Using Satellite Data and Fully Coupled Regional Hydrologic, Ecological and Atmospheric Models to Study Complex Coastal Environmental Processes

1
Using Satellite Data and Fully Coupled Regional
Hydrologic, Ecological and Atmospheric Models to
Study Complex Coastal Environmental Processes
Funded by NASA Interdisciplinary Science Program
PI 1Zong-Liang Yang Co-PI 1Guo-Yue Niu
1David Maidment 2Paul Montagna
1James McClelland 3Hongjie
Xie 1Postdoc Bryan Hong, Yongsheng Xu
1University of Texas at Austin 2Texas AM
University-Corpus Christi 3University of Texas
at San Antonio
2
Objectives
Improve our understanding of how linked upland
and estuarine ecosystems respond to combined
changes in the hydrological and nutrient cycles
that result from changes in climate and land
use/land cover (LULC). Integrate research
expertise from a diversity of fields that
includes climate modeling, remote sensing
analysis, biogeochemical cycling in watersheds,
surface hydrology and estuary ecology.
3
Key Science Questions

1. What is the relationship between global climate
   forcing and seasonal-to-interannual climate
   variability and extreme storm events over the
   Gulf Coast region? (Yang/Niu/Jiang)
2. What are the spatial patterns in LULC as defined
   by satellite data in the Gulf Coast region?
   (Xie/Hong)
3. How does riverine nutrient export to Gulf Coast
   estuaries vary with LULC patterns and hydrologic
   conditions? (Maidment/McClelland)
4. What is the relationship between the frequency of
   extreme events in the hydrologic and nutrient
   cycles and the mean productivity and the
   resiliency of productivity in Gulf Coast
   estuaries? (McClelland/Montagna)
5. Can we use the answers to the questions above to
   predict the response of Gulf Coast estuaries to
   future climate perturbations? (All)

4
Deliverables

1. Develop a nested regional atmospheric modeling
   system augmented with satellite remote sensing
   data to predict high-resolution spatial and
   temporal hydrometeorological variables for the
   Gulf Coast region.
2. Characterize two biologically distinct watersheds
   in the semi-arid region of Central and South
   Central Texas, the Nueces River watershed and the
   San Antonio/Guadalupe watershed using modeling
   data, existing satellite observations, existing
   water quality data and new fieldwork.
3. Provide an assessment of the uncertainties
   related to data products and modeling in order to
   derive confidence values for the models
   predictive capabilities.

5
A Systematic Assessment of Temperature and
Precipitation Changes under Different Future
Emissions Scenarios in Texas
6
Data

• WCRP CMIP3 dataset
• 16 global climate models
• Three emission scenarios (A1B, A2, B1)
• A1B 39 simulations
• A2 37 simulations
• B1 36 simulations
• Precipitation and temperature (monthly)
• Statistical downscaling with bias-correction

7
Present-day Evaluation (temperature and
precipitation)
NCDC
NCDC
NARR
NARR
8
Temperature projections
9
Projected probability distributions of surface
temperature changes in the period of 20702099
relative to 1971-2000 means by different climate
models over Texas
10
Projected annual surface temperature anomalies in
the period of 20702099 over Texas under
different scenarios (A2, A1B and B1)
11
Projected surface temperature changes in winter
(DJF) and summer (JJA)
12
95 Confidence intervals for surface temperature
changes between 20702099 and 19712000 under A1B
Scenario
13
Projected precipitation changes
14
Projected precipitation changes () under A2, A1B
and B1 scenarios between 2070-2099 and 1971-2000
for winters (DJF) and summers (JJA)
15
Projected monthly precipitation anomalies over
individual five regions in Texas
16
Trends of precipitation anomalies relative to
19712000 year after applying wavelet analysis
17
RMSE for precipitation
RMSE for precipitation (mm/day)
18
Dynamically downscaled precipitation in the
Guadalupe River Basin
19
Summary

• Texas is getting warmer (2-5ºC by the end of this
  century) more warming in the north than in the
  south.
• Overall decreasing trend of precipitation.
  Decreasing precipitation in the winter (5-15),
  and increasing precipitation in the summer (5).
• Downscaled precipitation (and other variables) at
  3-hourly and fine-spatial scales are needed for
  hydrological studies. Bias correction must be
  made to precipitation before it is used to drive
  hydrological models.

20
Taylor Plot of Precipitation