Mika Rantanen

Copernicus ECMWF @copernicusecmwf.bsky.social [ View ] Feb 16, 2024 at 11:33 UTC

Three #ERA5-based charts you shouldn't miss this month:

📈 Global Sea Surface Temperature absolute record in January - #C3S 
📈 October-January surface temperature anomalies - @mikarantane.bsky.social  
📈 #ERA5-Land data contributes to assess scattered data in Brazil - Environmental Data Science

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Mika Rantanen @mikarantane.bsky.social [ View ] Feb 13, 2024 at 10:07 UTC

Second, comparison of global monthly mean temperature margins between observations and model simulations.

The 0.5°C record-margin in September 2023 was very rare event in model simulations

www.nature.com/articles/s41...

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Mika Rantanen @mikarantane.bsky.social [ View ] Feb 13, 2024 at 09:19 UTC

Two recent papers about September 2023 warmth.

First, an attribution study of the record warm September in Helsinki: according to our study, the new monthly record would probably not have been set without the observed global warming.

rmets.onlinelibrary.wiley.com/doi/10.1002/...

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Mika Rantanen @mikarantane.bsky.social [ View ] Feb 13, 2024 at 06:16 UTC

Yeah, February will be probably colder than average, but only about 1-1.5°C (unless some very cold air flow from the Siberia for the last week of the month)

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Mika Rantanen @mikarantane.bsky.social [ View ] Feb 09, 2024 at 07:23 UTC

Sure! One option is to download the global radiation observations from FMI open data and calculate how much more you get solar radiation now vs. a week ago.

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Mika Rantanen @mikarantane.bsky.social [ View ] Feb 08, 2024 at 09:08 UTC

In Finland, there have been now four consecutive months with a nationwide temperature anomaly < -2°C (Oct-Jan). The last such streak of cold months occurred in the winter of 2009-2010. Will February be the fifth such month?

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Mika Rantanen @mikarantane.bsky.social [ View ] Feb 06, 2024 at 08:11 UTC

Yes it was, although the warm days during the end of the month increased the mean temperature. I haven't seen a proper analysis or study yet. Maybe I should make one by myself 😀

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Mika Rantanen @mikarantane.bsky.social [ View ] Jan 22, 2024 at 09:46 UTC

Another milestone reached. The ERA5 365-day running mean global temperature has reached 1.5 °C warming. The running mean will continue to rise for at least several months from now, probably until at least May-June this year.

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Mika Rantanen @mikarantane.bsky.social [ View ] Jan 05, 2024 at 12:19 UTC

The Fennoscandian cold blob was well alive also in December. Last three months featured positive temperature anomalies almost everywhere else than in northern Europe.

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Mika Rantanen @mikarantane.bsky.social [ View ] Jan 01, 2024 at 13:14 UTC

Forecast minimum temperatures can be exceptionally cold for this 7-day period. But for the whole winter, not so exceptional. Let's see how these verify.

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Mika Rantanen @mikarantane.bsky.social [ View ] Dec 31, 2023 at 14:17 UTC

Cold wave is about to begin in southern Finland. This type of cloud formation will be common in the coming days as Arctic air masses flow over the open Baltic Sea.

MODIS satellite image 31.12.2023 from fmiarc.fmi.fi/data/latest-...

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Mika Rantanen @mikarantane.bsky.social [ View ] Dec 18, 2023 at 07:20 UTC

Another new paper highlighting the importance of internal variability in the strong Arctic amplification of recent decades.

Internal Variability Increased Arctic Amplification During 1980–2022 (Sweeney et al. 2023, GRL).

agupubs.onlinelibrary.wiley.com/doi/10.1029/...

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Mika Rantanen @mikarantane.bsky.social [ View ] Dec 12, 2023 at 20:23 UTC

Malaga airport reached today 29.4°C, smashing its December heat record by an unprecedented margin. The previous record of 24.6°C (from 1998) was beaten by almost 5 degrees.

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Mika Rantanen @mikarantane.bsky.social [ View ] Dec 05, 2023 at 11:20 UTC

I think anomalous upper-air circulation would be a more likely cause.

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Mika Rantanen @mikarantane.bsky.social [ View ] Dec 05, 2023 at 07:29 UTC

In both October and November, temperatures were mainly above the 1981-2010 average, except in northern Europe.

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Mika Rantanen @mikarantane.bsky.social [ View ] Nov 27, 2023 at 13:22 UTC

Beautiful cloud streets and formation of sea-effect snow due to cold air mass flowing over the open Baltic Sea.

If you look closely, you can also see the phenomenon in the Lake Päijänne.

Image from fmiarc.fmi.fi/data/latest-...

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Mika Rantanen @mikarantane.bsky.social [ View ] Nov 20, 2023 at 07:20 UTC

El Niño is intensifying.

Over the past few days, sea surface temperatures in the El Niño region have risen rapidly to around 2°C for the first time in this El Niño event.

Figure from cyclonicwx.com/sst/

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Mika Rantanen @mikarantane.bsky.social [ View ] Nov 16, 2023 at 08:30 UTC

The "cold spot" in northern Europe last month was associated with an atmospheric trough (i.e. an upper-level low), which means that circulation anomalies can explain a large part of the observed temperature anomalies.

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Mika Rantanen @mikarantane.bsky.social [ View ] Nov 13, 2023 at 06:20 UTC

Last night was the coldest night of the current winter with -27.0 °C in Enontekiö, Lapland. Even during this upcoming global temperature peak, northern Fennoscandia will remain colder than average.

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Mika Rantanen @mikarantane.bsky.social [ View ] Nov 02, 2023 at 18:43 UTC

It's difficult since the preindustrial temperatures from Finland have high uncertanties. But here's October temperatures from Finland relative to 1900-1950 baseline. The current one would have been slightly colder than normal even back then.

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