---
platform: King Air
flight_id: KA-20250929a
nickname: Diving through the melting layer
takeoff: "2025-09-29 12:53:00Z"
landing: "2025-09-29 15:53:00Z"
departure_airport: KRN
arrival_airport: KRN
crew:
  - name: Tim Carlsen
    job: PI
  - name: Sorin Ghemulet
    job: Instrument operator
  - name: Alex Vlad
    job: Instrument operator
instruments:
  FCDP:
    comment:
    operational: true
  2D-S:
    comment:
    operational: true
  CPI:
    comment: camera connection issue
    operational: false
  CAS-DPOL:
    comment:  CAPS computer failure
    operational: false
  CIP:
    comment: CAPS computer failure
    operational: false
  LWC Hotwire:
    comment: CAPS computer failure
    operational: false
  Gopros:
    comment: None
    operational: true
categories: [ec_under, mpc, melt_layer, precip, multi, marine_sc]
orphan: true
jupyter:
  jupytext:
    cell_metadata_filter: -all
    notebook_metadata_filter: all,-language_info,-jupytext.text_representation.format_version,-jupytext.text_representation.jupytext_version
    text_representation:
      extension: .md
      format_name: markdown
  kernelspec:
    display_name: Python 3 (ipykernel)
    language: python
    name: python3
---

{logo}`CELLO`

# {front}`flight_id`

```{badges}
```

## Crew

```{crew}
```

```{admonition} EarthCARE target scenarios
:class: tip
<b>Melting layer:</b> Porpoising through melting layer over ocean.<br>
<b>Rain:</b> Precipitating clouds over ocean.<br>
<b>Marine Sc:</b> Vertical profiles including drizzle.<br>
<b>Complex multi-layer scenes:</b> Multiple low cloud decks.
```


```{admonition} Flight summary
:class: note
<p style='text-align: justify;'>During the research flight on 29th September 2025, we targeted <b>mixed-phase clouds</b>, and specifically the <b>melting layer</b> between <b>1.2 and 3.5 km altitude</b> underneath <b>EarthCARE (orbit #7603C)</b>. We performed porpoising through the melting layer, covering temperatures between <b>-6°C and +5°C</b> and sampling liquid droplets, ice crystals, drizzle, rain and snow. </p>
```


## Track

```{figure} ../figures/KA-20250929a/KA-20250929a_7603C.png
---
name: KA-20250929a-flown
---
Flight track for KA-20250929a.
```
Flight path (dashed line) superimposed on the MSI-RGR-1C product on 29th September 2025. The ATLID ground track is shown in yellow, while the EC leg (for correlative observations) is shown as a continuous line.


## Conditions

During the EC leg, we experienced low mixed-phase clouds (with some overlying high clouds). Mostly continuous cloud decks, but sometimes a bit broken up in the vertical. We sampled between 1.2 and 3.5 km altitude, covering temperatures between -6°C and +5°C. This way, we measured rain and snow above and below the melting layer in addition to sampling cloud droplets and ice crystals.


## Flight video

Video cutting and editing in progress...

## Events

Time (UTC) | Comment
-------------| -----
12:53 | Takeoff Kiruna
14:04 | Start ec_leg
14:20 | EarthCARE overpass (orbit #7603C)
14:37 | End ec_leg
15:53 | Landing Kiruna


## Execution

- Takeoff KRN: 12:53 UTC (14:53 LT)
- Hawkeye running
- 13:20 UTC: delayed due to strong headwinds, expected arrival @WP1 at 14:00 UTC, request for arrival @FL100 so try to go down already
- 13:30 UTC: will start descent to FL100 after we passed the mountains
- 13:44 UTC: start descending towards WP, 800ft/min
- 13:59 UTC: vicinity of WP1, FL150
- 14:04 UTC, WP1, start ec_leg
- 14:07 UTC: WPA
- 14:10 UTC: WPB
- 14:13 UTC: start ascent after porpoising down
- 14:15 UTC: WPC
- ground speed 237 kt, Temperatures from cockpit were ~2°C higher than SAT
- 14:19 UTC: going a bit higher to cover temperatures down to -5°C
- 14:19 UTC: start descent again, 1000 ft/min, EC overpass
- 14:24 UTC: WPE
- 14:27 UTC: alt capture, start ascent again
- 14:30 UTC: WP2, continue same heading to extend ec_leg
- 14:32 UTC: continue climb until FL150
- 14:37 UTC: finish ec_leg, going home
- Landing KRN: 15:53 UTC (17:53 LT)


## Impressions

- 13:30 UTC: -34°C, TAS230, FL270, no clouds
- 13:50 UTC: TAS240, -21°C, FL200, in-cloud, Hawkeye works, 2DS sees crystals
- 13:52 UTC: TAS237, -20°C, FL190, FCDP sees droplets + small ice in 2DS, many thin layers
- 13:54 UTC: TAS228, -17°C, FL170
- 13:56 UTC: TAS216, -13°C, FL160
- 13:58 UTC: in-cloud, close to cloud top
- 13:59 UTC: big ice, TAS210, -11°C, FL150
- 14:01 UTC: TAS206, -11°C, FL140, Hawkeye works
- 14:03 UTC: windshield iced up
- 14:04 UTC: TAS196, -6°C, FL110, big ice
- 14:06 UTC: TAS204, -4°C, FL100
- 14:07 UTC: TAS206, -2°C, FL090, some icing, lots of droplets in FCDP, small ice in 2DS
- 14:09 UTC: TAS183, 0°C, FL070
- 14:10 UTC: TAS180, 2°C, FL060, some cloud gaps in the vertical
- 14:12 UTC: in cloud again, big drops, rain
- 14:13 UTC: 5°C, ascent, big drops, FL040
- 14:15 UTC: TAS163, 3°C, FL050
- 14:16 UTC: TAS162, 1°C, FL070
- 14:17 UTC: TAS170, -1°C, FL080, lots of crystals (columns?)
- 14:18 UTC: TAS179, -2°C, FL090
- 14:19 UTC: TAS187, -4°C, FL100, going a bit up to -5°C
- 14:19 UTC: TAS188, -5°C, FL107, small and big ice on 2DS, EC overpass
- 14:21 UTC: TAS198, -3°C, FL097
- 14:23 UTC: TAS193, 0°C, FL079
- 14:24 UTC: TAS192, 2°C, FL065, in cloud all the time
- 14:25 UTC: can see ocean below, little rain, much less than before
- 14:27 UTC: TAS190, 5°C, FL040, below cloud, can still see ocean, looks like little rain still on windshield
- 14:29 UTC: cloud base roughly, TAS175, 3°C, FL063, completely in cloud again
- 14:30 UTC: snowing @WP2
- 14:31 UTC: TAS179, 1°C, FL080
- 14:32 UTC: TAS183, -1°C
- 14:34 UTC: 2DS not updating, but receiving bytes, no image update (took video), just doesn't seem to see a particle right now
- 14:34 UTC: TAS189, -4°C, FL110, FCDP updating, very small droplets (maybe that's why nothing 2DS)
- 14:36 UTC: TAS196, -8°C, FL131
- 14:37 UTC: TAS198, -10°C, FL150
- 14:37 UTC: out of cloud top, going home, 2DS updating again and seeing particles
- 14:39 UTC: TAS205
- 14:40 UTC: sundog to the right
- 14:48 UTC: FL240, above cirrus, -30°C
- 14:49 UTC: still a bit in cloud, 2DS + FCDP see something, 180kts ground speed
- in-flight entertainment + service starts
- 14:57 UTC: no cloud anymore, we are above it it seems
- 15:36 UTC: in cloud during approach



## Instrument status & quicklooks
```{instrument-table}
```
````{card-carousel} 3
```{card}
:img-top: ../figures/KA-20250929a/clouds_start_ecleg.jpg
Cloud situation right before start of EC leg: descending into low cloud deck with some high clouds above.
```
```{card}
:img-top: ../figures/KA-20250929a/temp_profiles.jpg
Temperature profiles for the 4 profiles while porpoising during EC overpass.
```
```{card}
:img-top: ../figures/KA-20250929a/quicklook_ecmeet.jpg
Quicklook live-view from FCDP (right) and 2DS (left) during EC overpass: lots of droplets and small+big ice.
```