain upper air observations through remote sensing from satellites and, to some degree, GPS propagation, radars, and SODAR. These are subject to greater errors and have some limitations. But in some areas like over large portions of the world's oceans, these are some of the best observations we have available. Without satellite observations, hurricane forecasting would be considerably more difficult.
Data assimilation is also a complicated and nuanced matter. More observations don't always equate to better performance. Models typically get their initial conditions from cycled assimilation systems. Perhaps the model state is updated with all the observations within a window of +/-30 minutes. Then the model is integrated forward to simulate the state of the atmosphere an hour later. Then the model state is updated again with all the observations within a window of +/- 30 minutes at the new time. And this process repeats continuously. It's entirely possible that if we get 10 takeoffs and landings within the one hour assimilation window, it may not actually be any better than if we only had two takeoffs and landings. The additional data may well be redundant and contribute little to improved forecasts.
If you really want to know how much of an impact the decrease in AMDAR observations is having, run a data denial experiment. Go forecast past weather cases but only assimilate 50% of the AMDAR observations. Run the model and see if it has a significant impact on the forecast skill. The article talks about a 15% decrease in skill for jet stream forecasts and 3% decrease in skill for surface pressure forecasts, but that's if AMDAR observations are eliminated entirely. I don't think the impact is nearly as severe with AMDAR observations halved. It's also possible that there's virtually no impact in areas that have freight aircraft hubs but a more noticeable impact in areas with less freight and more passenger traffic. But I suspect the overall impact on weather forecasts is quite small.
(Score: 2) by Bot on Tuesday April 28 2020, @02:19AM
It's also not a big deal cause you gotta stay home anyway :D
Account abandoned.
(Score: -1, Flamebait) by Anonymous Coward on Monday April 27 2020, @10:33PM (4 children)
If you believe man impacts climate, it's not a stretch to believe a virus impacts the weather.
(Score: -1, Offtopic) by Anonymous Coward on Monday April 27 2020, @10:53PM (2 children)
The virus is impacting air pollution.
(Score: -1, Troll) by Anonymous Coward on Monday April 27 2020, @11:32PM
By emitting methane? Jesus Christ, you Gretaphiles are idiots.
(Score: 0, Troll) by Bot on Tuesday April 28 2020, @02:16AM
Yeah in fact in Rome and Milan after covid there was an INCREMENT in air pollution. No cars around. Turns out most of it comes from heating. So after we spent billions on electric car infrastructure we will probably be at square 1/2.
Sometimes actual science (experimental) can be still performed heh.
Account abandoned.
(Score: -1, Offtopic) by Anonymous Coward on Tuesday April 28 2020, @01:38AM
If?
Denialist loony.
(Score: 2) by krishnoid on Tuesday April 28 2020, @01:15AM
The air quality index [aqicn.org] is much improved -- it's only at 'unhealthy' for the time being.
(Score: 0) by Anonymous Coward on Tuesday April 28 2020, @06:37AM
Here's the code (in COBOL): today = 50% yesterday + 50% last year
The reason it takes a supercomputer is because the code only runs on 1950's version of COBOL and no-one alive knows how to port it.
(Score: 0) by Anonymous Coward on Tuesday April 28 2020, @03:20PM (2 children)
When the imaginary disease that causes you to stay in bed and eat cheese sticks until midday... makes the weather prediction that 50% of us don't trust anyway slightly less accurate.
(Score: 1, Insightful) by Anonymous Coward on Tuesday April 28 2020, @04:37PM (1 child)
Real 1st world problems, over-privileged and under educated bored people inventing conspiracies to make their lives seem a little more exciting.
(Score: 0) by Anonymous Coward on Tuesday April 28 2020, @06:52PM
To be fair, for much of the population these could be replaced with a weather rock:
https://en.wikipedia.org/wiki/Weather_rock [wikipedia.org]