nasa-gesdisc/es-publications-researchareas huggingface dataset:
Climate risk information as a basis for adaptive spatial planning: A case study from Thailand (2021)

Spatial planning has an important role to play in climate change adaptation and disaster risk reduction. Particularly in growing urban regions, cities are expanding into hazard-prone areas and lack of planning is leading to increased vulnerability of people and structures and is exacerbating hazards. Gathering and understanding information about the determinants of climate riskhazard, exposure, and vulnerabilityand how physical climate and environmental changes interact with the human socioeconomic system, is an important basis for spatial planning that reduces risk. Using the case study of the Andaman Coast of Thailand, this paper provides an example of the determinants of climate risk and how they are relevant to spatial planning. The paper highlights the importance of considering not just climate-related hazards but also how human settlements are exposed and vulnerable to these hazards.

Research areas: Habitat Conversion/Fragmentation, Atmospheric/Ocean Indicators
High-resolution African population projections from radiative forcing and socio-economic models, 2000 to 2100 (2017)

For its fifth assessment report, the Intergovernmental Panel on Climate Change divided future scenario projections (20052100) into two groups: Socio-Economic Pathways (SSPs) and Representative Concentration Pathways (RCPs). Each SSP has country-level urban and rural population projections, while the RCPs are based on radiative forcing caused by greenhouse gases, aerosols and associated land-use change. In order for these projections to be applicable in earth system models, SSP and RCP population projections must be at the same spatial scale. Thus, a gridded population dataset that takes into account both RCP-based urban fractions and SSP-based population projection is needed. To support this need, an annual (20002100) high resolution (approximately 1km at the equator) gridded population dataset conforming to both RCPs (urban land use) and SSPs (population) country level scenario data were created.

Research areas: Habitat Conversion/Fragmentation
Assessment of Coastal Governance for Climate Change Adaptation in Kenya (2017)

The coastline of Kenya already experiences effects of climate change, adding to existing pressures such as urbanization. Integrated coastal management (ICM) is increasingly recognized as a key policy response to deal with the multiple challenges facing coastal zones, including climate change. It can create an enabling governance environment for effective local action on climate change by facilitating a structured approach to dealing with coastal issues. It encompasses the actions of a wide range of actors, including local governments close to people and their activities affected by climate change. Functioning ICM also offers opportunities for reducing risks and building resilience. This article applied a modified capitals approach framework (CAF), consisting of five "capitals," to assess the status of county government capacity to respond to climate change within the context of coastal governance in three county governments in Kenya. The baseline was defined in terms of governance relating to the implementation of the interrelated policy systems of ICM and coastal climate change adaptation (CCA). The CAF framework provided a systematic approach to building a governance baseline against which to assess the progress of county governments in responding to climate change. It identified gaps in human capacity, financial resource allocation to adaptation and access to climate change information. Furthermore, it showed that having well-developed institutions, including regulatory frameworks at the national level can facilitate but does not automatically enable adaptation at the county level.

Research areas: Habitat Conversion/Fragmentation
Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process (2020)

The irregular interannual variations observed in the Greenland ice sheet (GrIS) mass balance can be interpreted as stochastic. These variations often have large amplitudes, and, if not accounted for correctly in the mass change model parameterization, could have profound impacts on the estimate of the secular trend and acceleration. Here we propose a new mass trajectory model that includes both the conventional deterministic components and a stochastic component. This new model simultaneously estimates the secular rate and acceleration, seasonal components, and the stochastic component of mass changes. Simulations show that this new model improves estimates of model parameters, especially accelerations, over the conventional model without stochastic component. Using this new model, we estimate an acceleration of 1.6  1.3 Gt/yr2 in mass change (minus means mass loss) for 2003-2017 using the Gravity Recovery and Climate Experiment (GRACE) data and an acceleration of 1.1  1.3 Gt/yr2 using the modeled surface mass balance plus observed ice discharge. The corresponding rates are estimated to be 288.2  12.7 Gt/yr and 274.9  13.0 Gt/yr. The greatest discrepancies between the new and the conventional model parameter determinations are found in the acceleration estimates, 1.6 Gt/yr2 vs. 7.5 Gt/yr2 from the GRACE data. The estimated accelerations using the new method are apparently smaller than those estimated by other studies in terms of mass loss. Our quantitative analysis elucidates that the acceleration estimate using the conventional method is the lower bound (i.e., 7.5 Gt/yr2 for 20032017) while the acceleration estimated by the new method lies in the middle of the possible ranges. It is also found that these discrepancies between the new and the conventional methods diminish with sufficiently long (>20 yr) observation records.

Research areas: Cryospheric Indicators
Link between the time‐space behavior of rainfall and 3D dynamical structures of equatorial waves in global convection‐permitting simulations (2023)

Equatorial waves (EWs) control a considerable portion of tropical rainfall variability but numerical models often struggle to capture them. Increased computing power now enables global simulations with resolved deep convection, which is believed to produce more realistic EWs. Here we identify EWs in global ICON simulations with varying horizontal resolution by (a) filtering rainfall based on space-time spectral analysis and (b) projecting wind and geopotential onto theoretical wave patterns. The simulations demonstrate that Kelvin, mixed-Rossby gravity and equatorial Rossby waves are consistently represented, regardless of model resolution and convective treatment. For smaller-scale inertio-gravity waves, however, explicit convection appears to be a prerequisite. Surprisingly, the associated rainfall signals are not accompanied by corresponding wind patterns but appear to be connected to mesoscale convective systems. This demonstrates the importance of analyzing rainfall and dynamical aspects of EWs jointly for a robust assessment.

Research areas: Atmospheric/Ocean Indicators
Large-scale environmental conditions related to midsummer extreme rainfall events around Japan in the TRMM region (2018)

Abstract The precipitation characteristics of extreme events in August determined from 13 years of satellite data around Japan in the TRMM observation region and their relationship with large-scale environmental conditions are examined. Two types of extreme events, extreme rainfall and extreme convective events, are defined in each analysis grid box using maximum near-surface rainfall and maximum 40-dBZ echo-top height in each event, respectively. There are clear differences in precipitation characteristics between the two types of extreme events. Extreme rainfall events are more organized precipitation systems than the extreme convective events, with relatively lower echo-top heights and very low lightning activity. There are also clear differences in the related environmental conditions, where the environments related to the extreme rainfall events are somewhat convectively stable and very humid in almost the entire troposphere. These facts are consistent with our previous studies and reinforce the importance of warm-rain processes in extremely intense precipitation productions. The environments related to the extreme rainfall events exhibit a zonally extended moist anomaly in the free troposphere from southern China to the east of Japan, indicating that the excessive moisture transported from the west by a large-scale flow may partially play a role in producing environmental conditions favorable for extreme rainfall. On the other hand, the environments related to extreme convective events are not associated with free-tropospheric moisture inflow. The relationships with the tropical cyclones and upper-tropospheric dynamical fields are also examined, and are found to be clearly different between the extreme rainfall events and extreme convective events.

Research areas: Atmospheric/Ocean Indicators
Sea surface pCO2 variability and air-sea CO2 exchange in the coastal Sudanese Red Sea (2021)

The dynamics of sea surface pCO2 (pCO2w) and airsea CO2 exchange of the Sudanese coastal Red Sea has for the first time been studied over a full annual cycle (October 2014October 2015) based on semi-continuous measurements from moored autonomous sensors. pCO2w showed a seasonal amplitude of approximately 70 atm, overlaid by a high frequency (3-4 days) signal of around 10 atm. The highest values, of about 440 atm occurred during summer and fall, while the lowest values of about 370 atm occurred during winter. The monthly pCO2w change was primarily driven by temperature, i.e., heating and cooling of the water surface. Additionally, Dissolved Inorganic Carbon (DIC) and Total Alkalinity (AT) contributed significantly to the observed change in pCO2w as a consequence of along-coast advection and upwelling of CO2-rich deep water, and likely biological production, and uptake of atmospheric CO2. The area is a net annual source for atmospheric CO2 of 0.180  0.009 mol CO2 m2 y1. Based on a compilation of historic and our new data, altogether covering the years 1977 to 2015, long term trends of pCO2w were determined for the seasons winterspring (1.75  0.72 atm y1) and summer -fall (180  0.41 atm y1), both weaker than the atmospheric trend (1.96  0.02 atm y1). We are suggesting that the study region has transformed from being a source of CO2 to the atmosphere throughout the year to becoming a sink of CO2 during parts of the year. The long term pCO2w trend was to a large degree driven by increasing DIC, but increasing AT and temperature also played a role.

Research areas: Ecosystems
Southern Ocean sea ice concentration budgets of five ocean-sea ice reanalyses (2022)

In this study, sea ice concentration (SIC) budgets were calculated for five ocean-sea ice reanalyses (CFSR, C-GLORSv7, GLORYS12v1, NEMO-EnKF and ORAS5), in the Southern Ocean and compared with observations. Benefiting from the assimilation of SIC, the reanalysis products display a realistic representation of sea ice extent as well as sea ice area. However, when applying the SIC budget diagnostics to decompose the changes in SIC into contributions from advection, divergence, thermodynamics, deformation and data assimilation, we find that both atmospheric and oceanic forcings and model configurations are significant contributors on the budget differences. For the CFSR, the primary source of deviation compared to other reanalyses is the stronger northward component of ice velocity, which results in stronger sea ice advection and divergence. Anomalous surface currents in the CFSR are proposed to be the main cause of the ice velocity anomaly. Furthermore, twice the mean ice thickness in the CFSR compared to other reanalyses makes it more susceptible to wind and oceanic stresses under Coriolis forces, exacerbating the northward drift of sea ice. The C-GLORSv7, GLORYS12v1 and NEMO-EnKF have some underestimation of the contribution of advection and divergence to changes in SIC in autumn, winter and spring compared to observations, but are more reasonable in summer. ORAS5, although using the same coupled model and atmospheric forcing as C-GLORSv7 and GLORYS12v1, has a more significant underestimation of advection and divergence to changes in SIC compared to these two reanalyses. The results of the SIC budgets of five ocean-sea ice reanalyses in the Southern Ocean suggest that future reanalyses should focus on improving the modelling of sea ice velocities, for example through assimilation of sea ice drift observations.

Research areas: Cryospheric Indicators
General and Local Characteristics of Current Marine Heatwave in the Red Sea (2021)

In the ocean, heat waves are vital climatic extremes that can destroy the ecosystem together with ensuing socioeconomic consequences. Marine heat waves (MHW) recently attracted public interest, as well as scientific researchers, which motivates us to analyze the current heat wave events over the Red Sea and its surrounding sea region (Gulf of Aden). First, a comprehensive evaluation of how the extreme Red Sea surface temperature has been changing is presented using 0.25 daily gridded optimum interpolation sea surface temperature (OISST, V2.1) data from 1982 to 2020. Second, an analysis of the MHWs general behavior using four different metrics over the study area, together with a study of the role of climate variability in MHW characteristics, is presented. Finally, the main spatiotemporal characteristics of MHWs were analyzed based on three different metrics to describe MHWs local features. Over the studied 39 years, the current results showed that the threshold of warm extreme sea surface temperature events (90th percentile) is 30.03 C, providing an additional average thermal restriction to MHW threshold values (this value is changed from one grid to another). The current analysis discovered 28 separate MHW events over the Red+, extending from 1988 to 2020, with the four longest events being chosen as a study case for future investigation. For the effect of climate variability, our results during the chosen study cases prove that ENSO and ISMI do not play a significant role in controlling MHW characteristics (except the MHW intensity, which has a clear relation with ENSO/ISMI) on Red+. Moreover, the chlorophyll concentration decreases more significantly than its climatic values during MHW events, showing the importance of the MHW effect on biological Red Sea features. In general, the MHW intensity and duration exhibit a meridional gradient, which increases from north to south over the Red Sea, unlike the MHW frequency, which decreases meridionally.

Research areas: Atmospheric/Ocean Indicators, Heat
Mid-level clouds over the Sahara in a convection-permitting regional model (2020)

The simulation of Saharan mid tropospheric clouds is investigated with the weather research and forecasting (WRF) regional atmospheric model at convection permitting (4 km) horizontal grid-spacing. We identify two potential problems in such simulations: one that affects cloud cover, and another that affects the mean and geographic patterns of both cloud and precipitation. Our simulations show that using a vertical grid typical of GCMs (38 levels) inhibits the formation of Saharan mid-level clouds. In particular, it underestimates the supercooled water content that often resides at the top of these clouds, in favour of ice which falls out of the cloud quickly. When the vertical resolution becomes high enough to allow layers of supercooled water and ice to exist separately, the simulation of the Saharan mid-level clouds improves significantly. Additional improvement is achieved by using realistic high resolution surface albedo, which also shows that low albedo areas favour the formation of mid-level clouds much more than high albedo ones. The simulation of precipitation on the northern edge of the Sahel is also improved with the use of realistic surface albedo. Overall, despite the disagreement of the simulated and the observed clouds, our results show that using increased resolution and realistic surface albedo seems to fully reproduce their observed radiative effect.

Research areas: Atmospheric/Ocean Indicators
A Precipitation Recycling Network to Assess Freshwater Vulnerability: Challenging the Watershed Convention (2019)

Water resources and water scarcity are usually regarded as local aspects for which a watershed-based management appears adequate. However, precipitation, as a main source of freshwater, may depend on moisture supplied through land evaporation from outside the watershed. This notion of evaporation as a local "green water" supply to precipitation is typically not considered in hydrological water assessments. Here we propose the concept of a watershed precipitation recycling network, which establishes atmospheric pathways and links land surface evaporation as a moisture supply to precipitation, hence contributing to local but also remote freshwater resources. Our results show that up to 74% of summer precipitation over European watersheds depends on moisture supplied from other watersheds, which contradicts the conventional consideration of autarkic watersheds. The proposed network approach illustrates atmospheric pathways and enables the objective assessment of freshwater vulnerability and water scarcity risks under global change. The illustrated watershed interdependence emphasizes the need for global water governance to secure freshwater availability.

Research areas: Land Surface/Agriculture Indicators
“Can you take the heat?” Heat-induced health symptoms are associated with protective behaviors (2019)

Abstract The risks associated with extreme heat are increasing as heat waves become more frequent and severe across larger areas. As people begin to experience heat waves more often and in more places, how will individuals respond? Measuring experience with heat simply as exposure to extreme temperatures may not fully capture how people subjectively experience those temperatures or their varied impacts on human health. These impacts may also influence an individuals response to heat and motivate risk-reduction behaviors. If subjectively experiencing negative health effects from extreme heat promotes protective actions, these effects could be used alongside temperature exposure to more accurately measure extreme heat experience and inform risk prevention and communication strategies according to local community needs. Using a multilevel regression model, this study analyzes georeferenced national survey data to assess whether Americans exposure to extreme heat and experience with its health effects are associated with self-reported protective behaviors. Subjective experience with heat-related health symptoms strongly predicted all reported protective behaviors while measured heat exposure had a much weaker influence. Risk perception was strongly associated with some behaviors. This study focuses particularly on the practice of checking on family, friends, and neighbors during a heat wave, which can be carried out by many people. For this behavior, age, race/ethnicity, gender, and income, along with subjective experience and risk perception, were important predictors. Results suggest that the subjective experience of extreme heat influences health-related behavioral responses and should therefore be considered when designing or improving local heat protection plans.

Research areas: Heat
The effects of cloud–aerosol interaction complexity on simulations of presummer rainfall over southern China (2020)

Abstract. Convection-permitting simulations are used to understand the effects of cloudaerosol interactions in a case of heavy rainfall over southern China. The simulations are evaluated using radar observations from the Southern China Monsoon Rainfall Experiment (SCMREX) and remotely sensed estimates of precipitation, clouds and radiation. We focus on the effects of complexity in cloudaerosol interactions, especially the depletion and transport of aerosol material by clouds. In particular, simulations with aerosol concentrations held constant are compared with a fully cloudaerosol-interacting system to investigate the effects of two-way coupling between aerosols and clouds on a line of organised deep convection. It is shown that the cloud processing of aerosols can change the vertical structure of the storm by using up aerosols within the core of line, thereby maintaining a relatively clean environment which propagates with the heaviest rainfall. This induces changes in the statistics of surface rainfall, with a cleaner environment being associated with less-intense but more-frequent rainfall. These effects are shown to be related to a shortening of the timescale for converting cloud droplets to rain as the aerosol number concentration is decreased. The simulations are compared to satellite-derived estimates of surface rainfall, a condensed-water path and the outgoing flux of short-wave radiation. Simulations for fewer aerosol particles outperform the more polluted simulations for surface rainfall but give poorer representations of top-of-atmosphere (TOA) radiation.

Research areas: Atmospheric/Ocean Indicators
Utilization of remote sensing data for thermal comfort estimation in the coastal urban of Jakarta (2021)

Remote sensing has been completing limitation of meteorological data observed on the station. Meteorological data of temperature and humidity is necessary to estimate thermal comfort. As a coastal urban area, Jakarta has been experiencing rapid urbanization that leads to densely populated and built-up area. The objective of this study is to measure thermal comfort by estimating Discomfort Index. MODIS land surface temperature (LST) used to obtain air temperature. The temperature dew point data was derived from ERA5 climate data. The data was validated by meteorological station data, afterward were computed and classified based on the Thom's discomfort index. Seasonal analysis for thermal comfort was represented by 4 seasonal period included DJF (December, January, February), MAM (March, April, May), JJA (June, July, August), and SON (September, October, November). The results show that discomfort index values were varied by season. Generally, the dry season (JJA) tends to be less discomfort than the rainy season (SON and MAM). JJA is the peak of dry season which is characterized by lower temperature and lower humidity. MAM and SON are the transition season which is characterized by higher temperature and higher humidity.

Research areas: Heat