Flight Plans for VOCALS 1. Cross Section Mission …robwood/VOCALS/info/VOCALS...Flight Plans for...
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Flight Plans for VOCALS 1. Cross Section Mission Table 1 and Figure 1 shows the key parameters and C-130 flight plan agreed upon by the C-130 PIs at the VOCALS meetings in June 2007 and March 2008. Table 1 shows a brief summary of the critical aspects of the Cross-Section flights. Table 2 shows a leg-by-leg summary of the outbound portion of the Cross- Section flight for a typical 9 hour flight out to approximately 85°W. Take off will be within 1 hour of 3am to minimize diurnal aliasing when combining data from these missions. Level (fixed altitude) legs of 10 minute duration will be conducted at three different nominal altitudes: 1) Subcloud layer (layer below almost all cloud, typically 150 m altitude, the minimum permitted for night flying); 2) Cloud layer (layer close to center of stratocumulus cloud deck, which will range from 800-1300 m depending upon synoptic conditions, and will usually increase gradually westwards); the cloud layer will periodically be of a broken nature and the expectation is that this run may therefore pass into clear regions between clouds; small height adjustment can be made close to the start of the run to ensure the optimal cloud sampling. 3) Free-tropospheric layer (layer approximately 500-1000 m above cloud top in the free-troposphere). This layer will be cloud free. In between these level legs, the C-130 will conduct profiles between the layers, and also up to approximately 4 km (exact height depending upon aerosol structure) as shown in Figure 1. The nominal ascent/descent rate will be 1000 ft min -1 (300 m min -1 ). At some point during the Cross-Section missions the C-130 will rendezvous with the NOAA R/V Ronald H Brown (RHB) and a collaborative flight maneuver described in Figure 2 will be conducted on the return portion rendezvous location. This involves: 1) Low level run (150 m) to intercept the RHB 2) Turn to upwind direction (usually ESE, or SE) for subcloud run for 10 minutes at 150 m altitude 3) 180 degree turn and profile up to cloud level to conduct 10 minute return leg toward RHB at nominal cloud altitude 4) Turn back onto Cross-Section Mission and resume cloud leg. Table 1: Key parameters for the C-130 Cross-Section Missions Flight duration Typically 9 hours Take off time Within 1 hour of 03:00 local Landing time Approximately noon local Key waymarkers From Arica (18° 29' S, 70° 20' W) to waypoint (20°S, 72°W) then along 20°S to final location (82-85°W, 20°S) Notes Rendezvous for 20-30 minute cosampling with Ronald H Brown which will be located at different locations along 20°S. Profile ascent/descent rate 1000 ft min -1 (300 m min -1 ) Level leg duration 10 minutes (all runs)
Transcript of Flight Plans for VOCALS 1. Cross Section Mission …robwood/VOCALS/info/VOCALS...Flight Plans for...
Flight Plans for VOCALS
1. Cross Section Mission
Table 1 and Figure 1 shows the key parameters and C-130 flight plan agreed upon by the C-130 PIs at the
VOCALS meetings in June 2007 and March 2008. Table 1 shows a brief summary of the critical aspects
of the Cross-Section flights. Table 2 shows a leg-by-leg summary of the outbound portion of the Cross-
Section flight for a typical 9 hour flight out to approximately 85°W. Take off will be within 1 hour of 3am
to minimize diurnal aliasing when combining data from these missions. Level (fixed altitude) legs of 10
minute duration will be conducted at three different nominal altitudes:
1) Subcloud layer (layer below almost all cloud, typically 150 m altitude, the minimum permitted for
night flying);
2) Cloud layer (layer close to center of stratocumulus cloud deck, which will range from 800-1300 m
depending upon synoptic conditions, and will usually increase gradually westwards); the cloud layer
will periodically be of a broken nature and the expectation is that this run may therefore pass into clear
regions between clouds; small height adjustment can be made close to the start of the run to ensure the
optimal cloud sampling.
3) Free-tropospheric layer (layer approximately 500-1000 m above cloud top in the free-troposphere).
This layer will be cloud free.
In between these level legs, the C-130 will conduct profiles between the layers, and also up to
approximately 4 km (exact height depending upon aerosol structure) as shown in Figure 1. The nominal
ascent/descent rate will be 1000 ft min-1
(300 m min-1
).
At some point during the Cross-Section missions the C-130 will rendezvous with the NOAA R/V Ronald
H Brown (RHB) and a collaborative flight maneuver described in Figure 2 will be conducted on the
return portion rendezvous location. This involves:
1) Low level run (150 m) to intercept the RHB
2) Turn to upwind direction (usually ESE, or SE) for subcloud run for 10 minutes at 150 m altitude
3) 180 degree turn and profile up to cloud level to conduct 10 minute return leg toward RHB at nominal
cloud altitude
4) Turn back onto Cross-Section Mission and resume cloud leg.
Table 1: Key parameters for the C-130 Cross-Section Missions
Flight duration Typically 9 hours
Take off time Within 1 hour of 03:00 local
Landing time Approximately noon local
Key waymarkers From Arica (18° 29' S, 70° 20' W) to waypoint (20°S,
72°W) then along 20°S to final location (82-85°W, 20°S)
Notes
Rendezvous for 20-30 minute cosampling with Ronald H
Brown which will be located at different locations along
20°S.
Profile ascent/descent rate 1000 ft min-1
(300 m min-1
)
Level leg duration 10 minutes (all runs)
Figure 1: Schematic flightplan for Cross-Section missions.
Figure 2: Schematic of Cosampling with Ronald H Brown during rendezvous on the C-130 Cross-Section Missions.
Table 2: Leg-by-leg summary of the outbound portion of the Cross-Section flight for a typical 9 hour flight out to
approximately 85°W. Assumed parameters are: Ascent/Descent rate 300 m/min, cloud leg height = 1100 m,
subcloud leg height = 150 m, free-tropospheric (FT) leg height= 2000 m; maximim height for profiles, i.e. level H =
4000 m, aircraft ground speed = 100 m/s. The inbound portion of the flight will be a mirror image of the outbound
portion.
Leg type Leg time
[min]
Leg dist
[km] Altitude change [m]
Profile S-C 3.33 20 1000
Cloud 10.00 60 0
Profile C-H 9.67 58 2900
Profile H-S 13.00 78 -3900
Subcloud 10.00 60 0
Profile S-C 3.33 20 1000
Cloud 10.00 60 0
Profile C-F 3.00 18 900
FT 10.00 60 0
Profile F-S 6.33 38 -1900
Subcloud 10.00 60 0
Profile S-C 3.33 20 1000
Cloud 10.00 60 0
Profile C-F 3.00 18 900
FT 10.00 60 0
Profile F-S 6.33 38 -1900
Subcloud 10.00 60 0
Profile S-C 3.33 20 1000
Cloud 10.00 60 0
Profile C-H 9.67 58 2900
Profile H-S 13.00 78 -3900
Subcloud 10.00 60 0
Profile S-C 3.33 20 1000
Cloud 10.00 60 0
Profile C-F 3.00 18 900
FT 10.00 60 0
Profile F-S 6.33 38 -1900
Subcloud 10.00 60 0
Profile S-C 3.33 20 1000
Cloud 10.00 60 0
Profile C-F 3.00 18 900
FT 10.00 60 0
Profile F-S 6.33 38 -1900
Subcloud 10.00 60 0
Total to halfway 4.38 1576 0
Deg W traveled 15.08
2. POC-Drift Mission
Table 3 and Figure 3 shows the key parameters and C-130 flight plan agreed upon by the C-130 PIs at the
VOCALS meetings in June 2007 and March 2008. Table 3 shows a brief summary of the critical aspects
of the Cross-Section flights. Table 4 shows a leg-by-leg summary of the POC-Drift flight for a typical 9
hour flight assuming that the POC boundary (target location) is situated at 21°S, 78°W. Stacks (probably
two at most) of level (fixed altitude) legs of 25-30 minute duration will be conducted at four different
nominal altitudes. To facilitate communication we will term these legs the subcloud, cloud-base, cloud,
and free-tropospheric legs, but it must be appreciated that, especially within the POC, the clouds are
particularly heterogeneous, so that the boundary layer will not be separable into clearly defined cloud
and subcloud layers. Instrument sampling strategy, particularly for those measurements which require
considerable integrating time, must take this into account.
1) Subcloud layer (layer below almost all cloud, typically 150 m altitude, the minimum permitted for
night flying);
2) Cloud-base layer. This is a layer approximately 100 m above the lifting condensation level (LCL) of
the surface air, which will contain a mixture of clouds and clear air. This is the critical level for
midlevel mesoscale inflow into the precipitating centers within the POC.
3) Cloud layer. This is a layer close to center of stratocumulus cloud deck, which will range from 800-
1300 m depending upon synoptic conditions); the cloud layer will periodically be of a broken nature
especially on the POC side of the POC boundary and the expectation is that this run may therefore
pass into clear regions between clouds; small height adjustment can be made close to the start of the
run to ensure the optimal cloud sampling.
4) Free-tropospheric layer (layer approximately 500-1000 m above cloud top in the free-troposphere).
This layer will be cloud free.
In between these level legs, the C-130 will conduct spiral or 180 degree turn profiles between the layers.
The nominal ascent/descent rate will be 1000 ft min-1
(300 m min-1
). At least two profiles will be
conducted in each of the two regions (POC and non-POC).
Table 3: Key parameters for the C-130 POC-Drift Missions
Flight duration Typically 9 hours
Take off time Either 03:00-4:00 local or 09:00-10:00 local depending
upon whether C-130 is in day or night mode
Landing time Either 12:00-13:00 local or 06:00-07:00 local depending
upon whether C-130 is in day or night mode
Key waymarkers
From Arica (18° 29' S, 70° 20' W) to predetermined POC
boundary location. Sampling within 150 km of this
boundary and then returning to Arica
Notes May occur in region with RHB, either upstream or
downstream
Profile ascent/descent rate 1000 ft min-1
(300 m min-1
)
Level leg duration 20-30 minutes (all runs)
Figure 3: Schematic flight plan for the POC-Drift missions.
Table 2: Leg-by-leg summary of the outbound portion of the POC-Drift flight for a typical 9 hour flight. Transit time
will vary depending upon POC location. Assumed parameters are: Ascent/Descent rate 300 m/min, cloud leg height
= 1100 m, cloudbase leg height 750 m, subcloud leg height = 150 m, free-tropospheric (FT) leg height= 2000 m;
maximim height for profiles, i.e. level H = 4000 m, aircraft ground speed = 100 m/s.
Leg type Leg time
[min]
Leg dist
[km]
Leg elev
change [m]
Transit from Arica
STACK 1:
Subcloud 30.00 180 0
Profile S-F in POC 6.50 39 1850
Profile turn F-Cb 3.00 18 -1250
Cloudbase 30.00 180 0
Profile turn Cb-C 3.00 18 350
Cloud 30.00 180 0
Profile turn C-F 3.00 18 900
FT 30.00 180 0
Profile F-S out of POC 6.50 39 -1850
STACK 2:
Subcloud 30.00 180 1850
Profile S-F in POC 6.50 39 -1250
Profile turn F-Cb 3.00 18 0
Cloudbase 30.00 180 0
Profile turn Cb-C 3.00 18 350
Cloud 30.00 180 0
Profile turn C-F 3.00 18 900
FT 30.00 180 0
Profile F-S out of POC 6.50 39 -1850
Repeat if time permits
Transit to Arica
Total on task 4.73 1704 0
