Table 3a. Required Measurements: Radiation
Resolution or Levels Absolute Relative Accuracy
Parameter Vertical Horizontal Temporal Accuracy (Precision) Platform Objective
Broadband longwave
flux (4-50 µm)		 ER-2 (18 km) * clear-sky fluxes for
aerosol direct effect
* radiative heating within
cirrus layer
* calibration of CERES
upflux 18 2 - 5 Wm-2 <= 2%
downflux 0.18 2 - 5 Wm-2 <= 2%
net flux 0.18 2 - 5 Wm-2 <= 2%


Narrow longwave
flux (8-12 µm)		 P-3 (30 m; 3 km)


ER-2 (18 km)
R/V		 * SST
* calibration of CERES, INSAT
and AVHRR IR temperatures
* heating within cirrus
* ozone greenhouse effect
* cloud-base altitude
upflux 12,18 2 - 3 Wm-2 <= 2%
downflux 0,12,18 2 - 3 Wm-2 <= 2%
net flux 12,18 2 - 3 Wm-2 <= 2%


Longwave Radiance WB-57 * IR effect of aerosols
* IR effect of tropical ozone
* identify the cirrus
(up, down) - <= 1 - <= 2% <= %0.5


Spectral radiance from
FTIR (5 to 50 µm) 12 to 18 - <= 2% <= %0.5


Broadband solar
flux (0-5 µm)		 C-130 (30 m; 3 km)
ER-2 (18 km)
WB-57 (12 km)
Malé
R/V and Moorings
(0 km)
 * cirrus albedo
* shortwave cloud forcing
* cloud effect on sea
surface insolation
* radiative heating
within cirrus
upflux 0.1,3,12,18 2 - 2% 1%
downflux 0.1,3,12,18 2 - 2% 1%
net flux 0.1,3,12,18 2 - 2% 1%


Narrow-band radiance
a) 5 channels: UV/
visible and near IR;
angular variation 		C-130 (30 m; 3 km)
ER-2 (18 km)
WB-57 (12 km)
Malé, R/V
 * aerosol optical depth
* phase function
* stratospheric aerosol
optical depth
* optical depth of low clouds
* spectral cloud forcing
* identify physics of solar
cloud absorption
* validate GCM radiation codes
upflux 12,18 - 2%
downflux 0,12,18 - 2%
b) High spectral resoltion FTIR 5% 2%


Vertical radiative
heating rates		 0.25 1 10% 10% C-130 (30 m; 3 km)
ER-2 (18 km)
WB-57 (12 km) 		* validate radiation models used
for computation of fluxes and use
such validated radiation models
for computing heating rates from
observed vertical profiles of
temperature and water vapor
Solar broadband 0.25 1 At least
30 profiles		 10% 10%
Solar visible
(0.5-0.8 µm)		 0.25 1 10% 10%


Radiance
0.6-0.7, 0.7-1.0 µm		 - 1.25 6 hours 5% 1% NOAA 12,14,K
(AVHRRa)		 * obtain synoptic and monthly
variations in:
1) aerosol optical depth
2) radiation budget
3) cloud cluster statistics
10.3-11.3, 11.5-12.5 µm - 1.25 6 hours ±0.55K


Radiance
0.5-0.74 µm		 - 2.75 1 hour 5% INSAT
(VHRRb)		 * diurnal variation in:
1) cloud albedo
2) cloud cover statistics
3) cloud IR
10.5-12.5 µm - 11 1 hour .5K


Column water Vapor - 2/day - - ±5%
relative
humidity		 DMSP * relate water vapor to
convective activity on
troposphere
aAVHRR: advanced very-high resolution radiometer
bVHRR: very-high resolution radiometer



Table 3b. Required Measurements: Aerosols, Chemistry and Cloud Microphysics
Resolution or Levels Absolute Relative Accuracy
Parameter Vertical Horizontal Temporal Accuracy (Precision) Platform Objective
Aerosol size distribution C-130
WB-57		 * determine aerosol size spectrum
for Mie scattering and radiative
closure calculation.
* estimate amounts of sulfates,
black carbon, dust aerosols.
* estimate amounts of mixed
aerosol types
Aerosol composition - 10 - 10% 5% C-130
WB-57
R/V, Malé
Cirrus cloud bulk
   properties
- cirrus top altitude - 1 - 100 m 50 m ER-2 (lidar)
INSAT
NOAA-12,14,K		 * estimate heating-rate statistics
(all) and vertical profiles of
optical depth (lidar)
- cirrus base altitude - 1 - 100 m 50 m


Microphysical
   properties
- ice-crystal size
   spectrum		 - 1 - 25% 10% WB-57 * examine the influence of low
clouds on column cloud forcing
* examine the influence of
ice-crystal properties on
cirrus radiative properties
- total concentration - 1 - 25% 10%
- effective radius - 1 - 25% 10%
- cross-sectional area - 1 - 25% 10%
- medium-volume diameter - 1 - 25% 10%
- ice-water content - 1 - 25% 10%
- ice-crystal shape - 1 - 25% 10%


Water-vapor distibution 100 m (surface to 20 km) 50 - 5% 5% ER-2

C-130

Dropsondes
(WB-57)

Sondes

(island stations) 		* measure the north-south cross
sections of water vapor
* input to radiation model
computations
* origin of vapor in the
lower stratosphere
* thermodynamic structure
* water budget of anvils


Ozone 0.5 km - 10% 10% 5% ER-2, WB-57,
C-130
R/V, Malé
Sondes 		* identify depth of mixing
by convection
* identify the parcel origin: whether
from stratosphere or troposphere


CO 0.5 km - 10% 10% 5% ER-2, WB-57,
C-130
R/V, Malé 		* identify the parcel origin:
continental or marine air; key
component of ozone photochemistry


NO/NO2/NOy
(Nitrogen Oxides)		 0.5 km - 10% 10% 5% ER-2, WB-57,
R/V, Malé
 * central to tropospheric chemistry;
perhaps important tropical lightning source


CH4 0.5 km - 10% 10% 5% WB-57
C-130 		* identify the parcel origin:
whether from stratosphere or
troposphere; key greenhouse gas;
input to total H2O column


Whole Air Samples 0.5 km - 10% 10% 5% ER-2, WB-57,
C-130
Malé
 * large variety of molecules,
incl.: NMHC, Halogenated species;
species with a variety of lifetimes
from days to years - key to assessing
tropospheric loss rates and global transport.