Precipitable water vapor (PWAT) is the vertically integrated amount of water vapor in the atmosphere, and it is a valuable predictor for forecasting storm formation, strength, and the potential for precipitation. Currently, the use of costly and sophisticated instrumentation limits the number of PWAT measurement sites in semi-arid to arid, higher elevation, and sparsely populated areas of the rocky mountain west and the high plains. This affects the accuracy of forecast models. We have analyzed relationships between PWAT and zenith clear sky temperature measurements for the dry climate zone found in the North American Desert Southwest, specifically over Socorro, New Mexico (34oN, 107oW). Daily measurements of the ground and zenith sky temperatures have been taken at Socorro for more than two complete annual cycles using low-cost infrared thermal sensors. National Weather Service Radiosonde measurements of PWAT from the Albuquerque WFO (ABQ) and the Santa Teresa WFO(EPZ), are input into our dataset and analysed via a newly developed computational tool. Our results show that an exponential relationship between PWAT and zenith clear sky temperature holds for the Desert Southwest, but with parameters that are different from those obtained previously over the more moist climate zone of the Gulf Coast of Texas. Model simulations can accurately reproduce the observed relationship between PWAT and temperature, and the results suggest that half of the signal in temperature is directly related to changes in opacity due to changes in PWAT, while the other half is due to changes in air temperature that usually accompany changes in PWAT.
The Precipitable-Water Model Analysis Tool (PMAT) is an open-source software suite designed to study the correlation between atmospheric brightness temperature and precipitable water (PWAT) data. PMAT addresses the need for an easily integrated analysis workflow to quantitatively characterize the relationship between regional PWAT and localized atmospheric brightness temperature observations for areas that lack high to moderate-resolution data collection infrastructure. The workflow contains three primary modules: deployment, pre-processing, and analysis. The deployment mechanism allows users to implement the software suite on local and cloud-based systems, which facilitates access to the generated data products and visualizations. The pre-processing stage involves aggregating atmospheric brightness temperature data collected in the field with data from radiosondes and local ground stations. The final element consists of an iterative algorithm that generates an average regression model from the collected data. This model allows for the estimation of PWAT through measured atmospheric brightness temperature. PMAT has already been configured and deployed for use in the South-Central New Mexico climate zone using a series of handheld infrared thermometers as the source of atmospheric brightness temperature data. We plan to expand the scope of the research with community science endeavors in South Dakota; while also expanding the suite’s analysis capabilities with machine learning and additional statistical products for predictive modeling.
Precipitable water vapor (PWAT) is the vertically integrated amount of water vapor in the atmosphere, and it is a valuable predictor for weather forecasting. Currently, the use of sophisticated instrumentation can limit the number of PWAT measurement sites, which affects the accuracy of forecast models in regards to storm formation, strength, and the potential for precipitation. We have analyzed relationships between PWAT and zenith clear sky temperature measurements for the dry climate zone found in the North American Desert Southwest, specifically over Socorro, New Mexico (34$^{\circ}$N, 107$^{\circ}$W). Daily measurements of the ground and zenith sky temperatures have been made at Socorro for two complete annual cycles using low-cost infrared thermal sensors. Radiosonde measurements of PWAT from National Weather Service stations located in nearby Albuquerque, and Santa Teresa, New Mexico, are input into our dataset and analysed via a newly developed computational tool. Our results show that an exponential relationship between PWAT and zenith clear sky temperature holds for the Desert Southwest, but with parameters that are different from those obtained previously over the more moist climate zone of the Gulf Coast of Texas. Model simulations can accurately reproduce the observed relationship between PWAT and temperature, and the results suggest that half of the signal in temperature is directly related to changes in opacity due to changes in PWAT, while the other half is due to changes in air temperature that usually accompany changes in PWAT.
Precipitable water is primarily measured using radiosondes, ground-based global positioning systems (GPS), sun photometers, and microwave radiometry (MWRI). This limits the number of precipitable water measurement sites, which affects forecast accuracy in regards to storm formation, strength, and the potential for precipitation. Socorro, NM is among the sites that do not have the capability to measure precipitable water. Our research builds upon a previous study which determined an exponential relationship between infrared clear sky temperature measurements and precipitable water over the Gulf Coast of Texas. We are analyzing this relationship for the climate zone found in Socorro, NM. Daily ground and clear sky temperature measurements are being taken with low-cost infrared thermometers. Radiosonde precipitable water measurements from Albuquerque and Santa Teresa NWS monitoring sites are input into our dataset and analysed via our newly developed computational tool; which shows that there is a correlation ($R^2 = 0.707$) between clear sky temperature and precipitable water. Our research demonstrates the capability to measure and analyze precipitable water with low cost instrumentation in higher altitude arid climate zones similar to those found in the desert Southwest. We are building a platform to expand our tools and methods so that they can be used to determine and analyse similar correlations over a greater variety of climate zones.
Precipitable water is the total amount of water vapor which is contained in a vertical column of air that stretches from the Earth’s surface to the top of the atmosphere. It is expressed in terms of what the depth of liquid water would measure once all the water vapor in the column is compressed down into liquid form. Meteorologists currently use ground-based global positioning systems (GPS), microwave radiometers (MWRI), and radiosondes to measure precipitable water. Due to the cost and complexity of these instruments, the number of locations where these measurements are taken is limited; therefore most National Weather Service (NWS) monitoring sites do not measure precipitable water. Meteorologists need precipitable water measurements to help accurately forecast storm formation, strength, and the likelihood of precipitation. We utilize the methodology from a previous study in which relatively low-cost infrared thermometers were used to determine the precipitable water over the Gulf Coast of Texas. This approach is being tested in the climate zone found in Socorro, NM using daily ground and clear sky temperature measurements. This research demonstrates the ability to measure precipitable water with low-cost tools in higher altitude arid climate zones similar to that found in the desert Southwest.
Precipitable water can be defined as the total amount of water vapor that exists in a vertical column of air, traditionally measured via radiosondes. Global Positioning System (GPS) networks and microwave-infrared radiometers can also be used to measure precipitable water by analyzing signal delay; these methods are used by NOAA. Precipitable water measurements can be used to forecast extreme weather events and the potential for precipitation. Based on a previous that analyzed the relationship between precipitable water and zenith sky temperature using infrared thermometers, we have developed a rigorous computational utility to study this same correlation for the Socorro, NM climate system. This research highlights the impact of using low-cost instrumentation to accurately forecast precipitation in regions where the data is not available. After thirty-five weeks, the results of our analysis show an exponential correlation ($R^2 = 0.707$) between precipitable water and clear sky temperature, similar to the trends found in previous studies. However, as we continue to collect data, the intrinsic properties of the correlation are continuously evolving. With the availability of our computational tool, we aim to widen our data to include a diverse set of climate systems to further study the relationship between clear sky temperature and precipitable water while also continuing to collect data for the Socorro, NM area.