Recent in situ observations of light to moderate precipitation during the 1985 hawaiian warm rain project revealed drops with diameters >2mm in much higher concentrations than previously reported. it now appears that these larger drops have often been missed due to the limited sample volume of the… More

The optical properties of cirrus clouds remain a major unsolved component in cloud and climate research (liou 1986). the current instrumentation available for in-situ measurement of the size, shape, and light-scatteringproperties of ice crystals is not capable of providing sufficient information to… More

In fogs, accretion of supercooled water drops is responsible for icing of power lines and structures. In clouds, the same process causes icing on aircraft. In both cases the concentration and size of liquid wate drops, along with their velocity relative to the icing surface, primarily determines the… More

Cirrus clouds continuously cover nearly 40 percent of the earth's surface and are known to have a significant influence on the global radiation budget. tropical storms generate cirrus anvils that are blown hundreds of kilometes downwind and limit warming of the sea surface. this may influence the… More

General aviation and commuter aircraft generally do not have adequate deicing equipment to operate safely in all types of icing conditions. Since icing forecasts are not yet sufficiently reliable for pilots to avoid icing conditions, an airborne system that remotely detects icing conditions ahead… More

Atmospheric aerosols have a strong potential impact on both global radiative forcing and the planetary hydrological cycle. Quantitative measurements of the particle size distribution and composition of aerosols are required to reliably predict theinfluence aerosols are having on global climate… More

The Earth Observing System (EOS), a constellation of satellites that will observe clouds from space, needs reliable in situ measurements of cloud drops and ice particles for validation of remote retrieval algorithms. Current aircraft cloud particle measurements do not give good statistical data sets… More

The Earth Observing System (EOS), a constellation of satellites that will observe clouds from space, needs reliable in situ measurements of cloud drops and ice particles for validation of remote retrieval algorithms. Current aircraft cloud particle measurements do not give good statistical data sets… More

60195 Climatological studies in both the Arctic and Antarctic show that global warming is having a dramatic effect on the rate of ice melt in polar regions. Polar clouds appear to play a crucial role in contributing to the formation of melt ponds; however, long-term, in situ measurements of… More

60195 Climatological studies in both the Arctic and Antarctic show that global warming is having a dramatic effect on the rate of ice melt in polar regions. Polar clouds appear to play a crucial role in contributing to the formation of melt ponds; however, long-term, in situ measurements of… More

"Atmospheric aerosols have a significant effect on the earth'sradiation budget and global climate. Several studies have shownthat significant losses occur in inlets and tubing used tomeasure aerosol particle size distribution. In Phase II, anaerosol inlet calibration device will be fabricated and… More

The largest error source in validation of NASA's EOS satellite cloud products is the mismatch in sampling volumes between the remote sensors and the in situ cloud probes. The sampling error from the extrapolation of the in situ cloud probe measurement of a few cm3 to the remote sensing measurement… More

The largest error source in validation of NASA's EOS satellite cloud products is the mismatch in sampling volumes between the remote sensors and the in situ cloud probes. The sampling error from the extrapolation of the in situ cloud probe measurement of a few cm3 to the remote sensing measurement… More

This SBIR Phase II research project will provide research-aircraft and weather-balloon flight tests a new, novel device for measuring the electric field strength of thunderstorms and hurricanes. Electric field strength is a significant factor in the development of precipitation and lightning, and… More

One of the key areas of study of NASA?s Earth Observing System (EOS), a constellation of satellites equipped to remotely measure the earth's surface and atmospheric properties, is the role played by clouds and aerosols in climate change. However, these remote measurements of the size, shape and… More

75342-The Department of Energy¿s Atmospheric Radiation Measurement program assesses the radiative impact of clouds by using remote measurements from the earth¿s surface and from space. However, a cloud¿s radiative properties are strongly influenced by its liquid water content and drop size… More

This SBIR Phase II research project will provide research-aircraft and weather-balloon flight tests a new, novel device for measuring the electric field strength of thunderstorms and hurricanes. Electric field strength is a significant factor in the development of precipitation and lightning, and… More

One of the key areas of study of NASA's Earth Science enterprise is the role played by clouds in climate change. The duration of conventional research aircraft is limited so that long-term measurements required to validate satellite observations are not practical. Small uninhabited aerial vehicles… More

Measurements of cloud properties ¿ including volumetric extinction coefficient, cloud optical depth, liquid water content and effective cloud drop radius ¿ are critical parameters for determining the impact of clouds on radiative forcing, a major factor in climate change. Because clouds cover… More

An efficient, user-friendly, well documented data processing and analysis software package is needed to process the complex data produced by new airborne particle imaging probes, such as the SPEC 2D-S, cloud particle imager (CPI) and 3V-CPI probes. For example, the 3V-CPI, which combines features… More

Large-volume measurements of cloud microphysical properties are crucial for validating remote measurements from the earth¿s surface and satellites, which are necessary to improve predictions from global climate models. Current airborne in situ instruments are limited to microphysical… More

NASA has initiated a program to explore the upper troposphere/lower stratosphere (UT/LS) using the Global Hawk Unmanned Aerial System (UAS), which has a payload of over 1500 lb (680 kg), max ceiling of 65,000 ft (20 km) at a cruising speed of 335 kts and mission endurance of over 31 hours. These… More

In Phase I SPEC completed fabrication of a novel new instrument, the 3V-CPI, which makes high-speed size-distribution measurements and records high-resolution digital images of cloud particles. Also in Phase I SPEC continued to develop and improve software modules used to analyze 3V-CPI data. In… More

In Phase II SPEC will design, fabricate and flight test a state-of-the-art combined cloud particle probe called the Hawkeye. Hawkeye is the culmination of two decades of innovative instrument development at SPEC. The new probe will measure the size distribution of cloud and precipitation particles,… More

It is well known now that clouds have a particularly strong nonlinear influence on the surface energy budget in the Arctic including the timing of the onset of snowmelt. The greenhouse effect produced by low-level, thin Arctic cloud cover accelerates melting and increases the amount of open water,… More

The explosive eruption of a volcano under the Eyjafjallaj¿kull glacier in Iceland on 14 April 2010 brought air travel in Europe and across the Atlantic to a standstill. Millions of passengers were stranded for over a week and the shutdowns cost the airlines $200 million per day. Jet airliner… More

The Arctic as a region of particular sensitivity to climate change. In the past few decades, the annual average temperature over the Northern high latitude land surface has risen at almost twice the rate of the global average, disrupting the region and its people. Clouds are the primary factors… More