A21F-01
An Overview of the Tropical Composition, Clouds and Climate Coupling Experiment
The Tropical Composition, Clouds and Climate Coupling Experiment (TC4) took place in July and August of 2007 primarily in Costa Rica and Panama. Three research aircraft, the NASA ER-2, NASA WB-57f and NASA/University of North Dakota DC-8, participated in the mission. In addition to test flights and transit flights, we were able to conduct 4 research missions with three aircraft on coordinated flight paths, 5 missions with 2 aircraft on coordinated flight paths, and 5 missions using 1 aircraft. In the 23 flight days available during the primary deployment we conducted 13 separate missions involving 26 individual aircraft flights, a feat that was only possible due to the hard work of the flight crews, logistical teams and scientists involved in TC4. In addition to the aircraft, the University of Oklahoma SMART research radar was positioned in Costa Rica and the NASA NPOL radar was located in Panama. The Pennsylvania State University NATIVE research trailer facility was located in Panama. The Ticosonde balloon launch facilities were utilized in Costa Rica. Additional balloon launches took place from Panama and from the Galapagos Islands of Ecuador. TC4 had numerous research goals as summarized in this talk. Among other topics, flights addressed: the radiative and microphysical properties of marine stratus clouds, cirrus anvils, cumulus towers, and subvisible cirrus; the distribution of upper tropospheric and lower stratospheric water vapor and its isotopes; atmospheric chemistry from the marine and continental boundary layers through the troposphere and into the lower stratosphere; and the validation of numerous satellite instruments including many on the Aura, CloudSat, Calipso, Aqua and Terra platforms.
A21F-02
Synopsis of TC4 Missions and Meteorology
The TC4 (Tropical Composition, Clouds and Climate Coupling) Experiment conducted 26 aircraft sorties on 13 flight days from July 17 to August 8, 2007 (23 days). Quality science observations were also obtained during the transit flights to/from from San Jose, Costa Rica, where the mission was based. On 9 days, coordinated aircraft missions were flown with the NASA ER-2 and DC-8, and with the NASA WB-57 on 3 occasions (and transit flights). The ER-2 served as an A-Train simulator (MODIS, CloudSat, CALIPSO, AIRS/TES, partial AMSR-E) while the WB-57 provided in-situ measurements of upper tropospheric cloud particles, aerosols and trace gases. The DC-8 provided both in-situ and remote sensing measurements, where the latter were focused on Aura validation, and also including a down-looking scanning precipitation radar (TRMM PR simulator). This paper will provide a synopsis of the science observations that were obtained, as regards the clouds and cloud systems sampled, from a meteorological perspective. A diversity of clouds were sampled and the meteorology proved more interesting than expected, at least to this author. Upper tropospheric cirrus outflows were sampled from a number of convective cloud systems including ITCZ-type systems as well as systems close to and affected by land. The low level inflows to these systems were also sampled in some cases (DC-8) and missions were flown to sample stratocumulus clouds over the Pacific Ocean exploiting the unique instrumentation on the DC-8 to add to the knowledge of these clouds which are so important to the Earth radiation budget. Measurements were made in the tropical Tropopause Transition Layer (TTL) by the WB-57. Upper tropospheric clouds and TTL properties and processes were central TC4 objectives. Excellent data were also obtained on the fate of the Saharan Air Layer and its aerosols over the Caribbean and Central America, as well as samples of plumes from volcanoes in Ecuador and Columbia and biogenic emissions over Columbia and the Pacific Ocean. Satellite observations, including those from various A-Train sensors, were used in planning the missions which were, in many cases, coordinated, at least in part, with satellite overpasses, especially Aura and other A-Train sensors (DC-8) and Terra. http://www.espo.nasa.gov/tc4/
A21F-03 INVITED
An Overview of ER-2 Platform Science during TC4
The NASA high-altitude ER-2 aircraft flew 11 science flight out of San Jose, Costa Rica during July and August 2007 as part of the NASA-sponsored Tropical Composition, Clouds and Climate Coupling Experiment (TC4). The ER-2 flew a remote sensing payload consisting of passive optical and microwave imagers (MAS/MASTER, CoSSIR, AMPR), a high spectral resolution IR imager (S-HIS), active sensors (CPL lidar, CRS and EDOP radars), spectral solar (SSFR) and IR flux radiometers, a microwave temperature profiler (MTP), and a visible video camera (MVIS). This suite of sensors provided a high spatial resolution simulator for cloud, aerosol, sounding, and trace gas retrieval capabilities from the "A-Train" constellation, in particular, the Aqua, CloudSat, and CALIPSO satellites. In this talk we present an overview of the ER-2 TC4 science and validation objectives, and a summary of the campaign accomplishments. Science goals included observations of convective system development, anvil cirrus property evolution (i.e., microphysics, optical properties, narrow and broadband radiative fluxes), tropical Tropopause Transition Layer (TTL) and subvisual cirrus detection and characterization, marine boundary layer cloud properties, aerosol transport and optical properties, and trace gas and atmospheric state characteristics. Coordination with the DC-8 and/or WB-57 aircrafts allowed for validation of various retrievals from these observations. Morning flights (due to adverse local afternoon weather conditions) included coordination with the Terra spacecraft when feasible.
A21F-04 INVITED
Validation of Satellite-Derived Cloud Properties Using TC4 Data
Assessing the uncertainties in satellite-derived cloud properties is a challenging task because of the lack of ground truth measurements for many of the cloud systems occurring in remote areas. The NASA-sponsored Tropical Composition, Cloud and Climate Change Coupling (TC4) Mission conducted in Costa Rica during summer 2007 developed a variety of in situ and aircraft-based remote sensing datasets that are well suited for examining the errors in satellite-determined cloud parameters such as cloud top height, thickness, effective particle size, and overlap conditions. In this paper, cloud properties derived from the Twelfth Geostationary Operational Environmental Satellite (GOES-12) and the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua are compared with cloud lidar and radar taken from the NASA ER-2 and DC-8 aircraft during TC4 to evaluate the vertical structure of the clouds determined from the passive satellite imagers. Both low-level and high-altitude cirrus clouds are considered. Initial comparisons of cloud optical depth and effective particle size are also performed using passive retrievals from GOES and MODIS with in situ measurements taken by the DC-8 and the NASA WB-57 aircraft. The results will be valuable for understanding the diurnal cycle of cloud properties in the Tropics and for narrowing the acceptable range of cloud properties generated by climate models http://angler.larc.nasa.gov/tc4/
A21F-05
Remote Sensing of the Radiative and Microphysical Properties of Clouds during TC4: Results from MAS, MASTER, MODIS, and MISR
The MODIS Airborne Simulator (MAS) and MODIS/ASTER Airborne Simulator (MASTER) were used to obtain measurements of the bidirectional reflectance and brightness temperature of clouds at 50 discrete wavelengths between 0.47 and 14.3 µm (12.9 µm for MASTER). These observations were obtained from the NASA ER-2 aircraft as part of the Tropical Composition, Clouds and Climate Coupling Experiment (TC4) conducted over Central America and surrounding Pacific and Atlantic Oceans between July 17 and August 8, 2007. Multispectral images in eight distinct bands were used to derive a confidence in clear sky (or alternatively the probability of cloud) over land and ocean ecosystems. Based on the results of individual tests run as part of this cloud mask, an algorithm was developed to estimate the phase of the clouds (liquid water, ice, or undetermined phase). Finally, the cloud optical thickness and effective radius were derived for both liquid water and ice clouds that were detected during each flight, using a nearly identical algorithm as that implemented operationally to process MODIS cloud data from the Aqua and Terra satellites (Collection 5). This analysis shows that the cloud mask developed for operational use on MODIS, and tested using MAS and MASTER data in TC4, is quite capable of dis-tinguishing both liquid water and ice clouds during daytime conditions over both land and ocean. The cloud optical thickness and effective radius retrievals used three distinct bands of the MAS (or MASTER), and these results were com-pared with nearly simultaneous retrievals of MODIS on the Terra spacecraft. Fi-nally, this MODIS-based algorithm was adapted to MISR data to infer the cloud optical thickness of liquid water clouds from MISR. Results of this analysis will be presented and discussed.
A21F-06
A description of tropical cloud systems derived from the synergy between coordinated remote sensing and in situ data
The NASA TC4 deployment has provided a wealth of remote sensing and microphysical data from tropical cloud systems. We are using this data set as a tool for developing, implementing and validating remote sensing algorithms that will be applied to the ER2 and A-Train data streams. We will provide an initial assessment of the data by examining several case studies extracted from TC4 flights of the NASA DC8, WB57, and ER2. Specifically, we will compare cirrus microphysical properties observed by the DC8 with cloud properties derived from the A-Train and the A-Train simulator data on the ER2. While the in situ data serves as validation of algorithms, the synergy between in situ and remote sensing data adds significantly to what we can learn about the cloud systems that were examined. This aspect of the TC4 data will be highlighted.
A21F-07 INVITED
Small Ice Crystals in Tropical Anvil Cirrus
The NASA TC-4 field experiment included extensive sampling of tropical, maritime anvil cirrus. In situ measurements of ice crystal size distributions were made with multiple instruments on two aircraft. Instruments with inlets that have typically been used in the past for sampling small (< 50 microns) ice crystals were included, as well as open-path instruments for which artifacts caused by large-crystal shattering should be less significant. Preliminary results from these measurements will be presented. Comparisons with cloud-resolving model simulations will be used to evaluate the source of aerosols for production of the anvil ice crystals, and the importance of small crystals in anvil cirrus for cloud radiative forcing will be discussed.