Dmitri Moisseev

@ColeOsborne47 What was the wind direction? Could it be dust/debris plum coming from the lake?

No that is not lake effect precipitation in Tooele County. Most likely radar chaff or a massive flock of birds migrating south.

Snow being generated by 4 different processes simultaneously near Chicago!

@mikarantane @AriJLaaksonen @meteorologit See Heymsfield et al. (2011) "Formation and spread of aircraft-induced holes in clouds." Science (2011): 77-81. for the description of the mechanism. There was an altostratus cloud at about 3.5 km where a passing aircraft induced formation of ice particles

@am_sundstrom The dust can be seen from the ground as well. Here is the ceilometer observations from Kumpula (ceilometer.fmi.fi). It is interesting to compare 31.3-1.4 and 9.4-10.4 events

Saharan pölyn leviämisennusteet pitivät hyvin paikkansa. Tämän päivän satelliittihavainnot näyttävät pölyn kulkeutuneen Suomeen asti ennusteiden mukaisesti. Pölykerroksen korkeutta hankala arvioida havaintojen perusteella.

@Daaanvdb Any chance for elfstedentocht this winter?

Winter in the Netherlands🇳🇱 starts with -10.1°C in Leeuwarden. 🥶 In the north of the country, the sky was clear, while it was cloudy in other parts. In Leeuwarden, some snow fell last night. What a difference clear skies and a snow cover can make for the minimum temperature!

Congratulations to @TaruOlsson for the great job defending the thesis. Many thanks to @EloquentScience for stimulating and maintaining a very interesting discussion. @Dr_Pettersen your pre-examination of the thesis is highly appreciated.

This week is the last chance to register for the 4th International Summer Snowfall Workshop 11 - 13 September 2023 in Leipzig monsun.meteo.uni-leipzig.de/~drops/issw4/

Do you like snowflakes? Check out our new paper about the Video In Situ Snowfall Sensor egusphere.copernicus.org/preprints/2023…

Please mark your calendars for the 4th International Summer Snowfall Workshop 11 - 13 September 2023 in Leipzig monsun.meteo.uni-leipzig.de/~drops/issw4/

@LeonSimons8 @nephologue @AtmosFede @diegoaliaga2 @Atmosfera_UMSA @INAR_fin I think Tim’s point is, if there is an abundance of aerosols not all CCN will become cloud droplets, anyway. Adding more CCN (by fire for example) may not change anything. Whether it is true or not, depends on the background aerosol concentration, etc

@LeonSimons8 @nephologue @AtmosFede @diegoaliaga2 @Atmosfera_UMSA @INAR_fin I agree with Tim that in this case the cloud was initiated by heat. But speaking more generally, to form a cloud we need moisture, process of cooling air (needed for supersaturation development) and aerosols

Do aerosols form clouds? Yes! A fire-cloud has been form by the particles emitted from the fire. In this case the cloud lasted only few minutes. Does anyone have more pictures? Credits to @diegoaliaga2, taken from the Chacaltaya GAW station, Bolivia. @Atmosfera_UMSA @INAR_fin

@LeonSimons8 @nephologue @AtmosFede @diegoaliaga2 @Atmosfera_UMSA @INAR_fin I agree with Tim, the cloud was initiated by heat. But, some of smoke aerosols took part in the cloud droplets formation. Supersaturation development is a balance between cooling rate and condensation sink, which depends on CCN spectrum

@nephologue @AtmosFede @diegoaliaga2 @Atmosfera_UMSA @INAR_fin You seem to contradict yourself in a single tweet. Supersaturated air exists because of regional limitations in cloud condensation nuclei

@Cyclogenesis_au @DopplerChase @70_dbz @ATMS_Illinois @mgroverwx @armnewsteam BTW, here is what you can do by combining Parsivel and MRR: doi.org/10.1175/JAMC-D…

@Cyclogenesis_au @DopplerChase @70_dbz @ATMS_Illinois @mgroverwx @armnewsteam We have two Parsivels next to PIP, ping me if you need data

@nephologue @ProfGrantPetty Just include formation of cryptically sized embryo into consideration and one can argue that at some point less energy will be needed

@ProfGrantPetty I don't think that's thermodynamically possible -- think of how that would (couldn't) work for the snow crystal analog. But you're precisely right about the dichotomy. However, without even discussing the dynamics of open systems, we won't be able to avoid its implicit trap.

It seems a taboo to argue that the development of renewables is accelerating climate change. I don't get it. To me it seems pretty obvious they are.

After avoiding COVID for 2 years, I tested positive just 9 hours before my flight to @EradSwitzerland . I will be following the conference online, thank you Alexis and Urs for the hybrid meeting

@EGU_ACP A very promising data analysis method by @doppler_fan and co. Hope to see it applied to our @ACTRIS_Cloudnet measurements in @HyytialaHY

New #EGUhighlights: New insights on the prevalence of drizzle in marine stratocumulus clouds based on a machine learning algorithm applied to radar Doppler spectra doi.org/10.5194/acp-22…

@mikarantane @DPManchee It should not. Dual-polarization radar signatures of light rain and insects are very different