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The correlation between climate change and pine tree dieback must be understood to implement a proactive forest management system. In this study, an ensemble model combining random forest, the generalized boosting model, and the generalized linear model was used to analyze the topographical and environmental characteristics of pine trees suffering from dieback in the Wangpicheon Ecosystem and Landscape Conservation Area, and the areas in which pine trees are at risk of dieback were evaluated to promote efficient pine forest management. The results showed that pine trees suffering from dieback in the conservation area were mainly located on ridges, were age class 6 or older, or were in areas with a low topographic wetness index south of the conservation area. An evaluation of the risk of dieback among pine trees was performed based on the results of two ensemble models. An area of 365 ha accounting for 6.8% of the total area was identified as requiring "caution" with respect to the risk of dieback of coniferous forests and mixed forests. The developed methodology is expected to provide valuable information for the implementation of an appropriate management system for the protection of pine and mixed forests from the negative effects of climate change. [ABSTRACT FROM AUTHOR]

Latent heating (LH) profiles from the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement mission (GPM) were employed to examine the LH distribution during the quasi‐biennial oscillation (QBO) disruption in the 2015/2016 Northern Hemispheric (NH) winter. We used the LH anomalies from the observation era climatology to compensate for the discontinuity between the TRMM and GPM LH. The difference in the LH anomalies (LHd) between the 2015/2016 winter and the typical winter coinciding with the westerly QBO phase revealed that deeper convective systems in the 2015/2016 winter shifted to the equator, releasing more latent heat relative to the convective systems in the winters coinciding with the westerly QBO phase. Comparison of the LHds calculated for each winter of 1998–2019 shows that the changes in the convective systems in the 2015/2016 winter were statistically exceptional among the changes in other winters. Inside the convective systems, stronger latent heat release and more frequent occurrences of deep convective and deep‐stratiform rain cells made up the total LHd during the 2015/2016 winter. Specifically, convective rain cells mainly derived the LHd of the convective systems in the 2015/2016 winter, except in February 2016. The results suggest that the LH increase from the typical winter with the westerly QBO phase may be considered an unusual equatorial wave source during the 2015/2016 QBO disruption. The signatures of the LHd profiles in the 10°S–10°N zonal band are sourced from the abnormal convective systems that were shifted from the western Pacific to the central‐to‐eastern Pacific. Key Points: Differences in satellite‐based latent heating profiles between the 2015/2016 disruption of quasi‐biennial oscillation (QBO) and its westerly phase is analyzedStronger equatorial convection is revealed in the 2015/2016 boreal winter compared to the winters with the westerly phase of QBOChanges in latent heating distribution during the 2015/2016 winter are mainly sourced from convective systems being shifted eastward into the Central Pacific Ocean [ABSTRACT FROM AUTHOR]

Atmospheric temperature retrieval (or temperature sounding) is accomplished with infrared observations in carbon dioxide (CO2) absorption bands because CO2 is well mixed gas with known concentration. Because atmospheric CO2 concentration is steadily increasing, using a fixed CO2 concentration may lead to an uncertainty on temperature sounding. This paper investigates the impacts of increasing CO2 concentration on the one-dimensional variational (1D-Var) temperature retrievals from the Atmospheric Infrared Sounder (AIRS) measurements. A priori atmospheric profiles are generated by adding random forecast errors to the reference profile selected from the European Centre for Medium-Range Weather Forecasts 91-level diverse profile datasets and the AIRS observations are similarly generated by random observation errors to the simulated AIRS brightness temperatures given the reference profile. The retrieved temperatures are underestimated (overestimated) in the troposphere (lower stratosphere) with increasing CO2 concentration. The uncertainties of the retrieved temperatures increase in the troposphere and lower stratosphere with increasing CO2 concentration. This trend is more evident in the lower troposphere. In moist atmosphere, the accuracy of temperature sounding is slightly higher than that in dry atmosphere because the AIRS lower tropospheric temperature channels have large sensitivities to amount of water vapor. The results suggest that either adjustments to temperature sounding channels or considerations of the uncertainties in temperature retrievals in lower atmospheric layers are needed to obtain more accurate atmospheric temperature information with increasing CO2 concentrations. In addition, it would be desirable to consider the spatio-temporal variability of atmospheric CO2 concentration on temperature sounding. [ABSTRACT FROM AUTHOR]

Analysis of precipitation radar (PR) and Tropical Rainfall Measuring Mission (TRMM) microwave imager (TMI) data collected from the TRMM satellite shows that rainfall inhomogeneity, as represented by the coefficient of variation (CV), depends on a spatial scale, i.e., the CV appears to be nearly constant at all rain rates within the field of view (FOV) of the TMI 37-GHz channel, while it decreases with rain rate at lower spatial resolutions, such as the FOV sizes of the low-frequency TMI channels (10.7 and 19.4 GHz). It is known that the brightness temperature ([T.sub.b]) for a low-frequency channel decreases with increasing rainfall inhomogeneity for a given rain rate. As such, more inhomogeneous rainfall at low rain rates leads to a lower Tb compared with that of a FOV with homogeneous rainfall; however, less inhomogeneous rainfall at high rain rates tends to produce a Tb similar to that of homogeneous rainfalls. These results indicate that the observed radiometric signatures of low-frequency channels at low spatial resolutions are characterized by a larger response range and smaller variability than those at a higher spatial resolution. Based on the observational characteristics of the TMI and PR data sets, we performed synthetic retrievals of rainfalls, employing a Bayesian retrieval methodology at different retrieval resolutions corresponding to the FOV sizes of the TMI channels at 10.7, 19.4, and 37 GHz. Comparisons of the rainfalls retrieved at the different resolutions and their temporal and regional averages show that the systematic bias resulting from the rainfall inhomogeneity is smaller in the lower resolution data than in their higher resolution counterparts. We note that such low-resolution rainfall retrievals are not expected to describe the instantaneous features of rain fields; however, they could be useful for climatological estimates at large temporal and spatial scales. Index Terms--Passive microwave remote sensing, precipitation, rainfall variability.