--- platform: HALO flight_id: HALO-20240821a nickname: Meteor 1st date takeoff: "2024-08-21 12:23:35Z" landing: "2024-08-21 19:52:41Z" departure_airport: GVAC arrival_airport: GVAC crew: - name: Cathy Hohenegger job: PI - name: Georgios Dekoutsidis job: WALES - name: Tobias Kölling job: HAMP-Radiometer, HAMP-Radar - name: Helene Glöckner job: Dropsondes - name: Kevin Wolf job: Smart, VELOX, BACARDI - name: Zekican Demiralay job: SpecMACS - name: Divya Praturi job: Scientist - name: Julia Windmiller job: Ground contact instruments: BACARDI: comment: None operational: true BAHAMAS: comment: None operational: true Dropsondes: comment: Restart needed before first circle. Three no launch detects. No ATC permission to drop sondes on ITCZ center circle operational: true HAMP-Radar: comment: operational: true HAMP-Radiometer: comment: operational: true Smart: comment: fully functional operational: true SpecMACS: comment: Some icing on side windows. operational: true VELOX: comment: Some icing on KT-19 operational: true WALES: comment: operational: true categories: [c_north, c_mid, c_south, meteor] orphan: true --- {logo}`PERCUSION` # {front}`flight_id` ```{badges} ``` ## Crew ```{crew-list} ``` ## Track ![track](../figures/HALO-20240821a/HALO-20240821a-track.png) ## Conditions ```{track-animation} :flight_id: HALO-20240821a ``` Very clean air conditions over Sal with island-induced shallow clouds at departure. The flight was located on the 26.7W longitude. The ITCZ was narrow with a well defined northern band of deep convection and rain at around 9N. The northern edge in terms of deep convective clouds was in 'c_north', on its southern half, whereas there was a band of stratocumulus with an edge at its northern boundary. In terms of precipitable water, there was a second edge with a sharp gradient (from 65 to 30 mm) sampled by 'c_extra', whereas precipitable water only dropped to 50 mm in 'c_mid'. Yet there was no deep convective clouds in 'c_extra' but clear sky, and few isolated shallow cumuli. There was a secondary NE-SW oriented band of deep convection striking through the northern half of 'c_south'. Meteor was under this band while HALO sampled this band while flying around 'c_south' in its NW quadrant. On the leg between Sal and 26.7W we crossed regions/patches of clear sky and stratocumuli. Waves patterning on the clouds visible. On the way back, two layers of clouds with altocumulus/cirrus on top and stratocumuli/cumuli at the bottom. ## Execution The replacement for the emergency light battery did not arrive in time so that the flight was restricted to daylight hours. With a take-off at 12:20 UTC because of runaway restriction, the original flight plan had to be shorten to ensure a landing in daytime hours. The legs to south_tp (including overpass over Meteor) and to Mindelo were abandonned. Also it turned out that choosing 26.7W as longitude for flying was a mistake as it was below the main route of airliners going to south America. We didn't get clearance to drop sondes on 'c_mid'. We circled 1 h around it and then got an estimate that it might be possible to drop sondes in 40 min, which we couldn't wait anymore. We waved to Meteor from 'c_south' while Meteor was in the circle. We did CCW circles where possible as this gave better sight for the SpecMacs camera. ## Impressions Convection was not as deep as on Sunday, probably top around 12 km. While crossing the ITCZ and circling around 'c_mid2', we were in a soup of white. - Circles start time (in UTC, first sonde): 14:17 for 'c_south' (from N, CW), 15:20 for 'c_mid' (from S, CCW), 16:54 for 'c_north' (from N) and 17:55 for 'c_extra' (from S, CCW) - HAMP measured 100 mm of precipitable water in 'c_mid'. This seems unrealistically high. ```{note} South circle sampled an active convective line, also experienced by Meteor ``` ````{card-carousel} 2 ```{card} :img-top: ../figures/HALO-20240821a/crew.jpg Crew ``` ```{card} :img-top: ../figures/HALO-20240821a/20240821_1226UTC.jpeg Island-induced clouds by take-off (12:26 UTC) ``` ```{card} :img-top: ../figures/HALO-20240821a/20240821_1412UTC.jpeg In the ITCZ, entering 'c_south' (14:12 UTC) ``` ```{card} :img-top: ../figures/HALO-20240821a/20240821_1644UTC.jpeg Hole in the ITCZ (16:44 UTC) ``` ```{card} :img-top: ../figures/HALO-20240821a/20240821_1756UTC.jpeg Leaving the ITCZ, southern edge of 'c_north' (17:56 UTC) ``` ```{card} :img-top: ../figures/HALO-20240821a/20240821_1852UTC.jpeg Stratocumulus edge, southern edge of 'c_north' (18:52 UTC) ``` ```{card} :img-top: ../figures/HALO-20240821a/TOCAN_15UTC.png TOOCAN's segmented MCSs at 1500 UTC. ``` ```` ## Instrument status & quicklooks ```{instrument-table} ``` ````{card-carousel} 2 ```{card} :img-top: ../figures/HALO-20240821a/HALO_20240821a_BACARDI_QL.png BACARDI. ``` ```{card} :img-top: ../figures/HALO-20240821a/20240821_circle_profiles.png Dropsondes. ``` ```{card} :img-top: ../figures/HALO-20240821a/hamp_fullflight_HALO-20240821a.png HAMP ``` ```{card} :img-top: ../figures/HALO-20240821a/hamp_ec_under_HALO-20240821a.png HAMP EC underpass ``` ```{card} :img-top: ../figures/HALO-20240821a/hamp_radar_ec_under_HALO-20240821a.png Radar during EarthCARE underpass ``` ```{card} :img-top: ../figures/HALO-20240821a/HALO_20240821a_SMART_QL.png SMART Time series of upward and downward spectral irradiadiance, and albedo. ``` ```{card} [![specMACS RGB snapshots](../figures/HALO-20240821a/quicklook_20240821_polb_small.png)](https://www.meteorologie.lmu.de/~quicklooks/specMACS/PERCUSION/quicklooks/polcams/quicklook_20240821_polb.png) specMACS RGB snapshots from polb (lower right) with EarthCARE underpass marked in red. Find further quicklooks [here](https://www.meteorologie.lmu.de/~quicklooks/specMACS/PERCUSION/flight_HALO-0821.html). ``` ```{card} :img-top: ../figures/HALO-20240821a/HALO_20240821a_KT19_QL.png KT19 Timeseries of brigthness temperature. ``` ```{card} :img-top: ../figures/HALO-20240821a/QL_VELOX_HALO_20240821a.jpg VELOX broadband channel. ``` ```{card} :img-top: ../figures/HALO-20240821a/0821-wales-3d.jpg WALES (3D backscatter) ``` ```{card} :img-top: ../figures/HALO-20240821a/0821-wales-x.png WALES (cross section) ``` ````